Ten-year trends in the incidence, treatment, and outcome of Q-wave myocardial infarction

Abstract

The benefits of coronary reperfusion and antiplatelet therapy for patients with Q-wave acute myocardial infarction (Q-AMI) are well established in the context of randomized, controlled trials. The use and recent impact of these and other therapies on the broader, community-wide population of patients with Q-AMI is less well established. Residents of the Worcester, Massachusetts, metropolitan area (1990 census population 437,000) hospitalized with confirmed Q-AMI in all metropolitan Worcester, Massachusetts, hospitals in 4 1-year periods between 1986 and 1997 comprised the sample of interest. We examined the rates of occurrence, use of reperfusion strategies, and hospital mortality in a cohort of 711 patients with Q-AMI treated early in the reperfusion era (1986 and 1988) in comparison to 669 patients with Q-AMI treated a decade later (1995 and 1997). The percentage of Q-AMI among all hospitalized patients with AMI decreased over the decade of reperfusion therapy: 52% in 1986 and 1988 versus 35% in 1995 and 1997 (p < 0.001). Use of reperfusion therapy for patients with Q-AMI increased from 22% to 57%, with a marked increase in the use of primary angioplasty over time (1% vs 16%). The profile of patients receiving reperfusion therapy also changed significantly over the study period. Marked increases in use of antiplatelet therapy, beta blockers, angiotensin-converting enzyme inhibitors, and decreased use of calcium channel blockers, were observed over time. The crude in-hospital case fatality rate declined from 19% (1986 and 1988) to 14% (1995 and 1997) in patients with Q-AMI. Results of a multivariable regression analysis showed lack of reperfusion therapy, older age, anterior wall AMI, and cardiogenic shock to be independent predictors of in-hospital mortality in patients with Q-AMI. Thus, the percentage of all AMI's presenting as Q-AMI, and hospital mortality after Q-AMI, has decreased significantly in the past 10 years. The decrease in mortality occurs in the setting of broader use of reperfusion and adjunctive therapy (including primary angioplasty).