Comparison of clinical outcomes between patients with pulseless-ventricular tachycardia and ventricular fibrillation in out-of-hospital cardiac arrest

Aim: While previous studies have shown that the initial documented rhythm is associated with clinical outcomes in out-of-hospital cardiac arrest (OHCA), little is known about the difference in clinical outcomes between pulseless ventricular tachycardia (p-VT) and ventricular fibrillation (VF). Methods: From a nationwide, prospective population-based database of OHCA from 2011 to 2015, we selected bystander-witnessed adult patients who were not treated with a public automated external defibrillator. The outcomes examined were favorable 30-day neurological survival rates, 30-day survival rates, and prehospital return of spontaneous circulation (ROSC) rates. To determine the association of the initial documented rhythm with outcome, we used a logistic regression model while adjusting for patient factors and prehospital care-related factors. Results: A total of 19,594 bystander-witnessed OHCA patients who had a shockable rhythm were included: 454 (2.3%) were p-VT and 19,140 (97.7%) were VF. Compared to VF patients, p-VT patients were older, less likely to have a cardiogenic cause, and had shorter resuscitation-related time intervals (collapse to bystander cardiopulmonary resuscitation, collapse to emergency medical services contact, collapse to first ROSC, and first defibrillation to first ROSC). After adjustment for covariates, p-VT was associated with high favorable 30-day neurological survival rates (adjusted odds ratio [OR], 1.85; 95% confidence interval [CI], 1.30-2.64, p = 0.001), 30-day survival rates (adjusted OR, 1.41; 95% CI, 1.03-1.95, p = 0.037), and prehospital ROSC rates (adjusted OR, 1.90; 95% CI, 1.42-2.55, p < 0.001). Conclusion: In this study, patients with p-VT as the initial documented rhythm had significantly better outcomes than those with VF.