Adding a licensed drug to standard heart therapy for people suffering acute chest pain significantly lowered the incidence of death, heart attacks and strokes in a new study that was reported Monday at a major cardiology meeting.
The drug is clopidogrel, marketed by Sanofi-Synthelabo as Plavix and by Bristol-Myers Squibb as Iscover. The two companies paid the $50-million cost of the study, but it was conducted independently by a team at McMaster University in Canada.
The drug's benefits began within two hours of taking it and continued long-term, Dr. Salim Yusuf, the study's principal investigator, told a meeting of the American College of Cardiology in Orlando. Other experts at the meeting described the findings as a major advance in the treatment of heart disease.
The drug is already approved to prevent the formation of clots after angioplasty. Vice President Dick Cheney took Plavix for 30 days after undergoing angioplasty last November and began taking it again after another angioplasty this month.
If every American patient who needed it received it, Yusuf said, 50,000 to 100,000 of them might potentially escape heart attacks and strokes, and the lives of 5,000 to 10,000 might be saved each year.
The study compared patients treated with a variety of standard cardiac therapies with patients who received similar treatment with the addition of the drugs.
Dr. Robert Califf of Duke, who moderated Yusuf's presentation, said doctors should use clopidogrel for acute coronary syndrome.
Acute coronary syndrome is a life-threatening condition that doctors also call unstable angina and non-q-wave myocardial infarction, or a mild heart attack. The syndrome is characterized by frequent and severe attacks of chest pain and can occur during mild exercise or at rest.
In the syndrome, not enough blood can flow to nourish the heart because the coronary arteries are blocked by fatty deposits from the underlying condition, atherosclerosis. A heart attack can result unless urgent therapy is given.
Yusuf's study was the largest and longest of acute coronary syndrome and involved more than 12,500 patients in 428 hospitals in 28 countries.
Half the participants received standard therapy, including aspirin; the other half received standard therapy plus one clopidogrel pill a day.
In the group receiving standard therapy, death, stroke and heart attack occurred in 11.47 percent compared to 9.28 percent in the group receiving clopidogrel, a 20 percent reduction.
Heart attacks were reduced by 23 percent, from 6.68 percent to 5.19 percent. Strokes were reduced by 15 percent, from 1.4 percent to 1.2 percent.