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

Increased energy expenditure by a seabird in response to higher food abundance

Variability in forage fish abundance strongly affects seabird behavior and reproductive success, although details of this relationship are unclear. During 1997 and 1998, we measured (1) daily energy expenditure (DEE) of 80 parent black-legged kittiwakes Rissa tridactyla at 2 colonies in Prince William Sound, Alaska (North Icy Bay and Shoup Bay), (2) abundance of surface-schooling forage fishes within the foraging range of each colony, and (3) diet composition, energy delivery rates to nestlings, and reproductive success of kittiwakes at these same colonies. Female DEE was highest at North Icy Bay in 1998, while male DEE did not differ by colony year. Abundances of Pacific herring Clupea pallasi and sand lance Ammodytes hexapterus were highest near North Icy Bay in 1998 and nearly equal in density, although Age 1+ herring comprised the majority of the diet there. Energy delivery rates to nestlings, nestling growth rates, and productivity were also highest at North Icy Bay in 1998. We suggest that female kittiwakes responded to the increased abundance of Age 1+ herring near North Icy Bay in 1998 by increasing their DEE, which in turn positively affected reproductive success. Given that adult kittiwakes have been shown to suffer decreased survival as a response to increased energy expenditure during brood rearing, the positive correlation we observed between increased abundance of a high quality food source, parental effort, and productivity is consistent with maximizing lifetime reproductive success. The lack of a response in male DEE suggests that brood-rearing roles in kittiwakes differ between genders

A definition for the covalent and ionic bond index in a molecule

Formulae for hermitian operators representing covalent, ionic, and total bond indices are derived. The eigenstates of these operators come in pairs, and can be considered as bonding, anti-bonding and lone-pair orbitals. The form of these operators is derived by generalising the rule that the bond order be defined as the net number of bonding electron pairs. The percentage of covalency and ionicity of a chemical bond may be obtained, and bond indices can also be defined between groups of atoms. The calculation of the bond indices depends only on the electron density operator, and certain projection operators used to represent each atom in the molecule. Bond indices are presented for a series of first and second row hydrides and fluorides, hydrocarbons, a metal complex, a Diels–Alder reaction and a dissociative reaction. In general the agreement between the bond indices is in accord with chemical intuition. The bond indices are shown to be stable to basis set expansion