End-systolic wall stress predicts post-discharge heart failure after acute myocardial infarction.

Background: Compensatory mechanisms activated after myocardial infarction include an increase in systolic wall stress (SWS) and activation of the neurohormonal system. Nevertheless, left ventricular ejection fraction (LVEF) and infarct size are the established primary predictors of outcome after ST-segment elevation myocardial infarction.

Aims: To assess the relative impact of various cardiac magnetic resonance (CMR) imaging variables, such as infarct size, LVEF and SWS, on pre- and post-discharge heart failure (HF).

Methods: CMR was performed in a prospective study involving 169 patients with first ST-segment elevation myocardial infarction. Common CMR findings, such as SWS, were computed.

Results: Mean SWS was 16.3±5.1×10(3)N·m(-2), and was systematically higher in patients exhibiting either pre- or post-discharge HF (18.9±5.7 and 21.3±7.6×10(3) N·m(-2), respectively). SWS was moderately related to initial infarct size (r=0.405; P <0.001). In total, 28 patients presented with HF during the hospitalization phase and 14 during follow-up, with a median time of event of 93 days (25th-75th percentiles, 29-139.25 days). The univariate predictors of HF were age, LVEF, infarct size, SWS, microvascular obstruction, anterior infarction and heart rate at admission. Multivariable analysis revealed infarct size and age to be the predictors of predischarge HF, while SWS and heart rate at admission predicted post-discharge HF. The greatest SWS quartile provided a negative predictive value of 95.9%.

Conclusion: Regardless of LVEF and infarct size, SWS was shown to be an independent predictor of post-discharge HF after ST-segment elevation myocardial infarction.