Let's (Not) Do It Again: Secondary Prevention of Cardiovascular Disease in Women

Case History

A68-year-old woman with hypertension, hyperlipidemia, and coronary heart disease (CHD) reports for her annual examination. She had an episode of unstable angina 6 years ago that led to stenting of her right coronary artery. She has had no subsequent cardiac events and has no new complaints. She specifically denies any dyspnea or chest pain with exertion. Her mother had a heart attack at age 60.

Recommendations

In addition to discussing the importance of diet, exercise and nutritional goals to achieve weight loss, you also recommend:

A. Increase aspirin dose to 325 mg daily

Discussion

The annual examination provides an opportunity to assess risk factors for cardiovascular disease (CVD) and potential interventions to reduce risk in a given patient. Although this patient has no symptoms, she has already had revascularization for CHD and is at increased risk for subsequent cardiac events. Interventions to modify risk in this situation are considered secondary prevention. The pertinent modifiable risk factors include hypertension, hyperlipidemia, and her weight. Her BMI is in the obese range, and her waist circumference of >35 inches places her at increased risk for type 2 diabetes, dyslipidemia, hypertension, and CHD. ¹

Aspirin therapy (81 mg) should be used in women with a history of CHD unless it is contraindicated. This is a Class 1: Level of evidence A recommendation. ² The benefit of a higher dose of aspirin has not been established. Because this patient has no contraindication to aspirin therapy, her 81 mg dose should be continued.

Although initial observational studies suggested a role for antioxidant therapy in the prevention of CVD, randomized controlled clinical trials (RCTs) of vitamins E and C have failed to show reductions in cardiovascular risk, and several meta-analyses have suggested increased mortality with vitamin E intake in both primary and secondary prevention trials. Therefore, these are considered Class III interventions (not useful/effective and may be harmful) for the prevention of CVD in women. ^{3 –7}

The Iowa Women's Health Study recently demonstrated that multivitamins may be associated with an increased risk of death in women aged 55–69 years. This reaffirms that vitamin and mineral supplements cannot be recommended as a preventive measure for reducing risk of CHD. ⁸

In all women with a history of CHD, lipid lowering therapy is recommended to achieve an LDL-C <100 mg/dL (Class I: Level of evidence B), with an optional, more aggressive goal of a reduction to <70 mg/dL for those at very high risk, such as those with multiple or uncontrolled risk factors or a strong family history of CHD (Class IIa: Level of evidence B) In this patient, the current dose of simvastatin has resulted in an LDL-C at target levels of <100 mg/dL and near the more aggressive target. ¹

The use of aspirin in this patient also provides protection against ischemic stroke. In a meta-analysis of 6 RCTs, aspirin led to a 12% reduction in the risk of ischemic stroke in women. ⁹

Answer

B. Discontinuance of vitamin E.