Cardiac Arrest in Acute Ischemic Stroke: Incidence, Predisposing Factors, and Clinical Outcomes
Introduction
Cardiac arrest (CA) may occur unexpectedly after an acute ischemic stroke. Cardiac complications after stroke span a wide range and include acute myocardial infarction (MI), bradyarrhythmia and tachyarrhythmia, congestive heart failure (CHF), and CA. Patients with pre-existing cardiac disease have a higher rate of cardiac events post stroke.1 However, even among those patients without overt heart disease, 20%-40% can develop silent myocardial ischemia after stroke.2 Most bradyarrhythmias and tachyarrhythmias occur soon after stroke, with 74% of all arrhythmias detected within 24 hours of admission3; one fourth of these arrhythmias required urgent evaluation and treatment. Poststroke arrhythmias are hypothesized to result from abnormalities in autonomic control, causing release of catecholamines and dysregulated blood pressure and heart rate, particularly with insular lesions.4
Overall, 19% of ischemic stroke patients experience a serious adverse cardiac event,1 peaking between day 2 and day 3. In the first 1-2 weeks, cardiac death is the second most common cause of death of stroke after neurological causes,1, 5 with a maximal rate at day 14.1 At 4 years, 7% of stroke patients have died of a primary cardiac cause.6
Despite the importance of CA, there is no large study to date identifying the incidence, patient characteristics, risk factors, outcomes, and overall impact of CA after stroke. Therefore, we conducted a registry-based study using the Ontario Stroke Registry (OSR) to identify patients who had suffered from “cardiac or respiratory arrest” after admission for stroke.
The objectives of our study were as follows: (1) to determine the prevalence of CA in patients admitted to a tertiary care center after ischemic stroke; (2) to identify differences in baseline characteristics that may predispose to CA, and compare factors and outcomes associated with CA in patients admitted with ischemic stroke; and (3) to compare mortality between ischemic stroke patients with and without CA.
Section snippets
Methods
We conducted a retrospective observational study using the OSR, a clinical database including patients who have experienced an acute stroke and admitted to the participating institutions. Participants were included in the study if they were admitted to any of 11 regional stroke centers in the province of Ontario, Canada, with first acute ischemic stroke between July 2003 and June 2008. The OSR was previously known as the Registry of the Canadian Stroke Network; further details can be obtained
Results
Overall, there were 9378 patients with an acute ischemic stroke that fulfilled our inclusion criteria. After excluding patients with missing data of stroke severity, glucose on admission, and mRS at discharge (n = 359), 9019 patients had complete data and were included in our study. Among those 9019 patients with an acute ischemic stroke, 352 (3.9%) had CA.
Patients with CA were older than those without CA (mean age 77.3 versus 72.0; P < .0001, and age more than 80 years 50.9% versus 34.2%; P
Discussion
CA can be an unexpected and devastating outcome for stroke patients and their families. In the present study, we shed light on the impact of CA after an acute ischemic stroke using a large registry-based cohort of 9019 ischemic stroke patients. We showed that CA may affect up to 4% of patients admitted with an acute ischemic stroke. In a sensitivity analysis with palliative patients removed, the incidence was reduced to 2.5%. In a subcohort of patients without cardiovascular risk factors, the
Summary
In conclusion, our study shows that between 2.5 and 4 out of 100 patients with an acute ischemic stroke may develop CA in the hospital. Pre-existing cardiovascular disease, older age, and greater stroke severity are the most common predisposing factors. Our study argues for prolonged cardiac monitoring post stroke, in particular when patients have additional risk factors. Our data also encourage frank discussions with the patient and families regarding the potential risk of CA and extremely
Acknowledgments
The Ontario Stroke Registry (OSR) is funded by the Canadian Stroke Network (CSN) and the Ontario Ministry of Health and Long-Term Care (MOHLTC). The Institute for Clinical Evaluative Sciences (ICES) is supported by an operating grant from the Ontario MOHLTC. The opinions, results, and conclusions are those of the authors and should not be attributed to any supporting or sponsoring agencies. No endorsement by the CSN, ICES, or the Ontario MOHLTC is intended or should be inferred.
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Cited by (0)
Funding: Dr. Gustavo Saposnik is supported by the Distinguished Clinician Scientist Award from Heart and Stroke Foundation of Canada. Dr. Jack Tu holds a Tier 1 Canada Research Chair in Health Services Research.