CORONARY ANGIOPLASTY IMPROVES PATENCY AND OUTCOME BETTER THAN tPA, STREPTO

CORONARY ANGIOPLASTY IMPROVES PATENCY AND OUTCOME BETTER THAN tPA, STREPTO when used to treat acute myocardial infarction, two studies in the March 11 issue of the New England Journal of Medicine find. The studies show that use of percutaneous transluminal coronary angioplasty (PTCA) to treat acute MI reduces mortality and other complications and improves vessel patency compared to the thrombolytic agents streptokinase and tissue plasminogen activator (Activase). Cindy Grimes, MD, William Beaumont Hospital, Royal Oak, Mich., et al., compared immediate angioplasty to Genentech's Activase. The 395-patient study found an in-hospital death rate of 2.6% in the PTCA group, compared to 6.5% in the tPA group, a statistically significant difference. The mortality benefit of immediate PTCA "was seen mainly among patients who were classified as 'not [at] low risk'" of death, Grimes et al. comment. For these high-risk patients, the mortality rate was 2% in the PTCA group and 10.4% in the tPA group. The authors conclude that the potential benefits of immediate angioplasty outweigh the possible risks. "When the necessary facilities and personnel are available, immediate angioplasty is an attractive alternative to intravenous thrombolysis and may even be preferable for high-risk patients." Felix Zijlstra, Ziekenhuis de Weezenlanden, Zwolle, The Netherlands, et al., compared clinical outcomes of 142 patients randomly assigned to receive either PTCA or streptokinase. Vessel patency was achieved in 68% of patients in the streptokinase group and 91% of patients in the PTCA group. In addition, "quantitative coronary angiography revealed stenosis of 36% [+ or -20%] of the luminal diameter in the angioplasty group, as compared with 76% [+ or -19%] in the streptokinase group." Thirty-eight percent of the patients in the streptokinase group experienced recurrent ischemia, compared to 9% in the angioplasty group. Reinfarction occurred in 12.9% of streptokinase patients group and none in the PTCA group. The authors concluded: "Immediate angioplasty after acute myocardial infarction was associated with a higher rate of patency of the infarct-related artery, a less severe residual stenotic lesion, better left ventricular function, and less recurrent myocardial ischemia and infarction than was intravenous streptokinase." A third study in the March 11 NEJM by Raymond Gibbons, MD, Mayo Clinic and Foundation, Rochester, Minn., et al., compared PTCA to tPA therapy using myocardial salvage -- an indicator of the amount of tissue damage associated with PTCA and tPA -- as an endpoint. Based on results of their 108-patient study, the authors concluded that "immediate angioplasty does not appear to result in greater myocardial salvage than the administration of a thrombolytic agent followed by conservative treatment, although a small difference between these two therapeutic approaches cannot be excluded." In an editorial accompanying the three studies, Richard Lange, MD, and David Hillis, MD, University of Texas Southwestern Medical Center, comment that the study results indicate that immediate angioplasty should "now be the standard of care" for "a minority of patients" with myocardial infarctions. While MI treatment traditionally "seemed attainable with conservative management and without the need for invasive [PTCA] procedures," the commentators note, in light of the new study results, "the pendulum now appears to be swinging in the opposite direction" towards use of angioplasty.