Summary
A pre-specified CAMEO-SEMA imaging substudy found that semaglutide improved left atrial strain and left ventricular filling measures over 52 weeks in people with obesity-related heart failure with preserved ejection fraction. The imaging changes were associated with lower pressure during exercise.
A pre-specified cardiac magnetic resonance (CMR) substudy of the randomized CAMEO-SEMA trial found that semaglutide improved measures of left atrial function and left ventricular filling in people with obesity-related heart failure with preserved ejection fraction (HFpEF). The 49 participants had CMR scans at the start of the study and after 52 weeks; 33 received semaglutide and 16 placebo. The researchers also found that improvements in the imaging measures were associated with reductions in pressure during exercise.
HFpEF is a form of heart failure in which the heart’s ejection fraction—the proportion of blood expelled from the left ventricle with each contraction—remains preserved. The heart can still have problems filling. The study used CMR to examine cardiac structure and function, alongside invasive measurements of exercise haemodynamics, or blood-flow pressures during physical exertion.
Changes in atrial strain and ventricular filling
The pre-specified primary CMR endpoint was change in left atrial reservoir strain, a measure of how the left atrium deforms as it fills. Compared with placebo, semaglutide improved this measure by 5.7 percentage points (95% confidence interval, 0.3 to 9.7; P=0.037).
A second pre-specified measure assessed early left ventricular filling rate relative to end-diastolic volume (eFR/EDV). It improved by 0.64 s−1 with semaglutide compared with placebo (95% CI, 0.42 to 1.00; P<0.0001). The measure describes early filling in relation to the ventricle’s volume at the end of its filling phase.
The researchers reported that greater improvements in left atrial reservoir strain and eFR/EDV were associated with larger reductions in exercise pulmonary artery wedge pressure (PAWP). PAWP is an invasive pressure measurement used to assess pressures on the left side of the heart. The reported correlations were r=−0.46 (P<0.001) for atrial strain and r=−0.65 (P<0.0001) for ventricular filling dynamics.
Structural and functional findings
The study also reported reductions in left ventricular mass, a shift towards more physiologic left ventricular geometry, improved right ventricular function and better mechanics of the heart muscle in both ventricles. The abstract does not provide numerical effect estimates for these additional CMR findings.
The results add imaging evidence to earlier findings in obesity-related HFpEF that semaglutide reduces exertional PAWP. They suggest that changes in cardiac function may contribute to the observed haemodynamic improvement. The substudy’s reported associations connect changes in imaging measures with exercise PAWP; whether those changes mediate the pressure reduction is not established by these results.
The findings come from a 49-person imaging substudy with measurements at baseline and 52 weeks. They describe cardiac imaging and exercise pressure measures in people with obesity-related HFpEF, rather than establishing effects across other heart-failure populations.