Abstract 16642: Distinctive Characteristics of Left Atrial Remodeling in Heart Failure With Preserved or Reduced Ejection Faction
Introduction: Left atrial structure and function (LA) is affected by the presence of heart failure (HF), but the specific impact of HF subtype is poorly characterized. Hypothesis: HF-induced LA remodeling differs between patients with preserved (pEF) or reduced ejection fraction (rEF). Methods: 198 consecutive HF patients referred to Mayo Clinic (51% HFpEF, NYHA 3.1±0.7, 66±13 years, 39% females) and 40 HF-free controls of similar age and gender underwent right heart catheterization (LA pressures), echocardiography (LA volumes) and follow-up. Results: Compared with controls, HF patients had larger atria and more impaired LA reservoir and contractile function (total and active LAEF, all p<0.001). At identical mean LA pressure (20 vs 20 mmHg, p=0.9), HFrEF patients had larger LA volumes (LAVI 50 vs 41 ml/m 2 p<0.001), but HFpEF patients had higher LA peak (V-wave) and lower LA minimal pressures, with higher LA stiffness (0.79 vs 0.48 mmHg.ml -1 , p<0.001, Fig-A) and LA pressure pulsatility (19 vs 13 mmHg, p<0.001). Despite smaller LA size, better LA function (total LAEF 39 vs 35 %, p=0.04, active LAEF 30 vs 22 %, p<0.001) and less mitral regurgitation (grade 1.8 vs 2.5, p<0.001), HFpEF patients had more atrial fibrillation (42 vs 26%, p=0.02). After a median follow-up 350 days, 31 HFpEF and 28 HFrEF patients died. LA function was associated with mortality in HFpEF, but not in HFrEF (Fig-B). Conclusions: HFrEF is characterized by greater eccentric LA remodeling, but HFpEF is associated with increased LA stiffening and greater LA pressure pulsatility which may contribute to greater burden of atrial fibrillation. The observation that LA function is more closely linked to outcome in HFpEF supports the goal to maintain or improve LA function in HFpEF.