Recent Advances in Preventive Cardiology and Lifestyle Medicine
2011; Lippincott Williams & Wilkins; Volume: 123; Issue: 20 Linguagem: Inglês
10.1161/circulationaha.110.981613
ISSN1524-4539
AutoresBarry A. Franklin, Mary Cushman,
Tópico(s)Obesity, Physical Activity, Diet
ResumoHomeCirculationVol. 123, No. 20Recent Advances in Preventive Cardiology and Lifestyle Medicine Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBRecent Advances in Preventive Cardiology and Lifestyle MedicineA Themed Series Barry A. Franklin, PhD and Mary Cushman, MD, MSc Barry A. FranklinBarry A. Franklin From the Departments of Medicine and Cardiology, Cardiac Rehabilitation and Exercise Laboratories, William Beaumont Hospital, Royal Oak, MI (B.A.F.); and Departments of Medicine and Pathology, University of Vermont College of Medicine, Burlington (M.C.). Dr Franklin is Immediate Past Chair, American Heart Association Council on Nutrition, Physical Activity, and Metabolism. Dr Cushman is Immediate Past Chair, American Heart Association Council on Epidemiology and Prevention. and Mary CushmanMary Cushman From the Departments of Medicine and Cardiology, Cardiac Rehabilitation and Exercise Laboratories, William Beaumont Hospital, Royal Oak, MI (B.A.F.); and Departments of Medicine and Pathology, University of Vermont College of Medicine, Burlington (M.C.). Dr Franklin is Immediate Past Chair, American Heart Association Council on Nutrition, Physical Activity, and Metabolism. Dr Cushman is Immediate Past Chair, American Heart Association Council on Epidemiology and Prevention. Originally published24 May 2011https://doi.org/10.1161/CIRCULATIONAHA.110.981613Circulation. 2011;123:2274–2283Multifactorial risk factor modification and control, especially interventions designed to reduce total cholesterol, systolic blood pressure, smoking prevalence, overweight/obesity, diabetes mellitus, and physical inactivity, can have a profound and favorable impact on decreasing the incidence of initial and recurrent cardiovascular events. Between 1980 and 2000, mortality rates from coronary heart disease (CHD) fell by >40%. Using a previously validated statistical model (IMPACT), researchers attempted to determine how much of this decrease could be explained by the use of medical and surgical treatments as opposed to changes in risk factors among US adults aged 25 to 84 years. Approximately half of the decline in cardiovascular deaths was attributed to reductions in major risk factors (obesity and diabetes mellitus were notable exceptions), and approximately half was attributed to evidence-based medical therapies (eg, secondary prevention medications, rehabilitation, and initial treatments for acute myocardial infarction [AMI]).1 In contrast, emergent and elective revascularization accounted for only 7% of the overall decline in deaths from CHD. Recently, similar results were reported in a Canadian study that evaluated the decrease in CHD mortality between 1994 and 2005.2Over the past decade, mortality rates from CHD and stroke in the United States decreased by >25% (Figure 1).3 Although there were also impressive reductions in the prevalence of uncontrolled high blood pressure, elevated blood cholesterol, and, to a lesser extent, cigarette smoking, there was only limited impact on other risk factors, including increases in the prevalence of obesity and diabetes mellitus, and a small reduction in those not engaged in moderate or vigorous physical activity.3 These indicators represent major challenges to achieving future goals for cardiovascular health promotion and disease reduction.Download figureDownload PowerPointFigure 1. Mortality rates from coronary heart disease and stroke, rate of uncontrolled blood pressure, and prevalence of high cholesterol from 2004 to 2008. Reproduced from Lloyd-Jones et al.3In 2009, a task force representing numerous professional organizations/associations developed a Competence and Training Statement on the Prevention of Cardiovascular Disease.4 More recently, the American Heart Association (AHA) released its bold new impact goal for the next 10 years, the 2020 Impact Goal: "to improve the cardiovascular health of all Americans by 20% while reducing deaths from cardiovascular diseases and stroke by 20%."3 This 2020 goal has an innovative new element to improve clinically relevant health and behavioral factors. Cardiovascular health is defined in 3 categories of ideal, intermediate, and poor on the basis of 7 simple health factors and modifiable behaviors, as detailed in the My Life Check assessment tool at http://www.mylifecheck.heart.org.This review provides a compendium of important advances in preventive and lifestyle medicine during the past decade, including discussion of some emerging but unproven interventions (ie, the polypill) as well as the value of conducting large-scale randomized clinical trials rather than relying on biological