By James de Lemos, M.D.
Professor in the Department of Internal Medicine
The HR increase fell within the expected range for this drug class. The substantial reductions in 24-hour BP suggest potential cardiovascular benefits of tirzepatide.” – James de Lemos, M.D.
Tirzepatide is a new GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptor agonist that recently received FDA approval for treatment of Type 2 diabetes. The drug, which is administered subcutaneously once weekly, is also under investigation to promote weight loss. The SURMOUNT-1 trial enrolled 2,539 patients with obesity, excluding individuals with diabetes or uncontrolled hypertension, and randomized them to placebo or 5, 10, or 15 mg of tirzepatide. Substantial weight loss was achieved: Up to 20% bodyweight reduction was seen in the highest dose of tirzepatide compared with placebo. In addition, office-based measurements of systolic and diastolic blood pressure (BP) were reduced with tirzepatide, but heart rate (HR) was increased, consistent with known effects of GLP-1 agonists.
Ambulatory blood pressure monitoring (ABPM) appears to provide more comprehensive assessment of the hemodynamic consequences of hypertension and may align better than in-office BP and HR measurement with cardiovascular outcomes.At #AHA22, we presented results from an ABPM substudy of the SURMOUNT-1 trial. This substudy was required by the FDA to ensure the drug did not cause excessive HR increase and included 600 patients who underwent ABPM prior to randomization and again at the end of the 36-week study period. We observed that average 24-hour systolic BP was reduced significantly with tirzepatide compared with placebo, ranging from 7.4 to 10.6 mmHg reduction in the dose arms; 24-hour diastolic BP was also reduced. Average HR increased by 2.1 to 5.4 BPM across the dose arms.
The HR increase fell within the expected range for this drug class. The substantial reductions in 24-hour BP suggest potential cardiovascular benefits of tirzepatide. Large clinical trials evaluating the effects of tirzepatide on cardiovascular outcomes are currently underway in patients with diabetes and those with obesity.
Disclosure: Dr. de Lemos has received honoraria for chairing the Data Safety and Monitoring Board for the SURMOUNT-1 trial.
james.delemos@utsouthwestern.edu
