Prognosis of low-flow low-gradient aortic valve stenosis with atrial fibrillation.

Background: The prognosis for patients with low-flow low-gradient (LFLG) aortic valve stenosis (AS) remains controversial. In general, atrial fibrillation (AF) is one factor determining the LF status in patients with severe AS (SAS). However, the association between concomitant AF in LFLG AS and the risk of heart failure (HF) remains unclear.

Methods: This study evaluated 278 consecutive patients with SAS (indexed aortic valve area < 0.6 cm²/m²). Among them, we enrolled patients with high-gradient (HG) SAS [mean pressure gradient (mPG) ≥40 mmHg] and LFLG AS (stroke volume index ≤35 ml/m², mPG <40 mmHg). The two groups were further categorized into four subgroups following the presence or absence of AF as HG SAS with AF (n = 27), HG SAS without AF (n = 68), LFLG AS with AF (n = 30), and LFLG AS without AF (n = 67). The primary endpoint was worsening HF that required unplanned hospitalization or HF drug therapy.

Results: We observed worsening HF in 65 patients. The Kaplan-Meier curve revealed a higher rate of worsening HF in LFLG AS with AF than that in HG SAS without AF (log-rank p < 0.001) without any significant difference compared to HG SAS with AF. The Cox hazard analysis among LFLG AS patients identified the presence of AF as an independent predictor for worsening HF [hazard ratio (HR): 2.79; 95 % confidence interval (CI): 1.17-6.96; p = 0.021]. In addition, the Kaplan-Meier analysis curve revealed a higher risk of worsening HF in patients with LFLG AS and paroxysmal AF (PAF) or chronic AF (CAF) than in those without AF (PAF: HR: 4.71, 95 % CI: 1.79-11.9, p = 0.0024; CAF: HR: 3.22, 95 % CI: 1.29-7.83, p = 0.013, respectively).

Conclusions: Patients with LFLG AS and concomitant AF exhibited an unfavorable prognosis for HF, with no significantly different rate of worsening HF compared with patients with HG SAS and conc.