Prognostic Significance of Complex Ventricular Arrhythmias Complicating ST-Segment Elevation Myocardial Infarction
omasz Podolecki; Radoslaw Lenarczyk, Jacek Kowalczyk et al.

KEYWORDS
ventricular fibrillation, ventricular tachycardia, acute myocardial infarction, percutaneous coronary intervention

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 STEMI-patients treated invasively between 2004 and 2014. The median follow-up was 69.6 months (range: 0–139.8 months). The study population was divided into 2 main groups: VA Group encompassed 476 (10.91 %) patients with VAs, whereas 3887 (89.09 %) subjects without VT/VF were included into the Control Group. Among VA-population, pre-reperfusion VA (34.24%; n=163) was the most common arrhythmia, whereas reperfusion-induced, early post-reperfusion and late post-reperfusion VAs were diagnosed in: 103 (21.64 %), 103 (21.64 %) and 107 (22.48 %) patients, respectively. Every type of sVT/VF complicating STEMI portended significantly worse in-hospital prognosis, however a late onset arrhythmia was associated with the highest (over 5-fold) and reperfusion-induced VA with the lowest (less than 3-fold) increase in mortality risk compared to the Control Group. On the contrary, long-term mortality was significantly increased only in subjects with late post-reperfusion and pre-reperfusion VAs compared to VA-free population (43.93% and 36.81%, respectively vs. 22.58%; p<0.001). Apart from cardiogenic shock on admission, late post-reperfusion (HR 3.39) and pre-reperfusion VAs (HR 2.76) were the strongest independent predictors of death in the analyzed population. In conclusion, one in 10 patients with STEMI treated invasively was affected by sVT/VF. The clinical impact of VAs was strongly dependent on timing of arrhythmia.