- Email: [email protected]
The influence of age on health status outcomes after acute myocardial infarction
The influence of age on health status outcomes after acute myocardial infarction P. Michael Ho, MD, PhD, a,b Marvin H. Eng, MD,b John S. Rumsfeld, MD, PhD,a,b John A. Spertus, MD, MPH,c Pamela N. Peterson, MD, MSPH,b,d Philip G. Jones, MS,c Eric D. Peterson, MD, MPH,e Karen P. Alexander, MD,e Edward P. Havranek, MD,b,d Harlan M. Krumholz, MD, SM,f and Frederick A. Masoudi, MD, MSPH b,d Denver, CO; Kansas City, MO; Durham, NC; and New Haven, CT
Background Older age is a risk factor for higher mortality after acute myocardial infarction (AMI), but the association with health status outcomes is largely unexplored. Methods In a prospective cohort of 2498 patients in the PREMIER study, we compared health-related quality of life (HRQL) and burden of angina symptoms among survivors of AMI by age strata (age groups ≥75, 65-74, 50-64, and 19-49 years) using the Seattle Angina Questionnaire. Multivariable analyses assessed the relationship between age and 1-year HRQL and angina burden, adjusting for differences in clinical characteristics, treatment, and baseline health status. Results
Older patients comprised a majority: 20.1% were ≥75 years of age, 41.7% were 65 to 74 years of age, 20.7% were 50 to 64 years of age, and 17.4% were <50 years of age. At 12 months, older patients had higher mortality (17.0% vs 8.7% vs 6.1% vs 3.2% for age groups ≥75, 65-74, 50-64, 19-49; P < .001). Among survivors of AMI, increasing age was associated with less angina and better HRQL. By 12 months, older patients reported less angina (10.9% vs 12.7% vs 19.3% vs 23.4% for age groups ≥75, 65-74, 50-64, 19-49; P < .0001) and better HRQL (scores 89.1 vs 88.1 vs 82.5 vs 80.0, respectively; P < .0001), which persisted after adjustment for baseline angina, HRQL, and other demographic, clinical, disease severity, and treatment differences.
Conclusions Although older patients have higher mortality after AMI, those who survive experience fewer symptoms and better HRQL at 1 year than younger patients. Angina remains present in a number of patients across the spectrum of age, supporting strategies to systematically assess and treat symptoms after AMI. (Am Heart J 2008;155:855- 61.)
Increasing age has been consistently identified as a risk factor for mortality after acute myocardial infarction (AMI). Possible contributors to this risk include the general increasing comorbidity burden with age and the declining rates of treatment with guideline-recommended therapies, which are often underused in the most functionally limited patients.1-8 Just as older persons have a higher risk for death, it is also possible that older patients will experience more angina and poorer health-
From the aMedical Service, Denver VA Medical Center, Denver, CO, bDepartment of Medicine, University of Colorado Health Sciences Center, Denver, CO, cMid America Heart Institute, Kansas City, MO, dDepartment of Medicine, Denver Health Medical Center, Denver, CO, eDuke Clinical Research Institute, Durham, NC, and fYale University School of Medicine, New Haven, CT. This project was principally supported by CV Therapeutics, Inc, Palo Alto, CA, who had no involvement in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript. Partial support was also provided by CV Outcomes, Inc, Kansas City, MO. Submitted August 10, 2007; accepted November 28, 2007. Reprint requests: P. Michael Ho, MD, PhD, 1055 Clermont St., Cardiology (111B), Denver, CO 80220. E-mail: [email protected] 0002-8703/$ - see front matter Published by Mosby, Inc. doi:10.1016/j.ahj.2007.11.032
related quality of life (HRQL) after AMI. Yet, indirect evidence suggests that the opposite is plausible. For example, older patients with heart failure have better HRQL than younger patients despite greater functional limitation, possibly reflecting changing expectations of health status with advancing age.9-10 Despite the importance of HRQL and symptom burden outcomes to survivors of AMI, little is known about the patterns of health status outcomes as a function of age in the year after AMI. Because AMI survival rates have improved, health status outcomes are relevant to a growing number of patients.11 Health status may be especially pertinent to older patients, who may focus more on symptom burden and quality of life than prolonging life.12,13 The Institute of Medicine and professional organizations have also emphasized the importance of patient centered care highlighting the value of understanding health status.14,15 However, given the clear relationship between higher mortality with age, clinicians may assume that older patients also have a greater likelihood of symptomatic and functional impairment, potentially encouraging therapeutic nihilism. A greater understanding of health status outcomes after AMI would allow patients and the
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clinicians caring for them to calibrate their expectations for successful recovery. Accordingly, the objectives of this study were to assess health status outcomes, including angina frequency and HRQL, across the spectrum of age after AMI among patients enrolled in a large multicenter prospective cohort study. Specifically, we assessed patterns of health status outcomes over the 12 months after hospitalization among AMI survivors to elucidate the extent to which older patients may experience successful recovery after AMI.
Methods Patient sample Between January 1, 2003, and June 28, 2004, 2498 AMI patients were recruited into the PREMIER study from 19 US hospitals. Details of the study methods have been published previously.16 In brief, all patients with biomarker evidence of myocardial necrosis and clinical evidence of an AMI during the initial 24 hours of admission were screened for possible inclusion. Using standard criteria, patients were eligible if they were 18 years or older and had additional evidence supporting the diagnosis of AMI, such as prolonged (N20 minutes) ischemic signs/symptoms or electrocardiographic ST changes.16 Patients not presenting initially to the enrolling institution were eligible only if they were transferred within the first 24 hours of presentation to ensure that the primary clinical decision making occurred at the enrolling site. Patients who were incarcerated and those having elevated cardiac biomarkers as a complication of elective coronary revascularization were not eligible. Institutional research board approval was obtained at each participating institution, and patients signed informed consent for baseline and follow-up interviews.
Outcomes assessment One-, 6-, and 12-month telephone follow-up interviews were conducted by a single center. Using contact information provided by patients at the time of enrollment, we made multiple attempts to conduct an interview that included quantification of patients' current health status using the Seattle Angina Questionnaire (SAQ). The SAQ is a 19-item, disease-specific health status measure that quantifies domains of patients' health status.17-19 For the purposes of this study, scores on the angina frequency and quality of life subscales were used, which can range from 0 to 100, and where higher scores represent fewer symptoms and better quality of life. A 5-point difference in scores is considered clinically significant. The SAQ is valid, reproducible, sensitive to clinical change, and prognostic of subsequent mortality and acute coronary syndrome admissions.19 Survival status was confirmed through patient contact, patients' suggested contacts, patients' primary care or cardiovascular physicians, and through the Social Security Death Master File for patients with valid social security numbers (99.8% of the cohort). The primary outcomes for this analysis were the SAQ angina frequency and HRQL subscales at 12 months after AMI hospitalization. Given the skewed distribution of the SAQ angina frequency scores, angina frequency was dichotomized into any angina (SAQ angina frequency score <100) and no angina (SAQ
angina frequency score 100). The SAQ HRQL subscale was analyzed as a continuous variable.
