PTCA STUDY FINDS 89% PER LESION ANGIOGRAPHIC SUCCESS RATE IN WOMEN VERSUS 88% IN MEN; MORTALITY RATE FOR WOMEN IS 10.5-FOLD HIGHER, NHLBI DATA SHOWS
This article was originally published in The Gray Sheet
Percutaneous transluminal coronary angioplasty has an 89% per lesion angiographic success rate in women, according to a study based on 1985/1986 data from the National Heart, Lung and Blood Institute's PTCA Registry. The study, conducted by Sheryl Kelsey, PhD, University of Pittsburgh, et al., was published in the March issue of the American Heart Association journal Circulation. The study included 2,136 patients, 546 (26) of whom were women; the patients underwent PTCA during a ten-month period in 1985 or 1986 at one of 16 medical centers in the United States. The study was conducted as a follow-up to an investigation using registry data from 1978- 1981 that found that "PTCA risk was higher and efficacy was lower in women" ("The Gray Sheet" Sept. 17, 1990, p.18). Angiographic success was defined in the registry as a reduction of stenosis by 20% or more. The 89% success rate in the 822 total lesions treated in women compared to an 88% success rate found with the 2508 lesions that were attempted in men. "The mean stenosis change of successfully dilated lesions was 56% for women and 55% for men," the study found. The rate of in-hospital clinical success, defined as "all lesions dilated by 20% without death, myocardial infarction, or additional coronary artery bypass graft surgery," was 79% in both men and women. Kelsey et al. conclude that "the success rate and long-term prognosis after PTCA are excellent and should be considered for women in need of vascularization." However, the researchers caution that women undergoing PTCA have "a considerably higher" hospital mortality rate of 2.6% compared to .3% in men. Of the 18 patients who died soon after the operation was performed, 14 were women, 12 (86) of whom were age 65 or older. Based on the mortality data, the authors calculate that women undergoing PTCA have a 10.5-fold higher risk than men of dying in the hospital. The researchers note that females were an average of 4.5 years older than male patients studied. Although the women had more cardiovascular risk factors such as diabetes and high blood pressure, and more angina, Kelsey et al. point out that "their coronary artery disease was not more extensive, either clinically or anatomically." The data was consistent with the idea that male sex is a risk factor for coronary artery disease, and that for women to reach the same degree of disease, "higher levels of other risk factors must be present," according to the researchers. Kelsey et al. report that significantly more women than men had one or more complications during PTCA (17% versus 11%) or outside of the catheterization lab (15% versus 11%). Overall, complications occurred in 29% of the women as compared to only 20% of men studied, indicating that women were 1.63 times more likely than men to experience complications. Women were more likely to have more intimal tears and coronary dissections, which might be attributed to "limited choice of balloon sizes, fragile arteries, long lesions or tortuous vessels," the article speculates. Besides sex, the study isolated other significant univariate risk factors for death such as age, history of congestive heart failure, history of disease, and multivessel disease. Even after researchers adjusted for these "independent predictors of mortality," they found the relative risk factor of mortality was still 4.53 times greater for women than men. The researchers, however, caution against overinterpretation of the data, stating that "although the sex differential found was substantial, the actual number of deaths was not large." For patients who survived the initial procedure, the four year mortality rate was less than 4% greater for women than for men. After four years, women had slightly fewer myocardial infarctions (11.9 % versus 12.3%) and less cases of repeat PTCA or coronary artery bypass grafting (36% versus 39%). Despite the higher proportion of women reporting the presence of angina (30% of women versus 18% of men) at four years, 51% of women and 59% of men "were alive and free of MI, CABG and angina." In an editorial in the same journal issue, Mark Greenberg, MD and Hiltrud Mueller, MD, cardiologists at Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, note that recent articles have concluded "women undergo fewer diagnostic and therapeutic cardiac procedures than do men," implying that "women's symptoms are taken less seriously." Noting that some doctors try to overcompensate for this perceived sex bias, they assert that this practice becomes problematic when referring "high-risk" elderly women for PTCA who might be better treated through other means. Greenberg and Mueller conclude that further retrospective analyses and prospective studies are needed to evaluate the risks of PTCA in the older female. They maintain that assessment of PTCA on short- and long-term prognoses is necessary, and suggest that other analyses emphasizing age, vessel size, and lumen morphology should be conducted to divide patients into high- and low-risk subgroups. Pending further analyses, the editorial warns that "careful clinical judgment must be exercised" when deciding on a course of treatment. Currently, Kelsey et al. are conducting the Bypass Angioplasty Revascularization Investigation, a clinical trial comparing PTCA to CABG. The study is designed to "provide insight into the comparative safety and efficacy" of the treatments in both sexes.
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