Increased parathyroid hormone concentration as a biomarker of atrial fibrillation in severe aortic stenosis.

Background: Atrial fibrillation (AF) is commonly observed in patients with aortic stenosis and comorbidities. Abnormal parathyroid hormone (PTH) concentration has been observed in heart failure.

Aims: We aimed to evaluate a potential association between increased concentration of PTH and AF in patients with severe aortic stenosis.

Material And Methods: Patients with severe aortic stenosis and heart failure were included. Demographic, clinical, and laboratory data were collected. Patients were assigned to the AF and the sinus rhythm groups.

Results: The study group comprised 106 consecutive patients (57 females [53.8%], median [interquartile range] age of 77 [72-82] years). All patients presented with severe aortic stenosis, with a median (interquartile range) peak transvalvular gradient of 86.5 (71-102.8) mm Hg. Left atrial diameter over 40 mm was found in 76 (71.7%) patients. A history of AF was identified in 39 patients (36.8%). Patients with any form of AF were characterized by an increased concentration of PTH compared to patients with sinus rhythm (P = 0.03). Patients with and without impaired kidney function had different PTH concentrations (P <0.001). After adjustment of clinical and echocardiographic data in multivariable analysis, only PTH concentration (P = 0.02; OR, 1.02; 95% CI, 1.00-1.03) together with left atrial diameter (P = 0.008; OR, 1.13; 95% CI, 1.03-1.23), with area under the curve of 0.752, 43.3% sensitivity, 90% specificity, remained significant predictors of AF. The cut-off value for PTH concentration over 84.1 pg/ml was predictive of paroxysmal AF.

Conclusions: Increased PTH concentration may characterize AF patients. Patients with aortic stenosis presenting with PTH concentration over 84 pg/ml should be screened for paroxysmal AF.