Abstract 15995: Etiology and Outcomes Associated With Endothelial Dysfunction in Post Cardiac Arrest Patients

Abstract

Background: Endothelial dysfunction (ED) may occur after cardiac arrest (CA) both due to the underlying patient comorbidities which result in CA and the global ischemia-reperfusion which results. The prevalence of ED after CA is poorly characterized as is any association with outcomes. Hypothesis: ED will be more common in asphyxial arrests, after prolonged CPR times and in subjects with multiple coronary artery risk factors. ED will associate with worsened outcomes. Methods: Prospective, observational study of 23 CA with return of spontaneous circulation (ROSC) expected to live >48 h. ED was assessed at 0-6 hours and at 36-48 hours after ROSC using measurements of plasma nitrite (n=14) or laser speckle contrast imaging (LSCI) (n=13) before and after 6 min vaso-occlusion (VO) of forearm blood flow. VO was achieved using a blood pressure cuff inflated at 200 mm Hg. LSCI quantified blood flow at baseline (pre-VO), during ischemia (trough), upon reperfusion (hyperemia peak) and 5 min later (nadir). LSCI values were all normalized to pre-VO baseline. Plasma nitrite was measured before after VO. Plasma nitrite was quantified by reductive chemiluminescence. ED is known to result in lower plasma nitrite and reduced post-VO hyperemia and nadir. Data was gathered on patient comorbidities, CA characteristics and outcomes and means compared by Mann Whitney U for dichotomous variables and Spearman correlation for continuous variables. Results: Lower ischemic trough and reperfusion nadir were associated with unfavorable features and outcomes ( Table ). No patient factors were associated ED. LSCI nadir at 0-6 hrs correlated with CPR duration (r = -0.7, p =0.01) and trough correlated with number of CPR epinephrine doses (r= -0.7, p = 0.01). Plasma nitrite levels were similar in all comparisons. Conclusions: LSCI features characteristic of ED were more often noted with prolonged and asphyxial, non-VF CA rather than patient factors and were associated with worsened outcome.