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.