New research has revealed that the addition of the blood-thinning drug Plavix to a daily dose of aspirin does not lower the risk of death, heart attack or stroke in high-risk patients.

The researchers say although the overall findings were negative a benefit was seen in patients with established cardiovascular disease.

Dr. Deepak Bhatt, associate director of the Cleveland Clinic Cardiovascular Coordinating Center and the study’s lead investigator, says the combination of Plavix and aspirin may do more harm than good for patients at risk of developing heart disease, but it can help those who have already suffered a heart attack or stroke.

In the trial, 15,603 patients at risk of heart attacks were randomly given either Plavix or a placebo, and all were given low-dose aspirin (75 to 162 mg per day).

At present Plavix is the standard treatment among the anti-platelet drugs, which are used to prevent blood clots that can cause a heart attack, unstable angina, or stroke.

and has been proven in previous trials to help prevent second heart attacks, strokes and death among patients with acute heart disease.

Aspirin which is also a blood thinner, affects a different platelet receptor than Plavix, which has more potent effects.

The latest study included patients with more stable cardiovascular disease as defined by a previous heart attack or stroke, or evidence of poor blood supply to the legs, as well as patients with risk factors for future atherosclerosis, such as diabetes, high blood pressure and High cholesterol.

The trial showed over a 28-month follow-up, that the combined rate of death, heart attack or stroke in the group taking placebo plus aspirin, compared with the patients on Plavix plus aspirin was not significantly different.

The addition of Plavix did slightly reduce the rate of hospitalization but when the analysis was limited to the 12,153 patients with heart disease, Plavix reduced the combined rate of death, heart attack, or stroke from 7.9 percent to 6.9 percent.

The researchers say that in addition to finding no significant benefit for the combination in the trial in more than 15,000 patients, Plavix plus aspirin for patients with multiple risk factors was associated with increased risk for moderate and serious bleeding.

It was also found that the Plavix/aspirin combo nearly doubled the risk for death from cardiovascular causes for high-risk asymptomatic patients compared with plain aspirin alone, says Dr.Bhatt.

Dr. Charles Hennekens, professor of medicine, epidemiology and public Health at the University of Miami School of Medicine, says the results of the study confirm that aspirin is “the gold standard” for treating heart risk.

Dr.Hennekens says the trial results support the belief that aspirin has the best benefit to risk and is the most cost efficient of the heart drugs.