Statistical analysis Baseline patient and clinical characteristics were compared across age groups using 1-way analysis of variance for continuous variables and χ2 for discrete variables. Health status outcomes at 1, 6, and 12 months were analyzed using repeated measures models (linear models for SAQ HRQL, logistic models for angina prevalence), including fixed effects for month, age group, and age group-by-month using an autoregressive moving average and a within-patient correlation structure. This model accounts for all observed follow-up health status data. For each outcome, three models were constructed: (1) unadjusted, (2) adjusted for baseline health status, and (3) multivariable-adjusted. Variables in the multivariable models were chosen by a combination of a priori clinical judgment and statistical association with age, and included demographics (sex, race), medical history (body mass index, diabetes, chronic heart failure, lung disease, smoking status, arthritis, cancer, hypertension, prior myocardial infarction, prior percutaneous coronary intervention [PCI], prior coronary artery bypass graft surgery [CABG], prior cerebrovascular disease), clinical presentation (ST-elevation MI, number of diseased vessels, left ventricular systolic dysfunction, glomerular filtration rate as estimated using the modified MDRD equation, hematocrit), treatment (coronary angiography, revascularization, discharge medications), socioeconomic status (education, self-reported economic burden of health care costs, lack of insurance), social support (marital status, ENRICHD social support score 20 ), PHQ-9 depression score, discharge medications (aspirin, β-blockers, angiotensinconverting enzyme [ACE] inhibitors or angiotensin receptor blockers, and statin medications) among patients without contraindications to therapy, baseline health status, and site. Interaction terms with month were included for all variables. For variables with <5% missing values, we assumed missingness at random given the observed data, and imputed using multiple imputation methods to allow use of all observations and to correctly account for uncertainty due to missing values. The imputation model included all baseline and follow-up variables. In the primary analyses, all observed follow-up health status data were included in the statistical models including health status data of patients at 1 and/or 6 months for all patients for whom these data were available. In sensitivity analyses, we only included patients completing the 12-month follow-up to examine for potential biases in the health status recovery curves because of differential survival and dropout. The results of these sensitivity analyses were consistent with the primary findings and therefore are not further reported. Second, because revascularization is an important determinant of future angina, interactions terms were included in the multivariable models to examine whether the relationship between age and health status changed according to whether patients received coronary revascularization during the index hospitalization. These analyses were further stratified by treatment strategy (medical management compared to revascularization with PCI or CABG). Third, we assessed the proportion of patients with angina at baseline and 12 months after AMI hospitalization and categorized patients into 4 angina categories (no angina at baseline or 12 months, angina at baseline and at 12 months, angina at baseline but not at 12 months, and no angina at baseline but angina at 12 months). Then, we compared angina
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Table I. Baseline characteristics of the study population by age strata Variables
21 to <50 (n = 503) 50 to <65 (n = 1042) 65 to <75 (n = 518) ≥≥75 (n = 435)
Demographic factors Age (mean [SD]) Male sex White race Body mass index (mean [SD]) Medical history Diabetes Heart failure Chronic lung disease Current smoker Arthritis Cancer Hypertension MI Prior PCI Prior CABG Cerebrovascular disease Socioeconomic factors High school education Medication costs are not a burden Self-pay Married ENRICHD social support score (mean [SD]) Hospital and MI treatment factors ST-elevation MI Diagnostic coronary angiogram Normal left ventricular systolic function Glomerular filtration rate (mean [SD]) Hematocrit (%) (mean [SD]) Aspirin within 24 h b-Blocker within 24 h Primary reperfusion therapy for STEMI Multivessel coronary artery disease Revascularization type None PCI CABG Medications prescribed at hospital discharge among Aspirin β-Blocker ACE inhibitor or ARB Statin
P
43.2 (5.2) 75.9 64.4 30.1 (6.8)
57.0 (4.2) 70.2 71.0 29.9 (6.5)
69.4 (2.8) 65.4 82.4 29.2 (5.9)
80.5 (4.4) 53.3 82.6 26.5 (5.1)
<.001 <.001 <.001 <.001
20.5 6.8 6.6 58.9 4.6 1.4 50.3 16.3 12.9 3.6 3.6
29.2 9.9 11.6 40.6 8.6 5.7 62.0 20.6 17.8 10.9 5.6
34.9 15.3 18.5 18.2 18.3 13.9 70.1 22.8 19.7 20.1 8.7
30.3 19.8 18.9 7.0 22.1 16.3 75.4 28.0 21.8 20.0 9.4
<.001 <.001 <.001 <.001 <.001 <.001 <.001 <.001 .003 <.001 <.001
32.0 61.8 24.0 52.6 28.7 (6.4)
31.7 62.4 15.2 63.2 29.3 (5.9)
29.1 65.9 3.0 66.9 30.0 (5.3)
26.5 67.7 0.7 51.8 29.7 (5.0)
<.001 .001 <.001 <.001 .003
51.5 88.3 55.7 77.3 (28.1) 41.0 (6.2) 94.6 86.7 86.9 28.8
46.8 90.0 54.2 68.3 (30.1) 40.0 (6.0) 95.6 87.0 83.4 39.2
37.5 88.8 49.4 58.9 (23.3) 38.8 (6.0) 94.2 83.2 84.5 47.4
34.0 75.9 47.2 50.0 (22.8) 36.9 (6.3) 92.6 78.6 71.6 50.3
<.001 <.001 .01 <.001 <.001 .145 <.001 <.001 <.001 <.001
25.4 63.4 11.1
26.8 56.0 17.2
41.6 46.2 12.2
97.8 91.9 84.6 89.0
96.1 91.1 79.5 84.2
95.9 86.0 78.8 83.1
27.8 66.4 5.8 ideal candidates 97.8 91.1 82.2 91.1
.08 .005 .23 .04
STEMI, ST elevation myocardial infarction.
categories across the spectrum of age. Fourth, we evaluated the proportion of patients with clinically significant changes in HRQL scores between baseline and at 12 months. We categorized patients into 3 HRQL categories: (1) worsening HRQL (decrease in HRQL score of N5 points); (2) no change (change in HRQL score of ≤5 points in either direction); (3) improving HRQL (increase in HRQL score of N5 points). These HRQL categories were compared across the spectrum of age. The analyses were conducted using SAS v9.1 (SAS Institute, Inc, Cary, NC) and R v2.3.0 (The R Project for Statistical Computing, Auckland, New Zealand).
Results Baseline characteristics Baseline characteristics of the study population are outlined in Table I according to age strata. In general,
older patients were more likely to be female, white, and to have a higher prevalence of cardiovascular and noncardiovascular comorbidities (eg, heart failure, chronic lung disease, prior myocardial infarction). In addition, older patients were less likely to present with a ST-elevation myocardial infarction and less likely to have preserved left ventricular systolic function.
Inhospital MI treatment Rates of aspirin use within 24 hours of MI presentation were similar across age strata. However, older patients were significantly less likely to receive a β-blocker within 24 hours of MI presentation or acute reperfusion therapy for ST-elevation MI (Table I). Rates of coronary angiography for the entire population were N75%, but older patients were still less likely to
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Figure 1
Figure 2
Prevalence of angina by age groups for the 12 months after hospital discharge (multivariable adjusted).
Seattle Angina Questionnaire quality of life scores by age groups for the 12 months after hospital discharge (multivariable adjusted).
undergo a diagnostic angiogram compared to younger patients. In addition, older patients more often had multivessel coronary artery disease and a minority of all patients underwent CABG.
