High Prevalence of Severe Aortic Stenosis in Low-Flow State Associated With Atrial Fibrillation

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.

Impact of atrial fibrillation on outcomes in asymptomatic severe aortic stenosis: a propensity-matched analysis

“…We matched the patients with AF and SR by age, sex, and clinical comorbidities to remove the effect of these differences on outcomes. Indeed, after propensity matching by age, sex, and clinical comorbidities, there was no difference in rates of AVR between patients in AF vs. SR, in contrast to unmatched cohorts showing lower rates of AVR among patients with AF ( 15 , 31 ). However, AF was still associated with increased risk of mortality even in the propensity-matched cohort, and the higher mortality in patients with AF was linked to lower forward flow, and to more prevalent right ventricular systolic dysfunction and mitral regurgitation in patients with AF.…”

“…However, symptoms from AS can be very similar to symptoms from AF, and patients with AF and symptoms in the setting of severe AS are sometimes not referred for AVR because clinicians attribute symptoms to AF instead of AS ( 15 ). In addition, it is known that patients with low-gradient compared to high-gradient AS have lower rates of AVR ( 31 , 38 , 39 ), and the lower rates of AVR in low-gradient AS have been shown to be more detrimental to patients with AF ( 31 ). Since AVR was associated with improvement in overall survival in both the AF and SR groups, the findings of the current study generate important clinical hypotheses about risk stratification in asymptomatic AS and whether the presence of AF should be considered a marker of increased risk of mortality and prompt referral to AVR.…”

“…This is a single center retrospective study. The duration of AF could not be determined precisely, although patients in AF during the echocardiogram typically have chronic persistent AF ( 15 , 31 ). Baseline symptom status was based on clinical assessment and what was documented in the medical record around the time of diagnosis of severe AS.…”

Vicious Cycle of Concurrent Low-Flow, Low-Gradient Aortic Stenosis and Atrial Fibrillation

“…19 In addition, there are limited outcome data for patients with concurrent AS and AF, as they are often excluded from clinical outcome trials due to the inability to accurately define the severity of their valvular stenosis. 19 It is with this background that Alsidawi et al 20 present their findings from a retrospective single-center study, where they evaluated the predictive and prognostic power of a conceptually novel approach to the evaluation of AS in patients with AF. The authors utilized the single highest Doppler-derived transvalvular velocity signal out of 5 signals obtained over 5 consecutive cardiac cycles.…”

“…It is with this background that Alsidawi et al 20 present their findings from a retrospective single-center study, where they evaluated the predictive and prognostic power of a conceptually novel approach to the evaluation of AS in patients with AF. The authors utilized the single highest Doppler-derived transvalvular velocity signal out of 5 signals obtained over 5 consecutive cardiac cycles.…”