- Email: [email protected]
Thrombolysis in myocardial infarction (TIMI) risk score remains relevant in the era of field triage of patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention
Letters to the Editor [19] Schouten O, van Laanen JH, Boersma E, et al. Statins are associated with a reduced infrarenal abdominal aortic aneurysm growth. Eur J Vasc Endovasc Surg 2006;32:21–6. [20] Schlösser FJ, Tangelder MJ, Verhagen HJ, et al. Growth predictors and prognosis of small abdominal aortic aneurysms. J Vasc Surg 2008;47:1127–33. [21] Sweeting MJ, Thompson SG, Brown LC, Greenhalgh RM, Powell JT. Use of angiotensin converting enzyme inhibitors is associated with increased growth rate of abdominal aortic aneurysms. J Vasc Surg 2010;52:1–4. [22] Thompson AR, Cooper JA, Ashton HA, Hafez H. Growth rates of small abdominal aortic aneurysms correlate with clinical events. Br J Surg 2010;97:37–44.
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[23] Terrin N, Schmid CH, Lau J, Olkin I. Adjusting for publication bias in the presence of heterogeneity. Stat Med 2003;22:2113–26. [24] Peters JL, Sutton AJ, Jones DR, Abrams KR, Rushton L. Performance of the trim and fill method in the presence of publication bias and between-study heterogeneity. Stat Med 2007;26:4544–62. [25] Sterne JA, Egger M, Moher D, editors. Chapter 10: addressing reporting biasesHiggins JP, Green S, editors. Cochrane Handbook for Systematic Reviews of Intervention. Version 5.1.0 (updated March 2011). The Cochrane Collaboration; 2011. Available from www.cochrane-handbook.org.
0167-5273/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2012.09.112
Thrombolysis in myocardial infarction (TIMI) risk score remains relevant in the era of field triage of patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention Usaid K. Allahwala ⁎, James Tang, John C. Murphy, Gregory I.C. Nelson, Ravinay Bhindi Dept of Cardiology, Royal North Shore Hospital, Sydney, Australia
a r t i c l e
i n f o
Article history: Received 15 July 2012 Accepted 16 September 2012 Available online 15 October 2012 Keywords: ST elevation myocardial infarction TIMI risk score Field triage Ischaemic time Prognosis
Predicting morbidity and mortality following an ST elevation myocardial infarction (STEMI) is vital for early identification of high risk patients as well as management of resources. The thrombolysis in myocardial infarction (TIMI) risk score (TRS) [1] is a clinical scoring tool which has been validated in multiple non-selected population cohorts, predominantly in the era of fibrinolysis [2] and non-selective cohorts of patients' undergoing primary percutaneous coronary intervention (pPCI) [3,4]. The ultimate goal in STEMI management is to reduce first medical contact to TIMI grade 3 flow time [5]. Field triage attempts to reduce ischaemic time by identifying patients in the community with STEMI and transferring them directly for pPCI. Field triage reduces total ischaemic time, improves clinical outcomes and shortens hospital stay [6]. Modern day pPCI centres often work using field triage, which has been shown to reduce treatment delay and improve clinical outcome [7]. The TRS has yet to be validated in this rapidly increasing patient subgroup. While contemporary prognostic risk scores, including the GRACE score [8], are becoming more widely utilised, the TRS remains a relevant and broadly used tool owing to the speed and ease with which it is calculated [3]. The ageing population will ensure that, in the future, increasing volumes of elderly patients will present with STEMI for pPCI. It is important therefore to scrutinise the validity of the TRS in this subgroup. Rathore et al. [9] in a community based study assessing the validity of ⁎ Corresponding author at: Dept of Cardiology, Royal North Shore Hospital, Reserve Road, St Leonards, Sydney, Australia 2065. Tel.: +61 2 99267111; fax: +61 2 99067807. E-mail address: [email protected] (U.K. Allahwala).
