Temporal Trends in Mechanical Complications of Acute Myocardial Infarction in the Elderly

Abstract

BackgroundReperfusion therapy led to an important decline in mortality after ST-segment elevation myocardial infarction (STEMI). Because the rate of cardiogenic shock has not changed dramatically, the authors speculated that a reduction in the incidence or fatality rate of mechanical complications (MCs), the second cause of death in these patients, could explain this decrease. ObjectivesThis study sought to assess time trends in the incidence, management, and fatality rates of MC, and its influence on short-term mortality in old patients with STEMI. MethodsTrends in the incidence and outcomes of MC between 1988 and 2008 were analyzed by Mantel-Haenszel linear association test in 1,393 consecutive patients ≥75 years of age with first STEMI. ResultsOverall in-hospital mortality decreased from 34.3% to 13.4% (relative risk reduction, 61%; p < 0.001). Although the absolute mortality due to MC decreased from 9.6% to 3.3% (p < 0.001), the proportion of deaths due to MC among all deaths did not change (28.1% to 24.5%; p = 0.53). The incidence of MC decreased from 11.1% to 4.3% (relative risk reduction 61%) with no change in their hospital fatality rate over time (from 87.1% to 82.4%; p = 0.66). The proportion of patients undergoing surgical repair decreased from 45.2% to 17.6% (p = 0.04), with no differences in post-operative survival (from 28.6% to 33.3%; p = 0.74). ConclusionsAlthough the incidence of MC has decreased substantially since the initiation of reperfusion therapy in elderly STEMI patients, this reduction was proportional to other causes of death and was not accompanied by an improvement in fatality rates, with or without surgery. MCs are less frequent but remain catastrophic complications of STEMI in these patients.