Highlights
The study emulated the use of GLP-1 receptor agonists (GLP-1RAs) for primary cardiovascular prevention in a large cohort of over 600,000 individuals. For obese individuals with a high baseline risk (SCORE2 ≥7.5%), the therapy was projected to lower the 10-year cardiovascular disease (CVD) incidence from 13.82% to 10.83%. This represents a significant 22% relative risk reduction and a 2.99% absolute risk reduction, with slightly higher absolute benefits observed in men compared to women.
Introduction: The Evolution of GLP-1 Receptor Agonists
Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have fundamentally transformed the management of type 2 diabetes and obesity. Beyond their glycemic and weight-loss effects, these agents have demonstrated robust cardioprotective benefits in secondary prevention. The landmark SELECT trial recently confirmed that semaglutide reduces the risk of major adverse cardiovascular events (MACE) by 20% in individuals with overweight or obesity and established cardiovascular disease, regardless of diabetes status. However, a critical question remains for the global medical community: can these benefits be extrapolated to primary prevention? As cardiovascular disease remains the leading cause of mortality worldwide, identifying effective interventions for high-risk individuals before the onset of clinical disease is a public health priority.
The Clinical Gap: From Secondary to Primary Prevention
While the evidence for GLP-1RAs in secondary prevention is conclusive, randomized controlled trials (RCTs) for primary prevention are resource-intensive and take years to reach fruition. In the interim, target trial emulation offers a sophisticated methodological framework to predict clinical outcomes by applying observed trial effects to real-world populations. This study, published in the Journal of the American College of Cardiology, seeks to bridge this gap by modeling the impact of GLP-1RAs on a primary prevention cohort using the risk factor modifications observed in the SELECT trial.
Study Design and Emulation Methodology
The researchers utilized data from 610,789 CVD-free individuals across European and North American cohorts within the Global Cardiovascular Risk Consortium. To estimate the 10-year incidence of CVD and all-cause mortality, they developed a predictive model based on five key risk factors: body mass index (BMI), glycosylated hemoglobin (HbA1c), systolic blood pressure (SBP), high-sensitivity C-reactive protein (hs-CRP), and non-high-density-lipoprotein (non-HDL) cholesterol.
The Emulation Model: Applying SELECT Trial Parameters
The model was applied to 200,012 individuals from contemporary health surveys. The researchers emulated GLP-1RA therapy by adjusting the five baseline risk factors according to the sex-stratified, placebo-adjusted changes reported in the SELECT trial. The primary focus was on a high-risk primary prevention group: individuals with a BMI ≥27 kg/m2 and a baseline 10-year cardiovascular risk ≥7.5% as determined by the SCORE2 (Systematic Coronary Risk Evaluation 2) algorithm. Secondary analyses explored the effects in nonobese individuals, lower-risk groups, and scenarios accounting for reduced medication compliance.
Key Findings: Quantifying the Preventive Benefit
The study identified 21,720 individuals in the surveys who met the high-risk criteria (BMI ≥27 kg/m2 and SCORE2 risk ≥7.5%). In this group, the observed 10-year CVD incidence was 13.82%.
Impact on Cardiovascular Incidence
The emulated GLP-1RA therapy reduced the projected 10-year CVD incidence to 10.83%. This corresponds to an absolute risk reduction (ARR) of 2.99% (95% CI: 2.67%-3.31%) and a relative risk reduction (RRR) of 22%. These results align closely with the findings of the SELECT trial, suggesting that the metabolic and anti-inflammatory improvements driven by GLP-1RAs translate effectively into primary prevention.
Sex-Specific Outcomes and Risk Stratification
While the relative risk reduction was similar between sexes (21% in men vs. 23% in women), the absolute reduction was more pronounced in men (3.14% vs. 2.70%). This difference is largely attributed to the higher baseline cardiovascular risk typically observed in male populations. Notably, the benefits were attenuated in individuals with lower baseline risk or lower BMI, and the projected efficacy dropped significantly when the model accounted for lower patient compliance.
Mechanistic Insights: How GLP-1RAs Protect the Heart
The cardiovascular benefits of GLP-1RAs extend far beyond weight loss. The study’s model included hs-CRP, a marker of systemic inflammation, and non-HDL cholesterol, highlighting the pleiotropic effects of these drugs. GLP-1RAs are known to improve endothelial function, reduce oxidative stress, and stabilize atherosclerotic plaques. By modulating systemic inflammation and improving the hemodynamic profile (via blood pressure reduction), these agents address multiple pathways of the atherosclerotic process simultaneously.
Expert Commentary and Clinical Perspective
The findings of this emulation study provide a compelling rationale for the expanded use of GLP-1RAs in primary prevention. For clinicians, the 3% absolute risk reduction over 10 years is a clinically significant margin, comparable to the benefits seen with long-term statin therapy or intensive blood pressure management.
The Role of Target Trial Emulation
Target trial emulation is an increasingly valuable tool in evidence-based medicine. By using high-quality longitudinal data and robust statistical modeling, researchers can simulate the impact of interventions in populations that are currently underrepresented in clinical trials. However, experts caution that while emulation provides strong evidence, it cannot fully replace the gold standard of the RCT, as it may not account for unknown confounders or the full spectrum of drug side effects.
Study Limitations and Future Directions
The study authors acknowledge certain limitations. The emulation assumes that the risk factor changes observed in a trial population (SELECT) will be identical in a general population. Furthermore, the model focused on five specific risk factors and may not capture the entirety of the GLP-1RA mechanism of action. The attenuation of benefit seen with lower compliance also underscores the real-world challenge of long-term adherence to injectable medications. Future randomized trials specifically designed for primary prevention are necessary to validate these projections.
Conclusion: A New Era in Preventive Cardiology
The study suggests that GLP-1RA therapy could be a powerful adjunct to existing primary prevention strategies. For the millions of individuals globally who struggle with obesity and high cardiovascular risk but have not yet experienced a cardiac event, these agents offer a promising path toward long-term health. As the cost-effectiveness and availability of GLP-1RAs improve, they are likely to become a cornerstone of preventive cardiology, shifting the focus from treating established disease to aggressively managing risk in its earliest stages.
References
1. Schrage B, et al. Emulated Effects of Glucagon-Like Peptide 1 Receptor Agonist Therapy in the General Population. J Am Coll Cardiol. 2026. PMID: 41811277.
2. Lincoff AM, et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT). N Engl J Med. 2023;389(24):2221-2232.
3. SCORE2 working group. SCORE2 cardiovascular risk prediction models for the European population. Eur Heart J. 2021;42(25):2439-2454.
