The efficacy of the Ventura interatrial shunt may depend on the subtype of heart failure, according to a press release from the American College of Cardiology (ACC). The interatrial shunt works by forming a connection between the left and right atria to aid blood in leaving the left atrium. In the RELIEVE-HF trial, results of which were presented by Stone et al at the ACC Annual Scientific Session 2024, researchers randomly assigned 508 patients who had heart failure with reduced ejection fraction (40%) or preserved ejection fraction (60%) to undergo either a Ventura interatrial shunt insertion or a placebo procedure in which no shunt was inserted. After a median follow-up of 22 months, although the interatrial shunt was found to be safe, there were no statistically significant differences in heart failure outcomes compared with placebo. In a prespecified analysis, patients who had heart failure with reduced ejection fraction experienced greater benefits across all outcomes—including hospitalizations for heart failure, all-cause mortality, heart transplant or left ventricular assist device, worsening of outpatient heart failure events, and change in quality of life—compared with patients who had heart failure with preserved ejection fraction. The researchers proposed that those in the reduced ejection fraction group had greater compliance of the heart muscle that allowed the accommodation of extra blood to enter the right atrium. However, they noted that their trial was not designed to demonstrate differences in outcomes between heart failure subtypes.