This multicenter, randomized, open-label, blinded-endpoint trial evaluates whether weekly subcutaneous tirzepatide for 12 months reduces atrial fibrillation (AF) recurrence after catheter ablation in adults with obesity and heart failure with preserved ejection fraction (HFpEF). HFpEF is diagnosed by direct intraprocedural measurement of mean left atrial pressure (mLAP ≥ 15 mmHg at rest) during the ablation procedure, providing a hemodynamically anchored, homogeneous study population free from the diagnostic ambiguities of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and E/e' in AF patients. Approximately 602 participants will be randomized 1:1 to tirzepatide (titrated to a target of 10 mg/week, maximum 15 mg/week) plus standard care, or standard care alone. Both groups receive an identical structured lifestyle intervention. The primary endpoint is the first documented AF/atrial flutter/atrial tachycardia episode lasting ≥ 30 seconds, occurring between day 91 and day 365 after ablation, adjudicated by an independent blinded clinical endpoint committee.