Abstract Aims Heart failure (HF) with preserved (HFpEF) and mildly reduced (HFmrEF) ejection fraction are prevalent, yet frequently underdiagnosed syndromes associated with high morbidity and mortality, impaired quality of life, and escalating healthcare expenditures. Although guideline-directed medications like SGLT2 inhibitors have been shown to reduce the risk of hospitalization and cardiovascular death, their use remains limited and substantial residual risk persists. This trial aims to evaluate the safety and performance of a novel left-atrium-to-coronary-sinus shunt (Edwards APTURE transcatheter shunt system) in HFpEF and HFmrEF patients. Methods ALT-FLOW II is a prospective multi-centre, randomized, sham-controlled, double-blinded (patient and assessor) trial. Approximately 100 symptomatic HF patients aged ≥18 years with left ventricular ejection fraction >40% and exercise pulmonary capillary wedge pressure (PCWP) ≥25 mm Hg with a PCWP to right atrial pressure gradient ≥8 mm Hg will be randomized 1:1 to the APTURE shunt vs sham control. Key exclusion criteria include severe HF, significant valvular disease, and more than mild right ventricular dysfunction. The primary endpoints are the safety of the APTURE device at 30 days and change in workload-corrected PCWP normalized to bodyweight at 6 months. Secondary endpoints include changes in patient-reported outcomes, and hemodynamic and echocardiographic parameters through 5 years. The trial will also explore the impact of the device on short-term cardiac remodelling and intra-cardiac flow patterns using multi-modality imaging. Conclusions The ALT-FLOW II trial will evaluate the safety and performance of the APTURE system in symptomatic HFpEF and HFmrEF patients with elevated left atrial pressure.
Left Atrial to Coronary Sinus Shunting in More Advanced Heart Failure with Preserved Ejection Fraction
Abstract Aims Inter-atrial shunt device therapy has shown mixed results in clinical trials, with clinical ‘non-responders’ typically showing features of more advanced heart failure. We aimed to analyse the haemodynamic and clinical response of a novel left atrial to coronary sinus (LA-CS) shunt device in patients with higher natriuretic peptide (NP) levels, a marker of disease severity. Methods and results An analysis population (n = 95) of patients from the ALT-FLOW early feasibility study with left ventricular ejection fraction >40% and 1-year follow up was analysed. The cohort was divided into low and high subgroups based on NP levels [b-type natriuretic peptide (BNP) and n-terminal pro BNP (NT-proBNP)]. The mean BNP and NT-proBNP levels for low versus high subgroups were 64.2 ± 34.3 versus 261 ± 103 and 322 ± 269 versus 2050 ± 1070 pg/mL, respectively. Patients in the high NP subgroup had evidence of more advanced disease including worse haemodynamic profiles, lower estimated glomerular filtration rate, and higher percentages of atrial fibrillation. The high NP subgroup experienced significant improvements in KCCQ-OSS and NYHA functional class (P < 0.0001 and P < 0.001, respectively) and to a similar magnitude compared with the low NP subgroup. Compared with pre-implant baseline, workload adjusted pulmonary artery wedge pressure at peak exercise declined in the high NP subgroup (PCWL, 164.1 vs. 96.0 mmHg/W/kg at 6 months, P < 0.003) as well as the low NP subgroup (115.9 vs. 65.9 mmHg/W/keg at 6 months, P < 0.001). Importantly, in both NP subgroups, there was preservation of cardiac index through 6 months as well as right ventricular structure (right ventricular diastolic dimension) and function (tricuspid annular systolic plane excursion) through 1 year. Conclusions The quality-of-life, haemodynamic, and functional class improvements along with stable right heart function seen in ALT-FLOW study of LA-CS shunt remain consistent in the subgroup with highest NP levels. This suggests that shunting location could influence outcomes in symptomatic heart failure patients.
Left Atrial to Coronary Sinus Shunting for Treatment of Heart Failure with Mildly Reduced or Preserved Ejection Fraction: The ALT FLOW Early Feasibility Study 1-Year Results
Abstract Aims Patients with heart failure and mildly reduced or preserved ejection fraction have limited therapeutic options. The ALT-FLOW Early Feasibility Study evaluated safety, haemodynamics and outcomes for the APTURE transcatheter shunt system, a novel left atrium to coronary sinus shunt in these patients. Methods and results Safety and shunt implantation success was evaluated for all 116 enrolled patients. An analysis population of implanted patients with a left ventricular ejection fraction (LVEF) >40% (n = 95) was chosen to assess efficacy via paired comparison between baseline and follow-up haemodynamic (3 and 6 months), and echocardiographic, clinical and functional outcomes (6 months and 1 year). Health status and quality of life outcomes were assessed using the Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OSS). The primary safety endpoint, major adverse cardiac, cerebral, and renal events, and reintervention through 30 days, occurred in 3/116 patients (2.6%). All implanted shunts were patent at 1 year. In patients with LVEF >40%, the mean (95% confidence interval) reduction in exercise pulmonary capillary wedge pressure (PCWP) at 20 W was −5.7 (−8.6, −2.9) mmHg at 6 months (p < 0.001). At baseline, 8% had New York Heart Association class I–II status and improved to 68% at 1 year (p < 0.001). KCCQ-OSS at baseline was 39 (35, 43) and improved at 6 months and 1 year by 25 (20–30) and 27 (22–32) points, respectively (both p < 0.0001). No adverse changes in haemodynamic and echocardiographic indices of right heart function were observed at 1 year. Overall, the reduction in PCWP at 20 W and improvement in KCCQ-OSS in multiple subgroups were consistent with those observed for the entire population. Conclusions In patients with heart failure and LVEF >40%, the APTURE shunt demonstrated an acceptable safety profile with significant sustained improvements in haemodynamic and patient-centred outcomes, underscoring the need for further evaluation of the APTURE shunt in a randomized trial.
Resting and Exercise Haemodynamic Characteristics of Patients with Advanced Heart Failure and Preserved Ejection Fraction
Abstract Aims This study aimed to describe haemodynamic features of patients with advanced heart failure with preserved ejection fraction (HFpEF) as defined by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC). Methods and results We used pooled data from two dedicated HFpEF studies with invasive exercise haemodynamic protocols, the REDUCE LAP-HF (Reduce Elevated Left Atrial Pressure in Patients with Heart Failure) trial and the REDUCE LAP-HF I trial, and categorized patients according to advanced heart failure (AdHF) criteria. The well-characterized HFpEF patients were considered advanced if they had persistent New York Heart Association classification of III–IV and heart failure (HF) hospitalization < 12 months and a 6 min walk test distance < 300 m. Twenty-four (22%) out of 108 patients met the AdHF criteria. On evaluation, clinical characteristics and resting haemodynamics were not different in the two groups. Patients with AdHF had lower work capacity compared with non-advanced patients (35 ± 16 vs. 45 ± 18 W, P = 0.021). Workload-corrected pulmonary capillary wedge pressure normalized to body weight (PCWL) was higher in AdHF patients compared with non-advanced (112 ± 55 vs. 86 ± 49 mmHg/W/kg, P = 0.04). Further, AdHF patients had a smaller increase in cardiac index during exercise (1.1 ± 0.7 vs. 1.6 ± 0.9 L/min/m2, P = 0.028). Conclusions A significantly higher PCWL and lower cardiac index reserve during exercise were observed in AdHF patients compared with non-advanced. These differences were not apparent at rest. Therapies targeting the haemodynamic compromise associated with advanced HFpEF are needed.