BACKGROUND: We aimed to investigate the incidence and risk factors for ventricular fibrillation (VF) before primary percutaneous coronary intervention (PPCI) among patients with ST-segment elevation myocardial infarction (STEMI) in a prospective nationwide setting.

METHODS AND RESULTS: In this case-control study, patients presenting within the first 12 hours of first STEMI who survived to undergo angiography and subsequent PPCI were enrolled. Over 2 years, 219 cases presenting with VF before PPCI and 441 controls without preceding VF were enrolled. Of the 219 case patients, 182 (83%) had STEMI with out-of-hospital cardiac arrest due to VF, and 37 (17%) had cardiac arrest upon arrival to the emergency room. Medical history was collected by standardized interviews and by linkage to national electronic health records. The incidence of VF before PPCI among STEMI patients was 11.6%. Multivariable logistic regression analysis identified novel associations between atrial fibrillation and alcohol consumption with VF. Patients with a history of atrial fibrillation had a 2.80-fold odds of experiencing VF before PPCI (95% CI 1.10 to 7.30). Compared with nondrinkers, patients who consumed 1 to 7 units, 8 to 14 units, or >15 units of alcohol per week had an odds ratio (OR) of 1.30 (95% CI, 0.80 to 2.20), 2.30 (95% CI, 1.20 to 4.20), or 3.30 (95% CI, 1.80 to 5.90), respectively, for VF. Previously reported associations for preinfarction angina (OR 0.46; 95% CI 0.32 to 0.67), age of <60 years (OR 1.75; 95% CI 1.20 to 2.60), anterior infarction (OR 2.10; 95% CI 1.40 to 3.00), preprocedural thrombolysis in myocardial infarction flow grade 0 (OR 1.65; 95% CI 1.14 to 2.40), and family history of sudden death (OR 1.60; 95% CI 1.10 to 2.40) were all associated with VF.

CONCLUSION: Several easily assessed risk factors were associated with VF occurring out-of-hospital or on arrival at the emergency room before PPCI in STEMI patients, thus providing potential avenues for investigation regarding improved identification and prevention of life-threatening ventricular arrhythmias.