Table II. Twelve-month health status across the spectrum of age according to receipt of revascularization during the index hospitalization
Discharge medications At hospital discharge, more than three quarters of patients were prescribed evidence-based medications among ideal candidates. There were no significant differences in rates of aspirin or ACE inhibitor/ARB prescription. However, older patients were less likely to receive β-blockers and statins compared to younger patients. Twelve-month outcomes Follow-up and mortality. In general, older patients were less likely to be lost to follow-up (1.8% vs 4.2% vs 11.1% vs 22.9% incomplete 12-month follow-up for age groups ≥75, 65-74, 50-64, 19-49; P < .001) but had higher mortality rates (17.0% vs 8.7% vs 6.1% vs 3.2% for age groups ≥75, 65-74, 50-64, 19-49; P < .001) compared to younger patients. Angina prevalence. In unadjusted analysis, the prevalence of any angina at baseline was lower among older patients (49.3% vs 53.1% vs 54.8% vs 54.7% for age groups ≥75, 65-74, 50-64, 19-49; P < .0001). During the follow-up period, the prevalence of any angina across age strata decreased significantly with the largest decline occurring within the first month after hospital discharge (Figure 1). At 12 months, older patients continued to have less angina compared to younger patients even after multivariable adjustment for differences in baseline angina prevalence and other patient characteristics (10.9% vs 12.7% vs 19.3% vs 23.4% for age groups ≥75, 65-74, 50-64, 19-49; P < .0001).
Twelve-month health status ⁎
≥≥75 21 to <50 50 to <65 65 to <75 (n = 503) (n = 1042) (n = 518) (n = 435)
Overall Quality of life 80.4 score † (mean) Presence of 22.8 angina ‡ (%) Medical management Quality of life 77.8 score (mean) Presence of 27.4 angina (%) Coronary revascularization Quality of life 80.9 score (mean) Presence of 20.5 angina (%)
82.9
88.4
89.3
18.4
12.1
10.6
81.6
86.3
89.3
18.7
13.8
13.7
82.9
88.6
89.6
18.5
10.7
9.9
⁎ Adjusted for all Table I variables and baseline health status. †P = .54 for interaction between age and revascularization. ‡P = .44 for the interaction between age and revascularization.
Seattle Angina Questionnaire HRQL. In unadjusted analysis, older patients had better baseline HRQL compared to younger patients (SAQ HRQL scores 67.1 vs 64.3 vs 60.5 vs 58.8 for age groups ≥75, 65-74, 50-64, 1949; P < .0001). During the follow-up period, there were significant improvements in quality of life scores across age strata with the largest improvement occurring between hospital discharge and 1-month follow-up assessment (Figure 2). At 12 months, older patients continued to have better HRQL compared to younger patients, and these findings persisted even after
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Table III. Proportion of patients with any angina between baseline and 12 months of follow-up (N = 1950) Presence of angina Baseline
12 m
N N Y Y
N Y N Y
Age groups 19 to<50 (n[%]) 131 32 135 59
(36.7) (9.0) (37.8) (16.5)
50 to <65 (n[%])
65 to <74 (n[%])
325 (38.8) 56 (6.7) 321 (38.3) 135 (16.1)
188 (43.0) 19 (4.3) 185 (42.3) 45 (10.3)
≥75 (n[%]) 151 (47.3) 10 (3.1) 127 (39.8) 31 (9.7)
Total (N = 1950) 795 117 768 270
(40.8) (6.0) (39.4) (13.8)
Table IV. Proportion of patients with change in HRQL between baseline and 12 months of follow-up (n = 1881) Quality of life scores Change between baseline and 12 m (12 m baseline) Less than −5 points ⁎ −5 to +5 points † More than +5 points ‡
Age groups
19 to <50 (n[%])
50 to <65 (n[%])
65 (18.7) 42 (12.1) 240 (69.2)
131 (16.2) 100 (12.3) 579 (71.5)
65 to <75 (n[%]) 41 (9.6) 55 (12.8) 332 (77.6)
≥75 (n[%])
Total (n = 1881)
31 (10.5) 41 (13.8) 224 (75.7)
268 (14.2) 238 (12.7) 1375 (73.1)
⁎ Less than −5 points of decrease represents worsening in HRQL between baseline and 12 months of follow-up. † −5 to +5 points represent no significant change in HRQL between baseline and 12 months of follow-up. ‡ More than +5 points of increase represents an improvement in HRQL between baseline and 12 months of follow-up.
multivariable adjustment for baseline HRQL and other patient characteristics (89.1 vs 88.1 vs 82.5 vs 80.0 for age groups ≥75, 65-74, 50-64, 19-49; P < .0001). Secondary analyses. In secondary analysis, patients were stratified according to whether they underwent revascularization during the hospitalization. The interaction between age and revascularization was not statistically significant for SAQ HRQL (P = .54) nor for angina prevalence (P = .44) (Table II). Consistent with the primary analysis, older patients were less likely to have angina at 12 months compared to younger patients regardless of treatment received during the index hospitalization. Similarly, older patients were more likely to have better HRQL whether or not they underwent revascularization. In addition, a greater proportion of older patients were angina-free and had an improvement in HRQL (ie, increase of N5 points in HRQL score) at 12 months compared to younger patients (Tables III and IV). Finally, analyses accounting for potential bias in health status recovery curves due to differential survival and dropout did not change our primary findings.
Discussion In this study of a cohort of patients surviving AMI and receiving high rates of evidence-based therapy, older patients had better 1-year health status outcomes, including less angina burden and better HRQL compared to younger patients. These findings underscore the point that older patients have the potential for successful
functional recovery after AMI and support strategies to deliver high levels of evidence-based care to older patients. However, 1 in 10 of the oldest patients and nearly 1 in 4 younger patients still experience angina 1 year after AMI, highlighting the importance of continued symptom surveillance after AMI and suggest the need for better strategies to reduce symptom burden. The finding that older survivors of AMI have successful functional and symptomatic recovery after AMI despite receiving lower rates of some evidence-based therapies suggests even greater benefits in HRQL may be possible if ACC/AHA guideline recommendations were followed regardless of age. Prior studies suggest that older patients can achieve outcomes (ie, mortality and hospitalization) similar to younger patients when treated with evidencebased therapies for acute coronary syndrome hospitalization despite higher baseline risks.4,5 Older patients have significant improvements in quality of life and reductions in angina after AMI despite lower rates of some evidence-based therapies, certainly challenging the notion of therapeutic nihilism. Although treatment decisions in older patients are often complex because of their multidimensional health status and preferences, the belief that they will not experience good quality of life or symptom improvement is not supported by these data.21 This finding of less symptom burden and better quality of life after AMI with increasing age seems paradoxical but has been noted previously.9 The reasons for these apparent discrepancies between survival and HRQL are not known; however, it may result from changing
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patient expectations of their physical and mental health with increasing age.22 Because quality of life has been defined as the difference between actual and desired function, differences in expectations and perceptions of change between older and younger patients may potentially explain our result.9,22,23 In addition, symptoms of angina have been associated with quality of life deficits, which may also explain why older patients, who had less angina in this study, had better quality of life compared to younger patients.24 In addition, older patients may have more noncardiac symptoms that can limit their functional capacity before the threshold of angina (eg, arthritis and frailty), and these noncardiac conditions may have a greater perceived impact on their health. Further studies will be useful to identify the mediators of the differences in health status outcomes between older versus younger patients after AMI. Despite high rates of use of evidence-based medications and coronary revascularization during the index hospitalization, angina was common after AMI. Almost 1 in 4 of the youngest (age <50 years) and 1 in 5 of those aged 50 to 64 years still had angina 12 months after the index hospitalization. One potential