Recuperated out-of-hospital cardiac arrest (rOHCA) population is wide and heterogenous. Few studies focused specifically on outcomes in the rOHCA subgroup with proven significant coronary artery disease (SigCAD). Furthermore, the neutrophil-to-lymphocyte ratio (NLR), a marker of inflammation, is associated with prognosis in acute coronary syndromes but no data exists in patients with SigCAD presenting after rOHCA.
Our aim was to assess the prognostic significance of NLR ratio in this specific subgroup of patients.
Retrospective observational study of rOHCA patients submitted to coronary angiography. SigCAD was defined as >70% stenosis in major vessels or >50% in left main or performance of percutaneous coronary intervention (PCI). The finding of SigCAD was used to establish a coronary cause for OHCA and only those patients were included for further analysis.
Logistic regression and receiver operator curves (ROC) models were used for statistical analysis.
63 patients were included with a median age of 63 years old and 84% were male. In-hospital mortality was 36%. In coronary angiography, 90% had at least 1 suboclusive lesion and 73% had a recent total occlusion; 72% underwent PCI. The median NLR at 24h was 8 (interquartile range: 6.5). Patients with higher NLR were older (57±11yo vs 65±13, p= 0.02), more likely to be non-smokers (74% vs 47%, p=0.04) and to have a higher GRACE score at 24h (151±35 vs 172±31, p= 0.04). No statistically significant difference were found between groups regarding to other clinical characteristics, initial arrest rhythm, EKG changes, initial lactate and troponin values and extent of CAD.
At admission, a pH<7.2 (63% vs 34%, p=0.04) and a non-shockable rhythm (75% vs 34%, p=0.02) were associated with mortality. At 24 hours, only a lactate value >1.7mmol/L (33% vs 66%, p= 0.03) and NLR>8 (13% vs 55% p<0.01) significantly predicted death.
In multivariate analysis including all aforementioned significant predictors, only a 24h NLR>8 remained an independent predictor of in-hospital mortality (p=0.01) increasing the of death risk by 12 fold.
In ROC analysis, a 24h NLR>8 demonstrated a moderate discriminative performance (area under the curve: 0.7) to identify those patients who eventually died.
A 24h NLR>8 in rOHCA patients with SigCAD is significantly associated with in-hospital mortality, even after adjustment for other classical prognostic markers. Our findings suggest inflammation as a critical pathophysiological mechanism and NLR as a potentially novel prognostic marker for these patients.