the TRS in the context of elderly patients treated with fibrinolysis, suggested that it performs only modestly. It is not known to what degree the TRS is applicable in elderly patients undergoing pPCI. We aimed to examine the validity of the TRS in field triaged patients with STEMI, including a large proportion of elderly patients. From May 2004 to December 2010, we identified all consecutive STEMI patients field triaged directly for pPCI in our centre. The study end points were major adverse cardiac events (MACE) at 30 days and median hospital length of stay (LOS). The methods of unpaired Student's t-test and analysis of variance (ANOVA) univariate linear regression were used (SPSS for Windows 15.0). A total of 451 consecutive patients with a diagnosis of STEMI from ECG criteria were considered for the study. 65 patients were excluded due to incomplete data, while a further 56 were excluded as their symptom to TIMI 3 flow time was N6 h, a group not validated for the TRS [1]. A total of 329 patients were included. The mean age was 65 years (SD: 14.9), with 75% being male. Most patients scored 1 on the Killip score (85%). The commonest affected vessels were the right coronary artery (48%) followed by the left anterior descending artery (35%). The range of TRS was from 0 to 12, with a mean of 3.6 (SD 2.4) and a median of 4. Eight percent of patients had a TRS ≥8, while 35% had a TRS of ≤2. A total of 27 patients (8%) had a 30 day MACE, with 9 deaths (3%) in this time. The median hospital LOS was 3 days (IQR: 2–5). (Table 1) There were 132 patients with short ischaemic time (symptom onset to TIMI 3 time ≤120 min) while 197 patients had longer ischaemic time (N120 min). Within the short ischaemic time group, 34 patients had very short ischaemic time (≤90 min). 239 patients were aged ≤75 years, with 90 patients aged N75 years. The TRS directly correlated with MACE (R2 = 0.60, p b 0.01) and LOS (R2 = 0.90, p b 0.0001). In patients with short ischaemic time and very short ischaemic time, the TRS was found to directly correlate with MACE (R2 = 0.80, p b 0.005; R2 = 0.78, p b 0.01, respectively) and LOS (R2 = 0.75, p b 0.005; R2 = 0.73, p b 0.02, respectively). In patients with long ischaemic times, the TRS correlated with LOS (R2 = 0.95, p b 0.0001), but did not correlate with MACE (p= 0.28). In patients ≤75 years, the TRS correlated with MACE (R2 =0.60, pb 0.01) and LOS (R2 =0.84, p b 0.0005). In patients N75 years, the TRS correlated with LOS (R2 =0.71, p b 0.02), but not MACE (p= 0.90) (Fig. 1). Our study found, in the cohort of field triaged patients undergoing pPCI, the TRS correlated with MACE, as has previously been shown in
256
Letters to the Editor
Fig. 1. (A) The TIMI risk score as a predictor of 30 day MACE rates in different ischaemic times; (B) the TIMI risk score as a predictor of median length of hospital stay in different ischaemic times; (C) the TIMI risk score as a predictor of 30 day MACE rates in younger (≤75) and older patients (N 75); (D) the TIMI risk score as a predictor of median length of hospital stay in different ages.
patients undergoing fibrinolysis [1] and non selective pPCI cohorts [3,4], while we also found that the TRS correlated with LOS. The use of the TRS as a predictor of length of hospitalisation, is a novel finding with impacts on bed flow management in centres with a high turnover of STEMI patients, and may also have implications for funding requirements and societal costs for the health care system. The subgroup of short-ischaemic times is a relatively new cohort in which the TRS has not previously been investigated. Our study showed that in very short and short ischaemic times, the TRS correlated with both MACE and LOS. This underscores that the TRS is a suitable tool in the initial field triage of these patients in determining prognosis and may aid early identification of patients who may have a complicated hospital stay. The longer ischaemic time cohort correlated with LOS but not with MACE. Increasing ischaemic times have previously been shown to increase myocardial damage and adversely affect prognosis [10], while ischaemic time is an independent predictor of MACE in STEMI patients presenting through conventional admissions [11]. As the TRS does not directly take into account markers of myocardial damage, it may not be a suitable tool for those who have prolonged ischaemic times. However, in this cohort the TRS remained predictive of hospital LOS irrespective of ischaemic time, suggesting use may extend beyond classical clinical measures. Previous studies have shown that elderly populations have higher mortality rates following AMI even after adjusting for baseline characteristics [12]. In our study the TRS did not correlate with MACE, however it was associated with LOS in the elderly population. This may be due to the relatively small number of elderly patients in our study, but the results compliment those of Rathore et al. [9], who found that the TRS was not a robust indicator of prognosis in older patients ≥ 65 years.
