Restrictive filling pattern of transmitral inflow in acute decompensated heart failure with preserved ejection fraction: insights from the KCHF registry

Background The restrictive filling pattern of transmitral inflow has been shown to be associated with a poor prognosis in patients with heart failure (HF) with reduced ejection fraction or myocardial infarction. We aimed to investigate the significance of restrictive filling pattern in patients with HF with preserved ejection fraction (HFpEF). Methods Among 4056 patients with acute decompensated HF in the Kyoto Congestive Heart Failure registry, we analysed 830 patients with HFpEF who had transmitral inflow data available in echocardiography. Patients whose early to late diastolic transmitral flow velocity (E/A ratio) ≥2 were classified as having a restrictive filling pattern of transmitral inflow. The main outcome measures were all-cause death and HF hospitalisation at 1 year. Results Among 830 patients, a restrictive filling pattern was observed in 144 (17.3%) patients, who had higher prevalence of a history of atrial fibrillation and supranormal left ventricular ejection fraction (>65%), and higher brain natriuretic peptide level at discharge. The cumulative 1-year incidence of HF hospitalisation was significantly higher in patients with restrictive filling pattern than those without (31.0% vs 18.1%, p<0.001), while the cumulative 1-year incidence of all-cause death was not different between the two groups (14.2% vs 14.4%, p=0.93). After adjusting for confounding factors, the excess risk of restrictive filling pattern relative to non-restrictive filling pattern remained significant for HF hospitalisation (HR=1.58, 95% CI 1.10 to 2.27, p=0.01), but not for all-cause death (HR=0.92, 95% CI 0.60 to 1.42, p=0.70). Conclusions A restrictive filling pattern of transmitral inflow was associated with an increased risk for HF hospitalisation, but not for all-cause death, in patients with acute decompensated HFpEF.