Coronary artery disease burden relation with the presentation of acute cardiac events and ventricular fibrillation.

OBJECTIVES: Evaluate the differences in coronary artery disease (CAD) burden between patients with ischemic resuscitated, ischemic refractory VT/VF OHCA events and N/STEMI. BACKGROUND: Refractory out-of-hospital cardiac arrest patients presenting with initial shockable rhythms (VT/VF OHCA) have the highest mortality among patients with acute cardiac events. No predictors of VT/VF OHCA refractoriness have been identified. METHODS: A retrospective cohort design was used to assess baseline characteristics, clinical outcomes, and the angiographic severity of disease among patients with VT/VF OHCA undergoing emergent coronary angiography at the University of Minnesota Medical Center. The Gensini score was calculated for all patients to assess the angiographic burden of CAD. For patients with ischemia-related cardiac arrest, outcomes were further compared to an independent non-OHCA population presenting with N/STEMI. RESULTS: During the study period, 538 patients were admitted after VT/VF OHCA. Among them, 305 presented with resuscitated, and 233 with refractory VT/VF. 66% of resuscitated and 70% of refractory VT/VF had an underlying, angiographically documented, ischemic etiology. Ischemic resuscitated and refractory VT/VF had significant differences in Gensini score, (80.7 ± 3.6 and 127.6 ± 7.1, respectively, p < 0.001) and survival (77.3% and 30.0%, respectively, p < 0.001). Both groups had a higher CAD burden and worse survival than the non-OHCA N/STEMI population (360 patients). Ischemic refractory VT/VF was significantly more likely to present with chronic total occlusion in comparison to both N/STEMI and ischemic resuscitated VT/VF. CONCLUSION: Ischemia-related, refractory VT/VF OHCA has a higher burden of CAD and the presence of CTOs compared to resuscitated VT/VF OHCA and N/STEMI.

Advanced reperfusion strategies for patients with out-of-hospital cardiac arrest and refractory ventricular fibrillation (ARREST): a phase 2, single centre, open-label, randomised controlled trial.

BACKGROUND: Among patients with out-of-hospital cardiac arrest (OHCA) and ventricular fibrillation, more than half present with refractory ventricular fibrillation unresponsive to initial standard advanced cardiac life support (ACLS) treatment. We did the first randomised clinical trial in the USA of extracorporeal membrane oxygenation (ECMO)-facilitated resuscitation versus standard ACLS treatment in patients with OHCA and refractory ventricular fibrillation. METHODS: For this phase 2, single centre, open-label, adaptive, safety and efficacy randomised clinical trial, we included adults aged 18-75 years presenting to the University of Minnesota Medical Center (MN, USA) with OHCA and refractory ventricular fibrillation, no return of spontaneous circulation after three shocks, automated cardiopulmonary resuscitation with a Lund University Cardiac Arrest System, and estimated transfer time shorter than 30 min. Patients were randomly assigned to early ECMO-facilitated resuscitation or standard ACLS treatment on hospital arrival by use of a secure schedule generated with permuted blocks of randomly varying block sizes. Allocation concealment was achieved by use of a randomisation schedule that required scratching off an opaque layer to reveal assignment. The primary outcome was survival to hospital discharge. Secondary outcomes were safety, survival, and functional assessment at hospital discharge and at 3 months and 6 months after discharge. All analyses were done on an intention-to-treat basis. The study qualified for exception from informed consent (21 Code of Federal Regulations 50.24). The ARREST trial is registered with ClinicalTrials.gov, NCT03880565. FINDINGS: Between Aug 8, 2019, and June 14, 2020, 36 patients were assessed for inclusion. After exclusion of six patients, 30 were randomly assigned to standard ACLS treatment (n=15) or to early ECMO-facilitated resuscitation (n=15). One patient in the ECMO-facilitated resuscitation group withdrew from the study before discharge. The mean age was 59 years (range 36-73), and 25 (83%) of 30 patients were men. Survival to hospital discharge was observed in one (7%) of 15 patients (95% credible interval 1·6-30·2) in the standard ACLS treatment group versus six (43%) of 14 patients (21·3-67·7) in the early ECMO-facilitated resuscitation group (risk difference 36·2%, 3·7-59·2; posterior probability of ECMO superiority 0·9861). The study was terminated at the first preplanned interim analysis by the National Heart, Lung, and Blood Institute after unanimous recommendation from the Data Safety Monitoring Board after enrolling 30 patients because the posterior probability of ECMO superiority exceeded the prespecified monitoring boundary. Cumulative 6-month survival was significantly better in the early ECMO group than in the standard ACLS group. No unanticipated serious adverse events were observed. INTERPRETATION: Early ECMO-facilitated resuscitation for patients with OHCA and refractory ventricular fibrillation significantly improved survival to hospital discharge compared with standard ACLS treatment. FUNDING: National Heart, Lung, and Blood Institute.

Rationale and methods of the Advanced R2Eperfusion STrategies for Refractory Cardiac Arrest (ARREST) trial.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation has emerged as a prominent therapy for patients with refractory cardiac arrest. However, the optimal time of initiation remains unknown. AIM: The aim was to assess the rate of survival to hospital discharge in adult patients with refractory ventricular fibrillation/pulseless ventricular tachycardia out-of-hospital cardiac arrest treated with 1 of 2 local standards of care: (1) early venoarterial extracorporeal membrane oxygenation-facilitated resuscitation for circulatory support and percutaneous coronary intervention, when needed, or (2) standard advanced cardiac life support resuscitation. DESIGN: Phase II, single-center, partially blinded, prospective, intention-to-treat, safety and efficacy clinical trial. POPULATION: Adults (aged 18-75), initial out-of-hospital cardiac arrest rhythm of ventricular fibrillation/pulseless ventricular tachycardia, no ROSC following 3 shocks, body morphology to accommodate a Lund University Cardiac Arrest System automated cardiopulmonary resuscitation device, and transfer time of <30 minutes. SETTING: Hospital-based. OUTCOMES: Primary: survival to hospital discharge. Secondary: safety, survival, and functional assessment at hospital discharge and 3 and 6 months, and cost. SAMPLE SIZE: Assuming success rates of 12% versus 37% in the 2 arms and 90% power, a type 1 error rate of .05, and a 15% rate of withdrawal prior to hospital discharge, the required sample size is N = 174 evaluated patients. CONCLUSIONS: The ARREST trial will generate safety/effectiveness data and comparative costs associated with extracorporeal cardiopulmonary resuscitation, informing broader implementation and a definitive Phase III clinical trial.