Prognosis of Patients
Background Patients with recurrent acute myocardial infarction (AMI) are at increased risk for morbidity and mortality. We compared the outcome of patients with recurrent AMI hospitalized in coronary care units in the prereperfusion and reperfusion eras.
Methods The study population comprised 2 large-scale cohorts with recurrent AMI: (1) 1415 (24%) of 5839 consecutive patients with AMI hospitalized in 1981 to 1983 (Secondary Prevention Reinfarction Israeli Nifedipine Trial [SPRINT] Registry) and (2) 1093 (25%) of 4317 patients with AMI from three national surveys performed in 1992 to 1996.
Results Patients in the 1990s had significantly lower rates of heart failure and cardiogenic shock. The 7-day mortality declined from 18% in 1981-1983 to 10% in 1992-1996 (adjusted odds ratio [OR] 0.57 [0.44-0.75]), the 30-day mortality rate from 26% to 16% (OR 0.56 [0.44-0.71]), and the 1-year mortality rate from 39% to 26% (adjusted hazard ratio [HR] 0.64 [0.54-0.75]), respectively. In the 1992-1996 cohort, the adjusted risk of 7-day, 30-day, and 1-year mortality for patients with recurrent AMI treated with thrombolysis in comparison to patients without thrombolysis was OR 1.69 (1.07-2.65), 1.51 (1.03-2.23), and HR 1.18 (0.90-1.55), respectively. The mortality rate among patients treated with early percutaneous transluminal coronary angioplasty/coronary artery bypass grafting was 3% versus 12% at 7 days (OR 0.36 [0.16-0.73]), 7% versus 18% at 30 days (OR 0.45 [0.25-0.77]), and 16% versus 29% at 1 year (HR 0.64 [0.46-0.96]), in comparison to patients without revascularization.
Conclusion The prognosis of patients with recurrent AMI improved significantly during the reperfusion era. Although thrombolysis may have a limited therapeutic effect among patients with recurrent AMI, an interventional approach seems more appropriate when indicated. A randomized trial of thrombolysis versus early revascularization is needed in patients with recurrent AMI.
Patients with recurrent acute myocardial infarction are at increased risk for complications and death. They represent 14% to 30% of patients hospitalized for acute myocardial infarction, but their short- and long-term mortality constitutes 30% to 50% of all deaths resulting from acute myocardial infarction. During the last two decades, new effective therapeutic modalities for the management of acute myocardial infarction have been introduced. The beneficial effects of thrombolysis, early catheterization, and revascularization are well established and have contributed to the decline of in-hospital and long-term mortality after acute myocardial infarction. The addition of angiotensin-converting enzyme (ACE) inhibitors and the increased use of aspirin and b-blockers have also reduced morbidity and mortality. However, to what extent these innovative therapeutic modalities have influenced the fate of patients with recurrent acute myocardial infarction has not been directly addressed. The purpose of our study was to compare the management and prognosis of two large cohorts of patients with recurrent acute myocardial infarction, one hospitalized before and the other in the reperfusion era.
Between August 1981 and July 1983, 5839 consecutive patients with a confirmed diagnosis of acute myocardial infarction were hospitalized in 13 of the 21 coronary care units functioning in Israel at that time. They constitute the Secondary Prevention Reinfarction Israeli Nifedipine Trial (SPRINT) Registry. Demographic, historic, medical, in-hospital course, and complication data were collected for all SPRINT Registry participants. Nifedipine or placebo, given to 2276 patients, did not affect the outcome of the SPRINT Registry patients. The location of the acute myocardial infarction was determined by the Minnesota Code. Of these 5839 patients, 1415 (24%) had had one or more myocardial infarctions before the index myocardial infarction hospitalization.
A second cohort of 4317 consecutive unselected patients with acute myocardial infarction was compiled from three prospective national surveys conducted during January-February 1992 (941 patients), January-February 1994 (999 patients), and January, February, and May-July 1996 (2377 patients) in 25 coronary care units operating in Israel. Patient characteristics, in-hospital course, and management data were collected. Of these 4317 patients, 1093 (25%) had had one or more previous myocardial infarctions before the index myocardial infarction hospitalization. Reasons for exclusion from thrombolytic therapy were recorded and included contraindication, lack of electrocardiographic criteria, late arrival, and other reasons. The baseline characteristics, management, and early or 1-year mortality of patients in 1992-1996 hospitalized in the 13 coronary care units that participated in SPRINT were compared with that of patients hospitalized in the 12 coronary care units that did not participate in SPRINT. Overall, there was a remarkable similarity between these two groups in baseline characteristics, management, and early and 1-year outcome, as published previously.
