Purpose: To study the impact of chronic prearrest health conditions on mortality and neurological recovery in patients after witnessed cardiac arrest and primary successful resuscitation.
Patients and methods: The study was set in the community of Vienna, Austria. Data concerning cardiopulmonary resuscitation of adult patients who survived a witnessed cardiac arrest were collected according to an internationally recommended protocol (Utstein-Style). Chronic prearrest health conditions and New York Heart Association (NYHA) functional classes were evaluated. All patients were followed up for 6 months after the event or death. Adverse outcome was defined as death or severe neurological impairment. A forward stepwise logistic regression model was applied to assess the impact of pre-arrest morbidity on unfavorable outcome, expressed as odds ratio (OR) with 95% confidence intervals (CI).
Results: Of 411 patients, 269 (66%) had one or more of the following pre-arrest diseases: coronary heart disease (45%), hypertension (26%), congestive heart failure (20%), diabetes mellitus (14%), chronic pulmonary disease (6%), and cerebrovascular disease (5%). In 22% a NYHA class of III or IV was present before cardiac arrest. At 6-month follow-up, 161 (40%) of the patients were alive with favorable neurological recovery; overall mortality was 57% (n = 233). Increasing NYHA classes (OR 1.4 per NYHA class increase; CI 1.1 to 1.7) and increasing age were independent predictors of adverse outcome (OR 1.03 per 10-year increase; CI 1.01 to 1.05), as were durations of cardiac arrest (OR 1.10 per 5-minute increase; CI 1.07 to 1.12) and the presence of ventricular fibrillation or tachycardia (OR 0.3; CI 0.2 to 0.5). The remaining health conditions, as listed above, were not independently associated with outcome.
Conclusions: A large proportion of patients with cardiac arrest had chronic diseases before the event. The presence of impaired functional performance in patients with structural heart disease increased unfavorable outcome within 6 months in primary cardiac arrest survivors. However, the impact of chronic prearrest conditions on outcome seems to be very small, and should not influence decisions whether to withhold or withdraw therapy.