hypotheses and observational data (ie, the homocysteine story). We also provide a call to action to support the AHA's 2020 goals, summarize the impact of preventive interventions as a first-line strategy to combat stable cardiovascular disease (CVD), and discuss the potential impact of behavioral and complementary interventions in reducing the burden of CVD. Finally, we detail the goals of a new Circulation series of publications on Preventive Cardiology and Lifestyle Medicine.A Decade of Discovery: Implications for Primordial, Primary, and Secondary PreventionPrevention can be divided into 3 types: primordial (prevention of risk factors); primary (treatment of risk factors); and secondary (prevention of recurrent cardiovascular events) (Figure 2). Much of the success in reducing CVD in recent years has been through the latter 2 methods; however, additional emphasis on primordial prevention is needed to meet the AHA 2020 Impact Goal of improving cardiovascular health and achieving an additional 20% reduction in death from CVD and stroke.Download figureDownload PowerPointFigure 2. Risk factor framework and the progression of cardiovascular disease, with types of prevention interventions. Illustrated are primordial, primary, and secondary prevention, which have environmental modulators, including healthcare access; the built environment; public policy initiatives; and locations where interventions can be made (eg, personal, family, school, workplace). Cardiovascular health markers/interventions include the American Heart Association's Life's Simple 7 (smoking status, body mass index, physical activity, healthy diet score, total cholesterol, blood pressure, fasting plasma glucose), pharmacotherapies (eg, aspirin, β-blockers, statins, angiotensin-converting enzyme inhibitors) when indicated, and coronary revascularization, when appropriate. MI indicates myocardial infarction; CHF, congestive heart failure; and PAD, peripheral arterial disease.The importance of risk factors in the development of CVD has received increased attention over the past decade. In addition, along with cardioprotective medications, the roles of lifestyle interventions, psychosocial factors, air pollution, dietary patterns, physical inactivity, low cardiorespiratory fitness, obesity, cardiac rehabilitation, and inflammation have been better elucidated as modulators of CVD and as targets for education, behavioral interventions, and policy approaches to improving health. Newer statin drugs, in particular, which markedly decrease and increase low-density lipoprotein and high-density lipoprotein cholesterol, respectively, have been heralded as a potential breakthrough to prevent initial and recurrent atherosclerotic events.5 Consider the following key reports of the 2000s.Risk Factors as Antecedents of Cardiovascular Disease: Debunking the Only 50% MythThe INTERHEART study examined the risk factors associated with first AMI in 52 countries, including 15 152 cases and 14 820 controls.6 Collectively, 9 risk factors (abnormal lipids, smoking, hypertension, diabetes mellitus, abdominal obesity, psychosocial variables, consumption of fruits and vegetables, regular alcohol consumption, regular physical activity) accounted for 90% of the population attributable risk in men and 94% in women. Similarly, Khot et al7 and Greenland et al8 examined data from 14 randomized clinical trials (n=122 458) and 3 prospective cohort studies (n=386 915), reporting that >80% of patients who developed CHD and ≥87% of patients who experienced a fatal coronary event had antecedent exposure to ≥1 of the 4 conventional cardiovascular risk factors (cigarette smoking, dyslipidemia, hypertension, diabetes mellitus). People with optimal levels of cardiovascular risk factors and lifestyle behaviors at 50 years of age demonstrate a marked survival advantage and only a 5% and 8% lifetime risk of developing CVD for men and women, respectively.9 Collectively, these data and other recent reports discount the longstanding claim that only 50% of CHD is attributable to conventional risk factors, and suggest that a more rigorous focus on these and the lifestyle behaviors that promote them has great potential to reduce the burden of atherosclerotic heart disease.10,11Lifestyle and Mortality in Coronary PatientsOne review of prospective cohort studies and randomized, controlled trials among patients with established CHD sought to provide evidence for a prognostic benefit of lifestyle and dietary recommendations.12 Effect estimates for smoking cessation, higher levels of physical activity, and moderate alcohol consumption varied from a 20% to 35% lower risk of all-cause mortality. For individual dietary goals, data were too limited to provide reliable effect size estimates. If these estimates reflect the true value, they compare favorably with mortality reductions reported for low-dose aspirin, statins, β-blockers, and