Prognostic Significance of Complex Ventricular Arrhythmias Complicating ST-Segment Elevation Myocardial Infarction

The aim of the study was to assess the clinical significance of complex ventricular arrhythmias (VAs) (sustained ventricular tachycardia [sVT] and ventricular fibrillation [VF]) in patients with ST-segment elevation myocardial infarction (STEMI) depending on timing of arrhythmia. We analyzed 4,363 consecutive patients with STEMI treated invasively between 2004 and 2014. The median follow-up was 69.6 months (range: 0 to 139.8 months). The study population was divided into 2 main groups; VA group encompassed 476 patients (10.91%) with VAs, whereas 3,887 subjects (89.09%) without VT or VF were included into the control group. In VA population, prereperfusion VA (34.24%; n = 163) was the most common arrhythmia, whereas reperfusion-induced, early postreperfusion, and late postreperfusion VAs were diagnosed in 103 (21.64%), 103 (21.64%), and 107 (22.48%) patients, respectively. Every type of sVT or VF complicating STEMI portended significantly worse in-hospital prognosis, however a late onset arrhythmia was associated with the highest (over fivefold) and reperfusion-induced VA with the lowest (less than threefold) increase in mortality risk compared with the control group. On the contrary, long-term mortality was significantly increased only in subjects with late postreperfusion and prereperfusion VAs compared with VA-free population (43.93% and 36.81%, respectively vs 22.58%; p <0.001). Apart from cardiogenic shock on admission, late postreperfusion (hazard ratio 3.39) and prereperfusion VAs (hazard ratio 2.76) were the strongest independent predictors of death in the analyzed population. In conclusion, 1 in 10 patients with STEMI treated invasively was affected by sVT or VF. The clinical impact of VAs was strongly dependent on timing of arrhythmia.