Participation of Women in Cardiovascular Drug Clinical Trials

Study Questions:

Are women underrepresented in trials of cardiovascular medications submitted to the US Food and Drug Administration (FDA)?


The enrollment of women in trials supporting 36 drug approvals from 2005 to 2015 was assessed. Participation to prevalence ratio (PPR) was calculated as the percentage of women in the trial divided by the percentage of women in the disease population, with 0.8-1.2 reflecting similar representation. Efficacy and safety differences by sex were also assessed.


In the 36 trials, enrollment of women was 22%-81% (mean 46%). Diseases for which the PPR was within or above the desired range were atrial fibrillation (0.8-1.1), hypertension (0.9), and pulmonary arterial hypertension (1.4). The PPR was below the desirable range (<0.8) for heart failure (0.5-0.6), coronary artery disease (0.6), and acute coronary syndrome/myocardial infarction (0.6). No clinically meaningful sex differences in efficacy or safety were found. Four drugs included sex differences in efficacy or safety labeling.


The authors concluded that women were underrepresented (PPR <0.8) for medication trials for heart failure, coronary artery disease, and acute coronary syndrome. Women were adequately represented in trials for atrial fibrillation and hypertension, and overrepresented for pulmonary arterial hypertension. There were only minimal sex differences in drug efficacy and safety profiles.


Historically, women have been underrepresented in clinical trials. This study shows adequate representation of women in trials of medications for atrial fibrillation and hypertension, and women may actually be overrepresented in trials for pulmonary arterial hypertension. However, trials of medications for heart failure, coronary artery disease, and acute coronary syndrome still underrepresent women, even when corrected for disease prevalence. Although the authors did not find significant differences between men and women with respect to medication safety and efficacy, appropriate representation of the patient population to be treated is important. Future research should address reasons for sex-based differences in trial enrollment.

Clinical Topics: Acute Coronary Syndromes, Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Prevention, Pulmonary Hypertension and Venous Thromboembolism, Atherosclerotic Disease (CAD/PAD), Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Pulmonary Hypertension, Hypertension

Keywords: Acute Coronary Syndrome, Atrial Fibrillation, Clinical Trials as Topic, Cardiovascular Agents, Coronary Artery Disease, Drug Approval, Heart Failure, Hypertension, Hypertension, Pulmonary, Myocardial Infarction, Pharmaceutical Preparations, Secondary Prevention, Women, United States Food and Drug Administration

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