Predicted Impact of Atrial Flow Regulator on Survival in Heart Failure with Reduced and Preserved Ejection Fraction

AIMS: We aim to assess the theoretical impact of the atrial flow regulator (AFR) on survival in heart failure. METHODS AND RESULTS: The prospective, multicentre, open-label, non-randomised PRELIEVE study (NCT03030274) assessed the safety and efficacy of the Occlutech AFR device in patients with symptomatic heart failure with reduced ejection fraction (HFrEF) (left ventricular ejection fraction (LVEF) ≥ 15% and <40%) or heart failure with preserved ejection fraction (HFpEF) (LVEF ≥40% and <70%) and elevated PCWP (≥15 mmHg at rest or ≥25 mmHg during exercise). In this analysis, after the first 60 patients completed 12 months of follow-up, the theoretical impact of AFR implantation on survival was assessed by comparing the observed mortality rate with the median predicted probability for one-year mortality. Each subject's risk of mortality was predicted from individual baseline data using the Meta-Analysis Global Group in Chronic HF (MAGGIC) prognostic model. A total of 87 patients (46% female, median age 69 years [IQR 62-74]) had undergone successful device implantation for the treatment of HFrEF (53%) and HFpEF (47%). Sixty patients had a complete 12 month follow-up. The median follow-up was 351 days (interquartile range [IQR] 202-370). Six (7%) patients died during follow-up (8.6 deaths per 100 patient-years; 95% confidence interval [CI] 2.7 to 15.5), all of which had HFrEF. The median predicted mortality rate for the overall study population was 12.2 deaths per 100 patient-years (95% CI 10.2 to 14.7). While the observed mortality rate (0 deaths per 100 patient-years) was significantly lower than the median predicted mortality rate (9.3 deaths per 100 patient-years; 95% CI 8.4 to 11.1) in patients with HFpEF (-9.3 deaths per 100 patient-years; 95% CI -11.1 to -8.4), there was no difference in patients with HFrEF (-3.6 deaths per 100 patient-years; 95% CI -9.5 to 3.0). Four deaths were HF-related deaths (5.7 HF-related deaths per 100 patient-years; 95% CI 1.4 to 11.9; 10.8 HF-related deaths per 100 patient-years; 95% CI 2.5 to 23.1 in the HFrEF subgroup). CONCLUSIONS: In patients with HFpEF, the mortality rate following AFR implantation was lower than the predicted mortality rate. Dedicated randomised, controlled trials are needed - and currently ongoing - to investigate whether the AFR improves mortality.