By McCann, Jean
Drug Topics , Vol. 146, No. 8
The rules governing which cardiac patients should get what therapy seem to be changing, based on the results of studies reported at the annual meeting of the American College of Cardiology (ACC), held in Atlanta last month. Another reason for change is the recent revision of some ACC/American Heart Association (AHA) guidelines dealing specifically with the treatment of patients with unstable angina or non-ST-segment elevation myocardial infarction (NSTEMI).
One thing that stood out clearly, too, is that many patients who could benefit are not now getting optimal therapy, according to Duke University researcher Eric Peterson, M.D. He reported that only 25% of patients with acute coronary syndromes are receiving glycoprotein (GP) IIb/IIIa inhibitors, which have been shown to reduce the incidence of heart attacks, strokes, and other problems in many high-risk patients. He based this conclusion on a study by the National Registry of Myocardial Infarction, which found that of the 186,727 patients registered, 60,770 were eligible for this class of drugs, but only a quarter had gotten them.
Also, a so-called Crusade initiative, which involved the study in 80 hospitals of physician practices, showed that only 36% of patients were getting the GP IIb/IIa inhibitors, which are recommended to be given to patients within 24 hours of their arrival in the emergency room.
At the same time, however, the new ACC/AHA guidelines call for the use of the inhibitor abciximab (ReoPro, Lilly) only in patients having invasive procedares, such as balloon angioplasty or stenting. The use of two other GP IIb/IIIa inhibitors, eptifibatide (Integrilin injection, Millennium Pharmaceuticals) and tirofiban (Aggrastat injection, Merck), should be confined to high-risk patients who will be treated with medication only, according to the new guidelines drawn up by an expert panel headed by Eugene Braunwald, M.D., Distinguished Hersey Professor of Medicine at Harvard Medical School. As he put it, "We've learned more in a year about unstable angina and NSTEMI than we did in the preceding 20 years."
The new guidelines also recommend adding clopidogrel (Plavix, Bristol-Myers Squibb) to standard therapy, including aspirin, for the acute and continued treatment of unstable angina and mild heart attacks. The Food & Drug Administration recently approved clopidogrel for this purpose.
Meanwhile, at the ACC convention, one study indicated that there is something better than the ACC/AHA guidelines, which called for the use of unfractionated heparin with eptifibatide. Rather, the study, called INTERACT (Integrilin and Enoxaparin Randomized Assessment of Acute Coronary syndrome Treatment), showed that patients receiving a combination of eptifibatide plus the low molecular weight heparin enoxaparin sodium (Lovenox injection, Aventis) experienced a 44% reduction in the risk of heart attack or death compared with patients receiving eptifibatide plus unfractionated heparin, which was the standard. The newer combination was also associated with a 44% decrease in ischemia and a reduced incidence of major bleeding.
All the studies presented at the ACC meeting also highlighted what has become increasingly evident-that each patient is an individual, and not all will benefit from the same drugs. Indeed some patients, according to reports presented at the meeting, would benefit more from expensive implanted $20,000 devices than they would from drugs. Still, it is pharmacotherapy that is the mainstay of the treatment of cardiovascular disease, and below are some of the highlights from this year's ACC meeting:
* Is blocking two enzymes better than one? OVERTURE (Omapatrilat vs. Enalapril Randomized Trial of Utility in Reducing Events) had a combined endpoint of all-cause mortality or hospitalization for heart failure, and randomized 5,770 patients to either the standard ACE inhibitor enalapril or to omapatrilat (Vanlev, Bristol-Myers Squibb), a novel agent that inhibits neutral endopeptidase (NEP)/ angiotensin-converting enzyme (ACE), according to Milton Packer, M. …