angiotensin-converting enzyme inhibitors after AMI.12 On the other hand, there are no randomized trials showing that alcohol consumption improves health, and the overall harms are well known: addiction, social dysfunction, and motor vehicle accidents.13 One large-scale study showed that low to moderate alcohol consumption may be associated with an increased risk of cancer in women.14Cigarette Smoking, Mortality, and Effects of Secondhand SmokeA landmark study of 50 years of observation of 34 439 male British physicians found that, on average, cigarette smokers die ≈10 years younger than nonsmokers.15 For someone who has smoked since adulthood, cessation at age 50 years halved the hazard, and cessation at age 30 years avoided almost all of it. Quitting smoking at age 60 or 40 years increased life expectancy by ≈3 and 9 years, respectively. More recently, using data from the Survival and Ventricular Enlargement trial, investigators reported that in selected patients with left ventricular dysfunction after AMI, smoking cessation is associated with a 40% lower hazard of all-cause mortality compared with persistent smokers over an average follow-up of 42 months.16A moderate-sized randomized clinical trial, involving a 10-week smoking cessation program that included strong physician counseling and 12 group sessions using behavior modification and nicotine gum, plus either ipratropium or a placebo inhaler, found that over a 14.5-year follow-up, the intervention reduced the risk of death by 18% compared with a usual-care control group.17 It should be noted, however, that these findings applied to a special group of heavy smokers who had preexisting airway obstruction. Because the relative risk for lung cancer is so high among smokers, the need for randomized trials is less compelling. On the other hand, nearly all risk factors associated with CHD have effect sizes that are much smaller, making them seriously vulnerable to confounding variables and selection biases when evaluated in observational studies.Although it is tempting to believe that the tobacco war has been won because of the important strides that have been made in tobacco control, in terms of both interventions and outcomes, the prevalence of smoking in the United States hovers at 20%, >8 million people are sick or disabled as a result of tobacco use, and smoking kills an estimated 450 000 Americans annually.18 Even a very short period of passive smoke exposure has persistent vascular consequences, such as the mobilization of dysfunctional endothelial progenitor cells with blocked nitric oxide production.19 Secondhand smoke is responsible for an estimated 603 000 deaths worldwide each year, and more than half of the deaths (379 000) are due to CVD.20 Accordingly, despite the current emphasis on healthcare reform, escalating medical costs, and childhood obesity, cigarette smoking remains by far the most common cause of preventable death and disability in the United States.18 Unless legal challenges delay or defeat government plans, in 2012 each cigarette pack sold in the United States will carry powerful graphic label warnings of the dangers of smoking, which may serve to reduce smoking rates among younger people.Prevention of Type 2 Diabetes Mellitus With Lifestyle InterventionConsiderable data now strongly support the role of lifestyle intervention to improve glucose and insulin homeostasis. The Finnish Diabetes Prevention Study reported that a lifestyle intervention (reducing body weight by ≥5%; decreasing fat and saturated fat intake to <30% and 750 trials with ≈400 000 participants), as a population strategy to combat CVD. The daily formulation would include a statin, 3 blood pressure–lowering drugs, folic acid, and aspirin, and could theoretically reduce coronary events by 88% and stroke by 80%. Others have reported that a similar polypill (Polycap formulation) effectively reduced multiple risk factors and estimated cardiovascular risk in middle-aged individuals; however, the combined projected risk reductions for coronary events and stroke were lower than the aforementioned estimates, at 62% and 48%, respectively.40 The investigators emphasized that the effects of the polypill cannot be assumed to equal the combined effects of its individual components. On the basis of the homocysteine report, the expected benefit of including folic acid could also be questioned. More recently, a small, double-blind, randomized, placebo-controlled trial of a polypill reported more modest reductions in lipid levels and blood pressure than anticipated.41 Because of the independent and additive benefits of lifestyle modification on cardioprotective pharmacotherapies,42–44 it has been suggested that treatment with the polypill, or treatment with its components, be accompanied by the following user directions: "Take medication each day in the prescribed dosage, followed or preceded by ≥30 