explanation for the high burden of angina among younger patients may be related to the fact that younger patients may not recalibrate their expectations for physical functioning after AMI. Conversely, older patients may alter their expectations of their physical status and reduce their activity level accordingly, thereby experiencing less symptom burden. Our findings suggest the need for continued angina surveillance in young and old alike given the known relationship between angina and quality of life.19 Ultimately, clinical trials should identify effective interventions guided by angina symptoms, including intensification of current antianginal medications or coronary revascularization, on patient outcomes. Certain issues should be considered in the interpretation of the results of this study. First, a minority of patients did not have a 12-month assessment of their health status and our findings may reflect survivor bias. However, our multivariable models comprised a repeated-measures analysis that includes all observed follow-up health status information. Therefore, any potential bias in health status at 12 months may be accounted for by observed health status earlier in the study.25 Health status remained relatively stable after the 1-month follow-up, suggesting that any potential bias in 12-month health status outcomes was accounted for by health status at 1 or 6 months after hospital discharge. In addition, these results are directly relevant to survivors of AMI, whom comprise a significant proportion of patients in the PREMIER registry as well as in clinical practice. Second, because of the relatively small overall number of patients with angina at any time point, we could not provide significant detail into the number of
patients with changes in angina category across the spectrum of age because many of the categories of angina change would have very low numbers. Future studies should evaluate changes in angina category across the spectrum of age after AMI hospitalization. Third, we found that older patients have better quality of life and less angina 12 months after AMI hospitalization and speculate that a potential reason for less angina among older patients could be related to the fact that older patients may alter expectations of their physical status after AMI and reduce their activity level accordingly. However, exercise tolerance was not measured in the current study, and further research is needed to better understand the mediators of differences in health status outcomes between older versus younger patients after AMI, including objective measures of activity level. Finally, patients with atypical symptoms may have difficulty answering the SAQ angina frequency questions; however, the SAQ was validated in a broad range of patients with coronary artery disease and not just among patients with typical anginal symptoms.17 In conclusion, older patients have the potential for better health status outcomes after AMI compared to younger patients despite less intensive AMI therapy. Clinicians who may be inclined to treat the elderly less aggressively because of concerns that such patients who survive AMI will have poor quality of life or debilitating symptoms should be aware of the potential for successful health status recovery among older patients. Furthermore, angina continues to affect patients after AMI across the spectrum of age. Surveillance for angina should be considered as routine posthospitalization care for patients with AMI, and future studies should focus on more effective interventions to alleviate symptoms after AMI.
References 1. Yan RT, Yan AT, Tan M, et al. Age-related differences in the management and outcome of patients with acute coronary syndromes. Am Heart J 2006;151:352-9. 2. Avezum A, Makdisse M, Spencer F, et al. Impact of age on management and outcome of acute coronary syndrome: observations from the Global Registry of Acute Coronary Events (GRACE). Am Heart J 2005;149:67-73. 3. Tran CTT, Laupacis A, Mamdani MM, et al. Effect of age on the use of evidence-based therapies for acute myocardial infarction. Am Heart J 2004;148:834-41. 4. Alexander KP, Roe MT, Chen AY, et al. Evolution in cardiovascular care for elderly patients with non–ST-segment elevation acute coronary syndromes. J Am Coll Cardiol 2005;46:1479-87. 5. Bach RG, Cannon CP, Weintraub WS, et al. The effect of routine, early invasive management on outcome for elderly patients with non– ST segment elevation acute coronary syndromes. Ann Intern Med 2004;141:186-95. 6. Maggioni AP, Maseri A, Fresco C, et al. Age-related increase in mortality among patients with first myocardial infarctions treated with thrombolysis. The Investigators of the Gruppo Italiano per lo Studio
American Heart Journal Volume 155, Number 5
7.
8.
9.
10.
11.
12.
13.
14.
15.
Ho et al 861
della Sopravvivenza nell'Infarto Miocardico (GISSI-2). N Engl J Med 1993;329:1442-8. Vitagliano G, Curtis JP, Concato J, et al. Association between functional status and use and effectiveness of beta-blocker prophylaxis in elderly survivors of acute myocardial infarction. J Am Geriatr Soc 2004;52:495-501. Skolnick AH, Alexander KP, Chen AY, et al. Characteristics, management, and outcomes of 5,557 patients age N or = 90 years with acute coronary syndromes: results from the CRUSADE Initiative. J Am Coll Cardiol 2007;49:1790-7 Electronic publication 2007 Apr 16. Masoudi FA, Rumsfeld JS, Havranek EP, et al. Age, functional capacity, and health-related quality of life in patients with heart failure. J Card Fail 2004;10:368-73. Sarkisian CA, Hays RD, Mangione CM. Do older adults expect to age successfully? The association between expectations regarding age and beliefs regarding healthcare seeking among older adults. J Am Geriatr Soc 2002;50:1837-43. Thom T, Haase N, Rosamond W, et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2006 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2006;113:e85-e151 Electronic publication 2006 Jan 11. Mold JW, Looney SW, Viviani NJ, et al. Predicting the health-related values and preferences of geriatric patients. J Fam Pract 1994;39: 461-7. Tsevat J, Dawson NV, Wu AW, et al. Health values of hospitalized patients 80 years or older. HELP investigators. Hospitalized Elderly Longitudinal Project. JAMA 1998;279:371-5. Committee on Quality Health Care in America, Institute of Medicine. Crossing the quality chasm: a new health system for the 21st century. Washington, DC: National Academy Press; 2001. Krumholz HM, Peterson ED, Ayanian JZ, et al. Report of the National Heart, Lung, and Blood Institute working group on
16.
17.
18.
19.
20.
21.
22. 23. 24.
25.
outcomes research in cardiovascular disease. Circulation 2005;111: 3158-66. Spertus JA, Peterson ED, Rumsfeld JS, et al, for the Cardiovascular Outcomes Research Consortium. The PREMIER (Prospective Registry Evaluating Myocardial Infarction: Event and Recovery) Registry— evaluating the impact of myocardial infarction on patient outcomes. Am Heart J 2006;151:589-97. Spertus JA, Winder JA, Dewhurst TA, et al. Development and evaluation of the Seattle Angina Questionnaire: a new functional status measure for coronary artery disease. J Am Coll Cardiol 1995;25:333-41. Spertus JA, Winder JA, Dewhurst TA, et al. Monitoring the quality of life in patients with coronary artery disease. Am J Cardiol 1994;74:1240-4. Spertus JA, Jones P, McDonell M, et al. Health status predicts longterm outcome in outpatients with coronary disease. Circulation 2002;106:43-9. Mitchell PH, Powell L, Blumenthal J, et al. A short social support measure for patients recovering from myocardial infarction: the ENRICHD Social Support Inventory. J Cardiopulm Rehabil 2003;23:398-403. Alexander KP, Chen AY, Roe MT, et al. Excess dosing of antiplatelet and antithrombin agents in the treatment of non-ST-segment elevation acute coronary syndromes. JAMA 2005;294:3108-16. Albrecht GL, Devieger PJ. The disability paradox: high quality of life against all odds. Soc Sci Med 1999;42:374-80. Rumsfeld JS. Health status and clinical practice: when will they meet? Circulation 2002;106:5-7. Spertus JA, Dewhurst TA, Dougherty CM, et al. Benefits of an “angina clinic” for patients with coronary artery disease: a demonstration of health status measures as markers of health care quality. Am Heart J 2002;143:145-50. Fairclough DL. Design and analysis of quality of life studies in clinical trials. Boca Raton, IL: Chapman & Hall/CRC; 2002.
