Preoperative Thyroid Assessment in Pacemaker Recipients: Are We Falling Short?

Hypothyroidism is a reversible cause of bradyarrhythmias, including atrioventricular blocks and sinus node dysfunction. Guidelines recommend thyroid function assessment before pacemaker implantation. This study aims to evaluate the extent of preoperative assessment of thyroid dysfunction in pacemaker recipients. Data from a national database of consecutive transvenous pacemaker recipients (October 2004-October 2024) were analyzed. Initially, preoperative thyroid-stimulating hormone (TSH) was assessed at 12, 6, and 3 months before implantation. Subsequently, patients were classified according to their most recent thyroid profile. Among 45,683 eligible pacemaker recipients, thyroid-stimulating hormone (TSH) testing was performed in 37.1%, 52.7%, and 70.2% of patients within 3, 6 and 12 months before the procedure, respectively. The proportion of pacemaker recipients undergoing thyroid screening progressively increased over time, with screening rates rising in parallel with advancing age. After excluding individuals with missing free thyroxine data (n = 320), 31,774 patients were classified as euthyroid (84.3%), subclinical hypothyroid (12.2%), overt hypothyroid (0.7%), or subclinical hyperthyroid (2.7%). Patients with thyroid dysfunction were predominantly female, older, and exhibited a higher burden of comorbidities (all p < 0.001). In conclusion, significant gaps exist in the evaluation of thyroid function prior to pacemaker implantation, with a substantial proportion of recipients remaining suboptimally balanced. Further research is imperative to elucidate the association between thyroid status and the reversibility of conduction abnormalities.