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Hand-carried cardiac ultrasound as a tool to screen for important cardiovascular disease in an underserved minority health care clinic
ORIGINAL ARTICLES
Hand-carried Cardiac Ultrasound as a Tool to Screen for Important Cardiovascular Disease in an Underserved Minority Health Care Clinic James N. Kirkpatrick, MD, Andrew Davis, MD, Jeanne M. DeCara, MD, Anne E. Hong, MD, Patricia L. Kurtz, MD, Beth Balasia, BS, and Kirk T. Spencer, MD, Chicago, Illinois
The disparity in cardiovascular outcomes among racial and social strata may be, in part, because of delayed detection of cardiovascular disease in minority patients. The low cost and portability of hand-carried cardiac ultrasound devices may make screening of underserved patients for cardiac disease feasible. A general internist evaluated 153 patients at a clinic serving an underserved population with a hand-carried cardiac ultrasound device. A total of 27 cases of significant valvular heart disease or ventricular dysfunction were detected in 19 pa-
Cardiovascular disease is prevalent in the United
States and represents a leading cause of morbidity, mortality, and health care use.1 Cardiovascular outcomes for racial minorities and underserved populations are poor compared with affluent nonminority populations.2-7 This disparity in outcomes among racial and social strata is complex and multifactorial. Part of the difference may be a result of delayed detection of cardiovascular disease in minority patients. One of the reasons for this delayed detection may be lack of access to regular health care and medical technology. Recent guidelines have emphasized the progressive nature of cardiovascular disease and the importance of early identification of patients with preclinical cardiac disease.8 Screening of minority and underserved patients for cardiovascular disease to allow earlier identification and intervention might help lessen the morbidity in these populations. Echocardiography is a powerful, noninvasive tool and is superior to physical examination for the From the Sections of Cardiology and General Internal Medicine, Department of Medicine, University of Chicago. Supported by an outcomes research grant from the American Society of Echocardiography. Reprint requests: Kirk T. Spencer, MD, University of Chicago, 5841 S Maryland Ave, MC 5084, Chicago, IL 60637 (E-mail: [email protected]). 0894-7317/$30.00 Copyright 2004 by the American Society of Echocardiography. doi:10.1016/j.echo.2004.01.016
tients (12.4%). Detection of a major cardiac abnormality could not be predicted by cardiac risk factors, age, or chief symptom, whereas patients presenting for new or acute clinic visits were more likely to have an abnormality. The low cost and portability of hand-carried cardiac ultrasound devices may make them important tools for the early detection of cardiovascular disease in minority and underserved populations and, thereby, help to reduce disparities in cardiovascular outcomes. (J Am Soc Echocardiogr 2004;17:399-403.)
identification of cardiovascular disease. However, current echocardiographic platforms are expensive, and skilled sonographers are in limited supply in clinics and wards that care for underserved populations. The introduction of hand-carried cardiac ultrasound (HCU) devices, which are relatively inexpensive and portable, has allowed bedside evaluation of the heart at the time of physician encounter in a variety of settings.9,10 These devices could bring the diagnostic capabilities of echocardiography to busy and financially constrained providers caring for the medically underserved. Once available in a clinic, this technology may permit the identification of patients with undiagnosed cardiovascular disease during what may be their only encounter with a health care professional. We sought to test the feasibility of a primary care physician performing HCU examinations in an urban clinic that cares for underserved minority patients and to determine the incidence of significant cardiovascular disease detected by these devices in this population.
METHODS Patients were recruited from an urban health care clinic located in an impoverished area. The majority of the patients served by the clinic were African American and Hispanic. Women who were not pregnant presenting for a health care visit were approached after their visit with a primary care physician and asked to participate in a brief
399
400 Kirkpatrick et al
cardiac ultrasound screening examination. Demographic data collected included patient age, cardiac risk factors (diabetes, hypertension, smoking, family history, hypercholesterolemia), the presence of known cardiovascular disease, the visit type (acute, return, or new patient), and the organ system that accounted for the patient’s chief symptom. Patients who had previously had an echocardiogram or whose primary care physician thought had a clinical indication for echocardiography were excluded. Patients underwent a brief cardiac ultrasound examination using a hand-carried device (Optigo, Philips Medical Systems, Andover, Mass). A general internist who had 20 hours of didactic echocardiographic instruction and had completed 40 limited cardiac ultrasound examinations performed all examinations. The echocardiographic protocol included 2-dimensional echocardiography in the standard views from the parasternal, apical, and subcostal windows. A complete color Doppler examination was also performed. Echocardiographic interpretations were performed online and images were not recorded. A separate group of patients, also from an urban clinic, served as a validation group. The same internist using the HCU device imaged this group of consecutive patients. These patients then had an echocardiographic examination with a high-end platform (Sonos 5500, Philips Medical Systems) for comparison. Only echocardiographic findings that were considered to be of significant clinical importance (ie, those thought to require further evaluation or treatment) were tabulated. These findings included mild or greater aortic insufficiency; left ventricular (LV) dysfunction (estimated ejection fraction ⬍ 40%); right ventricular dysfunction; and moderate or greater mitral regurgitation, tricuspid regurgitation, and pericardial effusion. The presence of any regional wall-motion abnormality or intracardiac shunt was considered a major finding. Subgroups were analyzed to see whether the prevalence of major cardiovascular findings was related to specific clinical data. This analysis included grouping the patients by decade of age, clinic visit type, and number of cardiac risk factors. In addition, patients were subgrouped by history of cardiovascular disease or a chief symptom that was either cardiac or pulmonary. The statistical analysis of subgroups was performed with chi-square testing. A P value ⬍.05 was considered statistically significant. The study protocol was approved by the institutional review boards of the sponsoring institution and the clinic where the study took place.
