Journal club: STEP-HFpEF and symptom endpoints

Journal club: STEP-HFpEF and symptom endpoints — setting out what I have, and where I think it stops being reliable.

Comparing SURMOUNT-2 (Lancet, 2023) with SURMOUNT-1 (N Engl J Med, 2022) and finding the comparison harder than it looks.

Different populations, different durations, different endpoints defined slightly differently, and in one case a different estimand. People compare the headline percentages anyway, including me until recently.

Is there a defensible way to put these side by side, or is the honest answer that there is not and we should stop?

This follows the opening post rather than contradicting it.

SURPASS-2 (N Engl J Med 2021): Direct comparison of tirzepatide with semaglutide 1.0 mg. The 1.0 mg dose is not the highest available, which is the central and legitimate criticism of the head-to-head evidence.

Worth separating two things that the opening post runs together.

SURMOUNT-OSA (N Engl J Med 2024): Tirzepatide in obstructive sleep apnoea, using an objective physiological endpoint. Notable because soft endpoints are avoided. Two parallel trials addressed the confounder directly.

SOUL (N Engl J Med 2025): Oral semaglutide cardiovascular outcomes. Extends the cardiovascular evidence to the oral formulation. Note that oral bioavailability is lower and more variable than injectable.

Coming back to post #3, because the follow-up matters more than the original answer.

Session format: read the paper before posting. The discussion is much better when everyone has. Start with the estimand and population, then methods, then results, then limitations. That order makes critique coherent.

Picking up post #3: that is the part I would want checked first.

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

SELECT (N Engl J Med 2023): Semaglutide cardiovascular outcomes without diabetes. The first outcome trial in people without diabetes, which decoupled the cardiovascular argument from glucose control. Read the absolute numbers, not just the relative reduction.

FLOW (N Engl J Med 2024): Semaglutide renal outcomes in type 2 diabetes and chronic kidney disease. Stopped early for efficacy. Component-by-component analysis is essential because the components differ in how patient-important they are.

I read post #7 twice before replying, because I had assumed the opposite.

STEP 1 (N Engl J Med 2021): The pivotal obesity trial for semaglutide and the reference point for most subsequent comparison. Mean weight reduction was substantially larger than anything previously achieved pharmacologically.

SURMOUNT-1 (N Engl J Med 2022): Tirzepatide obesity trial. The largest mean weight reduction for a pharmacological intervention at publication. Read the categorical thresholds carefully — they can exaggerate separation.

TRIUMPH (ongoing): Retatrutide phase 3. No results yet. Nothing should be attributed to it because it has not finished. When it does, this discussion will return to it.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

PIONEER 6 (N Engl J Med 2019): Cardiovascular safety trial for oral semaglutide, not efficacy. Non-inferiority for safety was met. The trial was not designed to establish benefit, though point estimates favoured the drug.

Worth separating two things that post #10 runs together.

Critical appraisal template: (1) What did the trial set out to estimate? (2) Could the design answer that question? (3) Was the population sufficiently similar to your population to apply the results? (4) What was the absolute effect, not just the relative one? (5) What are the two strongest criticisms available?