More Than an Ounce: The 2011 Effectiveness-Based Guidelines for the Prevention of Cardiovascular Disease in Women
Pub Date: Tuesday, February 15, 2011
Author: Monique Chireau, MD, MPH
Citation:Effectiveness-Based Guidelines for the Prevention of Cardiovascular Disease in Women – 2011 Update
Since the first woman-specific guidelines for CVD prevention were published by the American Heart Association (AHA) in 1999, the pace of progress in reducing CVD morbidity and mortality among women has accelerated. In 2007, age-adjusted coronary heart disease (CHD) mortality among women was noted to be one-third of the 1980 rate. Vigorous advocacy as well as research and financial investments have provided the impetus for these improvements in women's health. It is clear, however, that despite much progress, many problems persist, and new challenges are already on the horizon. CVD still causes more deaths than cancer, chronic lung disease, Alzheimer's dementia, and trauma combined. Significant gender, age, and racial-ethnic disparities in CVD morbidity and mortality persist, especially for African-American and Hispanic women. However, for most women, CVD is probably preventable.
Given the scope of the problem and the high cost of treatment as well as evidence of reversal of downward trends in CHD death rates among women ages 35 to 54, the authors emphasize the need to strengthen prevention efforts, recognize CVD risk factors unique to women, and target special populations of women at high risk for CV events. In these updated guidelines, these issues are successfully incorporated into updated guidelines, with a continued focus on application of evidence-based therapies in women. The authors emphasize that both population- and patient-level interventions are needed to achieve reductions in CVD among women.
Cognizant of the lack of data from clinical trials that included women, previous guidelines attempted to critically examine the prevailing mindset that women should be treated similar to men. Over time, it has become apparent that most recommendations for prevention are, in fact, similar for men and women. However, the 2011 updated guidelines refocus attention on the fact that the risks and benefits of specific interventions, age-specific differences between men and women in the onset and severity of CVD, and unique risk factors such as pregnancy, differ between men and woman, mandating different prevention and treatment strategies. Risk classification remains the cornerstone of prevention. Similar to the 2007 guidelines, the 2011 update uses a risk classification algorithm to classify women as high risk, at risk, or at optimal risk. A 2010 analysis evaluated this algorithm using data from the Women's Health Initiative to stratify women by risk. The algorithm predicted CVD events [myocardial infarction, CHD mortality, and cerebrovascular accident (CVA)] in each risk stratum, and was comparable to ATP risk score for prediction of CHD events. These data support the panel's decision to continue using this risk stratification algorithm, with modifications. The most important of the latter is the concept of "ideal cardiovascular health" defined by the AHA as ideal blood pressure, total cholesterol, and fasting glucose, the absence of clinical CVD, and healthy behaviors [including physical activity, not smoking, lower body mass index, and DASH (Dietary Approaches to Stop Hypertension)-like diet]. Studies show that this combination of optimal behaviors and clinically measured risk factors decreases not only lifetime risk for CVD events but also Medicare costs, and increases longevity and quality of life. This new approach expands beyond clinical measures of cardiovascular (CV) risk to encompass a broader view of optimal health for patients.
Specific differences between the 2007 and 2011 guidelines are as follows:
Effectiveness versus efficacy. One of the most important differences between the old and new guidelines is that in the 2011 guidelines, evidence on effectiveness (how interventions and therapies function in a clinical context) was considered as well as evidence on efficacy (how interventions and therapies function in a clinical research context). This change, which is reflected in the change in the guidelines' title from "Evidence-Based Guidelines" to "Effectiveness-Based Guidelines", expands upon the 2007 guidelines' position that effectiveness of an intervention or therapy might differ from efficacy due to patient characteristics such as adherence. For example, depression screening was dropped from the recommendations because of lack of data on its effects on direct CVD outcomes; however, it is included in risk evaluation because it may affect CVD risk through other mechanisms such as adherence.
Assessment of CVD risk, including risk classification, focus on long-term CVD risk, risk reclassification using novel biomarkers, and unique risk factors. The risk classification algorithm described in the current guidelines has been modified to recognize other risk equations such as the updated Framingham CVD risk equation and the Reynolds risk score for women, because these risk scores include CVD events in addition to CHD [although the panel stopped short of recommending high-sensitivity C-reactive protein (hsCRP) screening]. The panel recommended a new cut point of greater than or equal to 10% ten-year risk for CVD (not CHD alone) as high risk. This is an important change from the previous cut point of greater than or equal to 20% ten-year risk for CVD. Data suggest that older women have higher risk for CHF and CVA than for CHD, in contrast to men, and focusing on CHD only is likely to underestimate CVD risk, possibly resulting in inadequate preventive interventions for women older age groups. Another change from the 2007 guidelines is in the use of novel CVD risk biomarkers and imaging. The authors recommend that rather than being used for screening, these technologies should be used to reclassify women in intermediate risk groups, although further research is needed to assess the costs, risks, and benefits of this approach as well as its effectiveness in preventing CVD events.
