Weight-Loss Drugs Show Promise but Remain Hard to Access

MANCHESTER, England — While evidence mounts to support the widespread use of both semaglutide (Wegovy) and tirzepatide (Mounjaro) in people with heart failure who need to lose weight, experts at the British Cardiovascular Society (BCS) Annual Conference 2025 warned that access to these drugs remains limited in both the UK and the US.

Christopher Kramer, president of the American College of Cardiology and chief of the Cardiovascular Division at the University of Virginia Health, Charlottesville, Virginia, said that US insurers seemed to be “working hard to try to limit the use of these drugs to hold down costs.”

He noted that insurance companies often require patients to have specific cardiovascular conditions, such as proof of disease via cardiac MRI, before approving tirzepatide, which is branded as Zepbound in the US.

Tricia Tan, a consultant in diabetes, endocrinology and metabolic medicine at Imperial College London and Imperial College Healthcare NHS Trust, London, England, said similar barriers exist in the UK.

“We are struggling to be able to use these drugs in the NHS,” she said. Although the National Institute for Health and Care Excellence (NICE) has recommended them for some people with a BMI over 35, NHS England has imposed additional restrictions.

High Demand, Limited Supply

NHS England said restrictions are needed due to high demand from people with weight-related conditions beyond heart disease.

NICE recommends the drugs only after dietary, exercise, and behavioural therapies have been started and stresses that these lifestyle changes should continue during treatment.

Diet and lifestyle remain central in the fight to curb rising obesity rates and are associated with “around a 3%-8% weight loss,” Tan said, but this is “often difficult to sustain,” with fluctuations in weight. By contrast, she noted, semaglutide and tirzepatide offer benefits beyond weight loss, including potential cardiovascular effects.

Most cardiovascular data so far relate to semaglutide. Similar evidence for tirzepatide is still emerging.

Evidence Builds for Use in Heart Failure

Several speakers at the conference said the evidence from studies in patients with heart failure — such as the STEP 1 trial with semaglutide and the SUMMIT trial with tirzepatide — is now strong enough to justify their wider use in clinical practice.

Cardiology registrar Matthew Todd from the Royal Victoria Hospital in Belfast, Northern Ireland, summarised findings from the SUMMIT trial, recently published in The New England Journal of Medicine.

This 52-week trial included 731 patients with heart failure, an ejection fraction (EF) of at least 50%, and a BMI of at least 30. Results showed a 38% reduction in the primary composite endpoint of death from cardiovascular causes or worsening heart failure for those on tirzepatide compared with placebo.

“We know that obesity drives heart failure with preserved ejection fraction [HFpEF] progression,” said Todd. “This is a population with limited treatment options but a high symptom burden.”

Rosita Zakeri, honorary consultant cardiologist at King’s College Hospital and Guys and St Thomas’ NHS Trusts, and a senior clinical lecturer at King’s College London, London, England, called the drugs “safe.”

She said that based on available evidence, “they’re largely well-tolerated, effective treatments for obesity and its impact on quality of life in patients with heart failure with preserved ejection fraction.”

However, she noted that the number of primary events in the SUMMIT trial was low. Many of the reported worsening heart failure cases were due to changes in diuretic therapy, not hospitalisations.

“We’re far from saying that these are treatments for heart failure specifically,” Zakeri cautioned.

Kramer also emphasised that these drugs are for HFpEF only and may not be safe for patients with heart failure with reduced EF. “They may even be deleterious,” he warned.

Long-Term Access Unclear

Some patients are self-funding their treatment. When asked what to advise a patient struggling to afford tirzepatide, Tan said she would not recommend stopping the medication.

“When you come off these treatments, you do regain the weight,” she said.

However, NHS access may be denied if patients do not meet strict criteria, such as having a BMI over 40 along with four comorbidities.

Gaurav Gulsin, National Institute for Health and Care Research academic clinical lecturer in cardiology at the University of Leicester, Leicester, England, also emphasised to Medscape News UK that these are likely to be long-term treatments. He noted that NHS funding typically covers 2 years before reassessment and that sustainability remains a concern.

“These drugs do make people feel a lot better,” he said. “I think it’s important that we consider using them if and when we can.”

Currently, semaglutide must be prescribed through specialist NHS clinics. Tirzepatide, however, can be prescribed in primary care. Gulsin said cardiologists could encourage GPs to consider initiating tirzepatide in eligible patients.

Kramer declared being an investigator for the SUMMIT trial and the principal investigator for the SUMMIT CMR sub-study. He disclosed research support from, and acting as a consultant to, Eli Lilly and Company. He has also received consulting fees and honoraria from Bristol Myers Squibb and Xencor. Tan, Todd, and Gulsin had no relevant conflicts of interest to disclose. Zakeri acknowledged relationships with AstraZeneca, Boehringer Ingelheim, and SERB Pharmaceuticals.

Sara Freeman, BSc, MSc, is a freelance medical journalist based in London, England. She has been reporting for specialist healthcare news organisations for more than 20 years.