Role of Ischemic Preconditioning and Inflammatory Response in the Development of Malignant Ventricular Arrhythmias After Reperfused ST-Elevation Myocardial Infarction

Abstract

Background Sustained ventricular tachycardia and ventricular fibrillation (VT/VF) are major complications of ST-elevation myocardial infarction (STEMI), even in the era of reperfusion therapy. We sought to clarify the determinants of VT/VF after reperfused STEMI. Methods and Results Consecutive STEMI patients treated with primary percutaneous coronary intervention (n = 457) were divided into 2 groups by the presence or absence of VT/VF during hospitalization. Serum C-reactive protein (CRP) level and peripheral white blood cell (WBC) count were serially measured. VT/VF was observed in 54 patients (12%). Prior infarction was more common and preinfarction angina was less in patients with VT/VF than those without. Peak CRP level ( P < .0001), WBC count on admission ( P = .008), and maximum WBC count ( P = .0014) were higher in patients with VT/VF than those without. VT/VF, especially VT/VF later than 48 hours after onset, was associated with greater left ventricular (LV) dimension during convalescence. Kaplan-Meier curves and log-rank test revealed VT/VF to be a significant determinant of long-term major adverse cardiac events. Multivariate analysis revealed that prior infarction, absence of preinfarction angina, and peak CRP ≥10 mg/dL were independent determinants of VT/VF. Conclusions Lack of ischemic preconditioning, enhanced inflammatory response, and subsequent LV dysfunction are related to the development of VT/VF after STEMI.