Sex differences in atrial fibrillation in India: Insights from the Kerala-AF registry

Background: Much data informing sex differences in atrial fibrillation (AF) comes from Western cohorts. In this analysis, we describe sex differences in Kerala, India, using the Kerala-AF registry—the largest AF registry from the Indian subcontinent. Methods: Patients aged ≥18 years were recruited from 53 hospitals across Kerala. Patients were compared for demographics, treatments, and 12-month outcomes, including major adverse cardiovascular events (MACE) and bleeding. Results: Male patients were more likely to have a smoking and/or alcohol history and had more ischaemic heart disease (46.2% vs. 25.5%; p < 0.001). Female patients had more valvular AF (35.1% vs. 18.0%; p < 0.001), and more use of calcium-channel blockers (23.3% vs. 16.5%; p < 0.001) or digoxin (39.6% vs. 28.5%; p < 0.001). Almost one in four patients were not anticoagulated despite raised CHA2DS2-VASc scores. 12-month MACE outcomes did not differ by sex (male: 30.2% vs. female: 29.4%; p = 0.685), though bleeding events were more common in male patients (2.4% vs. 1.3%; p = −0.038), driven by minor bleeding (1.2% vs. 0.5%). Conclusion: In this large AF cohort from India, male patients had a higher prevalence of ischaemic heart disease, smoking, and alcohol use, while female patients had a higher prevalence of valvular heart disease. MACE did not differ by sex, though bleeding was more common in males. Almost a quarter of patients were not anticoagulated despite raised thromboembolic risk

Phenotypes of South Asian patients with atrial fibrillation and holistic integrated care management: cluster analysis of data from KERALA-AF Registry

Background: Patients with atrial fibrillation (AF) frequently experience multimorbidity. Cluster analysis, a machine learning method for classifying patients with similar phenotypes, has not yet been used in South Asian AF patients. Methods: The Kerala Atrial Fibrillation Registry is a prospective multicentre cohort study in Kerala, India, and the largest prospective AF registry in South Asia. Hierarchical clustering was used to identify different phenotypic clusters. Outcomes were all-cause mortality, major adverse cardiovascular events (MACE), and composite bleeding events within one-year follow-up. Findings: 3348 patients were included (median age 65.0 [56.0–74.0] years; 48.8% male; median CHA2DS2-VASc 3.0 [2.0–4.0]). Five clusters were identified. Cluster 1: patients aged ≤65 years with rheumatic conditions; Cluster 2: patients aged >65 years with multi-comorbidities, suggestive of cardiovascular-kidney-metabolic syndrome; Cluster 3: patients aged ≤65 years with fewer comorbidities; Cluster 4: heart failure patients with multiple comorbidities; Cluster 5: male patients with lifestyle-related risk factors. Cluster 1, 2 and 4 had significantly higher MACE risk compared to Cluster 3 (Cluster 1: OR 1.36, 95% CI 1.08–1.71; Cluster 2: OR 1.79, 95% CI 1.42–2.25; Cluster 4: OR 1.76, 95% CI 1.31–2.36). The results for other outcomes were similar. Atrial fibrillation Better Care (ABC) pathway in the whole cohort was low (10.1%), especially in Cluster 4 (1.9%). Overall adherence to the ABC pathway was associated with reduced all-cause mortality (OR 0.26, 95% CI 0.15–0.46) and MACE (OR 0.45, 95% CI 0.31–0.46), similar trends were evident in different clusters. Interpretation: Cluster analysis identified distinct phenotypes with implications for outcomes. There was poor ABC pathway adherence overall, but adherence to such integrated care was associated with improved outcomes. Funding: Kerala Chapter of Cardiological Society of India