High Prevalence of Severe Aortic Stenosis in Low-Flow State Associated With Atrial Fibrillation
Said Alsidawi, Sana Khan, Sorin V. Pislaru, Jeremy J. Thaden, Edward El‐Am, Christopher G. Scott, Kareem Morant, Didem Oğuz, Sushil Allen Luis, Ratnasari Padang, Colleen E. Lane, Robert B. McCully, Patricia A. Pellikka, Jae K. Oh, Vuyisile T. Nkomo
Abstract
Background: Atrial fibrillation (AF) is a low-flow state and may underestimate aortic stenosis (AS) severity. Single-high Doppler signals (HS) consistent with severe AS (peak velocity ≥4 m/s or mean gradient ≥40 mm Hg) are averaged down in current practice. The objective for the study was to determine the significance of HS in AF low-gradient AS (LGAS). Methods: One thousand five hundred forty-one patients with aortic valve area ≤1 cm 2 and left ventricular ejection fraction ≥50% were identified and classified as high-gradient AS (HGAS) (≥40 mm Hg) and LGAS (<40 mm Hg), and AF versus sinus rhythm (SR). Available computed tomography aortic valve calcium scores (AVCS) were retrieved from the medical record. Outcomes were assessed. Results: Mean age was 76±11 years, female 47%. Mean gradient was 51±12 in SR-HGAS, 48±10 in AF-HGAS, 31±5 in SR-LGAS, and 29±7 mm Hg in AF-LGAS, all P ≤0.001 versus SR-HGAS; HS were present in 33% of AF-LGAS. AVCS were available in 34%. Compared with SR-HGAS (2409 arbitrary units; interquartile range, 1581–3462) AVCS were higher in AF-HGAS (2991 arbitrary units; IQR1978–4229, P =0.001), not different in AF-LGAS (2399 arbitrary units; IQR1817–2810, P =0.47), and lower in SR-LGAS (1593 arbitrary units; IQR945–1832, P <0.001); AVCS in AF-LGAS were higher when HS were present ( P =0.048). Compared with SR-HGAS, the age-, sex-, comorbidity index-, and time-dependent aortic valve replacement-adjusted mortality risk was higher in AF-HGAS (hazard ratio=1.82 [1.40–2.36], P <0.001) and AF-LGAS with HS (hazard ratio=1.54 [1.04–2.26], P =0.03) but not different in AF-LGAS without HS or SR-LGAS (both P =not significant). Conclusions: Severe AS was common in AF-LGAS. AVCS in AF-LGAS were not different from SR-HGAS. AVCS were higher and mortality worse in AF-LGAS when HS were present.