Atrial Cardiopathy independently predicts recurrent ischemic stroke and TIA in ESUS patients

Patients experiencing Embolic Stroke of Undetermined Source (ESUS) pose a clinical challenge, as the underlying cause, often paroxysmal atrial fibrillation (AF), frequently remains undetected. This diagnostic gap prevents targeted secondary prevention, leaving patients vulnerable to recurrent events. Current standard-of-care for ESUS typically involves antiplatelet therapy, but the benefit of anticoagulation, particularly for those with occult AF, is unclear. Identifying reliable biomarkers for atrial cardiomyopathy (AC), a precursor to AF and a marker of atrial remodeling, could improve risk stratification and guide more effective treatment strategies in this high-risk population.

Researchers prospectively enrolled 345 patients diagnosed with ESUS who were hospitalized within 7 days of stroke onset between January 2019 and December 2021. Atrial Cardiopathy (AC) was defined by the presence of any one of three criteria: an N-terminal pro-B-type natriuretic peptide level >250 pg/ml, a P-wave terminal force in lead V1 >5000 µV·ms, or an enlarged left atrial diameter. The primary endpoint was ischemic stroke/transient ischemic attack (TIA) recurrence, evaluated using Fine-Gray sub-distribution hazard models with death as a competing event. Cox proportional hazards models were used for supportive analyses and all-cause mortality.

Among the 345 ESUS patients (mean age 59.22±13.19 years; 69.0% men), 42.0% met the criteria for Atrial Cardiopathy (AC). During a median follow-up of 18.1 months, 36 patients experienced ischemic stroke, 2 had TIA, and 18 died. AC was strongly associated with ischemic stroke/TIA recurrence in competing risk analyses.

Atrial Cardiopathy was independently associated with a 3.36-fold increased risk of ischemic stroke/TIA recurrence (adjusted subdistribution hazard ratio [aSHR] 3.36, 95% CI 1.65-6.86; P<0.001). For all-cause mortality, AC was associated with a higher risk after adjusting for age and sex (adjusted hazard ratio 3.80, 95% CI 1.19-12.08; P = 0.024). Adding AC to conventional risk models significantly improved risk prediction, showing a Net Reclassification Improvement (NRI) of 72.45% (P<0.001) for ischemic stroke/TIA and 66.16% (P = 0.002) for mortality. The Integrated Discrimination Improvement (IDI) also improved by 4.52% (P<0.001) for stroke/TIA and 3.89% (P = 0.041) for mortality.