Revolutionary laser surgery for treating angina is dangerous, and at least 5 per cent of patients die soon after the operation, a damning new study has found.

The technique, known as transmyocardial laser revascularisation (TMLR), significantly increases the risk of death and serious illness, and yet offers no benefit to patients over traditional drug therapy.

The study, carried out by an influential team of specialists based at Papworth Hospital in Cambridge and at other centres, could mean that TMLR disappears as an option in British hospitals.

The research involved 188 patients with refractory angina who were randomly assigned TMLR plus normal medication or medical management alone. Both groups had their exercise capacity regularly assessed with a treadmill.

While differences in exercise capacity were not significant between the two groups, 5 per cent of the TMLR group died soon after surgery and, after 12 months, just 89 per cent were still alive compared with 96 per cent of the medical management group.

An earlier study had found that the mortality rate of TMLR patients was 10 per cent, but the Cambridge researchers believe they produced better results only because they were monitoring patients with less serious conditions.

In an accompanying editorial, Rene Pretre from the University Hospital in Zurich says that laser therapy should be made available only at a handful of specialist centres (Lancet, 1999; 353: 519-24).