Peripheral Artery Disease in Women: It’s Time

The last few years has seen an emergence of awareness campaigns focused on heart disease in women. These campaigns have included education for providers, public health promotions for the lay public and programs funded and strongly endorsed by powerful organizations such as the NHLBI, and the AHA/ASA, among others.¹ As a result, the awareness of heart disease among women has increased from 30% to 54% over a 12 year period.² Less emphasized in these programs is the oneness of the cardiovascular tree and the universality of atherosclerotic disease whether found in the coronary, peripheral, renal or the cerebral bed. Ignoring the rest of the cardiovascular system in women with coronary or cerebrovascular disease would indeed be myopic. It’s time to inform, educate and raise awareness of another type of cardiovascular disease (CVD), Peripheral Artery Disease (PAD). This gap is addressed by the recent Scientific Statement of the AHA: A Call to Action: Women and Peripheral Artery Disease.³ The Statement provides an in-depth review of current PAD epidemiology of PAD, its clinical presentations, potential treatments and need for further gender-specific research. Its greatest impact, however, will be on data concerning the impressive lack of awareness among the public and health care providers, as well as the paucity of education on PAD even in programs dedicated to women’s heart disease. The recommendations are clear and expansive and call for broad-based action ranging from government-sponsored programs and health campaigns to women’s health education groups.

Epidemiology

PAD is traditionally associated with male sex and a smoking history presenting as intermittent claudication. By objective criteria, the definition is an ankle-brachial index (ABI) <0.9. The risk factors for the development of PAD are the same as for other atherosclerotic diseases, such as older age, family history, diabetes, smoking, hypertension and hyperlipidemia.⁴ Yet, as pointed out by Hirsh et al. in this Statement, the true prevalence of PAD in women is not totally elucidated since registries and large population studies have not consistently reported results by gender. (See Table 1) Nonetheless, the prevalence increases with age for both genders and thus as the population ages, the burden of PAD will continue to undoubtedly increase. More concerning, as reflected by 2010 US census data, the burden of PAD appears to be more prevalent in women than in men. (Figure 2 from Statement).

Symptoms

Of further concern to the clinician is that as many as 50% of patients may be asymptomatic or only mildly symptomatic.^5,6 In fact, symptoms may be non-specific, such as fatigue in the extremities, and rest discomfort. The Women’s Health and Aging Study reported 63% of PAD patients had no exertional leg pain and among those with walking pain, other lower extremity symptoms were also present.⁷ The decline in function was also reported to be greater in women than in men.⁸ These low level activities coincide with activities of daily living which can subsequently lead to greater functional impairment and dependency for care.

Risk of CV Events

Regardless of whether PAD is symptomatic or not, the relative risk of all cause mortality is 3 times greater in women with an ABI <0.9 vs. those with an ABI >0.9 and for CVD the risk is 4 times greater. Vogt et a.,l reported the levels of risk were similar after excluding symptoms or a history of other CVD at baseline.⁹ More specifically, in a cohort of primary care patients the risk of stroke doubled over a 5 year follow-up in patients with PAD compared to those without PAD.¹⁰

Screening

Therefore, with paucity of classical symptoms, the increased burden and the high mortality risk, screening for PAD is essential for both genders. However, with a lower index of suspicion, screening may not occur. It is critical clinicians and importantly primary care providers, including Ob/Gyn providers consider the woman with risk factors for CVD as a potential PAD patient and conduct a careful history of peripheral symptoms which may lead to screening with ABI’s. In asymptomatic patients diagnosed with PAD through routine screening in a primary care setting, the ABI carries important prognosis.¹¹ The ABI is a non invasive, simple test with high sensitivity and specificity. Women at risk should be encouraged to undergo ABI testing by the providers they trust.

Treatment of PAD in Women

Although not perfect, the modalities for treatment do exist. These treatment options are clearly delineated by Hirsh et al. There are no data to suggest women respond differently to treatments such as revascularization, exercise or drug therapy, although reports of adverse events surrounding revascularization in women have been noted. However, these complications of vascular procedures may be confounded by age and comorbid conditions. Further research with a balanced inclusion of women is strongly recommended.

Often overlooked are the benefits of exercise therapy in PAD. Meta-analysis of randomized clinical trials of supervised programs has shown that exercise increased walking time significantly in patients with PAD.¹² Coupled to the overall benefits for patients with CVD, cardiac rehabilitation programs can be a powerful ally in the treatment of PAD. Exercise therapy can increase quality of life as well. The publication Performance Measures for Cardiac Rehabilitation assigns a Class 1 recommendation for a comprehensive risk reduction regimen, whether in a home or community based setting for women with CVD, including PAD, with a level of evidence A.¹³ Lack of motivation by women and lack of recommendations by providers, coupled to non-availability of insurance coverage are salient limitations, but must be addressed.

Risk Factor Burden and Reduction

In addition, we cannot, and must not ignore the traditional risk factors that require critical attention and treatment, such as hypertension, diabetes and hyperlipidemia. In the REACH Cohort, if coronary artery disease (CAD) was absent, PAD patients were undertreated for their risk factors.¹⁴ In this same cohort diabetics had higher rates of events than non-diabetics related to the number of diseased arterial sites.¹⁵ In the context of risk factor modification with medical therapy, the Statement by Hirsch et al. should be used together with the AHA/ACCF Practice Guidelines for the Management of Patients with Peripheral Arterial Disease which delineates the medical therapy of risk factors such as LDL cholesterol and diabetes.¹⁶ Statins commonly prescribed for CAD have a Class I recommendation to achieve an LDL cholesterol level < 100 mg/dL. Thus the same medical therapy that has now been widely applied to CAD should be recognized and applied to PAD.

A Call to Action

Although there have been public health campaigns concerning the awareness of risk factors and their potential modifications, Hirsh et al. point out in large population surveys, there is a substantial lack of awareness of risk factor burden and overall knowledge of PAD. The recommendations need to be disseminated in public health forums and incorporated into programs focusing on heart disease in women. Women have become a powerful part of the awareness of heart disease and now need to be engaged in awareness of PAD as well. See Recommendations below.

The current Statement is a worthy partner to the Effectiveness-based guidelines for the prevention of cardiovascular disease in women—2011 update: a guideline from the American Heart Association by expanding the scope of CVD which includes clinically manifest PAD as a high CVD risk classification. The need is manifest, data are accumulating, mortality and morbidity are impressive, screening is feasible, and treatments are available. Let’s mimic what we have accomplished with heart disease awareness if women. Women are powerful allies for their health and well being. It’s time to act….