Late recovery in left ventricular systolic function after discharge of patients with a first anterior myocardial infarction

Background: Left ventricular systolic function is a useful indicator of in-hospital prognosis in patients with acute myocardial infarction. For long-term risk stratification, however, the variable degree of recovery that may occur during the ensuing period has also to be taken into account.

Aims: To analyse the prevalence, time course, determinants and correlates of late left ventricular function recovery after myocardial infarction, from hospital discharge to 1-year follow-up, using systematic serial assessment of left ventricular function.

Methods: Data from 512 patients with a first anterior myocardial infarction included in two prospective studies on left ventricular remodelling (REVE and REVE-2) were analysed. Serial echocardiographic studies were performed before discharge, at 3 months and at 1 year after myocardial infarction. Left ventricular volumes, ejection fraction, and Wall Motion Score Index were determined at a core echocardiographic laboratory.

Results: In both cohorts, there was a significant decrease in Wall Motion Score Index between discharge and 1 year (from 1.87 ± 0.15 to 1.71 ± 0.21 [P<0.0001] in REVE; and from 1.91 ± 0.15 to 1.64 ± 0.28 [P<0.0001] in REVE-2), indicating an improvement in systolic function. Left ventricular ejection fraction increased from 49.6 ± 9.5% at baseline to 51.5 ± 9.5% at 1 year in REVE (P<0.008), and from 49.8 ± 8.3% to 55.5 ± 9.8% in REVE-2 (P<0.0001). Most of the recovery occurred within the first 3 months after discharge, but there was still significant recovery between 3 months and 1 year. Peak creatine kinase was the sole variable independently associated with left ventricular function recovery in both studies. Patients with no or minimal function recovery had the greater increase in left ventricular volumes at 1 year.

Conclusions: Late recovery in left ventricular function is common after discharge in patients with acute myocardial infarction. Further research is needed to identify new parameters that may help to predict this favourable outcome.