Long-Awaited Prevention and Treatment Guidelines for Heart Disease Published

Four new guidelines give primary care physicians direction as they help their patients reduce their risk of developing heart disease. (Image: JAMA, ©AMA)

Four new guidelines give primary care physicians direction as they help their patients reduce their risk of developing heart disease. (Image: JAMA, ©AMA)

Much-anticipated national guidelines for reducing most risk factors associated with cardiovascular disease have finally been released—with one exception. Updated guidelines for addressing hypertension, which had been expected to be available earlier this year, are not yet available.

The released guidelines focus on healthy lifestyles, atherosclerotic cardiovascular risk assessment, blood cholesterol management, and obesity.

The healthy lifestyles and risk assessment guidelines are new. The cholesterol management guideline is the first update since 2004. The obesity guideline is the first update of the original document, published in 1998.

Each guideline was created by expert panels convened by the National Heart, Lung, and Blood Institute, which handed over governance, management, and publication of the guidelines last June to the Obesity Society (for the obesity guideline) and to the American Heart Association and the American College of Cardiology along with the Obesity Society for the others.

Guideline for a Healthy Lifestyle
The healthy lifestyle guideline stresses eating a generally heart-healthy diet and engaging in physical activity as key elements for preventing heart attacks, strokes, and other cardiovascular diseases. The guideline’s recommendation on diet doesn’t endorse any specific eating plan, such as the Mediterranean diet; instead, it calls for primary care physicians to develop heart-healthy dietary plans based on the individual patient’s caloric requirements and personal and cultural food preferences, with additional tweaks to account for other medical conditions, such as diabetes.

The healthy lifestyle guideline also calls for a reduction in salt (sodium) consumption but doesn’t endorse a target level, such as limiting sodium intake to 1500 mg/d as advocated by the American Heart Association and others. Regarding physical activity, the guideline advises moderate or vigorous aerobic exercise, such as brisk walking, for an average of 40 minutes 3 or 4 times a week.

Guideline for Cardiovascular Risk Assessment
Previously, cardiovascular risk assessment focused only on coronary heart disease, but the new guideline includes stroke. This is intended to improve overall cardiovascular risk assessment, particularly for women and blacks, who are at much greater risk for stroke then white men.

The guideline promotes risk assessment methods for atherosclerosis-related risk factors that are easily ascertained by a primary care physician, such as age, cholesterol levels, blood pressure, smoking, and diabetes.

Cholesterol Guideline
The cholesterol guideline emphasized reducing low-density lipoprotein cholesterol (LDL-C), the “bad” cholesterol, but doesn’t set a specific target. Instead, the guideline authors recommended moderate- or high-intensity statin therapy for 4 groups:

• Patients with cardiovascular disease
• Patients with an LDL-C level of 190 mg/dL or higher
• Patients with type 2 diabetes who are between 40 and 75 years of age
• Patients with an estimated 10-year risk of cardiovascular disease of 7.5% or higher who are between 40 and 75 years of age

The 10-year risk threshold is a lower percentage than currently used and could lead to a doubling of statin use in the adult US population, from 15% to about 30%.

Guideline for Addressing Obesity
The obesity guideline recommends weight reduction— with a goal of losing 5% to 10% of one’s body weight within 6 months—through a nonspecific reduced-calorie diet, increased physical activity, and adoption of behavioral strategies introduced by a trained professional, who should meet in person with the patient 2 or 3 times a month for 6 months.

The guideline also said that bariatric surgery may provide significant health benefits for patients with a body mass index (BMI) of 40 or higher or a BMI of 35 or higher along with 2 other cardiovascular risk factors.

What About the Hypertension Guideline?
Not included in the rollout of the 4 guidelines was the hypertension guideline, which hasn’t been updated since 2003 and had been expected to be ready for release this summer. American Heart Association President Mariell Jessup, MD, said at a press conference last week that she wasn’t sure when the hypertension guideline would be published but that like the guidelines released today, it will be based on a similar approach, performed by an expert panel.

Patients Continue to Experience Benefits 3 Years After Weight-Loss Surgery for Severe Obesity

Anita P. Courcoulas, MD, MPH, director of Minimally Invasive Bariatric and General Surgery at the University of Pittsburgh Medical Center, and colleagues found that 3 years after undergoing bariatric surgery for severe obesity, patients had, on average, lost a substantial amount of weight and improved on several health measures. (Image: University of Pittsburgh Medical Center)

Anita P. Courcoulas, MD, MPH, director of Minimally Invasive Bariatric and General Surgery at the University of Pittsburgh Medical Center, and colleagues found that 3 years after undergoing bariatric surgery for severe obesity, patients had, on average, lost a substantial amount of weight and improved on several health measures. (Image: University of Pittsburgh Medical Center)

More encouraging data are emerging on the benefits of bariatric surgery in reducing substantial amounts of weight and improving health in severely obese patients, according to a study published by JAMA.

