Sept. 27, 2023
The prevalence and impact of atrial fibrillation (AF) versus sinus rhythm (SR) on outcomes in very severe aortic stenosis (vsAS) of the native valve is unknown. A Mayo Clinic study examined the prognostic significance of AF in vsAS. The findings, published in the February 2023 issue of The American Journal of Cardiology, included that AF was not uncommon among patients with vsAS, overall survival was lower in patients with AF than in patients in SR, and aortic valve replacement (AVR) was associated with improved outcomes in both the AF and the SR groups but, overall, was performed less often in patients with AF.
A total of 563 patients with vsAS (transaortic valve peak velocity 5 m/s or higher) and left ventricular ejection fraction 50% or greater were identified retrospectively. Patients were divided by rhythm at the time of index transthoracic echocardiogram: AF, n = 50 (9%) versus SR, n = 513 (91%). Patients with AF were older (83.1 ± 7.5 years versus 72.5 ± 12.2 years, P < 0.001) but had no difference in sex distribution (P = 0.49). Patients with AF had a higher Charlson comorbidity index score: 2 (1,3) versus 1 (0,2), P = 0.01. There was no difference in transaortic peak velocity (5.3 ± 0.3 m/s versus 5.4 ± 0.4 m/s, P = 0.13), and left ventricular ejection fraction was comparable (63% ± 7% versus 66% ± 7%, P = 0.01). Age-, sex-, Charlson comorbidity index- and time-dependent AVR-adjusted overall mortality at five years was significantly higher in patients with AF compared with patients with SR: hazard ratio (HR) 1.88 (1.23 to 2.85), P = 0.003.
AVR was associated with improved survival — HR = 0.30 (0.22 to 0.42), P < 0.001 — with no statistically significant interaction of AVR and rhythm (P = 0.36). Outcomes were also compared in the 2 SR:1 AF propensity-matched analyses (100 SR:50 AF), with matching done according to age, sex, clinical comorbidities and year of echocardiogram. In the propensity-matched analysis, age-, sex- and time-dependent AVR-adjusted all-cause mortality was higher in patients with AF: HR 2.32 (1.41 to 3.82), P < 0.001. In conclusion, AF was not uncommon in vsAS and identified a subset of patients at a much higher risk of mortality without AVR.
In patients with native valve aortic stenosis (AS), severe AS is defined by increased jet peak velocity of 4 to 4.9 m/s or higher across the aortic valve, and vsAS is defined by peak velocity 5 m/s or higher. The natural history of vsAS compared with severe AS is associated with worse outcomes and higher mortality risk even after AVR. Data on risk stratification in patients with vsAS are lacking. AF is common in AS and is associated with worse outcomes, irrespective of symptom presence, AVR or degree of stenosis, but the prevalence of AF and its impact on outcomes in patients with vsAS is unknown. The purpose of this study was to examine the prevalence of AF in patients with vsAS and its association with outcomes, including rates of AVR and all-cause mortality. Mayo Clinic researchers hypothesized that vsAS is associated with worse outcomes in those with AF versus SR.
A total of 563 patients with aortic jet velocity 5 m/s or greater were identified; 50 of 563 patients (9%) had AF and 513 of 563 patients (91%) had SR during the index transthoracic echocardiogram. Baseline clinical characteristics are summarized in a table in the journal. Patients with AF were older (83.1 ± 7.5 years versus 72.5 ± 12.2 years, P < 0.001) but had no difference in sex distribution (AF, 50% men versus SR, 58% men, P = 0.29). Patients with AF more frequently had a history of congestive heart failure (34% versus 13%, P < 0.001) and higher levels of N-terminal pro-B-type natriuretic peptide compared with patients with SR — 2,227 pg/mL (1,326 to 4,467 pg/mL) versus 773 pg/mL (343 to 1,793 pg/mL), P < 0.001). The overall prevalence of symptoms was higher in patients with AF (88% versus 74%, P = 0.03) because of more-prevalent dyspnea (84% versus 68%, P = 0.02). There was no significant difference in the frequency of angina (20% versus 30%, P = 0.14) or syncope (12% versus 12%, P = 0.99).
For more information
Ibrahim H, et al. Impact of atrial fibrillation on outcomes in very severe aortic valve stenosis. The American Journal of Cardiology. 2023;189:64.
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