minutes of moderate to vigorous physical activity, in combination with a low-fat, low-cholesterol diet, weight management, and the avoidance or cessation of cigarette smoking."45Lifestyle Factors Associated With Lower Cardiovascular RiskAccording to 2 recent studies, favorable lifestyle factors are associated with dramatically reduced risks of hypertension and heart failure.46,47 In the first study, an analysis of data from the longitudinal Nurses' Health Study II, adherence to 6 lifestyle factors—normal body mass index (<25 kg/m2); a low-sodium diet high in fruits, vegetables, and low-fat dairy products; a daily average of 30 minutes of vigorous exercise; modest alcohol intake (up to 10 g/d); infrequent use of nonnarcotic analgesics (less than once per week); and folic acid supplementation (≥400 μg/d)—was associated with a significantly lower incidence of self-reported hypertension.46 The authors acknowledged that if these associations were causal and independent, then lifestyle modification could have the potential to prevent a large proportion of new-onset hypertension occurring in young women. Similarly, the PREMIER randomized clinical trial reported that individuals with above optimal blood pressure, including stage 1 hypertension (120 to 159 mm Hg systolic and 80 to 95 mm Hg diastolic), who were not taking antihypertensive medications, can make multiple lifestyle changes that lower blood pressure and reduce cardiovascular risk.48 In another report, data were analyzed from 20 900 apparently healthy men (mean age at baseline, 53.6 years) in the Physicians' Health Study who were followed for 22.4 years, during which time 1200 developed heart failure.47 Men who adhered to ≥4 of 6 healthy lifestyle habits (normal body weight, not smoking, regular exercise, moderate alcohol intake, consumption of breakfast cereals, and a diet high in fruits and vegetables) had a 10% risk of developing heart failure. Men who did not adhere to any of these factors had a 21% risk of developing heart failure.Because the healthy adherer effect is well known, these reports from observational studies should be interpreted with caution. The Coronary Drug Project showed that individuals who adhere to placebo therapy generally have better health outcomes.49 Accordingly, people who adhere to healthy lifestyle practices often do better, but it remains unclear whether it is due to the intervention per se.Air Pollution and Cardiovascular RiskNumerous epidemiological studies have demonstrated consistent associations between short-term elevations in particulate matter (air pollution) and increases in nonfatal and fatal cardiovascular events, including myocardial ischemia and infarction, ventricular arrhythmia, heart failure exacerbation, and stroke.50,51 The pathways linking air pollution exposure to the onset of acute cardiovascular events may be explained by the direct effects from agents that cross the pulmonary epithelium into the circulation, including gases and the soluble constituents of particles (eg, transition metals). Although the increase in relative risk for CVD due to air pollution for an individual may be small compared with the impact of conventional risk factors, this omnipresent exposure likely translates into a substantial increase in total mortality within the population.52 The potential to substantially decrease cardiovascular morbidity and mortality by lowering particulate matter levels to current Environmental Protection Agency standards is apparent.50Dietary Pattern and Risk of Cardiovascular DiseaseA substantial and expanding body of evidence has now associated a healthy dietary pattern with lower rates of major coronary events and diabetes mellitus.53–56 One systematic review found strong evidence of a causal relationship for cardioprotective dietary practices, including vegetables, nuts, and Mediterranean eating patterns, as well as associations for harmful factors, including intake of trans fatty acids and foods with a high glycemic index or load, and CHD.56 Modest reductions in dietary salt may also substantially reduce cardiovascular events and associated medical costs.57 Epidemiological and controlled interventional studies have consistently demonstrated the beneficial effects of omega-3 fatty acid consumption, especially the longer-chain fatty acids (≥20 carbons) from marine sources, on cardiovascular end points.58 Moreover, a 2-year study of weight loss diets, using either low-fat, Mediterranean, or low-carbohydrate strategies, reported a significant regression of carotid atherosclerosis, irrespective of the dietary intervention.59 On the other hand, the Women's Health Initiative Dietary Modification Trial, the largest long-term randomized, controlled trial of a dietary intervention conducted to date, including 48 835 postmenopausal women aged 50 to 79 years who were followed over a mean of 8.1 years, showed that a dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD, and achieved only modest effects on CVD risk factors.60 Nevertheless, subgroup analyses showed positive trends toward greater reductions in low-density lipoprotein cholesterol levels and rates of CHD in women with the lowest intakes of saturated fat or trans fat or highest intakes of vegetables/fruits. Because the trial was designed to test the hypothesis that a dietary intervention could lower rates of breast and colorectal cancer rather than CVD, the investigators suggested that more focused diet and lifestyle interventions may be needed to reduce CVD risk.Mortality Benefits of Cardiac Rehabilitation in Modern CardiologyAmong older patients with documented CHD who undergo cardiac rehabilitation, mortality rates are generally 21% to 34% lower than among nonusers,61 and a significant dose-response relationship exists between the number of cardiac rehabilitation sessions attended and cardiovascular outcomes at 4 years.62 It has been suggested that contemporary thrombolytic and emergent revascularization procedures, which markedly diminish early postinfarction mortality, and newer cardioprotective drug therapies may serve to attenuate the impact of adjunctive exercise-based cardiac rehabilitation. Although a recent review of 48 randomized trials concluded that the mortality benefits of cardiac rehabilitation persist in modern cardiology,63 meta-analyses like these are suggestive but cannot be considered definitive.64,65 Despite the potential survival advantage and related beneficial outcomes, cardiac rehabilitation services remain vastly underutilized among Medicare beneficiaries.66Pharmacotherapies and Lifestyle Modification in Patients With Acute Coronary SyndromeAlthough individual drug therapies, such as antiplatelet medications, β-blockers, angiotensin-converting enzyme inhibitors, and lipid-lowering agents, are effective in reducing mortality in patients with acute coronary syndrome, it appears that the combination of these agents may have incremental and even synergistic benefits. Researchers created a composite appropriateness score for 6-month mortality based on the number of drugs used divided by the number of drugs potentially indicated for each patient, as follows: 0, none of the indicated medications used; I, 1 medication used if 3 or 4 medications indicated; II, 2 medications used if 3 or 4 medications indicated or 1 medication used if 2 medications indicted; III, 3 medications used if 4 medications indicated; and IV, all indicated medications used. The odds ratio for death for appropriate levels IV, III, II, and I were 0.10, 0.17, 0.18, and 0.36, respectively.67 A more recent study reported that adherence to behavioral advice (modify diet, exercise, and quit smoking) after acute coronary syndrome was associated with a substantially lower risk of recurrent cardiovascular events.68 Collectively, these data suggest that a combination of evidence-based medical therapies and behavioral recommendations in the immediate postevent care of patients with acute coronary syndrome should be given a high priority by physicians and adjunctive healthcare providers.Physical Activity, Cardiorespiratory Fitness, and MortalityA recent systematic review and meta-analysis of 33 physical activity studies (n=883 372 participants) reported risk reductions of 30% to 50% for cardiovascular mortality and of 20% to 50% for all-cause mortality, with pooled risk reductions of 35% and 33%, respectively.69 There are multiple mechanisms by which moderate to vigorous physical activity may decrease mortality rates associated with CVD (Figure 3), including antiatherosclerotic, antithrombotic, anti-ischemic, antiarrhythmic, and psychological effects. Numerous studies also suggest that cardiorespiratory fitness, expressed as metabolic equivalents (1 metabolic equivalent=3.5 mL O2 per kilogram per minute) is 1 of the strongest prognostic markers in persons with and without CHD.70 In healthy men and women, each 1-metabolic equivalent increase in exercise capacity confers a 13% and 15% reduction in all-cause mortality and cardiovascular events, respectively. Participants with an aerobic capacity ≥7.9 metabolic equivalents had the most favorable health outcomes.71 Dutcher et al72 reported that cardiorespiratory fitness more accurately predicts 5-year mortality than left ventricular ejection fraction in patients with ST-segment elevation MI treated with percutaneous coronary intervention (PCI). On the other hand, a disproportionate number of acute cardiovascular events occur in habitually sedentary individuals with known or occult CHD performing unaccustomed vigorous physical activity.73 Collectively, these data suggest that the least active, least fit, "high-risk" patient cohort (bottom 20%) may especially benefit from structured exercise, increased lifestyle activity, or both to improve survival.74 Future
Referência(s)