Researchers with the Longitudinal Assessment of Bariatric Surgery Consortium, a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse regions of the country looked at health measures for severely obese patients 3 years after weight-loss surgery. Patients who had undergone Roux-en-Y gastric bypass surgery had lost about 90 pounds, or about 30% of their original weight; those who had undergone laparoscopic adjustable gastric banding lost about 44 pounds, or about 16% of their original weight. The median presurgical weight for both groups was about 284 pounds.

The researchers also found among study participants who had diabetes at the time of surgery, partial remission of the disease occurred in about two-thirds of those undergoing Roux-en-Y bypass and just over a quarter of those undergoing gastric banding. Abnormal blood lipid levels were eliminated in about 62% of patients after Roux-en-Y bypass and in about 27% after gastric banding. Hypertension resolved in almost 40% of patients with Roux-en-Y bypass and in almost 20% of patients with gastric banding.

Lead author Anita P. Courcoulas, MD, MPH, director of Minimally Invasive Bariatric and General Surgery at the University of Pittsburgh Medical Center, discusses her team’s findings.

news@JAMA: Why did you do the study?

Dr Courcoulas: Our focus was to look at the durability of weight and health changes after bariatric surgery in a carefully studied, heterogeneous population with a high degree of follow-up.

news@JAMA: These patient populations had different results based on the procedure performed. Why is that?

Dr Courcoulas: Our study didn’t specifically address the potential mechanisms of weight change, nor was it designed to make head-to-head procedure comparisons. In our study, both bypass and banding did lead to substantial weight loss at 3 years that compares favorably to the modest weight loss resulting from lifestyle intervention alone. The weight loss after banding was less than reported in previous studies and not as large as the weight loss after bypass. This may be a function of patient, provider, and/or many other factors and deserves further attention.

news@JAMA: Given that Roux-en-Y bypass appears to outperform gastric banding, why not have everyone who needs bariatric surgery receive the bypass?

Dr Courcoulas: There are patients who come to see a bariatric surgeon who are not comfortable with bypass because of the anatomical changes they will undergo, so banding is appealing for those still wanting help to lose weight.

news@JAMA: So is bariatric surgery the best option for severely obese individuals looking to lose weight and improve health measures?

Dr Courcoulas: The extreme heterogeneity in outcomes we found highlights the need to better understand factors contributing to individual differences in weight loss results. It would make sense if one of the important variables in determining how much weight one will lose and how well that weight loss is maintained is lifestyle modification—how do you make the most of an operation to help enhance those results? Even so, longer-term follow-up is needed to determine the durability of the weight and health improvements we observed.

Eating a Vegetarian Diet May Reduce the Risk of Developing Heart Disease

A study from England that tracked the health of vegetarians vs nonvegetarians found that eating a vegetarian diet was associated with lower risks for heart disease hospitalizations and deaths. (Image: nullplus/iStockphoto.com)

A study from England that tracked the health of vegetarians vs nonvegetarians found that eating a vegetarian diet was associated with lower risks for heart disease hospitalizations and deaths. (Image: nullplus/iStockphoto.com)

Mom’s admonishment to “Eat your veggies” appears to be sound advice, at least with respect to reducing risk of heart disease.

Researchers from the University of Oxford in England found that compared with people who eat meat and fish, vegetarians were 32% less likely to be hospitalized for or die from ischemic heart disease, heart problems resulting from the narrowing or blockage of blood vessels that supply the heart. The findings appear today in the American Journal of Clinical Nutrition.

The research involved 44 561 men and women living in England and Scotland enrolled in the European Prospective Investigation into Cancer and Nutrition—Oxford study, about one-third of whom were consuming a vegetarian diet at the beginning of the study. The study participants were recruited between 1993 and 1999 and followed up into 2009. Continue reading

Author Insights: Fasting May Not Always Be Necessary for Accurate Assessment of Cholesterol Levels

Christopher Naugler, MD, MSc, University of Calgary in Alberta, Canada, and a colleague found having patients fast before their blood is drawn to accurately measure lipid levels may not be necessary. (Image: Sher Clain)

Current guidelines for testing blood lipid levels to assess cardiovascular health recommend that patients fast at least 9 hours before having their blood drawn, to ensure an accurate result. But a study appearing today in the Archives of Internal Medicine suggests that fasting may be unnecessary.

