Shortened telomere length is associated with paroxysmal atrial fibrillation among cardiovascular patients enrolled in the Intermountain Heart Collaborative Study

Abstract

Atrial fibrillation (AF) diminishes quality of life and accounts for approximately one-third of all strokes. Studies have associated mitochondrial dysfunction with both AF and telomere length (TL). The purpose of this study was to test the hypothesis of a relationship between AF and TL. Blood was collected from consenting participants in the Intermountain Heart Collaborative Study (n = 3576) and DNA extracted. TL was determined by multiplex quantitative polymerase chain reaction, normalized to a single copy gene, and reported as telomere/single gene ratio (t/s). Patient information was extracted from Intermountain Healthcare's electronic records database. Prevalent AF was determined by discharge ICD-9 code. AF subtype (paroxysmal [Px], persistent [Ps], long-standing persistent/permanent [Pm]) was determined by chart review. The t/s decreased with age (P <.00001). Subjects with a history of AF (n = 379 [10.6%] had shorter telomeres (mean t/s ± SD = 0.87 ± 0.29) compared to subjects without AF (mean t/s 0.95 ± 0.32, P <.0001). The association remained after adjustment for age (P = .017) and cardiovascular risk factors (P = .016). AF subtype was determined for 277 subjects; 110 (39.7%) had Px AF, 65 (23.5%) Ps, and 102 (36.8%) Pm AF. Mean t/s did not differ between Ps, Pm, and subjects without AF (0.94 ± 0.40, 0.94 ± 0.27, and 0.95 ± 0.32, respectively). However, the mean t/s for Px (0.81 ± 0.22) was significantly shorter than for Ps (P = .026), Pm (P = .004), or subjects without AF (P <.0001). The present study supports an association between Px AF and TL. Short TL may be a previously unrecognized risk factor for AF with potential applications in diagnosis and therapy.