RESULTS A total of 153 patients were imaged (69 men and 84 women). There were 61 African American, 88 Hispanic, and 4 Caucasian patients. Subject mean age was 45 ⫾ 16 years. Of the patients, 27% had none of the 5 recorded cardiac risk factors, whereas the percentages with 1, 2, or 3 risk factors were 69%,
Journal of the American Society of Echocardiography May 2004
Table 1 Cardiac finding on screening hand-carried cardiac ultrasound No
Aortic regurgitation (ⱖ mild) Mitral regurgitation (ⱖ moderate) Tricuspid regurgitation (ⱖ moderate) LV dysfunction RV dysfunction Pericardial effusion Regional wall-motion abnormality Shunt Total
7 2 0 5 3 1 7 2 27
LV, Left ventricular; RV, right ventricular
Table 2 Presence of cardiac abnormalities stratified by clinic data Major finding No
Visit type Acute Return New Cardiac risk factors 0 1 2 3 History cardiac disease No Yes Cardiopulmonary chief symptom No Yes
Yes
51 47 35
11 1 5
26 59 23 6
1 10 3 0
127 7
19 0
99 35
15 4
26%, and 6%, respectively. No patient had more than 3 risk factors. Only 5% of the patients had a history of atherosclerotic heart disease. However, 25% were being seen for a chief symptom that was cardiovascular or pulmonary. Nearly half (42%) of the patient visits were for an acute symptom, whereas 32% were scheduled return visits and 26% were newpatient visits. Major cardiovascular findings diagnosed by the internist using the HCU device are shown in Table 1. There were a total of 27 major findings in 19 patients. These findings included 9 patients with significant valvular heart disease, 8 with significant ventricular dysfunction, and 7 with evidence of a regional wall-motion abnormality suggesting ischemic heart disease. These findings represent a 12.4% incidence of major cardiovascular pathology. Results of the subgroup analysis are shown in Tables 2 and 3. There was a statistically higher likelihood that patients presenting for a new or acute clinic visit had a major cardiac finding on their screening ultrasound examination compared with patients returning for a scheduled follow-up. How-
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Table 3 Presence of cardiac abnormalities stratified by decade of life Decade of age Major finding
No Yes
<30
30
40
50
60
>70
28 5
19 7
33 2
19 2
24 3
8 0
ever, the likelihood of finding a major cardiac abnormality by HCU examination could not be predicted by a history of cardiac disease, total number of cardiac risk factors, or age. In addition, patients presenting with a chief symptom that was noncardiopulmonary were just as likely to have a cardiac abnormality detected as those whose chief symptom was pulmonary or cardiac in nature (Table 2). There were 43 patients in the validation study. The general internist identified 22 major abnormalities using the HCU device in these patients. In detecting regurgitant valvular lesions using color Doppler, the HCU device was very sensitive (100%); there were no false-negative findings. Specificities for the 3 regurgitant valvular lesions were 93% to 98%. Identifying LV/right ventricular dysfunction and regional wall-motion abnormalities proved more difficult for the internist. There was a higher incidence of false-negative findings with these abnormalities resulting in sensitivities that ranged between 40% and 57%. However, the specificities for the detection of regional wall motion and ventricular dysfunction were excellent (97%-100%).
DISCUSSION Cardiovascular disease is the leading cause of morbidity and mortality, and one of the most frequent reasons for health care use in the United States. Several studies have shown that minority and underserved populations have symptoms disproportionately in relation to many cardiovascular outcomes.2-7 The early detection of cardiovascular disease in these populations is hindered by several factors. One of these may be the reliance on the physical examination to detect cardiac disease because of limited access to health care technology. Multiple studies have demonstrated that the cardiac physical examination is quite poor for detecting important cardiac pathology.11-15 In addition, the nature in which many underserved populations use health care facilities (primarily for acute care) may not allow for elective screening of cardiovascular disease because of a necessary focus on evaluating and treating acute symptoms in busy clinics with limited resources.
