By Gary Faulds
STOCKHOLM (Reuters Health) – A direct thrombin inhibitor derived from leech saliva improves the prognosis of myocardial infarction patients, results from the HERO-2 (Hirulog Early Reperfusion/Occlusion) trial show.
The compound, bivalirudin, was 30% more effective at reducing re-infarction than heparin, translating to eight fewer re-infarctions within 30 days for every 1000 treated patients, researchers said here Sunday at the XXIII Congress of the European Society of Cardiology.
"The results of this trial are momentous," said Dr. Eric Topol, the Chairman of Cardiovascular Medicine at the Cleveland Clinic in Ohio, USA, who conducted a review of the HERO-2 study data.
"HERO-2 validates bivalirudin as an important drug in the management of ischemic heart disease, and we can look forward to further progress in other trials," he said. "The finding that bivalirudin achieves a substantial reduction in re-infarction without causing a significant increase in intra-cerebral hemorrhage represents a significant step forward in patient care."
Bivalirudin (Angiomax) is manufactured by US-based firm The Medicines Company. It was approved in the US last December for use with aspirin to treat patients with unstable angina who are undergoing coronary angioplasty, and recorded $2 million in sales during the first quarter of 2001.
The HERO-2 study enlisted 17,073 patients in 539 centers across 46 countries, including a large number of patients from Russia, Eastern Europe and South America. Patients received either bivalirudin or heparin. Both sets of patients also received aspirin and streptokinase. Uniquely, the HERO-2 study used a panel of experts to confirm the diagnosis of all possible re-infarctions reported by doctors in the study.
When combined risk of death, re-infarction or non-fatal disabling stroke was examined, patients receiving bivalirudin had 11 fewer events per 1000 patients than the heparin group, the researchers said.
However, in common with the ASSENT-3 and GUSTO-V trials, the HERO-2 study failed to show a statistically significant reduction in death or MI across the trial.
In addition, the death rate within 30 days post-MI observed in HERO-2, 10.8%, was higher than in the other two studies. According to the researchers, this could be accounted for by a higher number of risk factors in patients enrolled in this study and their geographical location. Among Western participants in HERO-2, the death rate was 6.7%, which is comparable with the other studies.
Professor Harvey White, of the University of Auckland, New Zealand, the principal investigator of the study, said: "We believe the higher mortality in our trial may be more reflective of the true death rates, certainly in the countries in which these patients are randomized."
White compared the HERO-2 trial with ASSENT-3 and GUSTO-V, and expressed confidence in the findings. "We believe that the data in HERO-2 is very robust, and it is the only trial where the MIs were adjudicated. We believe that bivalirudin is an improved foundation anti-thrombotic therapy and a new treatment option for patients with acute myocardial infarction treated with streptokinase."