The TIMI risk score is an accurate predictive tool of outcomes and predicted length of stay in STEMI patients who have undergone early field triage. The TIMI risk score is particularly relevant in those patients with short ischaemic times, while it does not appear to be robust in the elderly population. Its role may extend to influencing hospital logistics. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology. References [1] Morrow DA, Antman EM, Charlesworth A, et al. TIMI risk score for ST-elevation myocardial infarction: a convenient, bedside, clinical score for risk assessment at presentation: an intravenous nPA for treatment of infarcting myocardium early II trial substudy. Circulation 2000;102(17):2031–7. [2] Ilkhanoff L, O'Donnell CJ, Camargo CA, et al. Usefulness of the TIMI risk index in predicting short- and long-term mortality in patients with acute coronary syndromes. Am J Cardiol 2005;96(6):773–7. [3] Kozieradzka A, Kaminski KA, Maciorkowska D, et al. GRACE, TIMI, Zwolle and CADILLAC risk scores—do they predict 5-year outcomes after ST-elevation myocardial infarction treated invasively? Int J Cardiol 2011;148(1):70–5. [4] Lev EI, Kornowski R, Vaknin-Assa H, et al. Comparison of the predictive value of four different risk scores for outcomes of patients with ST-elevation acute myocardial infarction undergoing primary percutaneous coronary intervention. Am J Cardiol 2008;102(1):6–11. [5] Gibson CM, Pride YB, Frederick PD, et al. Trends in reperfusion strategies, door-toneedle and door-to-balloon times, and in-hospital mortality among patients with STsegment elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction from 1990 to 2006. Am Heart J 2008;156(6):1035–44. [6] Carstensen S, Nelson GC, Hansen PS, et al. Field triage to primary angioplasty combined with emergency department bypass reduces treatment delays and is associated with improved outcome. Eur Heart J 2007;28(19):2313–9. [7] Pedersen SH, Galatius S, Hansen PR, et al. Field triage reduces treatment delay and improves long-term clinical outcome in patients with acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. J Am Coll Cardiol 2009;54(24):2296–302.
Letters to the Editor Table 1 Patient characteristics. No. (%) Male Age (years) mean (SD) BMI (kg/m2) mean (SD) Co-morbidities Hypertension Smoking historya Dyslipidemia Diabetes mellitus Killip score 1 2 3 4 TIMI risk score 0–2 3–5 6–8 9–12 HR (beats/min) mean (SD) SBP (mm Hg) mean (SD) DBP (mm Hg) mean (SD) Symptom onset to TIMI 3 flow (min) mean (SD) Culprit artery Left main Left anterior descending Left circumflex Right coronary artery Saphenous vein graft Outcomes Death Re-infarction TIA/stroke Re-intervention 30 day MACE Median length of stay (days) (IQR)
248 (75%) 64.9 (14.9) 26.6 (4.8) 159 (48.3%) 94 (28.9%) 166 (50.5%) 48 (14.6%) 278 (84.5%) 33 (10.0%) 5 (1.5%) 13 (4.0%) 116 (35.3%) 152 (46.2%) 47 (14.3%) 14 (4.3%) 73.6 (23.1) 126.7 (26.9) 70.7 (14.6) 153.8 (90.1) 2 (0.6%) 116 (35.3%) 48 (14.6%) 158 (48.0%) 5 (1.5%) 9 (2.7%) 8 (2.4%) 3 (0.9%) 12 (3.6%) 27 (8.2%) 3 (2–5)
Data are presented as mean ± SD or number (%) of patients. BMI: Body Mass Index; DBP: Diastolic Blood Pressure; HR: Heart Rate; IQR: Interquartile range; SBP: Systolic Blood Pressure; and TIA: Transient Ischemic Attack. a Smoking history: current smoker or smoked within last 12 months regularly.
0167-5273/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2012.09.111
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[8] Granger CB, Goldberg RJ, Dabbous O, et al. Predictors of hospital mortality in the global registry of acute coronary events. Arch Intern Med 2003;163(19):2345–53. [9] Rathore SS, Weinfurt KP, Gross CP, et al. Validity of a simple ST-elevation acute myocardial infarction risk index: are randomized trial prognostic estimates generalizable to elderly patients? Circulation 2003;107(6):811–6. [10] Brodie BR, Stuckey TD, Wall TC, et al. Importance of time to reperfusion for 30-day and late survival and recovery of left ventricular function after primary angioplasty for acute myocardial infarction. J Am Coll Cardiol 1998;32(5):1312–9. [11] Afilalo J, Piazza N, Tremblay S, et al. Symptom-to-door time in ST segment elevation myocardial infarction: overemphasized or overlooked? Results from the AMI-McGill study. Can J Cardiol 2008;24(3):213–6. [12] Guagliumi G, Stone GW, Cox DA, et al. Outcome in elderly patients undergoing primary coronary intervention for acute myocardial infarction: results from the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial. Circulation 2004;110(12):1598–604.