HCU has the potential to offer sophisticated cardiovascular testing in underserved clinics. Because of their relatively low expense, HCU devices could be more readily available than full-featured ultrasound platforms. The portability of these devices would allow on-site use, which would remove the multiple barriers (eg, time, transportation, education level, and cost) that typically exist for underserved patients who are referred for cardiac testing at another site at a future date. The ease of use of these machines would allow screening for cardiac disease in unselected patients who present to underserved clinics for any indication. This is particularly important in a population of patients for whom regular physician visits may be particularly uncommon. The ability to screen patients at the time of a visit with their primary care physician may take advantage of a window of opportunity to diagnose cardiovascular disease in its early stage when the natural history can be altered. Despite their small size and reduced cost, HCU devices are diagnostically powerful.10,16,17 HCU is clearly superior to the physical examination for the detection of cardiac pathology.11,18 When used by physicians with training in echocardiography these devices have excellent clinical use.11,19,20 We and others have shown that adequate levels of accuracy are possible when these devices are used by physicians with less echocardiographic training.21-23 DeCara et al21 studied a group of 3 internists and showed that their overall diagnostic skills with HCU, whereas less than that of board-certified cardiologists, were quite good. This previous work supports responsible use of these devices by noncardiologist, as would likely need to be the case in underserved areas. The HCU diagnostic skills of the internist in this study were similar to those we and others have previously published.21-23 Inexperienced users tend to overcall color Doppler findings, leading to excellent negative-predictive value but lower positivepredictive value for major degrees of valvular regurgitation.24 The internist occasionally misinterpreted ventricular function and wall motion, findings that can be subtle and typically require more intensive training. Although some abnormalities would be undetected with HCU when used as a screening device for patients without overt cardiovascular signs or symptoms, the detection of abnormal cardiovascular findings still offers benefit to those patients who are identified. This study showed a detection rate of major cardiovascular findings of 12.4%. This rate is lower than that of patients admitted to a general medical service who were screened for cardiovascular abnormalities with a HCU device.24 The rate of major cardiac abnormalities in a group of hospitalized patients is expected to be higher than in outpa-
402 Kirkpatrick et al
tients. Furthermore, the average age of patients in this study is considerably lower than in the prior study, and the risk for cardiovascular disease increases substantially with age. The American Heart Association/American College of Cardiology task force on practice guidelines has recently highlighted the importance of identifying cardiac structural abnormalities like those detected in this study.8 In an effort to acknowledge the progressive nature of heart failure and promote early detection, this task force established 4 stages of congestive heart failure. Stage B represents patients in whom symptoms of heart failure have never developed but who have a structural disorder of the heart such as LV dilatation or hypocontractility, significant valvular heart disease, or previous myocardial infarction. All of these stage-B findings were identified using HCU in this study. One of the most important cardiovascular findings identified was significant LV systolic dysfunction. Because treatment of LV systolic dysfunction decreases morbidity, even for patients who are asymptomatic, identification of affected patients represents an ideal opportunity for intervention.25,26 The prevalence of systolic dysfunction of 3.3% in this study was similar to several community-based reports that used echocardiography to identify patients with LV dysfunction. The prior studies used similar cut-off values for LV systolic dysfunction as this study did (quantitative or qualitative ejection fraction ⬍ 40%) and had prevalence rates of reduced LV performance of 1.8% to 4.0%.27-32 These studies, however, used expensive echocardiographic platforms operated by highly trained sonographers that simply are not available in most underserved clinics. The detection of LV dysfunction at a similar rate, using a device that is a fraction of the size and cost and does not require expertise of ancillary staff, represents a significant advance. Previous population studies have shown an increase in the prevalence of LV systolic dysfunction in various subgroups such as male patients, elderly patients, or those with cardiac risk factors.27-29,32 These studies suggest that targeted screening of patients within certain subgroups is more valuable than undirected screening. However, abnormal cardiovascular findings were not predicted in this study by sex, cardiac risk factors, history of cardiovascular disease, or cardiopulmonary chief symptom. These results indicate that targeted screening in an underserved population may not be adequate. Patients who presented for a new or acute visit were more likely to have abnormal cardiovascular findings than return patients. Our data support the notion that the underserved patients using the clinic for acute or new problems represent an opportunity to screen for cardiovascular disease, as they may not have regular physician appointments.
Journal of the American Society of Echocardiography May 2004
Conclusion This study demonstrated the use of HCU devices in detecting cardiovascular disease in an underserved and predominantly minority outpatient population. The rate of detection for clinically significant findings was 12.4%, and the rate of detection of unsuggested LV dysfunction was 3.3%. The traditional risk factors for coronary disease did not predict positive findings, but acute or new (rather than return) visit was predictive, suggesting a particular benefit for patients who are not regular users of health screening services. The low cost and portability of HCU devices may make them important tools for the early detection and treatment of cardiovascular disease in minority and underserved populations and, thereby, help to reduce disparities in cardiovascular outcomes. The authors would like to thank William Clapp, MD, Arthur Jones, MD, and the staff of Lawndale Christian Health Center, Chicago, Illinois.
REFERENCES 1. McCullough PA, Philbin EF, Spertus JA, Kaatz S, Sandberg KR, Weaver WD. Confirmation of a heart failure epidemic: findings from the resource utilization among congestive heart failure (REACH) study. J Am Coll Cardiol 2002;39:60-9. 2. Barnett E, Halverson J. Local increases in coronary heart disease mortality among blacks and whites in the United States, 1985-1995. Am J Public Health 2001;91:1499-506. 3. Williams JE, Massing M, Rosamond WD, Sorlie PD, Tyroler HA. Racial disparities in CHD mortality from 1968-1992 in the state economic areas surrounding the ARIC study communities. Ann Epidemiol 1999;9:472-80. 4. Barnett E, Armstrong DL, Casper ML. Evidence of increasing coronary heart disease mortality among black men of lower social class. Ann Epidemiol 1999;9:464-71. 5. Smith GD, Neaton JD, Wentworth D, Stamler R, Stamler J. Mortality differences between black and white men in the USA: contribution of income and other risk factors among men screened for the MRFIT. Lancet 1998;351:934-9. 6. Dries DL, Exner DV, Gersh BJ, Cooper HA, Carson PE, Domanski MJ. Racial differences in the outcome of left ventricular dysfunction. N Engl J Med 1999;340:609-16. 7. Jha AK, Varosy PD, Kanaya AM, Hunninghake DB, Hlatky MA, Waters DD, et al. Differences in medical care and disease outcomes among black and white women with heart disease. Circulation 2003;108:1089-94. 8. Hunt SA, Baker DW, Chin MH, Cinquegrani MP, Feldman AM, Francis GS, et al. ACC/AHA guidelines for the evaluation and management of chronic heart failure in the adult: executive summary–a report of the American College of Cardiology/American Heart Association task force on practice guidelines (committee to revise the 1995 guidelines for the evaluation and management of heart failure). Circulation 2001;104:2996-3007. 9. Seward JB, Douglas PS, Erbel R, Kerber RE, Kronzon I, Rakowski H, et al. Hand-carried cardiac ultrasound (HCU) device: recommendations regarding new technology–a report from the echocardiography task force on new technology of
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10. 11.
