Frequency and prognosis of stroke/TIA among 4808 survivors of acute myocardial infarction. The SPRINT Study Group.

BACKGROUND AND PURPOSE

Stroke complicating acute myocardial infarction is associated with substantial morbidity and mortality. The purpose of this study was to assess the incidence, predictors, and impact on mortality of stroke/transient ischemic attacks occurring after hospital discharge in a large unselected population of acute myocardial infarction survivors.

METHODS

During a secondary prevention study with nifedipine (SPRINT), demographic, anamnestic, and clinical data were collected for 5839 consecutive acute myocardial infarction patients admitted to 13 coronary care units in Israel. Hospital survivors (n = 4808) were followed for a year after their discharge. Mortality was assessed for a mean follow-up of 5.5 years (range, 4.5 to 7 years).

RESULTS

One percent (48/4808) of hospital survivors from acute myocardial infarction experienced a stroke/transient ischemic attack in the year after acute myocardial infarction. Thirty-one percent (15 of 48) of events occurred in the first month after hospital discharge. Incidence was higher among older patients (> 70 years; 1.9%), those with anterior site of myocardial infarction (1.35%), a previous history of myocardial infarction (1.8%), hypertension (1.4%), stroke in the past (4.1%), and chronic atrial fibrillation (9%). Multivariate analysis identified the following as independent predictors of stroke/transient ischemic attacks occurring in the year after hospital discharge: chronic atrial fibrillation, older age, history of previous myocardial infarction, anterior myocardial infarction site, serum glutamic oxaloacetic transaminase levels more than four times above upper normal limits, and stroke in the past. The age-adjusted 1-year and long-term mortality rates (4.5 to 7 years; mean, 5.5 years) were significantly higher in patients with (31% and 62%) than in those without stroke/transient ischemic attacks (9% and 31%, respectively; P < .01).

CONCLUSIONS

Stroke/transient ischemic attack is a relatively rare (1%) complication in the year after hospital discharge from acute myocardial infarction, though more frequent in the first month. Chronic atrial fibrillation, older age, anterior myocardial infarction site, serum glutamic oxaloacetic transaminase levels more than four times above upper normal limits, past myocardial infarction, and stroke identify high-risk patients. Patients suffering from subsequent stroke/transient ischemic attacks experienced higher mortality than counterparts who remained free from this complication.