Coronary angiography findings in patients with refractory vs. non-refractory ventricular fibrillation cardiac arrest

Introduction Refractory ventricular fibrillation (VF) is usually defined as the need for >3 shocks and poses a therapeutic challenge during cardiac arrest. For these patients, new treatment strategies such as early invasive management are under active investigation, yet the underlying myocardial substrate has poorly been characterised. In search of potential therapeutic targets, we studied coronary angiography findings in refractory vs. non-refractory VF. Methods Out of our prospective cardiac arrest registry (2013–2018), we studied all VF-patients that were transported to our tertiary hospital, and underwent coronary angiography (CAG). CAGs were assessed by interventional cardiologists blinded for clinical outcomes and patient category, being either patients with refractory (>3 shocks) or non-refractory VF (≤3 shocks). CAG images were scored using predefined data-sheets with uniform definitions. Results We studied 301 patients, of which the majority was male (82%) and median age was 63 (53–70) years. Of all patients, 105 (35%) had refractory VF and 196 (66%) had non-refractory VF. We found no differences in baseline and arrest characteristics (i.e. arrest location, witnessed arrest, bystander CPR, EMS response time and AED use) between refractory and non-refractory VF. In both groups, significant coronary artery disease (≥1 stenosis >70%) was highly prevalent (78 vs. 77%, p=0.76). Acute coronary occlusions were more prevalent in the refractory VF group (41% in refractory VF vs. 26% in non-refractory VF, p=0.006). Figure 1 demonstrates that the proportion patients with an coronary occlusion increases with an increasing number of shocks (p for trend=0.003). Chronic total occlusions did not differ between both groups (29% vs. 33%, p=0.47). Refractory VF-patients had lower proportions 24-hour survival (75% vs. 93%, p<0.001) and survival to discharge (61% vs. 78%, p=0.002). Conclusion In this VF-cardiac arrest study on patients transported to the hospital and undergoing coronary angiography, acute coronary occlusions were more prevalent in refractory compared to non-refractory VF. After confirmation of these findings, further studies on the potential benefit of early treatment of acute coronary occlusions in patients with refractory VF are eagerly awaited. Figure 1 Funding Acknowledgement Type of funding source: None

Abstract 355: Performance of Inclusion and Exclusion Criteria Based on Prognosis in an Interventional Out-of-Hospital Cardiac Arrest Study

Introduction: Selection of out-of-hospital cardiac arrest (OHCA) patients for inclusion in randomized control trials (RCT) presents a challenge. The goal is to enroll patients with severe injury warranting intervention yet exclude those with extreme irreversible disease. Selection early after return of spontaneous circulation (ROSC) is complicated by a relative paucity of prognostic variables. We examined the accuracy of enrollment criteria in the iNO OHCA study (NCT03079102) in excluding patients likely to have good or poor outcomes within three hours (3h) of ROSC. Methods: OHCA patients arriving to two tertiary care centers in Pittsburgh were screened within 3h of ROSC. We excluded subjects that followed commands (good prognosis expected) and subjects expected to have poor prognosis based on: Full Outline of UnResponsiveness Brainstem (FOUR B) score <2; CPR time >40 min; investigator estimate of >95% mortality; CT evidence of cerebral edema or intracranial hemorrhage; clinical evidence of myoclonic status epilepticus; or traumatic OHCA etiology. We also excluded subjects not within 3h of ROSC. We compared discharge survival and good neurologic outcome based on disposition (location). Results: Over a nine-month period we screened 155 patients with ROSC following OHCA, 20 subjects (13%) were included in the study and 135 (87%) were excluded ( Table ). The odds ratio (OR) of survival if excluded for poor prognosis was 0.03 (95% CI: 0.01 - 0.08) and worsened when >1 criteria were met. Exclusion for good prognosis was associated with improved survival (OR = 67.2 [95% CI: 14.3 - 316.3]). Conclusions: Our criteria reliably exclude OHCA subjects with good or poor prognosis within 3h of ROSC, yielding a study population with intermediate survival which can be applicable to future OHCA trials. Our criteria selected a minority (13%) of OHCA patients likely to benefit from intervention while reserving resources.