Skip to content
This GLP
← Research
Evidence

Heart failure: the trial where placebo had more serious events

Symptom scores improved by 7.5 points and walk distance by 17 meters. Serious adverse events ran 161 on the drug against 301 on placebo.

Dana Sullivan5 min read
Symptom score at 52 weeks, between-group difference+7.5 points (95% CI 5.3 to 9.8)Six-minute walk distance+17.1 metersSerious adverse events161 on semaglutide · 301 on placebo

Heart failure with preserved ejection fraction is a condition with very little that works, and the pooled analysis of STEP-HFpEF and STEP-HFpEF DM is one of the few trials to move it. It combined individual patient data from two randomized placebo-controlled trials across 129 sites in 18 countries, 1,145 participants in all, every one with a BMI of at least 30 and heart failure symptoms [1]. The effect sizes are modest in absolute terms and the direction is consistent across everything measured — including one number that looks wrong until you understand it. Before weighing it against what a seller charges, it is worth knowing who was studied.

What improved

The dual primary endpoints were symptom score and body weight at 52 weeks. The Kansas City Cardiomyopathy Questionnaire clinical summary score improved by 7.5 points more on semaglutide than placebo (95% CI 5.3 to 9.8), and body weight fell 8.4 percentage points further (95% CI −9.2 to −7.5). Both at P < 0.0001.

Six-minute walk distance improved by 17.1 meters more (95% CI 9.2 to 25.0). A hierarchical composite of death, heart failure events and changes in those two measures gave a win ratio of 1.65 (95% CI 1.42 to 1.91). C-reactive protein, a marker of inflammation, fell to a treatment ratio of 0.64 (95% CI 0.56 to 0.72). Effects held consistently across subgroups defined by age, race, sex, BMI, blood pressure, baseline CRP and ejection fraction.

The number that looks like a typo

There were 161 serious adverse events in the semaglutide group and 301 in the placebo group. That is not a transcription error and it is not unusual in a sick population: when a drug prevents some of what the underlying illness would otherwise do, the treated arm can accumulate fewer serious events than the untreated one. It is also a reminder that the harms of a condition and the harms of its treatment are measured on the same page.

What it does not transfer to

These were people with diagnosed heart failure, a BMI of 30 or more, and symptoms bad enough to score under 90 on the questionnaire. The dose was 2.4 mg weekly, which is the weight-management dose most compounded sellers titrate toward — so unlike the kidney trial at 1.0 mg, the dose here does transfer. The population does not.

If you have heart failure and are considering a telehealth purchase, the gap is not the evidence. It is that this is a condition needing monitoring, and most sellers tracked here publish nothing about who reviews a case — the census is in what sellers publish and in what they will not tell you. A seller that cannot tell you who reads your history is not the right route into a cardiac diagnosis.

Frequently asked

How much did symptoms improve?
The heart-failure symptom score improved by 7.5 points more on semaglutide than placebo (95% CI 5.3 to 9.8), alongside 8.4 percentage points more weight loss and 17.1 meters more walking distance.
Why were there fewer serious events on the drug?
161 against 301. In a population sick enough to have symptomatic heart failure, a treatment that prevents some of what the illness does can produce fewer serious events than placebo.
Does the dose match what sellers offer?
Yes. The trials used 2.4 mg weekly, which is the weight-management dose most compounded sellers titrate toward. The population, however, was people with diagnosed heart failure.

Sources

  1. [1] Butler J, et al. (2024). Semaglutide versus placebo in people with obesity-related heart failure with preserved ejection fraction: a pooled analysis of the STEP-HFpEF and STEP-HFpEF DM randomised trials The Lancet. PMID 38599221

Where to get it

Best GLP-1 injections

Every injectable seller we can verify, with the price each one publishes and an honest read of what the trials measured.

Compare providers →

More in Evidence