People in a parallel group without the treatment in the trial, known as STEP HFpEF, saw a 8.7 point improvement, resulting in an estimated net benefit from Wegovy of 7.8 points.
The trial with 529 volunteers focused on a heart condition known as preserved ejection fraction, or HFpEF, where heart muscles stiffen and draw in less blood, mainly affecting overweight people.
The drug was shown to be "able to ease the disease burden for people with HFpEF and obesity in a substantial way,” said Martin Lange, head of development at Novo.
Novo this month raised the prospect of additional health benefits from taking Wegovy, apart from losing weight and cutting the risk of heart disease, as shown in a larger separate trial known as SELECT.
The Danish drugmaker also earlier this month published better-than-expected headline results from that study, saying the weekly injection cut the risk of heart attacks and strokes by 20%.
HFpEF accounts for about half of heart failure cases, with symptoms including shortness of breath and swelling of extremities.
The company said in a presentation in June that the drug had "demonstrated superiority" in that trial.
It said on Friday it would discuss the trial with regulators, who could potentially approve a wider use.
Showing specific medical benefits is crucial for Novo's push to move Wegovy beyond its image as a lifestyle drug. Such data may help persuade insurers in the United States and cost-conscious health authorities in Europe to cover its cost for a wider range of patients.
It costs as much $1,300 a month in the U.S., without any coupons or rebates, and about 300 euros ($324) per month in Germany.
It is unclear, though, what conclusions regulators and physicians will draw from the STEP HFpEF results because other heart failure treatments are emerging.
Entresto by Novartis (NOVN.S) won U.S. approval for certain cases of HFpEF in 2021 and AstraZeneca's (AZN.L) Farxiga was shown to help HFpEF patients according to trial results from late last year.
Novo Nordisk CEO Lars Fruergaard Jorgensen told a Reuters Newsmaker event on Friday the company planned to launch Wegovy in more countries, albeit in a "constrained" manner as it will take years before it can meet global demand,
($1 = 0.9266 euros)
