QRS fragmentation and long-term cardiovascular outcomes and mortality: a population-based cohort study.

Fragmented QRS (fQRS) on electrocardiography (ECG) has been identified as a possible marker of myocardial conduction abnormalities and adverse cardiovascular events. In this cohort study, we investigated the presence of fQRS and its association with the incidence of cardiovascular diseases (CVDs) and CVD-related mortality in participants of the Mashhad Stroke and Heart Atherosclerotic Disorder (MASHAD) study. A total of 8,834 individuals with interpretable baseline ECGs and without confirmed CVD were included and classified into the fQRS group (n = 146, 1.7%) and the non‑fQRS group (n = 8,688, 98.3%). During a 10‑year follow‑up period, CVD developed in 18 (12.3%) individuals in the fQRS group and 924 (10.7%) in the non‑fQRS group. CVD‑related mortality occurred in 6 (4.1%) individuals with fQRS and 149 (1.7%) individuals without fQRS. Unadjusted and partially adjusted Cox regression analyses demonstrated an association between the presence of fQRS and increased risk of CVD mortality (HR: 2.533, 95% CI: 1.120-5.730, p = 0.026) and coronary artery disease (CAD) mortality (HR: 2.852, 95% CI: 1.164-6.990, p = 0.022). However, this association was attenuated after adjustment for all baseline variables. Kaplan-Meier survival analysis demonstrated lower survival probability among individuals with fQRS. These findings suggest that the presence of fQRS may be associated with increased cardiovascular mortality, particularly in patients who develop CAD, although its independent predictive value requires further investigation.