Mortality in Patients With Out-of-Hospital Cardiac Arrest Undergoing a Standardized Protocol Including Therapeutic Hypothermia and Routine Coronary Angiography: Experience From the HACORE Registry

Abstract

Objectives: This study sought to analyze the impact of mandatory therapeutic hypothermia and cardiac catheterization in the absence of overt noncardiac cause of arrest as part of the Hannover Cardiac Resuscitation Algorithm before intensive care admission.

Background: Despite advanced therapies, out-of-hospital cardiac arrest (OHCA) is still associated with high mortality rates. Recently, the TTM (Target Temperature Management 33°C Versus 36°C After Out-of-Hospital Cardiac Arrest)-trial caused severe uncertainty about the efficacy of and need for therapeutic hypothermia. Furthermore, the role of early coronary angiography in OHCA survivors without ST-segment elevation remains undetermined.

Methods: In the HACORE (HAnnover Cooling REgistry) we investigated 233 consecutive patients (median age 64 [interquartile range: 53 to 74] years) with OHCA admitted to our institution between January 2011 and December 2015 who were treated according to the algorithm.

Results: A total of 73% had ventricular fibrillation as primary rhythm. Return of spontaneous circulation was achieved after 20 (interquartile range: 10 to 30) min. Immediate percutaneous coronary angiography was performed in 96% and coronary angioplasty in 59% of all cases. ST-segment elevation was present in 47%. Critical coronary stenosis requiring percutaneous coronary intervention was present in 67% of patients with and 52% of patients without ST-segment elevation. Overall 30-day intrahospital mortality in this real-world registry was 37%. Patients in our local registry who matched the inclusion/exclusion criteria of the TTM-trial (n = 145) had a markedly lower 30-day mortality (27%) compared with the published trial (44%).

Conclusions: Standardized treatment of patients with OHCA following a strict protocol incorporating computed tomography, cardiac catheterization and revascularization, liberal use of active hemodynamic support in presence of shock, and mandatory therapeutic hypothermia results in mortality rates lower than previously reported.

Keywords: cardiac arrest; cardiopulmonary resuscitation; coronary angiography; targeted temperature management; therapeutic hypothermia.