Myocardial Infarction Is Associated With Increased Stroke Severity, In-Hospital Mortality, and Complications: Insights From China Stroke Center Alliance Registries

Background Prior studies have shown an increased risk of ischemic stroke (IS) after myocardial infarction (MI); however, there are limited studies concerning the characteristics, in-hospital mortality, and complications of patients with IS with a medical history of MI. We hypothesized that patients with IS with a medical history of MI may experience more severe strokes and have a higher risk of in-hospital mortality and complications than patients with IS without a medical history of MI. Methods and Results Consecutive in-hospital data were extracted from the China Stroke Center Alliance database from August 2015 to July 2019. Patient characteristics, hospital tests, in-hospital mortality, and complications were analyzed and compared in patients with IS with or without a history of MI. Of 893 429 patients with IS, we identified 81 646 (9.1%) patients with a history of MI (MI group). Compared with patients with IS without MI, MI group patients were older, had a lower prevalence of current smoking, had a higher prevalence of a relative medical history, and took more medications before admission. Compared with the group with IS without MI, the MI group had a higher National Institute of Health Stroke Scale score after onset (4.0 versus 3.0; Hodges-Lehmann estimator, 22.5) and a higher proportion of severe strokes (National Institute of Health Stroke Scale score ≥15) (7.1% versus 4.4%; absolute standardized difference=11.6%). In the fully adjusted models, the risk of in-hospital mortality was higher in the MI group (odds ratio [OR], 1.74; 95% CI, 1.57-1.92; P<0.0001). MI group patients also had a higher risk of complications, including urinary tract infection (OR, 1.28; 95% CI, 1.2-1.36; P<0.0001), gastrointestinal bleeding (OR, 1.29; 95% CI, 1.19-1.39; P<0.0001), pneumonia (OR, 1.24; 95% CI, 1.21-1.28; P<0.0001), depression (OR, 1.33; 95% CI, 1.24-1.42; P<0.0001), seizure (OR, 1.35; 95% CI, 1.22-1.49; P<0.0001), atrial fibrillation (OR, 1.78; 95% CI, 1.71-1.86; P<0.0001), and cardiac or respiratory arrest (OR, 1.98; 95% CI, 1.78-2.2; P<0.0001). Conclusions Patients with IS with a medical history of MI have an increased risk of severe stroke, in-hospital mortality, and complications. Studies exploring the underlying mechanisms are needed to improve and tailor stroke treatment strategies.