Abstract 656: Impact of Percutaneous Coronary Intervention on Ventricular Function in Potential Candidates for Prophylactic Implantable Defibrillators
While left ventricular ejection fraction (LVEF) may improve in some pts with ischemic cardiomyopathy (ICM) following percutaneous coronary intervention (PCI), there are limited data with respect to the frequency and clinical predictors of this finding in pts who are candidates for subsequent placement of an implantable defibrillator (ICD). We retrospectively identified 105 consecutive pts with an initial LVEF <35% who underwent PCI and had follow-up echocardiographic assessment at least one mo (median 5.2 mo) later. No pt had a history of syncope or sustained ventricular arrhythmias. The indication for PCI was ST-elevation myocardial infarction (STEMI) in 17 patients (16.2%), non-ST-elevation MI (NSTEMI) in 76 pts (72.4%), and angina in 12 pts (11.4%). Mean age was 65 ± 12 yrs and 76% of pts were male. Hypertension was present in 80% of pts, diabetes in 47%, renal insufficiency in 30%, prior MI in 58%, and prior PCI in 51%. Following PCI, 85% received beta blockers, and 78% received ACEI or ARBs. These variables were distributed equally between groups. Overall, mean LVEF improved significantly at follow-up (27.8 ± 6.8% vs 38.3% ± 14.7%, p<0.001). LVEF improved for all indications, though there was a trend toward greater improvement in pts with STEMI (table⇓). LVEF improved by > 5% in 76 pts (72%). In 60 pts (57%) LVEF improved to a value > 35%, including 14 pts with initial LVEF ≤ 25%. Multivariate analysis of variance with repeated measures demonstrated that the improvement in LVEF was independent of all other clinical variables (p< 0.001), none of which alone or jointly predicted improvement. These results suggest that significant improvement in LVEF can be expected in a majority of pts with ICM following PCI, irrespective of clinical indication, and cannot be predicted easily from standard clinical variables. Decisions regarding prophylactic ICD implantation should be deferred until after late reassessment of LVEF in most of these pts.