49 Predictors and prognostic role of left ventricular ejection fraction recovery after st elevation myocardial infarction

Introduction Left ventricular ejection fraction (LVEF) is an important predictor of morbidity and mortality after ST elevation myocardial infarction (STEMI). In patients with left ventricular systolic dysfunction early after STEMI adverse ventricular remodelling can lead to a sustained reduction in LVEF, however, in some cases improvement may occur due to recovery of myocardial stunning and recuperation of hibernating myocardium. Predictors of recovery in LVEF following STEMI are not well established. We sought to investigate predictors of LVEF recovery in patients with left ventricular systolic dysfunction in the acute setting and assess the prognostic implications of change in LVEF. Methods Consecutive patients with STEMI undergoing primary PCI from a large volume single centre who had LVEF assessment prior to hospital discharge (acute LVEF) and during follow-up (follow-up LVEF) by echocardiogram were enrolled. Patients with preserved acute LVEF (>50%) were excluded from the analysis. LVEF recovery was calculated: EF Recovery = Follow-up LVEF – Acute LVEF. Clinical endpoint was defined as a composite of death, re-admission with heart failure, sustained ventricular arrhythmia or implantable cardioverter defibrillator (ICD) over three years follow-up. Results 313 patients with STEMI had both acute and follow-up LVEF assessments of which 103 patients with acute LVEF >50% were excluded. 210 patients with acute LVEF ≤50% were included in the analysis. Mean age was 64±13 years and 76% were male. Anterior STEMI occurred in 51% of cases and 17% were diabetic. There was marked heterogeneity in LVEF recovery with 39% of patients demonstrating no EF recovery (figure 1). Age, hypertension and acute LVEF predicted LVEF recovery in unadjusted model, nonetheless, only acute LVEF was an independent predictor after adjustment for other risk factors (table 1). For every 5% increase in acute LVEF there was 45% less likelihood of any LVEF recovery, plausibly reflecting a stunning phenomenon. In those individuals who demonstrated LVEF recovery, only acute LVEF was a predictor of the magnitude of LVEF recovery. For every 5% increase in acute LVEF, there was more than 2% reduction in LVEF recovery (table 2). Importantly, LVEF recovery was a predictor of clinical outcomes. With every 5% increase in LVEF recovery there was a 16% reduction in the likelihood of sustaining an event (Hazard ratio 0.84, CI 0.74 – 0.95, p<0.006). Using 15% as a cut-off, LVEF recovery had a negative predictive value of 84% and a sensitivity of 87% in predicting adverse events. Conclusion Acute LVEF is an independent predictor for recovery of left ventricular systolic function. LVEF recovery is a good measurement to predict patients who are less likely to have adverse clinical outcomes over long term follow-up.