Background:
Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) share a close bidirectional relationship. Atrial cardiomyopathy (AtCM) has been proposed as a potential pathophysiological link between these conditions. The aim of this study was to investigate the impact of HFpEF on AtCM in patients with AF based on a new AtCM score.
Methods:
In this prospective study, 73 patients with AF undergoing pulmonary vein isolation (PVI) were enrolled. HFpEF was defined as an H2FPEF score ≥6 points and a left ventricular ejection fraction (LV-EF) ≥50%. Atrial characterization was performed using transthoracic and transesophageal echocardiography, invasive pressure measurements, and electrophysiological assessment. To quantify AtCM, a novel score was developed encompassing four dimensions: atrial architecture, mechanics, electrophysiology, and hemodynamics. One point was assigned for each category (maximum score of 4 points). The score included a left atrial volume index (LAVI) >40 mL/m², a left atrial emptying fraction (LA-EF) <48% or left atrial reservoir strain (LASr) <23%, an amplified P-wave duration (APWD) ≥150 ms or invasive atrial activation time (IAAT) ≥143 ms, and a mean left atrial pressure (LAPmean) ≥15 mmHg or an E/e′ ratio > 14. A score of 0 indicated no AtCM, 1–2 points indicated moderate and 3–4 points indicated severe AtCM. Atrial arrhythmia recurrence during follow-up was defined as documented AF recurrence or the occurrence of other atrial tachyarrhythmias.
Results:
Compared with patients without HFpEF, patients with HFpEF showed a higher LAP mean (13.39 ± 5.3 vs. 8.56 ± 3.4 mmHg, p < 0.001), a larger LAVI (35.62 ± 12.8 vs. 26.45 ± 8.8 mL/m², p = 0.001), a lower LA-EF (33.52 ± 15.4 vs. 43.8 ± 16.1%, p = 0.01), and a longer IAAT (167.2 ± 18.6 vs. 150.9 ± 21.1 ms, p = 0.002). The prevalence of AtCM was higher in patients with HFpEF than in those without HFpEF (95.1% vs. 78.1%, p = 0.037). Furthermore, severe AtCM was more common in the HFpEF group (61% vs. 6.3%, p < 0.001). During follow-up (median follow-up duration: 446 days), patients with severe AtCM demonstrated a shorter arrhythmia-free survival after PVI compared with patients with moderate or no AtCM (Chi2 17. 27; p = 0.0002).
Conclusions:
HFpEF is associated with more advanced AtCM in patients with AF. The proposed score enabled quantification of the more pronounced architectural, mechanical, electrophysiological, and hemodynamic alterations and thereby captured not only the higher prevalence but also the greater severity of AtCM in patients with HFpEF. The prognostic relevance of AtCM became evident through its association with ablation outcomes after PVI and further underscores the growing recognition of AtCM as a distinct disease entity.
