The Association Between Right Ventricular Failure and Mortality after Out-of-hospital Cardiac Arrest

Right ventricular (RV) dysfunction is common as part of the post-cardiac arrest syndrome in resuscitated patients. Furthermore, RV failure following cardiac arrest has been associated with worse outcomes in retrospective studies, but prospective evidence is lacking. In our recently published sub-study of The Targeted Therapeutic Mild Hypercapnic After Resuscitated Cardiac Arrest (TAME) trial we found, contrary to the original hypothesis, that hypercapnic acidosis dit not increase pulmonary vascular resistance or decrease in RV function. In extension of this we wanted to assess if RV failure was associated with worse outcomes in our study-population. Investigate the association between death at 6 months and right ventricular failure during the initial stages of post-cardiac arrest care. Single center, pre-planned sub-study. Transthoracic echocardiography combined with time-matched invasive heamodynamic measurements during the initial 24 h after admission were used to assess RV function. RV failure was defined as echocardiographic objective evidence of right ventricular dysfunction, cardiac index ≤2.2 L/min/m2 and central venous pressure ≥ 15 mm Hg. Multivariate logistic regression was used to assess the association between RV failure and 6 month mortality. The covariates "Time to ROSC", "Age", "Initial rhythm", "Bystander CPR" and "Ischemic heart disease" were chosen from all relevant variables using the "glmulti" package in R which selects the best fitting model with the lowest Aikaike information criterion. 111 out 137 randomised patients had echocardiography performed and were elligible for this study. Overall, median age was 64, 80 % were male, median time to ROSC was 22 min, 47 % had ST-elevation myocardial infarction and approximately 90 % had a shockable initial rhythm and bystander CPR. Average time from admission to echocardiography was 19 h, and 50 (45 %) patients had signs of RV dysfunction, 30 (27 %) had RV failure, and isolated RV failure occured in only 3 patients. RV failure was associated with an increased 6 month mortality with an odd ratio (OR) of 4.2 (1.2 - 18.1), p = 0.039. RV failure was the only statistically significant haemodynamic parameter associated with death at 6 months in a multivariate analysis, and yielded a model AUC of 0.91 (95 % CI 0.84-0.97). Univariate analysis of other parameters of RV function found that increasing values of tricuspid annular plane excursion (TAPSE), RV fractional area change and stroke volumes were associated with increased probability of survival (p < 0.05), but were not statistically significant in multivariate analysis (p > 0.05). In patients resuscitated from OHCA, right ventricular failure during the initial 24 hours of intensive care was associated with increased mortality at 6 months. This adds valuable prospective data, but requires further validation and investigation in larger studies.Predictors of 6 month mortalityUnivariate logistic regression model