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Background Older age is a risk factor for higher mortality after acute myocardial infarction (AMI), but the association with health status outcomes is largely unexplored. Methods In a prospective cohort of 2498 patients in the PREMIER study, we compared health-related quality of life (HRQL) and burden of angina symptoms among survivors of AMI by age strata (age groups ≥75, 65-74, 50-64, and 19-49 years) using the Seattle Angina Questionnaire. Multivariable analyses assessed the relationship between age and 1-year HRQL and angina burden, adjusting for differences in clinical characteristics, treatment, and baseline health status. Results
Older patients comprised a majority: 20.1% were ≥75 years of age, 41.7% were 65 to 74 years of age, 20.7% were 50 to 64 years of age, and 17.4% were <50 years of age. At 12 months, older patients had higher mortality (17.0% vs 8.7% vs 6.1% vs 3.2% for age groups ≥75, 65-74, 50-64, 19-49; P < .001). Among survivors of AMI, increasing age was associated with less angina and better HRQL. By 12 months, older patients reported less angina (10.9% vs 12.7% vs 19.3% vs 23.4% for age groups ≥75, 65-74, 50-64, 19-49; P < .0001) and better HRQL (scores 89.1 vs 88.1 vs 82.5 vs 80.0, respectively; P < .0001), which persisted after adjustment for baseline angina, HRQL, and other demographic, clinical, disease severity, and treatment differences.
Conclusions Although older patients have higher mortality after AMI, those who survive experience fewer symptoms and better HRQL at 1 year than younger patients. Angina remains present in a number of patients across the spectrum of age, supporting strategies to systematically assess and treat symptoms after AMI. (Am Heart J 2008;155:855- 61.)
Increasing age has been consistently identified as a risk factor for mortality after acute myocardial infarction (AMI). Possible contributors to this risk include the general increasing comorbidity burden with age and the declining rates of treatment with guideline-recommended therapies, which are often underused in the most functionally limited patients.1-8 Just as older persons have a higher risk for death, it is also possible that older patients will experience more angina and poorer health-
From the aMedical Service, Denver VA Medical Center, Denver, CO, bDepartment of Medicine, University of Colorado Health Sciences Center, Denver, CO, cMid America Heart Institute, Kansas City, MO, dDepartment of Medicine, Denver Health Medical Center, Denver, CO, eDuke Clinical Research Institute, Durham, NC, and fYale University School of Medicine, New Haven, CT. This project was principally supported by CV Therapeutics, Inc, Palo Alto, CA, who had no involvement in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript. Partial support was also provided by CV Outcomes, Inc, Kansas City, MO. Submitted August 10, 2007; accepted November 28, 2007. Reprint requests: P. Michael Ho, MD, PhD, 1055 Clermont St., Cardiology (111B), Denver, CO 80220. E-mail: [email protected] 0002-8703/$ - see front matter Published by Mosby, Inc. doi:10.1016/j.ahj.2007.11.032
related quality of life (HRQL) after AMI. Yet, indirect evidence suggests that the opposite is plausible. For example, older patients with heart failure have better HRQL than younger patients despite greater functional limitation, possibly reflecting changing expectations of health status with advancing age.9-10 Despite the importance of HRQL and symptom burden outcomes to survivors of AMI, little is known about the patterns of health status outcomes as a function of age in the year after AMI. Because AMI survival rates have improved, health status outcomes are relevant to a growing number of patients.11 Health status may be especially pertinent to older patients, who may focus more on symptom burden and quality of life than prolonging life.12,13 The Institute of Medicine and professional organizations have also emphasized the importance of patient centered care highlighting the value of understanding health status.14,15 However, given the clear relationship between higher mortality with age, clinicians may assume that older patients also have a greater likelihood of symptomatic and functional impairment, potentially encouraging therapeutic nihilism. A greater understanding of health status outcomes after AMI would allow patients and the
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clinicians caring for them to calibrate their expectations for successful recovery. Accordingly, the objectives of this study were to assess health status outcomes, including angina frequency and HRQL, across the spectrum of age after AMI among patients enrolled in a large multicenter prospective cohort study. Specifically, we assessed patterns of health status outcomes over the 12 months after hospitalization among AMI survivors to elucidate the extent to which older patients may experience successful recovery after AMI.
Methods Patient sample Between January 1, 2003, and June 28, 2004, 2498 AMI patients were recruited into the PREMIER study from 19 US hospitals. Details of the study methods have been published previously.16 In brief, all patients with biomarker evidence of myocardial necrosis and clinical evidence of an AMI during the initial 24 hours of admission were screened for possible inclusion. Using standard criteria, patients were eligible if they were 18 years or older and had additional evidence supporting the diagnosis of AMI, such as prolonged (N20 minutes) ischemic signs/symptoms or electrocardiographic ST changes.16 Patients not presenting initially to the enrolling institution were eligible only if they were transferred within the first 24 hours of presentation to ensure that the primary clinical decision making occurred at the enrolling site. Patients who were incarcerated and those having elevated cardiac biomarkers as a complication of elective coronary revascularization were not eligible. Institutional research board approval was obtained at each participating institution, and patients signed informed consent for baseline and follow-up interviews.
Outcomes assessment One-, 6-, and 12-month telephone follow-up interviews were conducted by a single center. Using contact information provided by patients at the time of enrollment, we made multiple attempts to conduct an interview that included quantification of patients' current health status using the Seattle Angina Questionnaire (SAQ). The SAQ is a 19-item, disease-specific health status measure that quantifies domains of patients' health status.17-19 For the purposes of this study, scores on the angina frequency and quality of life subscales were used, which can range from 0 to 100, and where higher scores represent fewer symptoms and better quality of life. A 5-point difference in scores is considered clinically significant. The SAQ is valid, reproducible, sensitive to clinical change, and prognostic of subsequent mortality and acute coronary syndrome admissions.19 Survival status was confirmed through patient contact, patients' suggested contacts, patients' primary care or cardiovascular physicians, and through the Social Security Death Master File for patients with valid social security numbers (99.8% of the cohort). The primary outcomes for this analysis were the SAQ angina frequency and HRQL subscales at 12 months after AMI hospitalization. Given the skewed distribution of the SAQ angina frequency scores, angina frequency was dichotomized into any angina (SAQ angina frequency score <100) and no angina (SAQ
angina frequency score 100). The SAQ HRQL subscale was analyzed as a continuous variable.