The study, by Christopher Naugler, MD, MSc, and Davinder Sidhu, MD, both of the University of Calgary in Alberta, Canada, examined blood draws for assessing lipid levels among 209 180 people over a 6-month period in 2011. They divided patients into groups that were based on the number of hours (from 1 to 16 hours) the patients had fasted before having their blood drawn and then calculated the average of the lipid levels for all of the patients in each group. The average levels of total cholesterol and high-density lipoprotein cholesterol (HDL-C), elements used for calculating 10-year risk scores for having a heart attack, varied by less than 2% regardless of the time spent fasting. There was greater variation with 2 other lipid measures: average low-density lipoprotein cholesterol (LDL-C) levels varied by less than 10%, and average triglyceride levels differed by less than 20%. Continue reading

Pythons Offer New Clues in Heart Disease

Leslie Leinwand, PhD, heads a research team at the University of Colorado, Boulder, that studies how python heart function could lead to new therapies for human heart disease. (Image: Thomas Cooper)

Pythons aren’t usually thought of as big-hearted creatures. But after a Burmese python feeds on a huge meal, its heart size swells and so does the quantity of fatty acids in its bloodstream. The process is a healthy one that scientists say could offer clues to help develop new treatments for human heart disease.

In today’s Science, a team led by researchers at the University of Colorado in Boulder shows that a day after a big feast, pythons’ heart mass can grow by 40%, their triglyceride levels shoot up more than 50-fold, and their metabolism speeds up 40-fold. Their heart tissue has higher activity of superoxide dismutase, an antioxidant enzyme known to protect the heart. Researchers found no evidence of fat deposits in the snakes’ hearts.

Similar increases in heart mass, triglycerides, and metabolism occurred when researchers injected snakes that hadn’t fed recently with blood plasma from well-fed pythons or a fatty acid mixture they made to mimic the plasma. Results were the same in mice injected with the python plasma or the fatty acid mixture. Cultured rat heart cells also responded similarly. Continue reading

Author Insights: Cholesterol-Lowering Diet May Improve Heart Health

David J. A. Jenkins, MD, PhD, DSc, and colleagues found patients taking a cholesterol-lowering diet are able to reduce their levels of low-density lipoprotein cholesterol. (Image: St Michael’s Hospital)

A diet rich in cholesterol-lowering foods such as soy protein, nuts, and margarine appears to reduce low-density lipoprotein cholesterol (LDL-C)—the “bad” cholesterol—almost 14% compared with a diet low in saturated fat. The finding appears today in JAMA.

Researchers randomly assigned 351 volunteer participants with elevated cholesterol levels enrolled at 4 Canadian academic centers to receive dietary advice for consuming either a diet low in saturated fat or a diet rich in cholesterol-lowering foods. At 24 weeks, the LDL-C levels of those who were on a diet low in saturated fat decreased from an average of 167 mg/dL to 161 mg/dL, while the LDL-C levels of those consuming cholesterol-lowering foods dropped from an average of 171 mg/dL to 143 mg/dL.

Lead author David J. A. Jenkins, MD, PhD, DSc, St Michael’s Hospital, Toronto, Ontario, Canada, discusses his team’s findings:

“When you look at volunteer patients, you get people who are already devoted to wanting to achieve a healthy lifestyle, and so a 13% to 14% reduction in LDL-C is especially good. We would expect to see even better results in the average population. Continue reading

Evidence of Safety Issue for High Dose of Cholesterol-Lowering Drug Emerged Long Before FDA Action

The US Food and Drug Administration says that a high-dose version of simvastatin, which lowers levels of low-density lipoprotein cholesterol, should not be prescribed to new patients because of potential safety risks. (Image: JAMA, ©AMA)

The announcement earlier this week by the US Food and Drug Administration (FDA) that the high-dose formulation (80 mg per day) of the cholesterol-lowering drug simvastatin (Zocor) should not be prescribed for new patients was long awaited by critics of the drug, who questioned why the agency did not take such action sooner. Studies suggest that use of simvastatin may elevate a patient’s risk of developing myopathy, or muscle injury, resulting in muscle pain, tenderness, or weakness. In rare cases, the most serious form of myopathy can damage the kidneys and lead to kidney failure.

One vocal critic, cardiologist Steven E. Nissen, MD, of the Cleveland Clinic, first questioned the safety of simvastatin in 2004 in an editorial in JAMA. The editorial commented on study findings indicating that high-dose simvastatin, while increasing the risk of myopathy, was no better than low-dose simvastatin in reducing major cardiovascular events such as heart attack or stroke in patients with acute coronary syndrome. Results of another study (called REACH) of patients who had previously experienced a heart attack, announced in 2008, showed similar findings and eventually prompted the FDA to issue a safety announcement in March 2010 about the increased risk of myopathy in patients taking high-dose simvastatin. Continue reading