Semaglutide's cardiovascular benefits align more with dose exposure than achieved weight loss in 47,199 patients

While semaglutide has demonstrated significant cardiovascular (CV) event reduction in trials like SELECT, the precise mechanism driving this benefit—whether it's primarily due to the magnitude of weight loss or direct therapeutic exposure to the drug—remains a critical question. Current clinical practice often prioritizes maximizing weight loss, but understanding the independent contributions of dose versus weight reduction could optimize treatment strategies for patients with pre-existing cardiovascular disease.

Researchers conducted a retrospective observational study using a federated, de-identified U.S. electronic health record network, including 47,199 patients with pre-existing cardiovascular disease who initiated semaglutide. Among 12,519 patients with at least two years of follow-up, dose escalation and weight change during the first two years (pre-landmark period) were evaluated. These factors were then correlated with cardiovascular outcomes during the subsequent two years (post-landmark period). Propensity-matched analyses compared semaglutide outcomes against metformin, DPP-4 inhibitors, and SGLT2 inhibitors. Transcriptomic analyses were also performed to assess GLP1R expression in cardiac tissue.

Higher maximum semaglutide dose was strongly associated with greater weight loss during the pre-landmark period, showing 3.15% additional weight loss per 1 mg increase (r=-0.97, P<0.001). Crucially, higher dose was also linked to significantly lower post-landmark risks across multiple cardiovascular endpoints. > Higher maximum semaglutide dose was strongly associated with lower post-landmark risks of all-cause mortality (RR 0.42, P<0.001), composite cardiovascular events (death, myocardial infarction, or stroke; RR 0.51, P<0.001), cerebrovascular disease (RR 0.50, P<0.001), and heart failure (RR 0.55, P<0.001). In stark contrast, achieved weight loss was not significantly associated with subsequent all-cause mortality (P=0.14) or composite cardiovascular events (P=0.55), despite showing strong associations with improvements in hemoglobin A1c and blood pressure (both P<0.001). Propensity-matched analyses further demonstrated that semaglutide was associated with lower cardiovascular event rates compared to metformin, DPP-4 inhibitors, and SGLT2 inhibitors. Transcriptomic analyses revealed high GLP1R expression in cardiac tissue, particularly within cardiomyocytes and cardiac endothelial cells, supporting a direct cardiac mechanism.