Does Atrial Fibrillation at Diagnosis Change Prognosis in Patients with Aortic Stenosis?

Background: Aortic stenosis (AS) is a common valve disease and atrial fibrillation (AF) is the most common cardiac arrhythmia, frequently associated with AS. This study aimed to evaluate the impact of AF on mortality in patients with moderate and severe AS. Methods: We retrospectively analyzed 1070 consecutive moderate and severe AS patients (57% were male, age was 69 ± 10, severe AS 22.5%), who underwent transthoracic echocardiography from March 2018 to November 2021. AS severity was defined by specific threshold values with severe AS being defined by a peak velocity > 4 m/s, an MPG > 40 mmHg, and an AVA < 1 cm² and moderated by a peak velocity of 3-4 m/s, an MPG 20-40 mmHg and an AVA 1-1.5 cm. Patients with AF were defined as those having a history of AF when AS was found on the index echocardiography. The follow-up assessment in December 2023 ascertained vital status and data on aortic valve replacement (AVR). Results: 790 (73.8%) patients were with sinus rhythm (SR) and 280 (26.2%) patients with AF. Mortality was higher in patients with AF than in those with SR (46% vs. 36.2% HR 1.424, 95% CI 1.121-1.809, p = 0.004). After adjusting for clinical confounders, mortality risk in AF relative to SR remained significant (HR 1.284, 95% CI 1.03-1.643, p = 0.047). Patients with AF demonstrated high mortality risk in the moderate aortic stenosis stratum (HR 1.376, 95% CI 1.059-1.788, p = 0.017), with even greater risk in the severe AS stratum (HR 1.644, 95% CI 1.038-2.603, p = 0.034) with significant interaction (p = 0.007). In patients with AF AVR demonstrated a protective effect on survival (HR 0.365, 95% CI 0.202-0.627, p < 0.001), but to a lesser degree than in patients with sinus rhythm (HR 0.376, 95% CI 0.250-0.561, p < 0.001) without significant interaction (p = 0.278). In patients with AF mortality risk was high in the conservative treatment stratum (HR 1.361, 95% CI 1.066-1.739, p = 0.014), in the AVR stratum mortality risk was higher but did not reach statistical significance (HR 1.823, 95% CI 0.973-3.414, p = 0.061). However, when corrected for echocardiographic variables strongly correlated with AF, AF was no longer independently associated with all-cause mortality. (HR 0.97 95% CI 0.709-1.323, p = 0.84). Conclusions: Patients with moderate and severe AS and AF have worse prognosis than patients with SR which can be explained by cardiac damage. AVR improves survival in patients with AF and with SR.