Newly Diagnosed Atrial Fibrillation Indicators in Cryptogenic Stroke Survivors' P-Wave Indices: A Systematic Review and Meta-Analysis.

Background: Atrial fibrillation (AF) is the most common arrhythmia and a major cause of ischemic stroke recurrence. Cryptogenic stroke (CS) survivors face a higher risk for newly diagnosed AF (NDAF), with subtle ECG markers-prolonged P-wave duration (PWDur) and increased P-wave dispersion (PWDis)-potentially serving as early indicators. We aimed to quantify baseline PWDur and PWDis differences between CS survivors with NDAF and those in sinus rhythm. Methods: Following PRISMA guidelines, we systematically searched nine databases through January 2025 for observational studies assessing baseline P-wave indices in adult CS patients in sinus rhythm. Data extraction and risk of bias assessment using the ROBINS-E tool were performed independently. Pooled mean differences (MD) with 95% confidence intervals (CI) were calculated using a random-effects inverse-variance model. Subgroup/sensitivity analyses were conducted by age groups, male proportion, region, follow-up duration, percentage of comorbidities, AF definition and detection methods, and ECG parameter. Heterogeneity was assessed using Cochran's Results: Ten studies, encompassing 1508 patients (mean age 66.72 ± 13.74 years; 55.7% male), met the inclusion criteria. Baseline PWDur was longer in the NDAF (MD 6.36 ms, 95% CI: 0.69-12.03, Conclusion: Prolonged baseline PWDur may serve as a non-invasive marker of atrial conduction abnormalities and a predictor of AF in CS survivors. Larger prospective studies are needed to validate its role in risk stratification and secondary stroke prevention. Trial Registration: PROSPERO: CRD42025646135.