Risk Stratification Among Survivors of Cardiac Arrest Considered for Coronary Angiography

Abstract

Background: The American College of Cardiology Interventional Council published consensus-based recommendations to help identify resuscitated cardiac arrest patients with unfavorable clinical features in whom invasive procedures are unlikely to improve survival.

Objectives: This study sought to identify how many unfavorable features are required before prognosis is significantly worsened and which features are most impactful in predicting prognosis.

Methods: Using the INTCAR (International Cardiac Arrest Registry), the impact of each proposed "unfavorable feature" on survival to hospital discharge was individually analyzed. Logistic regression was performed to assess the association of such unfavorable features with poor outcomes.

Results: Seven unfavorable features (of 10 total) were captured in 2,508 patients successfully resuscitated after cardiac arrest (ongoing cardiopulmonary resuscitation and noncardiac etiology were exclusion criteria in our registry). Chronic kidney disease was used in lieu of end-stage renal disease. In total, 39% survived to hospital discharge. The odds ratio (OR) of survival to hospital discharge for each unfavorable feature was as follows: age >85 years OR: 0.30 (95% CI: 0.15 to 0.61), time-to-ROSC >30 min OR: 0.30 (95% CI: 0.23 to 0.39), nonshockable rhythm OR: 0.39 (95% CI: 0.29 to 0.54), no bystander cardiopulmonary resuscitation OR: 0.49 (95% CI: 0.38 to 0.64), lactate >7 mmol/l OR: 0.50 (95% CI: 0.40 to 0.63), unwitnessed arrest OR: 0.58 (95% CI: 0.44 to 0.78), pH <7.2 OR: 0.78 (95% CI: 0.63 to 0.98), and chronic kidney disease OR: 0.96 (95% CI: 0.70 to 1.33). The presence of any 3 or more unfavorable features predicted <40% survival. Presence of the 3 strongest risk factors (age >85 years, time-to-ROSC >30 min, and non-ventricular tachycardia/ventricular fibrillation) together or ≥6 unfavorable features predicted a ≤10% chance of survival to discharge.

Conclusions: Patients successfully resuscitated from cardiac arrest with 6 or more unfavorable features have a poor long-term prognosis. Delaying or even forgoing invasive procedures in such patients is reasonable.

Keywords: cardiac arrest; coronary angiography; risk stratification.