12.
13.
14.
15.
16.
17. 18.
19.
20. 21.
22.
the nomenclature and standards committee of the American Society of Echocardiography. J Am Soc Echocardiogr 2002; 15:369-73. Spencer KT, Lang RM. Point of service echocardiography. ACC Curr J Rev 2002;11:49-51. Spencer KT, Anderson AS, Bhargava A, Bales AC, Sorrentino M, Furlong K, et al. Physician-performed point-of-care echocardiography using a laptop platform compared with physical examination in the cardiovascular patient. J Am Coll Cardiol 2001;37:2013-8. Mangione S, Nieman LZ. Cardiac auscultatory skills of internal medicine and family practice trainees: a comparison of diagnostic proficiency. JAMA 1997;278:717-22. Badgett RG, Lucey CR, Mulrow CD. Can the clinical examination diagnose left-sided heart failure in adults? JAMA 1997;277:1712-9. Roldan CA, Shively BK, Crawford MH. Value of the cardiovascular physical examination for detecting valvular heart disease in asymptomatic subjects. Am J Cardiol 1996;77:132731. Stevenson LW, Perloff JK. The limited reliability of physical signs for estimating hemodynamics in chronic heart failure. JAMA 1989;261:884-8. Rugolotto M, Hu BS, Liang DH, Schnittger I. Rapid assessment of cardiac anatomy and function with a new handcarried ultrasound device (OptiGo): a comparison with standard echocardiography [see comments]. Eur J Echocardiogr 2001;2:262-9. Liang D, Schnittger I. Accuracy of hand-carried ultrasound. Echocardiography 2003;20:487-90. DeCara JM, Lang RM, Spencer KT. The hand-carried echocardiographic device as an aid to the physical examination. Echocardiography 2003;20:477-85. Rugolotto M, Chang CP, Hu B, Schnittger I, Liang DH. Clinical use of cardiac ultrasound performed with a handcarried device in patients admitted for acute cardiac care. Am J Cardiol 2002;90:1040. Gorcsan J. Utility of hand-carried ultrasound for consultative cardiology. Echocardiography 2003;20:463-9. DeCara JM, Lang RM, Koch R, Bala R, Penzotti J, Spencer KT. The use of small personal ultrasound devices by internists without formal training in echocardiography. Eur J Echocardiogr 2002;4:141-7. Kimura BJ, Amundson SA, Willis CL, Gilpin EA, DeMaria AN. Usefulness of a hand-held ultrasound device for bedside
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23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
examination of left ventricular function. Am J Cardiol 2002; 90:1038. Duvall WL, Croft LB, Goldman ME. Can hand-carried ultrasound devices be extended for use by the noncardiology medical community? Echocardiography 2003;20:471-6. Spencer KT, Fedson S, Neithardt G, Thomas P, Lickerman A, Radzienda M, et al. Unsuspected clinically important cardiac findings detected with a small portable ultrasound device in patients admitted to a general medicine service. Circulation 2002;106:507. SOLVD Investigators. Effect of enalapril on mortality and the development of heart failure in asymptomatic patients with reduced left ventricular ejection fractions. N Engl J Med 1992;327:685-91. Pfeffer MA, Braunwald E, Moye LA, Basta L, Brown EJ Jr, Cuddy TE, et al. Effect of captopril on mortality and morbidity in patients with left ventricular dysfunction after myocardial infarction: results of the survival and ventricular enlargement trial; the SAVE investigators. N Engl J Med 1992;327: 669-77. Devereux RB, Roman MJ, Paranicas M, Lee ET, Welty TK, Fabsitz RR, et al. A population-based assessment of left ventricular systolic dysfunction in middle-aged and older adults: the strong heart study. Am Heart J 2001;141:439-46. Devereux RB, Bella JN, Palmieri V, Oberman A, Kitzman DW, Hopkins PN, et al. Left ventricular systolic dysfunction in a biracial sample of hypertensive adults–the HyperGEN study. Hypertension 2001;38:417-23. Davies M, Hobbs F, Davis R, Kenkre J, Roalfe AK, Hare R, et al. Prevalence of left-ventricular systolic dysfunction and heart failure in the echocardiographic heart of England screening study: a population based study. Lancet 2001;358:439-44. Gottdiener JS, McClelland RL, Marshall R, Shemanski L, Furberg CD, Kitzman DW, et al. Outcome of congestive heart failure in elderly persons: influence of left ventricular systolic function–the cardiovascular health study. Ann Intern Med 2002;137:631-9. Morgan S, Smith H, Simpson I, Liddiard GS, Raphael H, Pickering RM, et al. Prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in general practice setting: cross sectional survey. BMJ 1999;318:36872. Mosterd A, Hoes AW, de Bruyne MC, Deckers JW, Linker DT, Hofman A, et al. Prevalence of heart failure and left ventricular dysfunction in the general population–the Rotterdam study. Eur Heart J 1999;20:447-55.
