Underweight predicts poststroke cardiovascular events in patients without atrial fibrillation

The purpose of this study was to determine whether underweight is associated with poststroke cardiovascular events and whether such association is different according to the presence of atrial fibrillation (AF).

Patients with acute stroke or transient ischemic attack who were prospectively registered in a multicenter stroke database from April 2008 to July 2020 were analyzed, excluding those aged 75 or older and those who were overweight. We prospectively captured major adverse cardiovascular events (MACE) within one year after stroke. Cox-proportional hazard regression analysis was conducted for each subgroup with or without AF after adjusting for predetermined vascular risk factors and potential confounders.

Among 30,912 patients, 1494 (4.8%) cases were underweight and 29,418 (95.2%) cases were normal weight. The cumulative event rate of 1-year MACE was higher in the underweight group (9.0%) than in the normal weight group (5.6%). In Cox-proportional regression, underweight was associated with significantly higher MACE (adjusted hazard ratio [HR]: 1.62, 95% confidence interval [CI]: 1.26-2.09) and recurrent stroke (adjusted HR: 1.42, 95% CI: 1.02-1.98) in all study patients. In patients with AF, the risk of MACE for the underweight group was not significantly increased. In contrast, in patients without AF, the underweight group had a consistently higher risk of MACE (adjusted HR: 1.66, 95% CI: 1.25-2.22) and recurrent stroke (adjusted HR: 1.50, 95% CI: 1.05-2.14).

Underweight increased the risk of MACE and recurrent stroke within one year after acute stroke, especially in stroke without AF.