Background Limited data exist on new-onset atrial fibrillation (NOAF) risk factors in Asian populations with hypertension (HTN). This study identified predictors of NOAF in Thai adults with HTN.

Methods We conducted a retrospective cohort study of adults (≥18 years) newly diagnosed with HTN at Ramathibodi Hospital, Bangkok (2010–2023). Patients with prior atrial fibrillation or predisposing conditions (e.g., valvular heart disease, hyperthyroidism) were excluded. Baseline demographics, comorbidities, and medication use were analyzed as time-varying covariates using a multivariate Cox proportional hazards model.

Results Of 293,798 HTN patients, 168,441 met inclusion criteria. Over a median 3.7-year follow-up (range: 2.2–8.0), 5,028 developed NOAF (incidence: 5.7 per 1,000 person-years). An age–body mass index (BMI) interaction was observed. In patients <60 years, low BMI increased NOAF risk [hazard ratio (HR) 2.3; 95% CI: 1.4–3.6], while overweight [HR 1.1; 0.8–1.4] and obesity [HR 0.8; 0.6–1.1] showed no significant effect. In patients ≥60 years, NOAF risk rose 2- to 4-fold across BMI categories. Male sex and comorbidities (vascular disease, stroke, heart failure, chronic kidney disease, hyperuricemia) increased risk by 1.2–1.8-fold. Statin use reduced risk [HR 0.8; 0.7–0.9]; sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists showed a non-significant protective trend [HR 0.8; 0.7–1.1].

Conclusions Older age, male sex, abnormal BMI, and the presence of comorbidities are significant risk factors for NOAF in Thai patients with HTN. In contrast, statin use may offer a protective effect.

The authors have declared no competing interest.

This is a retrospective cohort study and not a clinical trial or prospective interventional study; therefore, trial registration was not required per ICMJE guidelines.

This work was supported by the National Research Council of Thailand (grant number N42A640323). No additional payments or services were received from third parties for any aspect of the submitted work, including study design, data collection, analysis, or manuscript preparation."

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethics Committee of Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; Approval Number: COA. MURA 2024/681

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Data are not publicly available due to sensitivity but can be requested from the corresponding author, Thinnakrit Sasiprapha (Division of Cardiology, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama VI Road, Ratchathewi, Bangkok, Thailand 10400; email: [insert email]). Data are stored at the CEB Data Warehouse, Ramathibodi Hospital