Semaglutide and tirzepatide compared with MRAs as fourth-line therapy in resistant hypertension

People whose blood pressure stays high even after several medications face a real decision about what to add next. A retrospective cohort study published in eClinicalMedicine compared two of those options — the GLP-1 drugs semaglutide and tirzepatide against a mineralocorticoid receptor antagonist (MRA) — in adults who also have overweight or obesity, and tracked major adverse cardiovascular events over two years ^[1].

The study drew on the TriNetX US Collaborative Network, which pools electronic health records from 67 healthcare organizations ^[1]. Researchers identified 213,309 eligible patients with resistant hypertension and overweight or obesity before propensity matching, a statistical step that builds comparison groups with similar measured characteristics ^[1]. Everyone in the study was starting a fourth-line blood pressure medication, meaning they were already taking multiple drugs for their blood pressure ^[1].

The exposure group started semaglutide (sold as Ozempic, Wegovy and Rybelsus) or tirzepatide (Mounjaro and Zepbound). The comparison group started an MRA. The primary outcome was major adverse cardiovascular events over two years ^[1].

Semaglutide and tirzepatide were analyzed together rather than separately, so the study cannot show whether one of the two performed differently from the other ^[1]. The specific effect estimates — how much the rate of cardiovascular events differed between the groups — have not been disclosed in the published summary of the research ^[1].

The larger limitation is built into the design. This was not a randomized trial, and the authors describe confounding by indication as the central limitation ^[1]. In plain terms, the reasons a patient's clinician chose a GLP-1 drug instead of an MRA may themselves be tied to that patient's heart risk. A difference between the groups would therefore not prove that one drug caused it.

How the two strategies compared on blood pressure control itself, on side effects, on tolerability or on cost has not been reported ^[1].

Why it matters for patients

For someone already taking several blood pressure medications and still not at goal, the fourth-line choice is not abstract. This study speaks to that group specifically — adults with resistant hypertension who also have overweight or obesity — and it looks at serious cardiovascular events rather than at readings from a blood pressure cuff ^[1].

But the findings cannot be read as a reason to request one drug over another. Because the comparison was observational, patients who received a GLP-1 drug may have differed from those who received an MRA in ways the researchers could not fully measure ^[1]. Pooling semaglutide and tirzepatide into a single group also means the study says nothing about which of the two might be preferable ^[1].

Practical factors that often drive this decision — insurance coverage, out-of-pocket cost, a weekly injection versus a daily pill, and how well each option is tolerated — are not addressed in the report ^[1]. What the study offers is a large, real-world look at a question that has lacked one, not a settled answer.

What happens next

The paper appears in eClinicalMedicine ^[1]. A randomized trial designed to compare GLP-1 drugs with MRAs as fourth-line therapy in this patient group has not been reported ^[1]. The authors treat confounding by indication as the reason their results are not definitive, and until randomized data exist, the choice of a fourth-line agent remains a case-by-case discussion between patient and clinician ^[1].