Albumin Levels and Risk of Early Cardiovascular Complications After Ischemic Stroke: A Propensity-Matched Analysis of a Global Federated Health Network

Background: No studies have investigated the association between albumin levels and the risk of early cardiovascular complications in patients with ischemic stroke. Methods: Retrospective analysis with a federated research network (TriNetX) based on electronic medical records (International Classification of Diseases-Tenth Revision-Clinical Modification and logical observation identifiers names and codes) mainly reported between 2000 and 2023, from 80 health care organizations in the United States. Based on albumin levels measured at admission to the hospital, patients with ischemic stroke were categorized into 2 groups: (1) reduced (≤3.4 g/dL) and (2) normal (≥3.5 g/dL) albumin levels. The primary outcome was a composite of all-cause death, heart failure, atrial fibrillation, ventricular arrhythmias, myocardial infarction, and Takotsubo cardiomyopathy 30 days from the stroke. Secondary outcomes were the risk for each component of the primary outcome. Cox regression analyses were used to calculate hazard ratios (HRs) and 95% CIs following propensity score matching. Results: Overall, 320 111 patients with stroke had normal albumin levels (70.9±14.7 years; 48.9% females) and 183 729 (57.4%) had reduced albumin levels (72.9±14.3 years; 50.3% females). After propensity score matching, the primary outcomes occurred in 36.0% of patients with reduced and 26.1% with normal albumin levels (HR, 1.48 [95% CI, 1.46-1.50]). The higher risk in patients with reduced albumin levels was consistent also for all-cause death (HR, 2.77 [95% CI, 2.70-2.84]), heart failure (HR, 1.31 [95% CI, 1.29-1.34]), atrial fibrillation (HR, 1.11 [95% CI, 1.09-1.13]), ventricular arrhythmias (HR, 1.38 [95% CI, 1.30-1.46]), myocardial infarction (HR, 1.60 [95% CI, 1.54-1.65]), and Takotsubo cardiomyopathy (HR, 1.51 [95% CI, 1.26-1.82]). The association between albumin levels and the risk of cardiovascular events was independent of advanced age, sex, multimorbidity, and other causes of hypoalbuminemia. A progressively increased risk of adverse events was found in patients with mild and severe reduced compared to normal albumin levels. Conclusions: Albumin levels are associated with the risk of early cardiovascular events and death in patients with ischemic stroke. The potential pathophysiological or therapeutic roles of albumin in patients with stroke warrant further investigation.