Cardiac arrest in acute ischemic stroke: incidence, predisposing factors, and clinical outcomes

Background — Cardiac arrest is a devastating complication of acute ischemic stroke, but little is known about its incidence and characteristics. We studied a large ischemic stroke inpatient population and compared patients with and without cardiac arrest.

Methods — We studied consecutive patients from the Ontario Stroke Registry who had an ischemic stroke between July 2003 and June 2008 at 11 tertiary care stroke centers in Ontario. Multivariable analyses were used to determine independent predictors of cardiac arrest and associated outcomes. Adjusted survival curves were computed, and hazard ratios for mortality at 30 days and 1 year were determined for cardiac arrest and other major outcomes.

Results — Among the 9019 patients with acute ischemic stroke, 352 had cardiac arrest, for an overall incidence of 3.9%. In a sensitivity analysis with palliative patients removed, the incidence of cardiac arrest was 2.5%. Independent predictors of cardiac arrest were as follows: older age, greater stroke severity, preadmission dependence, and a history of diabetes, myocardial infarction, congestive heart failure, and atrial fibrillation. Systemic complications associated with cardiac arrest were as follows: myocardial infarction, pulmonary embolism, sepsis, gastrointestinal hemorrhage, and pneumonia. Patients with cardiac arrest had higher disability at discharge, and a markedly increased 30-day mortality of 82.1% compared with 9.3% without cardiac arrest.

Conclusions — Cardiac arrest had a high incidence and was associated with poor outcomes after ischemic stroke, including multiple medical complications and very high mortality. Predictors of cardiac arrest identified in this study could help risk stratify ischemic stroke patients for cardiac investigations and prolonged cardiac monitoring.