Atrial cardiomyopathy in the electrocardiogram: the prognostic value of p-wave abnormalities in a primary care population

Introduction Atrial cardiomyopathy (AC) is a pathology encompassing structural and functional changes in the atrial endomyocardium and is linked to cardiovascular risk factors. The existing gap in the etiological evidence for various ischemic phenomena, especially ischemic stroke (IS), has opened space for the study of AC as a potential cardioembolic source, regardless of the presence of atrial fibrillation (AF) or other established high-risk cardiac factors for thrombogenesis. Atrial abnormalities can be detected by graphical methods, such as the 12-lead electrocardiogram (ECG), a widely available exam in primary care centers. Objectives We aim to evaluate the association between two electrocardiographic changes related to AC, an increase in P-wave duration > 120 ms and terminal P-wave force in V1 (PTFV1) > 4,000 µv × ms, with the occurrence of ischemic stroke, overall mortality, cardiovascular death, incident AF or acute coronary syndrome. Methodology: This is a retrospective cohort from the CODE-BH database, a subset of ECGs extracted from the Telehealth Network of Minas Gerais between 2006 and 2018. Patients aged 40 years and older, in sinus rhythm, and without a history of previous stroke were included. Each ECG presented the clinical data of the patients, along with automatic measurements of P-wave duration and PTFV1 generated by the Glasgow 12-lead ECG analysis program. The CODE-BH database was linked to the public health information system. Cox proportional hazards regression method was used. Results The CODE-BH database included 245,588 patients (mean age: 59.5 years;36.5% male sex). 38% were hypertensive, 26.5% had a P-wave duration > 120 ms and 10.1% had a PTFV1 > 4,000 µv × ms. The mean follow up was 3.5 years. An association was found between the exposures and the primary outcome (death or hospitalization secondary to ischemic stroke), with a hazard ratio (HR) of 1.24 (95% CI; 1.12 - 1.36) for P-wave duration > 120 ms and 1.20 (95% CI; 1.05 - 1.38) for PTFV1 > 4,000 µv × ms. There was also an association with cardiovascular death and incident AF for P-wave duration > 120 ms, with HRs of 1.11 (95% CI; 1.01 – 1.23) and 1.34 (95% CI; 1.06 – 1.68), respectively. For increased PTFV1 > 4,000 µv × ms, an adjusted association was also found with overall mortality and cardiovascular death, with HRs of 1.11 (95% CI; 1.05 – 1.17) and 1.25 (95% CI; 1.09 – 1.43), respectively. Conclusion Atrial cardiomyopathy in the ECG was associated with higher risk of ischemic stroke, incident AF, overall mortality, and cardiovascular mortality in a primary care population.