Prognosis among survivors of primary ventricular fibrillation in the percutaneous coronary intervention era

Abstract

Background: Sudden cardiac death (SCD) constitutes one of the most prevalent modes of death and is mainly caused by primary ventricular fibrillation (VF), that is, VF in the acute setting of a first acute myocardial infarction (MI). Current guidelines for secondary prevention of SCD are based on data from the thrombolysis era. We analyzed follow-up data of a large group of primary VF survivors to determine prognosis and risk of SCD in patients who received contemporary MI treatment.

Methods: Patients in this study were included in the ongoing Dutch multicenter primary VF study between December 1999 and April 2007. Primary VF was defined as VF during the first ST-elevation myocardial infarction (STEMI). Patients surviving the first 30 days were analyzed in this study. Data on mortality, cause of death, hospitalization, and implantable cardioverter-defibrillator (ICD) implantation were retrieved from national databases. In addition, data on left ventricular ejection fraction and medication use during follow-up were retrieved.

Results: In total, 341 primary VF patients (cases) and 292 STEMI patients without VF (controls) were included in the study. Demographic and infarct characteristics were comparable between both groups. The median follow-up was 3.33 years for cases and 3.69 for controls (P = .02). The left ventricular ejection fraction post-STEMI was 45.1% versus 46.5% (P = .342). During follow-up, 19 cases died versus 24 controls. Cox regression analysis showed no significant difference in survival between cases and controls (relative risk 0.59, 95% CI 0.15-2.30). Implantable cardioverter-defibrillators were implanted in 22 cases and 2 controls (P < .001), but only 2 cases and 1 control patient received appropriate ICD shocks. beta-Blocker use during follow-up was 84.4% in cases versus 76.2% in controls (P = .049). Of cases, 2.5% were rehospitalized for acute MI versus 10.1% of controls (P < .001). The numbers of admissions for acute coronary syndromes and chest pain were not different between groups.

Conclusions: In conclusion, patients who survive the first month after primary VF have a similar prognosis as patients with a STEMI without VF. This is the first study to address this question in the modern era of reperfusion therapy. Implantable cardioverter-defibrillator treatment in primary VF patients without residual ischemia or other risk factors can be safely withheld.