Hand-carried Cardiac Ultrasound as a Tool to Screen for Important Cardiovascular Disease in an Underserved Minority Health Care Clinic James N. Kirkpatrick, MD, Andrew Davis, MD, Jeanne M. DeCara, MD, Anne E. Hong, MD, Patricia L. Kurtz, MD, Beth Balasia, BS, and Kirk T. Spencer, MD, Chicago, Illinois
The disparity in cardiovascular outcomes among racial and social strata may be, in part, because of delayed detection of cardiovascular disease in minority patients. The low cost and portability of hand-carried cardiac ultrasound devices may make screening of underserved patients for cardiac disease feasible. A general internist evaluated 153 patients at a clinic serving an underserved population with a hand-carried cardiac ultrasound device. A total of 27 cases of significant valvular heart disease or ventricular dysfunction were detected in 19 pa-
Cardiovascular disease is prevalent in the United
States and represents a leading cause of morbidity, mortality, and health care use.1 Cardiovascular outcomes for racial minorities and underserved populations are poor compared with affluent nonminority populations.2-7 This disparity in outcomes among racial and social strata is complex and multifactorial. Part of the difference may be a result of delayed detection of cardiovascular disease in minority patients. One of the reasons for this delayed detection may be lack of access to regular health care and medical technology. Recent guidelines have emphasized the progressive nature of cardiovascular disease and the importance of early identification of patients with preclinical cardiac disease.8 Screening of minority and underserved patients for cardiovascular disease to allow earlier identification and intervention might help lessen the morbidity in these populations. Echocardiography is a powerful, noninvasive tool and is superior to physical examination for the From the Sections of Cardiology and General Internal Medicine, Department of Medicine, University of Chicago. Supported by an outcomes research grant from the American Society of Echocardiography. Reprint requests: Kirk T. Spencer, MD, University of Chicago, 5841 S Maryland Ave, MC 5084, Chicago, IL 60637 (E-mail: [email protected]). 0894-7317/$30.00 Copyright 2004 by the American Society of Echocardiography. doi:10.1016/j.echo.2004.01.016
tients (12.4%). Detection of a major cardiac abnormality could not be predicted by cardiac risk factors, age, or chief symptom, whereas patients presenting for new or acute clinic visits were more likely to have an abnormality. The low cost and portability of hand-carried cardiac ultrasound devices may make them important tools for the early detection of cardiovascular disease in minority and underserved populations and, thereby, help to reduce disparities in cardiovascular outcomes. (J Am Soc Echocardiogr 2004;17:399-403.)
identification of cardiovascular disease. However, current echocardiographic platforms are expensive, and skilled sonographers are in limited supply in clinics and wards that care for underserved populations. The introduction of hand-carried cardiac ultrasound (HCU) devices, which are relatively inexpensive and portable, has allowed bedside evaluation of the heart at the time of physician encounter in a variety of settings.9,10 These devices could bring the diagnostic capabilities of echocardiography to busy and financially constrained providers caring for the medically underserved. Once available in a clinic, this technology may permit the identification of patients with undiagnosed cardiovascular disease during what may be their only encounter with a health care professional. We sought to test the feasibility of a primary care physician performing HCU examinations in an urban clinic that cares for underserved minority patients and to determine the incidence of significant cardiovascular disease detected by these devices in this population.
METHODS Patients were recruited from an urban health care clinic located in an impoverished area. The majority of the patients served by the clinic were African American and Hispanic. Women who were not pregnant presenting for a health care visit were approached after their visit with a primary care physician and asked to participate in a brief
399
400 Kirkpatrick et al
cardiac ultrasound screening examination. Demographic data collected included patient age, cardiac risk factors (diabetes, hypertension, smoking, family history, hypercholesterolemia), the presence of known cardiovascular disease, the visit type (acute, return, or new patient), and the organ system that accounted for the patient’s chief symptom. Patients who had previously had an echocardiogram or whose primary care physician thought had a clinical indication for echocardiography were excluded. Patients underwent a brief cardiac ultrasound examination using a hand-carried device (Optigo, Philips Medical Systems, Andover, Mass). A general internist who had 20 hours of didactic echocardiographic instruction and had completed 40 limited cardiac ultrasound examinations performed all examinations. The echocardiographic protocol included 2-dimensional echocardiography in the standard views from the parasternal, apical, and subcostal windows. A complete color Doppler examination was also performed. Echocardiographic interpretations were performed online and images were not recorded. A separate group of patients, also from an urban clinic, served as a validation group. The same internist using the HCU device imaged this group of consecutive patients. These patients then had an echocardiographic examination with a high-end platform (Sonos 5500, Philips Medical Systems) for comparison. Only echocardiographic findings that were considered to be of significant clinical importance (ie, those thought to require further evaluation or treatment) were tabulated. These findings included mild or greater aortic insufficiency; left ventricular (LV) dysfunction (estimated ejection fraction ⬍ 40%); right ventricular dysfunction; and moderate or greater mitral regurgitation, tricuspid regurgitation, and pericardial effusion. The presence of any regional wall-motion abnormality or intracardiac shunt was considered a major finding. Subgroups were analyzed to see whether the prevalence of major cardiovascular findings was related to specific clinical data. This analysis included grouping the patients by decade of age, clinic visit type, and number of cardiac risk factors. In addition, patients were subgrouped by history of cardiovascular disease or a chief symptom that was either cardiac or pulmonary. The statistical analysis of subgroups was performed with chi-square testing. A P value ⬍.05 was considered statistically significant. The study protocol was approved by the institutional review boards of the sponsoring institution and the clinic where the study took place.