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[23] Terrin N, Schmid CH, Lau J, Olkin I. Adjusting for publication bias in the presence of heterogeneity. Stat Med 2003;22:2113–26. [24] Peters JL, Sutton AJ, Jones DR, Abrams KR, Rushton L. Performance of the trim and fill method in the presence of publication bias and between-study heterogeneity. Stat Med 2007;26:4544–62. [25] Sterne JA, Egger M, Moher D, editors. Chapter 10: addressing reporting biasesHiggins JP, Green S, editors. Cochrane Handbook for Systematic Reviews of Intervention. Version 5.1.0 (updated March 2011). The Cochrane Collaboration; 2011. Available from www.cochrane-handbook.org.
0167-5273/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2012.09.112
Thrombolysis in myocardial infarction (TIMI) risk score remains relevant in the era of field triage of patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention Usaid K. Allahwala ⁎, James Tang, John C. Murphy, Gregory I.C. Nelson, Ravinay Bhindi Dept of Cardiology, Royal North Shore Hospital, Sydney, Australia
a r t i c l e
i n f o
Article history: Received 15 July 2012 Accepted 16 September 2012 Available online 15 October 2012 Keywords: ST elevation myocardial infarction TIMI risk score Field triage Ischaemic time Prognosis
Predicting morbidity and mortality following an ST elevation myocardial infarction (STEMI) is vital for early identification of high risk patients as well as management of resources. The thrombolysis in myocardial infarction (TIMI) risk score (TRS) [1] is a clinical scoring tool which has been validated in multiple non-selected population cohorts, predominantly in the era of fibrinolysis [2] and non-selective cohorts of patients' undergoing primary percutaneous coronary intervention (pPCI) [3,4]. The ultimate goal in STEMI management is to reduce first medical contact to TIMI grade 3 flow time [5]. Field triage attempts to reduce ischaemic time by identifying patients in the community with STEMI and transferring them directly for pPCI. Field triage reduces total ischaemic time, improves clinical outcomes and shortens hospital stay [6]. Modern day pPCI centres often work using field triage, which has been shown to reduce treatment delay and improve clinical outcome [7]. The TRS has yet to be validated in this rapidly increasing patient subgroup. While contemporary prognostic risk scores, including the GRACE score [8], are becoming more widely utilised, the TRS remains a relevant and broadly used tool owing to the speed and ease with which it is calculated [3]. The ageing population will ensure that, in the future, increasing volumes of elderly patients will present with STEMI for pPCI. It is important therefore to scrutinise the validity of the TRS in this subgroup. Rathore et al. [9] in a community based study assessing the validity of ⁎ Corresponding author at: Dept of Cardiology, Royal North Shore Hospital, Reserve Road, St Leonards, Sydney, Australia 2065. Tel.: +61 2 99267111; fax: +61 2 99067807. E-mail address: [email protected] (U.K. Allahwala).