Statistical analysis Baseline patient and clinical characteristics were compared across age groups using 1-way analysis of variance for continuous variables and χ2 for discrete variables. Health status outcomes at 1, 6, and 12 months were analyzed using repeated measures models (linear models for SAQ HRQL, logistic models for angina prevalence), including fixed effects for month, age group, and age group-by-month using an autoregressive moving average and a within-patient correlation structure. This model accounts for all observed follow-up health status data. For each outcome, three models were constructed: (1) unadjusted, (2) adjusted for baseline health status, and (3) multivariable-adjusted. Variables in the multivariable models were chosen by a combination of a priori clinical judgment and statistical association with age, and included demographics (sex, race), medical history (body mass index, diabetes, chronic heart failure, lung disease, smoking status, arthritis, cancer, hypertension, prior myocardial infarction, prior percutaneous coronary intervention [PCI], prior coronary artery bypass graft surgery [CABG], prior cerebrovascular disease), clinical presentation (ST-elevation MI, number of diseased vessels, left ventricular systolic dysfunction, glomerular filtration rate as estimated using the modified MDRD equation, hematocrit), treatment (coronary angiography, revascularization, discharge medications), socioeconomic status (education, self-reported economic burden of health care costs, lack of insurance), social support (marital status, ENRICHD social support score 20 ), PHQ-9 depression score, discharge medications (aspirin, β-blockers, angiotensinconverting enzyme [ACE] inhibitors or angiotensin receptor blockers, and statin medications) among patients without contraindications to therapy, baseline health status, and site. Interaction terms with month were included for all variables. For variables with <5% missing values, we assumed missingness at random given the observed data, and imputed using multiple imputation methods to allow use of all observations and to correctly account for uncertainty due to missing values. The imputation model included all baseline and follow-up variables. In the primary analyses, all observed follow-up health status data were included in the statistical models including health status data of patients at 1 and/or 6 months for all patients for whom these data were available. In sensitivity analyses, we only included patients completing the 12-month follow-up to examine for potential biases in the health status recovery curves because of differential survival and dropout. The results of these sensitivity analyses were consistent with the primary findings and therefore are not further reported. Second, because revascularization is an important determinant of future angina, interactions terms were included in the multivariable models to examine whether the relationship between age and health status changed according to whether patients received coronary revascularization during the index hospitalization. These analyses were further stratified by treatment strategy (medical management compared to revascularization with PCI or CABG). Third, we assessed the proportion of patients with angina at baseline and 12 months after AMI hospitalization and categorized patients into 4 angina categories (no angina at baseline or 12 months, angina at baseline and at 12 months, angina at baseline but not at 12 months, and no angina at baseline but angina at 12 months). Then, we compared angina
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Table I. Baseline characteristics of the study population by age strata Variables
21 to <50 (n = 503) 50 to <65 (n = 1042) 65 to <75 (n = 518) ≥≥75 (n = 435)
Demographic factors Age (mean [SD]) Male sex White race Body mass index (mean [SD]) Medical history Diabetes Heart failure Chronic lung disease Current smoker Arthritis Cancer Hypertension MI Prior PCI Prior CABG Cerebrovascular disease Socioeconomic factors High school education Medication costs are not a burden Self-pay Married ENRICHD social support score (mean [SD]) Hospital and MI treatment factors ST-elevation MI Diagnostic coronary angiogram Normal left ventricular systolic function Glomerular filtration rate (mean [SD]) Hematocrit (%) (mean [SD]) Aspirin within 24 h b-Blocker within 24 h Primary reperfusion therapy for STEMI Multivessel coronary artery disease Revascularization type None PCI CABG Medications prescribed at hospital discharge among Aspirin β-Blocker ACE inhibitor or ARB Statin
P
43.2 (5.2) 75.9 64.4 30.1 (6.8)
57.0 (4.2) 70.2 71.0 29.9 (6.5)
69.4 (2.8) 65.4 82.4 29.2 (5.9)
80.5 (4.4) 53.3 82.6 26.5 (5.1)
<.001 <.001 <.001 <.001
20.5 6.8 6.6 58.9 4.6 1.4 50.3 16.3 12.9 3.6 3.6
29.2 9.9 11.6 40.6 8.6 5.7 62.0 20.6 17.8 10.9 5.6
34.9 15.3 18.5 18.2 18.3 13.9 70.1 22.8 19.7 20.1 8.7
30.3 19.8 18.9 7.0 22.1 16.3 75.4 28.0 21.8 20.0 9.4
<.001 <.001 <.001 <.001 <.001 <.001 <.001 <.001 .003 <.001 <.001
32.0 61.8 24.0 52.6 28.7 (6.4)
31.7 62.4 15.2 63.2 29.3 (5.9)
29.1 65.9 3.0 66.9 30.0 (5.3)
26.5 67.7 0.7 51.8 29.7 (5.0)
<.001 .001 <.001 <.001 .003
51.5 88.3 55.7 77.3 (28.1) 41.0 (6.2) 94.6 86.7 86.9 28.8
46.8 90.0 54.2 68.3 (30.1) 40.0 (6.0) 95.6 87.0 83.4 39.2
37.5 88.8 49.4 58.9 (23.3) 38.8 (6.0) 94.2 83.2 84.5 47.4
34.0 75.9 47.2 50.0 (22.8) 36.9 (6.3) 92.6 78.6 71.6 50.3
<.001 <.001 .01 <.001 <.001 .145 <.001 <.001 <.001 <.001
25.4 63.4 11.1
26.8 56.0 17.2
41.6 46.2 12.2
97.8 91.9 84.6 89.0
96.1 91.1 79.5 84.2
95.9 86.0 78.8 83.1
27.8 66.4 5.8 ideal candidates 97.8 91.1 82.2 91.1
.08 .005 .23 .04
STEMI, ST elevation myocardial infarction.
categories across the spectrum of age. Fourth, we evaluated the proportion of patients with clinically significant changes in HRQL scores between baseline and at 12 months. We categorized patients into 3 HRQL categories: (1) worsening HRQL (decrease in HRQL score of N5 points); (2) no change (change in HRQL score of ≤5 points in either direction); (3) improving HRQL (increase in HRQL score of N5 points). These HRQL categories were compared across the spectrum of age. The analyses were conducted using SAS v9.1 (SAS Institute, Inc, Cary, NC) and R v2.3.0 (The R Project for Statistical Computing, Auckland, New Zealand).
Results Baseline characteristics Baseline characteristics of the study population are outlined in Table I according to age strata. In general,
older patients were more likely to be female, white, and to have a higher prevalence of cardiovascular and noncardiovascular comorbidities (eg, heart failure, chronic lung disease, prior myocardial infarction). In addition, older patients were less likely to present with a ST-elevation myocardial infarction and less likely to have preserved left ventricular systolic function.
Inhospital MI treatment Rates of aspirin use within 24 hours of MI presentation were similar across age strata. However, older patients were significantly less likely to receive a β-blocker within 24 hours of MI presentation or acute reperfusion therapy for ST-elevation MI (Table I). Rates of coronary angiography for the entire population were N75%, but older patients were still less likely to
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Figure 1
Figure 2
Prevalence of angina by age groups for the 12 months after hospital discharge (multivariable adjusted).
Seattle Angina Questionnaire quality of life scores by age groups for the 12 months after hospital discharge (multivariable adjusted).
undergo a diagnostic angiogram compared to younger patients. In addition, older patients more often had multivessel coronary artery disease and a minority of all patients underwent CABG.
