Improvement in the Prognosis of Patients With Acute Myocardial Infarction in the 1990s Compared With the Prethrombolytic Era: An Analysis by Age Subgroups

Am J Geriatr Cardiol. 1995 Nov;4(6):17-31.

Abstract

The number of elderly patients experiencing myocardial infarction (MI) is growing rapidly, and their hospital mortality rate remains high, although mortality after acute MI declined in the 1990s. The in-hospital and first-year mortality rates in 5,839 patients with acute MI in 1981-1983 were compared with 1,014 consecutive patients admitted in 1992 to the coronary care units in Israel. The clinical characteristics of gender, prior MI, and acute MI location were similar in the age subgroups in both periods. Patients admitted in 1981-1983 did not receive thrombolytic therapy, percutaneous transluminal coronary angioplasty (PTCA), or coronary artery bypass grafting (CABG), whereas in those admitted in 1992, the frequency of thrombolytic therapy in the age subgroups at or below 55 years, 56-74 years, and at or above 75 years decreased with advanced age (56%, 48%, and 24%, respectively, P is less than.0001). The frequency of PTCA also declined (11%, 7%, and 3%, respectively, P is less than.002). The in-hospital mortality rate for the entire study population declined from 18% in 1981-1983 to 11% in 1992 (adjusted odds ratio [OR] 0.49; 95% confidence interval, 0.39-0.62). The decline in in-hospital mortality was more marked among patients aged 56-74 (18.0%-10.0%; OR 0.48) and those aged at or above 75 years (35.0%-21.5%; OR 0.44), than among patients aged at or below 55 years (6.9%-4.3%; OR 0.70). This decline was most marked in reperfused patients, particularly the very elderly (OR 0.31; 95% CI 0.14-0.69). The cumulative first-year mortality declined by 40% (from 25.5% in 1981-1983 to 17.9% in 1992, hazard ratio (HR) 0.61; 95% CI 0.52-0.72). The decline was more marked among patients aged 56-74 years (26.2%-16.5%; HR 0.56) and those aged at or above 75 years (49.6%-37.6%; HR 0.58) than among counterparts aged at or below 55 years (10.2%-7.9%; HR 0.86). The decline was most marked in reperfused patients, particularly the very elderly (HR 0.31; 95% CI 0.16-0.59). In conclusion, (1) during the last decade in Israel, cumulative first-year mortality after an acute MI declined by 40% and was most marked in patients aged greater than 55 years and in particular the very elderly (at or above 75 years); (2) the main improvement in survival was achieved early after the acute MI, and was maintained thereafter during the first postinfarction year; 3) the favorable outcome in 1992 is related to changes in patients management, mainly reperfusion therapy (thrombolysis, PTCA, CABG); and (4) reperfusion therapy in elderly patients with acute MI should be considered systematically unless specific contraindications are present.