PROGNOSIS AFTER HOSPITALIZATION FOR ACUTE MYOCARDIAL-INFARCTION NOT ACCOMPANIED BY TYPICAL ISCHEMIC CHEST PAIN

PURPOSE: Although ischemic-type chest pain generally identifies acute myocardial infarction (AMI), some patients are hospitalized for AMI wi thout this symptom. Long-term mortality and morbidity after AMI presen ting with alternative warning symptoms have not been examined previous ly. We therefore assessed the prognostic implications of the absence o f typical chest gain as well as other recognized risk predictors in pa tients hospitalized with AMI. PATIENTS AND METHODS: Data were obtained during the Multicenter Diltiazem Postinfarction Trial. Pain status an d other baseline characteristics were determined prospectively by stud y coordinators according to simple, prespecified criteria. Patients we re then examined every 3 to 4 months until trial completion. We applie d chi-square methods, life-table analysis, and multivariate analysis t o assess the strength and independence of prognostic power associated with each baseline variable. RESULTS: Of 2,464 patients enrolled 3 to 15 days after enzyme-documented AMI, 115 patients lacked typical ische mic-type chest pain on presentation (the ''nonpainful'' group). After 25 months' mean follow-up, cardiac mortality was 20% for nonpainful pa tients and 10% for 2,349 patients with typical pain (the ''painful'' g roup), P <0.001. Similar increments were seen in total deaths (27% non painful versus 13% painful, P <0.001) and cardiac events, namely, card iac death or nonfatal reinfarction (24% nonpainful versus 17% painful, P = 0.001). Late congestive heart failure was more frequent (17% nonp ainful versus 7% painful, P <0.001), but unstable angina was less (6% nonpainful versus 16% painful, P = 0.005). At outset, nonpainful patie nts had more left ventricular dysfunction and diabetes mellitus. Howev er, nonpainful AMI predicted worse outcome even when these problems we re absent. Logistic regression confirmed greater cardiac death risk in the nonpainful group (hazard ratio = 2.05) and showed that predictive power of nonpainful status was independent of baseline ejection fract ion, Holter data, concomitant diabetes mellitus, and other covariates. CONCLUSIONS: Patients hospitalized with nonpainful AMI are much more likely to experience late cardiac death or congestive heart failure th an are patients with painful AMI. In part, this probably reflects more ventricular damage with alternative warning symptoms such as dyspnea. However, our data suggest that defective perception of warning pain a lso provides a long-term risk to life that is independent of previousl y known predictors of poor outcome.