Table II. Twelve-month health status across the spectrum of age according to receipt of revascularization during the index hospitalization
Discharge medications At hospital discharge, more than three quarters of patients were prescribed evidence-based medications among ideal candidates. There were no significant differences in rates of aspirin or ACE inhibitor/ARB prescription. However, older patients were less likely to receive β-blockers and statins compared to younger patients. Twelve-month outcomes Follow-up and mortality. In general, older patients were less likely to be lost to follow-up (1.8% vs 4.2% vs 11.1% vs 22.9% incomplete 12-month follow-up for age groups ≥75, 65-74, 50-64, 19-49; P < .001) but had higher mortality rates (17.0% vs 8.7% vs 6.1% vs 3.2% for age groups ≥75, 65-74, 50-64, 19-49; P < .001) compared to younger patients. Angina prevalence. In unadjusted analysis, the prevalence of any angina at baseline was lower among older patients (49.3% vs 53.1% vs 54.8% vs 54.7% for age groups ≥75, 65-74, 50-64, 19-49; P < .0001). During the follow-up period, the prevalence of any angina across age strata decreased significantly with the largest decline occurring within the first month after hospital discharge (Figure 1). At 12 months, older patients continued to have less angina compared to younger patients even after multivariable adjustment for differences in baseline angina prevalence and other patient characteristics (10.9% vs 12.7% vs 19.3% vs 23.4% for age groups ≥75, 65-74, 50-64, 19-49; P < .0001).
Twelve-month health status ⁎
≥≥75 21 to <50 50 to <65 65 to <75 (n = 503) (n = 1042) (n = 518) (n = 435)
Overall Quality of life 80.4 score † (mean) Presence of 22.8 angina ‡ (%) Medical management Quality of life 77.8 score (mean) Presence of 27.4 angina (%) Coronary revascularization Quality of life 80.9 score (mean) Presence of 20.5 angina (%)
82.9
88.4
89.3
18.4
12.1
10.6
81.6
86.3
89.3
18.7
13.8
13.7
82.9
88.6
89.6
18.5
10.7
9.9
⁎ Adjusted for all Table I variables and baseline health status. †P = .54 for interaction between age and revascularization. ‡P = .44 for the interaction between age and revascularization.
Seattle Angina Questionnaire HRQL. In unadjusted analysis, older patients had better baseline HRQL compared to younger patients (SAQ HRQL scores 67.1 vs 64.3 vs 60.5 vs 58.8 for age groups ≥75, 65-74, 50-64, 1949; P < .0001). During the follow-up period, there were significant improvements in quality of life scores across age strata with the largest improvement occurring between hospital discharge and 1-month follow-up assessment (Figure 2). At 12 months, older patients continued to have better HRQL compared to younger patients, and these findings persisted even after
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Table III. Proportion of patients with any angina between baseline and 12 months of follow-up (N = 1950) Presence of angina Baseline
12 m
N N Y Y
N Y N Y
Age groups 19 to<50 (n[%]) 131 32 135 59
(36.7) (9.0) (37.8) (16.5)
50 to <65 (n[%])
65 to <74 (n[%])
325 (38.8) 56 (6.7) 321 (38.3) 135 (16.1)
188 (43.0) 19 (4.3) 185 (42.3) 45 (10.3)
≥75 (n[%]) 151 (47.3) 10 (3.1) 127 (39.8) 31 (9.7)
Total (N = 1950) 795 117 768 270
(40.8) (6.0) (39.4) (13.8)
Table IV. Proportion of patients with change in HRQL between baseline and 12 months of follow-up (n = 1881) Quality of life scores Change between baseline and 12 m (12 m baseline) Less than −5 points ⁎ −5 to +5 points † More than +5 points ‡
Age groups
19 to <50 (n[%])
50 to <65 (n[%])
65 (18.7) 42 (12.1) 240 (69.2)
131 (16.2) 100 (12.3) 579 (71.5)
65 to <75 (n[%]) 41 (9.6) 55 (12.8) 332 (77.6)
≥75 (n[%])
Total (n = 1881)
31 (10.5) 41 (13.8) 224 (75.7)
268 (14.2) 238 (12.7) 1375 (73.1)
⁎ Less than −5 points of decrease represents worsening in HRQL between baseline and 12 months of follow-up. † −5 to +5 points represent no significant change in HRQL between baseline and 12 months of follow-up. ‡ More than +5 points of increase represents an improvement in HRQL between baseline and 12 months of follow-up.
multivariable adjustment for baseline HRQL and other patient characteristics (89.1 vs 88.1 vs 82.5 vs 80.0 for age groups ≥75, 65-74, 50-64, 19-49; P < .0001). Secondary analyses. In secondary analysis, patients were stratified according to whether they underwent revascularization during the hospitalization. The interaction between age and revascularization was not statistically significant for SAQ HRQL (P = .54) nor for angina prevalence (P = .44) (Table II). Consistent with the primary analysis, older patients were less likely to have angina at 12 months compared to younger patients regardless of treatment received during the index hospitalization. Similarly, older patients were more likely to have better HRQL whether or not they underwent revascularization. In addition, a greater proportion of older patients were angina-free and had an improvement in HRQL (ie, increase of N5 points in HRQL score) at 12 months compared to younger patients (Tables III and IV). Finally, analyses accounting for potential bias in health status recovery curves due to differential survival and dropout did not change our primary findings.
Discussion In this study of a cohort of patients surviving AMI and receiving high rates of evidence-based therapy, older patients had better 1-year health status outcomes, including less angina burden and better HRQL compared to younger patients. These findings underscore the point that older patients have the potential for successful
functional recovery after AMI and support strategies to deliver high levels of evidence-based care to older patients. However, 1 in 10 of the oldest patients and nearly 1 in 4 younger patients still experience angina 1 year after AMI, highlighting the importance of continued symptom surveillance after AMI and suggest the need for better strategies to reduce symptom burden. The finding that older survivors of AMI have successful functional and symptomatic recovery after AMI despite receiving lower rates of some evidence-based therapies suggests even greater benefits in HRQL may be possible if ACC/AHA guideline recommendations were followed regardless of age. Prior studies suggest that older patients can achieve outcomes (ie, mortality and hospitalization) similar to younger patients when treated with evidencebased therapies for acute coronary syndrome hospitalization despite higher baseline risks.4,5 Older patients have significant improvements in quality of life and reductions in angina after AMI despite lower rates of some evidence-based therapies, certainly challenging the notion of therapeutic nihilism. Although treatment decisions in older patients are often complex because of their multidimensional health status and preferences, the belief that they will not experience good quality of life or symptom improvement is not supported by these data.21 This finding of less symptom burden and better quality of life after AMI with increasing age seems paradoxical but has been noted previously.9 The reasons for these apparent discrepancies between survival and HRQL are not known; however, it may result from changing
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patient expectations of their physical and mental health with increasing age.22 Because quality of life has been defined as the difference between actual and desired function, differences in expectations and perceptions of change between older and younger patients may potentially explain our result.9,22,23 In addition, symptoms of angina have been associated with quality of life deficits, which may also explain why older patients, who had less angina in this study, had better quality of life compared to younger patients.24 In addition, older patients may have more noncardiac symptoms that can limit their functional capacity before the threshold of angina (eg, arthritis and frailty), and these noncardiac conditions may have a greater perceived impact on their health. Further studies will be useful to identify the mediators of the differences in health status outcomes between older versus younger patients after AMI. Despite high rates of use of evidence-based medications and coronary revascularization during the index hospitalization, angina was common after AMI. Almost 1 in 4 of the youngest (age <50 years) and 1 in 5 of those aged 50 to 64 years still had angina 12 months after the index hospitalization. One potential explanation for the high