RESULTS A total of 153 patients were imaged (69 men and 84 women). There were 61 African American, 88 Hispanic, and 4 Caucasian patients. Subject mean age was 45 ⫾ 16 years. Of the patients, 27% had none of the 5 recorded cardiac risk factors, whereas the percentages with 1, 2, or 3 risk factors were 69%,
Journal of the American Society of Echocardiography May 2004
Table 1 Cardiac finding on screening hand-carried cardiac ultrasound No
Aortic regurgitation (ⱖ mild) Mitral regurgitation (ⱖ moderate) Tricuspid regurgitation (ⱖ moderate) LV dysfunction RV dysfunction Pericardial effusion Regional wall-motion abnormality Shunt Total
7 2 0 5 3 1 7 2 27
LV, Left ventricular; RV, right ventricular
Table 2 Presence of cardiac abnormalities stratified by clinic data Major finding No
Visit type Acute Return New Cardiac risk factors 0 1 2 3 History cardiac disease No Yes Cardiopulmonary chief symptom No Yes
Yes
51 47 35
11 1 5
26 59 23 6
1 10 3 0
127 7
19 0
99 35
15 4
26%, and 6%, respectively. No patient had more than 3 risk factors. Only 5% of the patients had a history of atherosclerotic heart disease. However, 25% were being seen for a chief symptom that was cardiovascular or pulmonary. Nearly half (42%) of the patient visits were for an acute symptom, whereas 32% were scheduled return visits and 26% were newpatient visits. Major cardiovascular findings diagnosed by the internist using the HCU device are shown in Table 1. There were a total of 27 major findings in 19 patients. These findings included 9 patients with significant valvular heart disease, 8 with significant ventricular dysfunction, and 7 with evidence of a regional wall-motion abnormality suggesting ischemic heart disease. These findings represent a 12.4% incidence of major cardiovascular pathology. Results of the subgroup analysis are shown in Tables 2 and 3. There was a statistically higher likelihood that patients presenting for a new or acute clinic visit had a major cardiac finding on their screening ultrasound examination compared with patients returning for a scheduled follow-up. How-
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Kirkpatrick et al 401
Table 3 Presence of cardiac abnormalities stratified by decade of life Decade of age Major finding
No Yes
<30
30
40
50
60
>70
28 5
19 7
33 2
19 2
24 3
8 0
ever, the likelihood of finding a major cardiac abnormality by HCU examination could not be predicted by a history of cardiac disease, total number of cardiac risk factors, or age. In addition, patients presenting with a chief symptom that was noncardiopulmonary were just as likely to have a cardiac abnormality detected as those whose chief symptom was pulmonary or cardiac in nature (Table 2). There were 43 patients in the validation study. The general internist identified 22 major abnormalities using the HCU device in these patients. In detecting regurgitant valvular lesions using color Doppler, the HCU device was very sensitive (100%); there were no false-negative findings. Specificities for the 3 regurgitant valvular lesions were 93% to 98%. Identifying LV/right ventricular dysfunction and regional wall-motion abnormalities proved more difficult for the internist. There was a higher incidence of false-negative findings with these abnormalities resulting in sensitivities that ranged between 40% and 57%. However, the specificities for the detection of regional wall motion and ventricular dysfunction were excellent (97%-100%).
DISCUSSION Cardiovascular disease is the leading cause of morbidity and mortality, and one of the most frequent reasons for health care use in the United States. Several studies have shown that minority and underserved populations have symptoms disproportionately in relation to many cardiovascular outcomes.2-7 The early detection of cardiovascular disease in these populations is hindered by several factors. One of these may be the reliance on the physical examination to detect cardiac disease because of limited access to health care technology. Multiple studies have demonstrated that the cardiac physical examination is quite poor for detecting important cardiac pathology.11-15 In addition, the nature in which many underserved populations use health care facilities (primarily for acute care) may not allow for elective screening of cardiovascular disease because of a necessary focus on evaluating and treating acute symptoms in busy clinics with limited resources.