Mortality during the first year after the acute event was assessed similarly in both cohorts in 99% of hospital survivors by matching their identification numbers with the Israeli National Population Registry. The criteria used in the first population for diagnosis and determination of the infarct site were also used in the second cohort.
All analyses were performed with use of SAS software (SAS Institute, Cary, NC). Survival curves were estimated by the Kaplan-Meier method. The significance of the difference between the survival curves was assessed by the log-rank test (SAS LIFETEST Procedure). To compare 7-day and 30-day mortality in 1992-1996 versus 1981-1983 in terms of odd ratios with 95% confidence intervals, logistic regression analyses (SAS LOGISTIC Procedure) were performed, adjusting for age, sex, hypertension, diabetes mellitus, angina before the index infarction, anterior location of the index infarction, Killip class >=2 on admission, "period" (where the 1981-1983 cohort was the reference group, odds ratio = 1), and "center" (where the 13 coronary care units that participated in 1981-1983 and 1992-1996 were the reference group, odds ratio = 1).
A stepwise Cox proportional-hazard regression model (SAS PHREG Procedure) adjusting for the same variables was used to compare the hazard ratio of 1-year mortality in 1992-1996 relative to 1981-1983. A variable was allowed to enter into the model if it made a significant contribution at the .15 level of significance and was removed if, after subsequent addition of other variables to the model, it no longer made a contribution at the .10 level of significance. Similar models were used to compare 7-day, 30-day, and 1-year mortality in the patients who received or did not receive thrombolysis or revascularization in the 1992-1996 period. When we compared the 1981-1983 and the 1992-1996 cohorts, the former was used as the reference group. For comparisons between patients treated with or without thrombolysis or revascularization in the 1992-1996 cohort, those without intervention served as the reference group. When the thrombolysis-treated patients were compared with the subgroups of untreated counterparts, the thrombolysis-treated patients were the reference group.
Background Patients with recurrent acute myocardial infarction (AMI) are at increased risk for morbidity and mortality. We compared the outcome of patients with recurrent AMI hospitalized in coronary care units in the prereperfusion and reperfusion eras.
Methods The study population comprised 2 large-scale cohorts with recurrent AMI: (1) 1415 (24%) of 5839 consecutive patients with AMI hospitalized in 1981 to 1983 (Secondary Prevention Reinfarction Israeli Nifedipine Trial [SPRINT] Registry) and (2) 1093 (25%) of 4317 patients with AMI from three national surveys performed in 1992 to 1996.
Results Patients in the 1990s had significantly lower rates of heart failure and cardiogenic shock. The 7-day mortality declined from 18% in 1981-1983 to 10% in 1992-1996 (adjusted odds ratio [OR] 0.57 [0.44-0.75]), the 30-day mortality rate from 26% to 16% (OR 0.56 [0.44-0.71]), and the 1-year mortality rate from 39% to 26% (adjusted hazard ratio [HR] 0.64 [0.54-0.75]), respectively. In the 1992-1996 cohort, the adjusted risk of 7-day, 30-day, and 1-year mortality for patients with recurrent AMI treated with thrombolysis in comparison to patients without thrombolysis was OR 1.69 (1.07-2.65), 1.51 (1.03-2.23), and HR 1.18 (0.90-1.55), respectively. The mortality rate among patients treated with early percutaneous transluminal coronary angioplasty/coronary artery bypass grafting was 3% versus 12% at 7 days (OR 0.36 [0.16-0.73]), 7% versus 18% at 30 days (OR 0.45 [0.25-0.77]), and 16% versus 29% at 1 year (HR 0.64 [0.46-0.96]), in comparison to patients without revascularization.
Conclusion The prognosis of patients with recurrent AMI improved significantly during the reperfusion era. Although thrombolysis may have a limited therapeutic effect among patients with recurrent AMI, an interventional approach seems more appropriate when indicated. A randomized trial of thrombolysis versus early revascularization is needed in patients with recurrent AMI.
