Results of Systematic Review of Research on Diagnosis and Treatment of Coronary Heart Disease in Women

Objectives:

The Agency for Healthcare Research and Quality and several partner organizations charged the University of California, San Francisco-Stanford Evidence-based Practice Center to review the evidence on five key topics related to coronary heart disease (CHD) in women: (1) accuracy of noninvasive testing for diagnosis of CHD; (2) efficacy of treatments; (3) strength of risk factors and efficacy of risk factor reduction; (4) utilization of tests and treatments in men compared to women, and (5) accuracy of biomarkers for diagnosis of myocardial infarction. These five key questions included 42 discrete subtopics. We used standard methods to systematically review the medical literature to address each subtopic. The evidence identified was reviewed, graded and summarized for each subtopic and further research was recommended as appropriate.

Search Strategy:

We identified 6,403 citations from searching electronic databases from 1985 through July 2001, reviewing bibliographies, and by recommendation from our peer reviewers.

Selection Criteria:

After the titles were screened, abstracts were reviewed independently by two investigators who coded each abstract for eligibility for full text review. In order to be categorized as providing evidence regarding a research question, the article had to address the predictor variable and the clinical outcome and contain data to address the question specifically in women. Articles meeting inclusion criteria were abstracted independently on a standardized form by two investigators, and received a quality score based on predefined criteria. All studies rated good or fair were included in this review.

Data Collection and Analysis:

The titles and abstracts were entered and coded in EndNote^® files. Data from the standardized review form was entered into a Microsoft^® Access database, which allowed tracking of the eligibility, quality and type of study of each article reviewed.

Main Results:

We reviewed the full text of 819 articles and found 162 that provided evidence in women. We found no data in women to address 13 of the subtopics, weak data to address 15, fair data for eight and good data to address six.

Fair evidence suggests that the accuracy of exercise EKG and exercise thallium testing for CHD in women is low. The accuracy of exercise echocardiography appears to be higher, but data are limited.

Fair or good evidence suggests that beta-blockers, aspirin and angiotensin converting enzyme inhibitors reduce risk for CHD events and that nitrates are ineffective in women with known heart disease.

Fair evidence suggests that glycoprotein IIb/IIIa inhibitor drugs given to women undergoing percutaneous revascularization result in a reduced risk of CHD events and need for revascularization, but treatment of women suffering acute coronary syndromes may result in increased mortality. This was the only treatment for which there was evidence of a possible interaction by gender: men treated with IIb/IIIa drugs during acute coronary syndromes appear to benefit.

Fair or good evidence suggests that hyperlipidemia, diabetes, and hyperhomocysteinemia are risk factors for CHD in women.

Fair or good evidence suggests that smoking cessation after MI and treatment of hypertension and hyperlipidemia lower risk for CHD events in women.

We found little evidence to address the key questions in women of different races or ethnicities. The only evidence regarding differences by ethnicity suggests that African-American women may benefit more from treatment of hypertension than white women.

Conclusions:

New or updated systematic reviews of the literature appear to be feasible and would likely provide clinically important information for 14 of the subtopics. The major limitation in performing these systematic reviews is that data stratified by gender and race/ethnicity from completed studies may not available. We recommend that, in addition to requiring participation of women and minorities in research, the National Institutes of Health, U.S. Food and Drug Administration and other funding and regulatory agencies insist that outcome data by subgroup be published or archived.