HCU has the potential to offer sophisticated cardiovascular testing in underserved clinics. Because of their relatively low expense, HCU devices could be more readily available than full-featured ultrasound platforms. The portability of these devices would allow on-site use, which would remove the multiple barriers (eg, time, transportation, education level, and cost) that typically exist for underserved patients who are referred for cardiac testing at another site at a future date. The ease of use of these machines would allow screening for cardiac disease in unselected patients who present to underserved clinics for any indication. This is particularly important in a population of patients for whom regular physician visits may be particularly uncommon. The ability to screen patients at the time of a visit with their primary care physician may take advantage of a window of opportunity to diagnose cardiovascular disease in its early stage when the natural history can be altered. Despite their small size and reduced cost, HCU devices are diagnostically powerful.10,16,17 HCU is clearly superior to the physical examination for the detection of cardiac pathology.11,18 When used by physicians with training in echocardiography these devices have excellent clinical use.11,19,20 We and others have shown that adequate levels of accuracy are possible when these devices are used by physicians with less echocardiographic training.21-23 DeCara et al21 studied a group of 3 internists and showed that their overall diagnostic skills with HCU, whereas less than that of board-certified cardiologists, were quite good. This previous work supports responsible use of these devices by noncardiologist, as would likely need to be the case in underserved areas. The HCU diagnostic skills of the internist in this study were similar to those we and others have previously published.21-23 Inexperienced users tend to overcall color Doppler findings, leading to excellent negative-predictive value but lower positivepredictive value for major degrees of valvular regurgitation.24 The internist occasionally misinterpreted ventricular function and wall motion, findings that can be subtle and typically require more intensive training. Although some abnormalities would be undetected with HCU when used as a screening device for patients without overt cardiovascular signs or symptoms, the detection of abnormal cardiovascular findings still offers benefit to those patients who are identified. This study showed a detection rate of major cardiovascular findings of 12.4%. This rate is lower than that of patients admitted to a general medical service who were screened for cardiovascular abnormalities with a HCU device.24 The rate of major cardiac abnormalities in a group of hospitalized patients is expected to be higher than in outpa-
402 Kirkpatrick et al
tients. Furthermore, the average age of patients in this study is considerably lower than in the prior study, and the risk for cardiovascular disease increases substantially with age. The American Heart Association/American College of Cardiology task force on practice guidelines has recently highlighted the importance of identifying cardiac structural abnormalities like those detected in this study.8 In an effort to acknowledge the progressive nature of heart failure and promote early detection, this task force established 4 stages of congestive heart failure. Stage B represents patients in whom symptoms of heart failure have never developed but who have a structural disorder of the heart such as LV dilatation or hypocontractility, significant valvular heart disease, or previous myocardial infarction. All of these stage-B findings were identified using HCU in this study. One of the most important cardiovascular findings identified was significant LV systolic dysfunction. Because treatment of LV systolic dysfunction decreases morbidity, even for patients who are asymptomatic, identification of affected patients represents an ideal opportunity for intervention.25,26 The prevalence of systolic dysfunction of 3.3% in this study was similar to several community-based reports that used echocardiography to identify patients with LV dysfunction. The prior studies used similar cut-off values for LV systolic dysfunction as this study did (quantitative or qualitative ejection fraction ⬍ 40%) and had prevalence rates of reduced LV performance of 1.8% to 4.0%.27-32 These studies, however, used expensive echocardiographic platforms operated by highly trained sonographers that simply are not available in most underserved clinics. The detection of LV dysfunction at a similar rate, using a device that is a fraction of the size and cost and does not require expertise of ancillary staff, represents a significant advance. Previous population studies have shown an increase in the prevalence of LV systolic dysfunction in various subgroups such as male patients, elderly patients, or those with cardiac risk factors.27-29,32 These studies suggest that targeted screening of patients within certain subgroups is more valuable than undirected screening. However, abnormal cardiovascular findings were not predicted in this study by sex, cardiac risk factors, history of cardiovascular disease, or cardiopulmonary chief symptom. These results indicate that targeted screening in an underserved population may not be adequate. Patients who presented for a new or acute visit were more likely to have abnormal cardiovascular findings than return patients. Our data support the notion that the underserved patients using the clinic for acute or new problems represent an opportunity to screen for cardiovascular disease, as they may not have regular physician appointments.
Journal of the American Society of Echocardiography May 2004
Conclusion This study demonstrated the use of HCU devices in detecting cardiovascular disease in an underserved and predominantly minority outpatient population. The rate of detection for clinically significant findings was 12.4%, and the rate of detection of unsuggested LV dysfunction was 3.3%. The traditional risk factors for coronary disease did not predict positive findings, but acute or new (rather than return) visit was predictive, suggesting a particular benefit for patients who are not regular users of health screening services. The low cost and portability of HCU devices may make them important tools for the early detection and treatment of cardiovascular disease in minority and underserved populations and, thereby, help to reduce disparities in cardiovascular outcomes. The authors would like to thank William Clapp, MD, Arthur Jones, MD, and the staff of Lawndale Christian Health Center, Chicago, Illinois.
REFERENCES 1. McCullough PA, Philbin EF, Spertus JA, Kaatz S, Sandberg KR, Weaver WD. Confirmation of a heart failure epidemic: findings from the resource utilization among congestive heart failure (REACH) study. J Am Coll Cardiol 2002;39:60-9. 2. Barnett E, Halverson J. Local increases in coronary heart disease mortality among blacks and whites in the United States, 1985-1995. Am J Public Health 2001;91:1499-506. 3. Williams JE, Massing M, Rosamond WD, Sorlie PD, Tyroler HA. Racial disparities in CHD mortality from 1968-1992 in the state economic areas surrounding the ARIC study communities. Ann Epidemiol 1999;9:472-80. 4. Barnett E, Armstrong DL, Casper ML. Evidence of increasing coronary heart disease mortality among black men of lower social class. Ann Epidemiol 1999;9:464-71. 5. Smith GD, Neaton JD, Wentworth D, Stamler R, Stamler J. Mortality differences between black and white men in the USA: contribution of income and other risk factors among men screened for the MRFIT. Lancet 1998;351:934-9. 6. Dries DL, Exner DV, Gersh BJ, Cooper HA, Carson PE, Domanski MJ. Racial differences in the outcome of left ventricular dysfunction. N Engl J Med 1999;340:609-16. 7. Jha AK, Varosy PD, Kanaya AM, Hunninghake DB, Hlatky MA, Waters DD, et al. Differences in medical care and disease outcomes among black and white women with heart disease. Circulation 2003;108:1089-94. 8. Hunt SA, Baker DW, Chin MH, Cinquegrani MP, Feldman AM, Francis GS, et al. ACC/AHA guidelines for the evaluation and management of chronic heart failure in the adult: executive summary–a report of the American College of Cardiology/American Heart Association task force on practice guidelines (committee to revise the 1995 guidelines for the evaluation and management of heart failure). Circulation 2001;104:2996-3007. 9. Seward JB, Douglas PS, Erbel R, Kerber RE, Kronzon I, Rakowski H, et al. Hand-carried cardiac ultrasound (HCU) device: recommendations regarding new technology–a report from the echocardiography task force on new technology of
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10. 11.
