Cohort Study: Late Ventricular Arrhythmias After Primary PCI for STEMI Are Rare but Increase Mortality
5 Nov, 2024 | 15:24h | UTCBackground: Ventricular tachycardia (VT) and ventricular fibrillation (VF) are critical complications following ST-segment elevation myocardial infarction (STEMI). While early VT/VF typically occurs before or shortly after reperfusion, contemporary data on the incidence of late VT/VF post-primary percutaneous coronary intervention (PCI) are limited. Understanding the risk of late VT/VF is essential for optimizing in-hospital monitoring and discharge timing.
Objective: To assess the risk of late VT and VF after primary PCI in patients with STEMI, identify associated factors, and evaluate their impact on in-hospital mortality.
Methods: This cohort study analyzed data from 174,126 adults with STEMI treated with primary PCI between January 1, 2015, and December 31, 2018, using the National Cardiovascular Data Registry Chest Pain–MI Registry. Late VT/VF was defined as events occurring one or more days after PCI. Multivariable logistic regression was employed to identify factors associated with late VT/VF and its association with in-hospital mortality.
Results: Among the patients, 8.9% experienced VT or VF after primary PCI. Late VT/VF occurred in 2.4% of patients overall and 1.7% of those with uncomplicated STEMI. Late VT/VF associated with cardiac arrest was rare, occurring in 0.4% of all patients and 0.1% of patients with uncomplicated STEMI. Decreased left ventricular ejection fraction (LVEF) was the most significant factor associated with late VT/VF with cardiac arrest (adjusted odds ratio [AOR] for every 5-unit decrease ≤40%: 1.67; 95% CI, 1.54–1.85). Late VT/VF was linked to increased odds of in-hospital mortality (AOR, 6.40; 95% CI, 5.63–7.29).
Conclusions: Late VT/VF after primary PCI for STEMI is infrequent, particularly in patients with uncomplicated presentations. However, when late VT/VF occurs, it is associated with a significantly higher risk of in-hospital mortality.
Implications for Practice: While vigilant monitoring remains crucial, patients with uncomplicated STEMI may be candidates for earlier discharge through shared decision-making. Identifying high-risk patients for late VT/VF can enable tailored monitoring strategies to improve outcomes.
Study Strengths and Limitations: Strengths include a large, contemporary cohort and detailed data on in-hospital VT/VF events. Limitations involve the observational design, potential unmeasured confounders, and the inability to differentiate between VT and VF due to registry definitions.
Future Research: Further studies are warranted to develop precise risk prediction models for late VT/VF and to explore effective out-of-hospital monitoring strategies post-STEMI.