Clot-busting drugs are just as effective as emergency angioplasties atrestoring blood flow to heart attack victims. A study of 3,145 heartattack victims shows no difference in mortality between people whoreceived antithrombolytics and those who had angioplasties uponarriving at the hospital.
"Doctors who are using antithrombolytics as a primary therapy canbe reassured that this is a reasonable approach," said Nathan Every,of the Seattle Veterans Affairs Hospital and lead study author whichwas published in the Oct. 24 New England Journal of Medicine.
Every and his colleagues initiated their study in response to severalsmaller studies that showed patients who had an angioplasty to re-establish blood flow to the heart during a heart attack were morelikely to survive their heart attacks than those who received clot-busters. While those studies used the gold standard method ofrandomly assigning heart attack victims to a therapy, they were smalland conducted at institutions which had expertise in primaryangioplasty.
"We wanted to test how thrombolytic therapies compared to primaryangioplasty out in the community where many hospitals don't evenhave the trained staff or specialized facilities to do angioplasties,"Every said.
The researchers compared the mortality during hospitalization as wellas long-term mortality in 1,050 heart attack patients who had primaryangioplasty and 2,095 patients who received clot-busting drugs inSeattle area hospitals. The physicians at these hospitals chose thetype of therapy that patients received rather than randomly assigningpatients to one therapy or another. However, the researchers used thismethod because it represents the real life experience of physiciansand patients. Of those who got the clot busters, 65 percent receivedGenentech Inc.'s recombinant tissue plasminogen activator, Activase,32 percent received streptokinase and 3 percent receivedprourokinase.
The researchers found that there was no difference in either short-term or long-term mortality between the two therapies with 5.6percent mortality in the hospital among patients receiving clot bustersand 5.5 percent mortality for those undergoing angioplasties.However, 32 percent of the patients who had clot-buster therapiessubsequently had angioplasties.
"This represents the real world where a patient comes into anemergency room and receives antithrombolytic therapy to re-establishblood flow and if that fails to provide adequate flow to the heart, thepatient is transferred to a hospital that has the facilities to performangioplasties," Every said. In essence, the clot-busters are serving asa therapeutic bridge to buy patients more time.
In the study, 1.5 percent of the patients who received the clot-bustershad cerebral hemorrhages which is an expected number for thiscomplication.
Paul Laland, associate director for corporate communications atGenentech, of South San Francisco, said the study helps those whoare doing primary angioplasty realize that they can get good resultswith Activase. "And, for those using Activase as their primarytherapy, it gives them the assurance that they are getting the bestoutcome possible."
Laland noted that this study is unlikely to affect sales of Activase asthe drug currently has about 80 percent of the market share forantithrombolytics. n
-- Lisa Seachrist Washington Editor
(c) 1997 American Health Consultants. All rights reserved.