the TRS in the context of elderly patients treated with fibrinolysis, suggested that it performs only modestly. It is not known to what degree the TRS is applicable in elderly patients undergoing pPCI. We aimed to examine the validity of the TRS in field triaged patients with STEMI, including a large proportion of elderly patients. From May 2004 to December 2010, we identified all consecutive STEMI patients field triaged directly for pPCI in our centre. The study end points were major adverse cardiac events (MACE) at 30 days and median hospital length of stay (LOS). The methods of unpaired Student's t-test and analysis of variance (ANOVA) univariate linear regression were used (SPSS for Windows 15.0). A total of 451 consecutive patients with a diagnosis of STEMI from ECG criteria were considered for the study. 65 patients were excluded due to incomplete data, while a further 56 were excluded as their symptom to TIMI 3 flow time was N6 h, a group not validated for the TRS [1]. A total of 329 patients were included. The mean age was 65 years (SD: 14.9), with 75% being male. Most patients scored 1 on the Killip score (85%). The commonest affected vessels were the right coronary artery (48%) followed by the left anterior descending artery (35%). The range of TRS was from 0 to 12, with a mean of 3.6 (SD 2.4) and a median of 4. Eight percent of patients had a TRS ≥8, while 35% had a TRS of ≤2. A total of 27 patients (8%) had a 30 day MACE, with 9 deaths (3%) in this time. The median hospital LOS was 3 days (IQR: 2–5). (Table 1) There were 132 patients with short ischaemic time (symptom onset to TIMI 3 time ≤120 min) while 197 patients had longer ischaemic time (N120 min). Within the short ischaemic time group, 34 patients had very short ischaemic time (≤90 min). 239 patients were aged ≤75 years, with 90 patients aged N75 years. The TRS directly correlated with MACE (R2 = 0.60, p b 0.01) and LOS (R2 = 0.90, p b 0.0001). In patients with short ischaemic time and very short ischaemic time, the TRS was found to directly correlate with MACE (R2 = 0.80, p b 0.005; R2 = 0.78, p b 0.01, respectively) and LOS (R2 = 0.75, p b 0.005; R2 = 0.73, p b 0.02, respectively). In patients with long ischaemic times, the TRS correlated with LOS (R2 = 0.95, p b 0.0001), but did not correlate with MACE (p= 0.28). In patients ≤75 years, the TRS correlated with MACE (R2 =0.60, pb 0.01) and LOS (R2 =0.84, p b 0.0005). In patients N75 years, the TRS correlated with LOS (R2 =0.71, p b 0.02), but not MACE (p= 0.90) (Fig. 1). Our study found, in the cohort of field triaged patients undergoing pPCI, the TRS correlated with MACE, as has previously been shown in
256
Letters to the Editor
Fig. 1. (A) The TIMI risk score as a predictor of 30 day MACE rates in different ischaemic times; (B) the TIMI risk score as a predictor of median length of hospital stay in different ischaemic times; (C) the TIMI risk score as a predictor of 30 day MACE rates in younger (≤75) and older patients (N 75); (D) the TIMI risk score as a predictor of median length of hospital stay in different ages.
patients undergoing fibrinolysis [1] and non selective pPCI cohorts [3,4], while we also found that the TRS correlated with LOS. The use of the TRS as a predictor of length of hospitalisation, is a novel finding with impacts on bed flow management in centres with a high turnover of STEMI patients, and may also have implications for funding requirements and societal costs for the health care system. The subgroup of short-ischaemic times is a relatively new cohort in which the TRS has not previously been investigated. Our study showed that in very short and short ischaemic times, the TRS correlated with both MACE and LOS. This underscores that the TRS is a suitable tool in the initial field triage of these patients in determining prognosis and may aid early identification of patients who may have a complicated hospital stay. The longer ischaemic time cohort correlated with LOS but not with MACE. Increasing ischaemic times have previously been shown to increase myocardial damage and adversely affect prognosis [10], while ischaemic time is an independent predictor of MACE in STEMI patients presenting through conventional admissions [11]. As the TRS does not directly take into account markers of myocardial damage, it may not be a suitable tool for those who have prolonged ischaemic times. However, in this cohort the TRS remained predictive of hospital LOS irrespective of ischaemic time, suggesting use may extend beyond classical clinical measures. Previous studies have shown that elderly populations have higher mortality rates following AMI even after adjusting for baseline characteristics [12]. In our study the TRS did not correlate with MACE, however it was associated with LOS in the elderly population. This may be due to the relatively small number of elderly patients in our study, but the results compliment those of Rathore et al. [9], who found that the TRS was not a robust indicator of prognosis in older patients ≥ 65 years.
