https://doi.org/10.1007/s00392-025-02625-4
1Evangelisches Krankenhaus Düsseldorf Klinik für Kardiologie Düsseldorf, Deutschland; 2Stiftung Institut für Herzinfarktforschung Ludwigshafen am Rhein, Deutschland; 3IHF GmbH Ludwigshafen am Rhein, Deutschland; 4IHF GmbH Statistik Ludwigshafen am Rhein, Deutschland; 5Universitätsklinikum Schleswig-Holstein Klinik für Rhythmologie Lübeck, Deutschland; 6Medical School / Regiomed GmbH Coburg, Deutschland; 7Internistisches Klinikum München Süd Klinik für Kardiologie München, Deutschland; 8Universitätsklinikum Münster Klinik für Kardiologie II - Rhythmologie Münster, Deutschland
Background:
Hypothyroidism is a relevant comorbidity with a prevalence of up to 10% in Western populations and may increase atrial fibrillation (AF) risk. Limited data exist on its impact on AF ablation outcomes, particularly compared to euthyroid patients in terms of cardiovascular comorbidities, in-hospital management, and acute outcomes.
Objective:
To analyze characteristics, ablation management, and in-hospital outcomes of hypothyroid patients in a large contemporary cohort undergoing AF ablation.
Methods:
Patients enrolled in the VARY registry from seven German centers undergoing AF catheter ablation between 2019 and 2023 were investigated. Patient datasets were collected by the German Institute for Heart Attack Research (IHF) from hospitals using ICD-10 diagnoses (ICD-10-GM) and in-hospital operation and procedure codes. Patients with hypothyroidism (treated, subclinical or manifest) were compared to patients with hyperthyroidism or euthyroidism.
Results:
Among 17,469 patients, 2,109 (12.1%) displayed the diagnosis hypothyroidism. These patietns were older (median 68 vs. 67 [hyperthyroid] vs. 65 [euthyroid], p<0.01) and more frequently female (64.6% vs. 42.4% vs. 33.0%, p<0.01). Patients with hypothyroidism presented more often with cardiovascular comorbidities, including dyslipidemia (34.4% vs. 28.8% vs. 27.1%, p<0.01), hypertension (74.5% vs. 73.3% vs. 65.1%, p<0.01), diabetes (11.1% vs. 9.1% vs. 9.8%, p<0.01), and heart failure (26.7% vs. 35.0% vs. 23.5%, p<0.01).
Paroxysmal and persistent AF distribution was similar between patients with hypo- and euthyroidism, while showing less frequent persistent AF than in patients with hyperthyroidism (Figure A, p<0.01). Typical atrial flutter was more common in hypothyroid patients (11.4% vs. 8.6% vs. 9.5%, p<0.01), while atypical flutter prevalence was similar. Hypothyroid patients underwent more radiofrequency ablation (49.6% vs. 49.4% vs. 44.0%, p<0.01) and 3-D mapping (33.9% vs. 36.2% vs. 30.3%, p<0.01) than euthyroid patients; cryoablation was less frequent (47.6% vs. 44.4% vs. 51.9%, p<0.01). Intensive care unit transfer was more frequent in patients with hypothyroidism (Figure B: 3.7% vs. 1.6% vs. 2.4%, p<0.01; median duration 0.8 vs. 0.6 vs. 0.8 days, p=0.92), and hospital stays were longer (3.8±5.2 vs. 3.2±4.1 vs. 3.1±4.2 days, p<0.01). Further acute in-hospital events such as pacemaker implantation (0.6% vs. 1.2% vs. 0.5%, p=0.31), mechanical ventilation (0.6% vs. 0.0% vs. 0.4%, p=0.36), or mortality (0.0% vs. 0.0% vs. 0.06%, p=0.50), were similar across groups.
Conclusion:
Hypothyroidism is common among patients undergoing AF ablation. It conveys clinically relevant implications possibly due to a higher cardiovascular comorbidity burden which may impact the timing, ablation setup and course of in-hospital stay. Whether periprocedural achievement of an euthyroid state might improve patient outcomes needs to be determined.