12.
13.
14.
15.
16.
17. 18.
19.
20. 21.
22.
the nomenclature and standards committee of the American Society of Echocardiography. J Am Soc Echocardiogr 2002; 15:369-73. Spencer KT, Lang RM. Point of service echocardiography. ACC Curr J Rev 2002;11:49-51. Spencer KT, Anderson AS, Bhargava A, Bales AC, Sorrentino M, Furlong K, et al. Physician-performed point-of-care echocardiography using a laptop platform compared with physical examination in the cardiovascular patient. J Am Coll Cardiol 2001;37:2013-8. Mangione S, Nieman LZ. Cardiac auscultatory skills of internal medicine and family practice trainees: a comparison of diagnostic proficiency. JAMA 1997;278:717-22. Badgett RG, Lucey CR, Mulrow CD. Can the clinical examination diagnose left-sided heart failure in adults? JAMA 1997;277:1712-9. Roldan CA, Shively BK, Crawford MH. Value of the cardiovascular physical examination for detecting valvular heart disease in asymptomatic subjects. Am J Cardiol 1996;77:132731. Stevenson LW, Perloff JK. The limited reliability of physical signs for estimating hemodynamics in chronic heart failure. JAMA 1989;261:884-8. Rugolotto M, Hu BS, Liang DH, Schnittger I. Rapid assessment of cardiac anatomy and function with a new handcarried ultrasound device (OptiGo): a comparison with standard echocardiography [see comments]. Eur J Echocardiogr 2001;2:262-9. Liang D, Schnittger I. Accuracy of hand-carried ultrasound. Echocardiography 2003;20:487-90. DeCara JM, Lang RM, Spencer KT. The hand-carried echocardiographic device as an aid to the physical examination. Echocardiography 2003;20:477-85. Rugolotto M, Chang CP, Hu B, Schnittger I, Liang DH. Clinical use of cardiac ultrasound performed with a handcarried device in patients admitted for acute cardiac care. Am J Cardiol 2002;90:1040. Gorcsan J. Utility of hand-carried ultrasound for consultative cardiology. Echocardiography 2003;20:463-9. DeCara JM, Lang RM, Koch R, Bala R, Penzotti J, Spencer KT. The use of small personal ultrasound devices by internists without formal training in echocardiography. Eur J Echocardiogr 2002;4:141-7. Kimura BJ, Amundson SA, Willis CL, Gilpin EA, DeMaria AN. Usefulness of a hand-held ultrasound device for bedside
Kirkpatrick et al 403
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
examination of left ventricular function. Am J Cardiol 2002; 90:1038. Duvall WL, Croft LB, Goldman ME. Can hand-carried ultrasound devices be extended for use by the noncardiology medical community? Echocardiography 2003;20:471-6. Spencer KT, Fedson S, Neithardt G, Thomas P, Lickerman A, Radzienda M, et al. Unsuspected clinically important cardiac findings detected with a small portable ultrasound device in patients admitted to a general medicine service. Circulation 2002;106:507. SOLVD Investigators. Effect of enalapril on mortality and the development of heart failure in asymptomatic patients with reduced left ventricular ejection fractions. N Engl J Med 1992;327:685-91. Pfeffer MA, Braunwald E, Moye LA, Basta L, Brown EJ Jr, Cuddy TE, et al. Effect of captopril on mortality and morbidity in patients with left ventricular dysfunction after myocardial infarction: results of the survival and ventricular enlargement trial; the SAVE investigators. N Engl J Med 1992;327: 669-77. Devereux RB, Roman MJ, Paranicas M, Lee ET, Welty TK, Fabsitz RR, et al. A population-based assessment of left ventricular systolic dysfunction in middle-aged and older adults: the strong heart study. Am Heart J 2001;141:439-46. Devereux RB, Bella JN, Palmieri V, Oberman A, Kitzman DW, Hopkins PN, et al. Left ventricular systolic dysfunction in a biracial sample of hypertensive adults–the HyperGEN study. Hypertension 2001;38:417-23. Davies M, Hobbs F, Davis R, Kenkre J, Roalfe AK, Hare R, et al. Prevalence of left-ventricular systolic dysfunction and heart failure in the echocardiographic heart of England screening study: a population based study. Lancet 2001;358:439-44. Gottdiener JS, McClelland RL, Marshall R, Shemanski L, Furberg CD, Kitzman DW, et al. Outcome of congestive heart failure in elderly persons: influence of left ventricular systolic function–the cardiovascular health study. Ann Intern Med 2002;137:631-9. Morgan S, Smith H, Simpson I, Liddiard GS, Raphael H, Pickering RM, et al. Prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in general practice setting: cross sectional survey. BMJ 1999;318:36872. Mosterd A, Hoes AW, de Bruyne MC, Deckers JW, Linker DT, Hofman A, et al. Prevalence of heart failure and left ventricular dysfunction in the general population–the Rotterdam study. Eur Heart J 1999;20:447-55.