Patients with recurrent acute myocardial infarction are at increased risk for complications and death. They represent 14% to 30% of patients hospitalized for acute myocardial infarction, but their short- and long-term mortality constitutes 30% to 50% of all deaths resulting from acute myocardial infarction. During the last two decades, new effective therapeutic modalities for the management of acute myocardial infarction have been introduced. The beneficial effects of thrombolysis, early catheterization, and revascularization are well established and have contributed to the decline of in-hospital and long-term mortality after acute myocardial infarction. The addition of angiotensin-converting enzyme (ACE) inhibitors and the increased use of aspirin and b-blockers have also reduced morbidity and mortality. However, to what extent these innovative therapeutic modalities have influenced the fate of patients with recurrent acute myocardial infarction has not been directly addressed. The purpose of our study was to compare the management and prognosis of two large cohorts of patients with recurrent acute myocardial infarction, one hospitalized before and the other in the reperfusion era.
Between August 1981 and July 1983, 5839 consecutive patients with a confirmed diagnosis of acute myocardial infarction were hospitalized in 13 of the 21 coronary care units functioning in Israel at that time. They constitute the Secondary Prevention Reinfarction Israeli Nifedipine Trial (SPRINT) Registry. Demographic, historic, medical, in-hospital course, and complication data were collected for all SPRINT Registry participants. Nifedipine or placebo, given to 2276 patients, did not affect the outcome of the SPRINT Registry patients. The location of the acute myocardial infarction was determined by the Minnesota Code. Of these 5839 patients, 1415 (24%) had had one or more myocardial infarctions before the index myocardial infarction hospitalization.
A second cohort of 4317 consecutive unselected patients with acute myocardial infarction was compiled from three prospective national surveys conducted during January-February 1992 (941 patients), January-February 1994 (999 patients), and January, February, and May-July 1996 (2377 patients) in 25 coronary care units operating in Israel. Patient characteristics, in-hospital course, and management data were collected. Of these 4317 patients, 1093 (25%) had had one or more previous myocardial infarctions before the index myocardial infarction hospitalization. Reasons for exclusion from thrombolytic therapy were recorded and included contraindication, lack of electrocardiographic criteria, late arrival, and other reasons. The baseline characteristics, management, and early or 1-year mortality of patients in 1992-1996 hospitalized in the 13 coronary care units that participated in SPRINT were compared with that of patients hospitalized in the 12 coronary care units that did not participate in SPRINT. Overall, there was a remarkable similarity between these two groups in baseline characteristics, management, and early and 1-year outcome, as published previously.
Mortality during the first year after the acute event was assessed similarly in both cohorts in 99% of hospital survivors by matching their identification numbers with the Israeli National Population Registry. The criteria used in the first population for diagnosis and determination of the infarct site were also used in the second cohort.
All analyses were performed with use of SAS software (SAS Institute, Cary, NC). Survival curves were estimated by the Kaplan-Meier method. The significance of the difference between the survival curves was assessed by the log-rank test (SAS LIFETEST Procedure). To compare 7-day and 30-day mortality in 1992-1996 versus 1981-1983 in terms of odd ratios with 95% confidence intervals, logistic regression analyses (SAS LOGISTIC Procedure) were performed, adjusting for age, sex, hypertension, diabetes mellitus, angina before the index infarction, anterior location of the index infarction, Killip class >=2 on admission, "period" (where the 1981-1983 cohort was the reference group, odds ratio = 1), and "center" (where the 13 coronary care units that participated in 1981-1983 and 1992-1996 were the reference group, odds ratio = 1).
A stepwise Cox proportional-hazard regression model (SAS PHREG Procedure) adjusting for the same variables was used to compare the hazard ratio of 1-year mortality in 1992-1996 relative to 1981-1983. A variable was allowed to enter into the model if it made a significant contribution at the .15 level of significance and was removed if, after subsequent addition of other variables to the model, it no longer made a contribution at the .10 level of significance. Similar models were used to compare 7-day, 30-day, and 1-year mortality in the patients who received or did not receive thrombolysis or revascularization in the 1992-1996 period. When we compared the 1981-1983 and the 1992-1996 cohorts, the former was used as the reference group. For comparisons between patients treated with or without thrombolysis or revascularization in the 1992-1996 cohort, those without intervention served as the reference group. When the thrombolysis-treated patients were compared with the subgroups of untreated counterparts, the thrombolysis-treated patients were the reference group.