burden of angina among younger patients may be related to the fact that younger patients may not recalibrate their expectations for physical functioning after AMI. Conversely, older patients may alter their expectations of their physical status and reduce their activity level accordingly, thereby experiencing less symptom burden. Our findings suggest the need for continued angina surveillance in young and old alike given the known relationship between angina and quality of life.19 Ultimately, clinical trials should identify effective interventions guided by angina symptoms, including intensification of current antianginal medications or coronary revascularization, on patient outcomes. Certain issues should be considered in the interpretation of the results of this study. First, a minority of patients did not have a 12-month assessment of their health status and our findings may reflect survivor bias. However, our multivariable models comprised a repeated-measures analysis that includes all observed follow-up health status information. Therefore, any potential bias in health status at 12 months may be accounted for by observed health status earlier in the study.25 Health status remained relatively stable after the 1-month follow-up, suggesting that any potential bias in 12-month health status outcomes was accounted for by health status at 1 or 6 months after hospital discharge. In addition, these results are directly relevant to survivors of AMI, whom comprise a significant proportion of patients in the PREMIER registry as well as in clinical practice. Second, because of the relatively small overall number of patients with angina at any time point, we could not provide significant detail into the number of
patients with changes in angina category across the spectrum of age because many of the categories of angina change would have very low numbers. Future studies should evaluate changes in angina category across the spectrum of age after AMI hospitalization. Third, we found that older patients have better quality of life and less angina 12 months after AMI hospitalization and speculate that a potential reason for less angina among older patients could be related to the fact that older patients may alter expectations of their physical status after AMI and reduce their activity level accordingly. However, exercise tolerance was not measured in the current study, and further research is needed to better understand the mediators of differences in health status outcomes between older versus younger patients after AMI, including objective measures of activity level. Finally, patients with atypical symptoms may have difficulty answering the SAQ angina frequency questions; however, the SAQ was validated in a broad range of patients with coronary artery disease and not just among patients with typical anginal symptoms.17 In conclusion, older patients have the potential for better health status outcomes after AMI compared to younger patients despite less intensive AMI therapy. Clinicians who may be inclined to treat the elderly less aggressively because of concerns that such patients who survive AMI will have poor quality of life or debilitating symptoms should be aware of the potential for successful health status recovery among older patients. Furthermore, angina continues to affect patients after AMI across the spectrum of age. Surveillance for angina should be considered as routine posthospitalization care for patients with AMI, and future studies should focus on more effective interventions to alleviate symptoms after AMI.
References 1. Yan RT, Yan AT, Tan M, et al. Age-related differences in the management and outcome of patients with acute coronary syndromes. Am Heart J 2006;151:352-9. 2. Avezum A, Makdisse M, Spencer F, et al. Impact of age on management and outcome of acute coronary syndrome: observations from the Global Registry of Acute Coronary Events (GRACE). Am Heart J 2005;149:67-73. 3. Tran CTT, Laupacis A, Mamdani MM, et al. Effect of age on the use of evidence-based therapies for acute myocardial infarction. Am Heart J 2004;148:834-41. 4. Alexander KP, Roe MT, Chen AY, et al. Evolution in cardiovascular care for elderly patients with non–ST-segment elevation acute coronary syndromes. J Am Coll Cardiol 2005;46:1479-87. 5. Bach RG, Cannon CP, Weintraub WS, et al. The effect of routine, early invasive management on outcome for elderly patients with non– ST segment elevation acute coronary syndromes. Ann Intern Med 2004;141:186-95. 6. Maggioni AP, Maseri A, Fresco C, et al. Age-related increase in mortality among patients with first myocardial infarctions treated with thrombolysis. The Investigators of the Gruppo Italiano per lo Studio
American Heart Journal Volume 155, Number 5
7.
8.
9.
10.
11.
12.
13.
14.
15.
Ho et al 861
della Sopravvivenza nell'Infarto Miocardico (GISSI-2). N Engl J Med 1993;329:1442-8. Vitagliano G, Curtis JP, Concato J, et al. Association between functional status and use and effectiveness of beta-blocker prophylaxis in elderly survivors of acute myocardial infarction. J Am Geriatr Soc 2004;52:495-501. Skolnick AH, Alexander KP, Chen AY, et al. Characteristics, management, and outcomes of 5,557 patients age N or = 90 years with acute coronary syndromes: results from the CRUSADE Initiative. J Am Coll Cardiol 2007;49:1790-7 Electronic publication 2007 Apr 16. Masoudi FA, Rumsfeld JS, Havranek EP, et al. Age, functional capacity, and health-related quality of life in patients with heart failure. J Card Fail 2004;10:368-73. Sarkisian CA, Hays RD, Mangione CM. Do older adults expect to age successfully? The association between expectations regarding age and beliefs regarding healthcare seeking among older adults. J Am Geriatr Soc 2002;50:1837-43. Thom T, Haase N, Rosamond W, et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2006 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2006;113:e85-e151 Electronic publication 2006 Jan 11. Mold JW, Looney SW, Viviani NJ, et al. Predicting the health-related values and preferences of geriatric patients. J Fam Pract 1994;39: 461-7. Tsevat J, Dawson NV, Wu AW, et al. Health values of hospitalized patients 80 years or older. HELP investigators. Hospitalized Elderly Longitudinal Project. JAMA 1998;279:371-5. Committee on Quality Health Care in America, Institute of Medicine. Crossing the quality chasm: a new health system for the 21st century. Washington, DC: National Academy Press; 2001. Krumholz HM, Peterson ED, Ayanian JZ, et al. Report of the National Heart, Lung, and Blood Institute working group on
16.
17.
18.
19.
20.
21.
22. 23. 24.
25.
outcomes research in cardiovascular disease. Circulation 2005;111: 3158-66. Spertus JA, Peterson ED, Rumsfeld JS, et al, for the Cardiovascular Outcomes Research Consortium. The PREMIER (Prospective Registry Evaluating Myocardial Infarction: Event and Recovery) Registry— evaluating the impact of myocardial infarction on patient outcomes. Am Heart J 2006;151:589-97. Spertus JA, Winder JA, Dewhurst TA, et al. Development and evaluation of the Seattle Angina Questionnaire: a new functional status measure for coronary artery disease. J Am Coll Cardiol 1995;25:333-41. Spertus JA, Winder JA, Dewhurst TA, et al. Monitoring the quality of life in patients with coronary artery disease. Am J Cardiol 1994;74:1240-4. Spertus JA, Jones P, McDonell M, et al. Health status predicts longterm outcome in outpatients with coronary disease. Circulation 2002;106:43-9. Mitchell PH, Powell L, Blumenthal J, et al. A short social support measure for patients recovering from myocardial infarction: the ENRICHD Social Support Inventory. J Cardiopulm Rehabil 2003;23:398-403. Alexander KP, Chen AY, Roe MT, et al. Excess dosing of antiplatelet and antithrombin agents in the treatment of non-ST-segment elevation acute coronary syndromes. JAMA 2005;294:3108-16. Albrecht GL, Devieger PJ. The disability paradox: high quality of life against all odds. Soc Sci Med 1999;42:374-80. Rumsfeld JS. Health status and clinical practice: when will they meet? Circulation 2002;106:5-7. Spertus JA, Dewhurst TA, Dougherty CM, et al. Benefits of an “angina clinic” for patients with coronary artery disease: a demonstration of health status measures as markers of health care quality. Am Heart J 2002;143:145-50. Fairclough DL. Design and analysis of quality of life studies in clinical trials. Boca Raton, IL: Chapman & Hall/CRC; 2002.
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