Cyproterone Acetate + Ethinylestradiol and Acute Coronary Syndrome Risk
Combined oral contraceptives containing cyproterone acetate and ethinylestradiol do increase the risk of acute coronary syndrome (myocardial infarction), with the risk being strongly amplified by cardiovascular risk factors, particularly smoking, hypertension, age >35 years, and diabetes.
Magnitude of Risk
The evidence demonstrates that COCs containing cyproterone acetate with 30-35 μg ethinylestradiol carry approximately 1.5-2.3 fold increased risk of myocardial infarction compared to non-users 1, 2. Specifically, cyproterone acetate-containing COCs show similar thrombotic risk profiles to other third-generation progestins like desogestrel and drospirenone—approximately 50-80% higher risk than levonorgestrel-containing COCs 3.
The absolute risk remains low in healthy young women (approximately 10 per 100,000 person-years for myocardial infarction) 4, but this baseline risk increases dramatically with specific risk factors.
Risk Amplification by Cardiovascular Factors
The risk of acute coronary syndrome with cyproterone acetate/ethinylestradiol escalates substantially in the presence of:
Smoking + age >35: Risk increases 10-fold for myocardial infarction 5. The French Society of Endocrinology guidelines explicitly state that combined contraception is formally contraindicated in smokers over 35 years, especially those smoking >15 cigarettes daily 6.
Hypertension: Poorly controlled hypertension (≥160/100 mmHg) increases MI risk approximately 3-fold, and combined contraception is formally contraindicated in this setting 6. Even controlled hypertension represents a relative contraindication unless the patient is <35 years with no other risk factors 6.
Diabetes with vascular complications: Formal contraindication per guidelines 6.
Multiple risk factors: The WHO reports that COCs are not associated with increased MI risk in healthy, normotensive, nondiabetic nonsmokers at any age 3, but the presence of multiple factors creates exponential risk.
Estrogen Dose Effect
Higher estrogen doses increase arterial thrombotic risk. The risk appears dose-dependent, with preparations containing >50 μg ethinylestradiol carrying the highest risk 1. Standard cyproterone acetate formulations contain 35 μg ethinylestradiol, placing them in the moderate-risk category.
Clinical Decision Algorithm
Absolute contraindications for cyproterone acetate/ethinylestradiol:
- Age >35 years AND current smoking
- Uncontrolled hypertension (≥160/100 mmHg)
- Personal history of MI, stroke, or coronary artery disease 6
- Diabetes with vascular disease
- Multiple cardiovascular risk factors
Relative contraindications (use only if benefits clearly outweigh risks):
- Age <35 with controlled hypertension AND no other risk factors 6
- Single cardiovascular risk factor in women <35 years
Acceptable use:
- Healthy, normotensive, nondiabetic nonsmokers of any age 3
- Mandatory blood pressure measurement before prescribing 6
Alternative Recommendations
For women with cardiovascular risk factors requiring treatment for PCOS-related hyperandrogenism or acne, progestin-only contraceptives or non-hormonal methods should be strongly preferred 6. Progestin-only methods carry substantially less cardiovascular risk than combined hormonal contraceptives 5.
Critical Pitfalls to Avoid
Failing to measure blood pressure before prescribing: This single intervention reduces MI and stroke risk by 2-2.5 fold 5.
Underestimating smoking risk: Even light smoking (<15 cigarettes/day) in women >35 years creates unacceptable risk 6.
Assuming "low-dose" pills are safe in high-risk patients: Even 20-35 μg ethinylestradiol formulations increase arterial risk in the presence of cardiovascular risk factors 2.
Not reassessing risk factors during ongoing use: Cardiovascular risk factors can develop during treatment, necessitating discontinuation 7.
The FDA drug label explicitly warns that cigarette smoking increases the risk of serious cardiovascular events from COC use, with this risk increasing with age, particularly in women over 35 years 7. Combined contraception containing cyproterone acetate shares these same contraindications and warnings 8.