The TIMI risk score is an accurate predictive tool of outcomes and predicted length of stay in STEMI patients who have undergone early field triage. The TIMI risk score is particularly relevant in those patients with short ischaemic times, while it does not appear to be robust in the elderly population. Its role may extend to influencing hospital logistics. The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology. References [1] Morrow DA, Antman EM, Charlesworth A, et al. TIMI risk score for ST-elevation myocardial infarction: a convenient, bedside, clinical score for risk assessment at presentation: an intravenous nPA for treatment of infarcting myocardium early II trial substudy. Circulation 2000;102(17):2031–7. [2] Ilkhanoff L, O'Donnell CJ, Camargo CA, et al. Usefulness of the TIMI risk index in predicting short- and long-term mortality in patients with acute coronary syndromes. Am J Cardiol 2005;96(6):773–7. [3] Kozieradzka A, Kaminski KA, Maciorkowska D, et al. GRACE, TIMI, Zwolle and CADILLAC risk scores—do they predict 5-year outcomes after ST-elevation myocardial infarction treated invasively? Int J Cardiol 2011;148(1):70–5. [4] Lev EI, Kornowski R, Vaknin-Assa H, et al. Comparison of the predictive value of four different risk scores for outcomes of patients with ST-elevation acute myocardial infarction undergoing primary percutaneous coronary intervention. Am J Cardiol 2008;102(1):6–11. [5] Gibson CM, Pride YB, Frederick PD, et al. Trends in reperfusion strategies, door-toneedle and door-to-balloon times, and in-hospital mortality among patients with STsegment elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction from 1990 to 2006. Am Heart J 2008;156(6):1035–44. [6] Carstensen S, Nelson GC, Hansen PS, et al. Field triage to primary angioplasty combined with emergency department bypass reduces treatment delays and is associated with improved outcome. Eur Heart J 2007;28(19):2313–9. [7] Pedersen SH, Galatius S, Hansen PR, et al. Field triage reduces treatment delay and improves long-term clinical outcome in patients with acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. J Am Coll Cardiol 2009;54(24):2296–302.
Letters to the Editor Table 1 Patient characteristics. No. (%) Male Age (years) mean (SD) BMI (kg/m2) mean (SD) Co-morbidities Hypertension Smoking historya Dyslipidemia Diabetes mellitus Killip score 1 2 3 4 TIMI risk score 0–2 3–5 6–8 9–12 HR (beats/min) mean (SD) SBP (mm Hg) mean (SD) DBP (mm Hg) mean (SD) Symptom onset to TIMI 3 flow (min) mean (SD) Culprit artery Left main Left anterior descending Left circumflex Right coronary artery Saphenous vein graft Outcomes Death Re-infarction TIA/stroke Re-intervention 30 day MACE Median length of stay (days) (IQR)
248 (75%) 64.9 (14.9) 26.6 (4.8) 159 (48.3%) 94 (28.9%) 166 (50.5%) 48 (14.6%) 278 (84.5%) 33 (10.0%) 5 (1.5%) 13 (4.0%) 116 (35.3%) 152 (46.2%) 47 (14.3%) 14 (4.3%) 73.6 (23.1) 126.7 (26.9) 70.7 (14.6) 153.8 (90.1) 2 (0.6%) 116 (35.3%) 48 (14.6%) 158 (48.0%) 5 (1.5%) 9 (2.7%) 8 (2.4%) 3 (0.9%) 12 (3.6%) 27 (8.2%) 3 (2–5)
Data are presented as mean ± SD or number (%) of patients. BMI: Body Mass Index; DBP: Diastolic Blood Pressure; HR: Heart Rate; IQR: Interquartile range; SBP: Systolic Blood Pressure; and TIA: Transient Ischemic Attack. a Smoking history: current smoker or smoked within last 12 months regularly.
0167-5273/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2012.09.111
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[8] Granger CB, Goldberg RJ, Dabbous O, et al. Predictors of hospital mortality in the global registry of acute coronary events. Arch Intern Med 2003;163(19):2345–53. [9] Rathore SS, Weinfurt KP, Gross CP, et al. Validity of a simple ST-elevation acute myocardial infarction risk index: are randomized trial prognostic estimates generalizable to elderly patients? Circulation 2003;107(6):811–6. [10] Brodie BR, Stuckey TD, Wall TC, et al. Importance of time to reperfusion for 30-day and late survival and recovery of left ventricular function after primary angioplasty for acute myocardial infarction. J Am Coll Cardiol 1998;32(5):1312–9. [11] Afilalo J, Piazza N, Tremblay S, et al. Symptom-to-door time in ST segment elevation myocardial infarction: overemphasized or overlooked? Results from the AMI-McGill study. Can J Cardiol 2008;24(3):213–6. [12] Guagliumi G, Stone GW, Cox DA, et al. Outcome in elderly patients undergoing primary coronary intervention for acute myocardial infarction: results from the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial. Circulation 2004;110(12):1598–604.