Although previous guidelines briefly discussed the association between pregnancy events and CVD, the updated guidelines expand upon this association, in part because increasingly, adverse pregnancy outcomes have been proposed as unique risk factors for future CV disease in women. In large epidemiologic studies, preterm birth and small-size-for-gestational age have been associated with future development of maternal cardiovascular disease.[5,6] Pregnancy complications such as preeclampsia and gestational diabetes are also associated with long-term CVD. The updated guidelines now include a history of preeclampsia, gestational diabetes, and pregnancy-induced hypertension as criteria for at-risk classification for CVD, and recommend that obstetrician-gynecologists refer patients with pregnancy complications to other primary care physicians postpartum. Health care providers should also take a detailed pregnancy history when seeing new patients later in life to help assess CVD risk.
Diversity and disparities. The 2011 guidelines include new recommendations addressing the challenges of diversity and disparities. Diversity, defined simply as racial-ethnic, language, or other sociodemographic asymmetry between provider and patient, is strongly associated with CVD risk, treatment response, patient adherence, and health disparities. In addition to examining diversity as a risk factor for disparities, the authors encourage providers to develop cultural competence, acquaint themselves with the sociodemographic and cultural characteristics of their diverse patients, and be aware of the prevalent risk factors in population subgroups they see in practice, as a means of attempting to reduce CVD health disparities. These relationships, however, are extremely complex. The recommendations not only challenge clinicians to increase their knowledge in this area, but also increase the guidelines' utility for racial-ethnic minority patients and their advocacy organizations.
Global perspectives. Globally, CVD is a leading cause of death among women in both developed and developing nations. The 2011 update features also includes a new section on "international applicability." Rising rates of obesity are an international phenomenon, with an anticipated increase in the number of women potentially at risk for CVD. The authors emphasize that many of the recommendations in the guidelines can be adapted for use nationally or regionally, with modifications for local economies, patient populations, and available therapies (e.g., generic drugs). Caution is recommended in applying the guidelines in internationally diverse populations.
Healthcare professional implementation of guidelines. Adherence receives increased emphasis in the updated guidelines. The authors point out that in general, the implementation of guidelines is constrained by barriers to adherence at the patient, clinician, and systemic levels. Research suggests that management algorithms that are tailored to improve adherence may help to improve clinical outcomes. These issues have not been considered in detail in earlier versions of the guidelines. It is clear, however, that developing evidence-based guidelines incorporating adherence is difficult at present due to methodological issues and gaps in the knowledge base on changing provider and patient behavior. As the authors imply, advances in interventions and therapies alone cannot reduce rates of CVD in women without incorporation of interventions to improve adherence.
Education targeting patients and the public. As noted above, adherence continues to be a problem associated not only with noncompliance with treatment regimens, but also rates of hospitalization. The authors place very high priority on evaluating adherence to guidelines. For prevention efforts, patient education is seen as being of paramount importance, even though providing patient education is at best challenging, and at worst difficult due to time and financial pressures as well as sociodemographic and psychosocial factors. Understanding and utilizing theoretical frameworks for behavioral change and patient education is especially important in CVD prevention for women, given multiple lifestyle barriers to adherence.
Cost-effectiveness. The current guidelines break new ground by including cost-effectiveness analyses. Although data that is specifically applicable to women is limited, research suggests that specific treatments, such as aspirin in older women, antihypertensive therapy, and smoking cessation, are cost effective. Weight reduction interventions may also be cost effective in specific subgroups of women. Overall, the guidelines stress the need for better quality research on cost-effectiveness. Multiple changes have been made to the updated tables of guidelines. As noted above, preeclampsia, gestational diabetes, and pregnancy-induced hypertension are now included as criteria for at-risk status in the classification of CVD risk in women. Changes have also been made to the tables of guidelines for preventing CVD in women. More specific recommendations are included for physical activity; weight maintenance; consumption of omega-3 fatty acids; use of statins in women more than 60 years old with an estimated CHD risk greater than 10% and elevated hsCRP; use of aspirin, warfarin, and dabigatran in women with atrial fibrillation; and use of beta blockers. Cautions for the use of medications during pregnancy have also been added. Finally, as a first step, a table of specific dietary intake recommendations for women has been added as an appendix. Although this table is neither prescriptive nor proscriptive, it provides a basis for initial discussions with patients regarding optimal lifestyle choices for cardiovascular health.
In conclusion, the 2011 updated guidelines expand CVD prevention for women into previously unexplored territory, and present a stronger and more multifaceted message. The latter includes the following: (1) All women should be screened with a view to risk stratification and prevention, given high lifetime risk for CVD (50% overall); (2) women have unique CVD risk factors, and differential patterns of risk based on age and gender-specific risk factors such as pregnancy complications, which should be considered in preventive efforts; (3) the risks and benefits of preventive therapies and interventions should be interpreted in the context of effectiveness, rather than efficacy, especially when considering data from trials with low representation of women or specific population subgroups of women; (4) diversity presents both a challenge and an opportunity for improving care to racial-ethnic and other minorities; (5) addressing adherence is key to improving patient outcomes; and (6) lifestyle approaches to the prevention of CVD are probably the best strategy for reducing CVD morbidity and mortality.
2011 guidelines provide not only clinicians and policymakers, but also patients and advocacy groups with widely applicable (indeed, internationally applicable) tools to help achieve the goal of preventing CVD in women.
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-- The opinions expressed in this commentary are not necessarily those of the editors or of the American Heart Association