2013 top 10 advances in heart disease and stroke science
American Heart Association/American Stroke Association Top 10 Research Report
DALLAS, Jan. 2, 2014 – New prevention guidelines, programs to control blood pressure, getting more people to access cardiac rehab services and a possible link between digestive bacteria and heart disease risk are included in a recap of last year’s top cardiovascular and stroke advances identified by the American Heart Association and American Stroke Association.
“To become a nation of healthier people who live longer, better quality lives, it’s important to reflect on the progress we’ve made,” said Mariell Jessup, M.D., president of the American Heart Association and medical director of the Penn Heart and Vascular Center and professor of medicine at the University of Pennsylvania School of Medicine in Philadelphia. “Medical research answers critical questions we have about cardiovascular disease, raises important new questions and sets the stage for future concepts.”
The association has been compiling an annual list of the top 10 major advances in heart disease and stroke science since 1996. Here are the association’s top scientific advances for 2013:
1. Prevention guidelines
In November, the American Heart Association and American College of Cardiology published a set of four guidelines on obesity, cholesterol, risk assessment and lifestyle to help patients and physicians prevent more heart attacks and strokes. The guidelines, based on a thorough review of scientific evidence, were completed by the AHA and ACC after being initiated by the National Heart, Lung, and Blood Institute in 2008. Highlights:
Obesity requires long-term professional management
Obesity is more than a lifestyle issue, according to the AHA, and patients are more likely to stay on track when guided long-term by a trained professional in a healthcare setting. Losing weight and maintaining weight loss requires eating fewer calories than your body uses, exercising more and changing unhealthy behaviors. This guideline features a roadmap with multiple different approaches to help patients lose weight and keep it off, starting with evaluating every American’s body mass index – a ratio of height to weight. Patients with a BMI of 30 or higher are considered obese and need treatment and chronic follow-up. In the U.S., nearly 78 million adults are obese.
Lower overall heart attack and stroke risk, not just cholesterol
After lifestyle changes, cholesterol-lowering statin drugs could benefit about 33 million Americans who have a greater than 7.5 percent 10-year risk for heart attack and stroke. The term “ASCVD” in this guideline refers to the type of cardiovascular disease caused by atherosclerosis, or hardening of the arteries, that can lead to heart attack or stroke.
The guideline recommends that patients and their healthcare providers assess the patient’s risk of ASCVD events, and then discuss treatment options, including patient preferences. It also describes four major groups of people whose benefit from lowering their heart attack or stroke risk would clearly outweigh the risk of side effects from statin medications. These include patients: 1) with diagnosed ASCVD; 2) with LDL, or “bad,” cholesterol of more than 190 mg/dL with no secondary cause; 3) who are 40-75 years old with type 2 diabetes, an LDL cholesterol of 70 to 189 mg/dL, and don’t have diagnosed ASCVD; and 4) who have an estimated 10-year risk of ASCVD of more than 7.5 percent, but don’t have diagnosed ASCVD or type 2 diabetes with the LDL levels described above.
Treating for higher overall risk using the criteria in the guideline will replace the previous approach of treating LDL cholesterol to a specific target level.
Assessing risk of heart attack and stroke in more people
Updated risk equations for white men and women – and a new risk equation for African-Americans – were published in the risk assessment guideline. To calculate 10-year risk, the equations use race, gender, age, total cholesterol, HDL “good” cholesterol, blood pressure, use of blood pressure medication, diabetes status and smoking status. Importantly, stroke risk is included, giving patients a better assessment of their future cardiovascular health.
Lifestyle guidelines: dietary patterns and exercise
Lifestyle recommendations target the many people who need to lower cholesterol and blood pressure. They recommend an overall heart-healthy dietary pattern and 40 minutes of moderate to vigorous aerobic exercise three to four times a week. Dietary patterns should emphasize fruits, vegetables, whole grains, low-fat dairy products, poultry, fish and nuts, and limit red meat and sugary foods and beverages. To lower blood pressure, the guideline recommends a step-down approach to no more than 2,400 milligrams of sodium a day. To lower it further, the guidelines recommend getting sodium down to 1,500 mg a day.
2. Controlling high blood pressure
Although researchers understand the best ways to treat hypertension, many patients do not know they have it, and only half of the 75 percent of patients being treated control it to a healthy level.
One important study showed a dramatic increase in patients whose hypertension was controlled — from 44 percent to more than 87 percent over 10 years — through an evidence-based program implemented by a large healthcare provider. It strongly encouraged lifestyle changes, improved tracking of patient information, simplified drug therapies, made in-office blood pressure checks more accessible, provided doctors more feedback and overall, treated patients according to scientific evidence.
This program also followed other principles recommended by the AHA, including cost considerations, simple approaches and easy-to-understand patient materials.
3. Combatting poor childhood and early adulthood heart health and its aftermath
Two studies looked at heart health in young people — one used the American Heart Association’s Life’s Simple 7 health measures to determine how ideal health affected brain function in middle age. The other evaluated a preschool curriculum’s effect on the health habits of preschoolers and their families.
A study of nearly 3,000 people aged 18-30 over 25 years found that those maintaining ideal health had better brain function in middle life. Each one of the seven health measures — avoiding being overweight or obese, eating a healthy diet, not smoking, and being physically active, and keeping total cholesterol, blood pressure, and fasting glucose at goal level — improved cognitive function.
A structured curriculum based on Sesame Street’s Healthy Habits for Life used in Bogota, Columbia improved hundreds of preschoolers’ knowledge, attitudes and heart-healthy habits. The program resulted in a 13 percent improvement in the percentage of children at a healthy weight — from 62 percent to 75 percent.
4. Getting more people to cardiac rehabilitation has big results
Following hospitalization for cardiovascular disease, simple changes can greatly increase enrollment and participation in cardiac rehabilitation, and rehabilitation significantly lowered the death rate after heart bypass surgery, according to several 2013 studies. Not enough eligible patients participate in cardiac rehabilitation, despite known benefits, said study authors.
Setting outpatient rehabilitation appointments soon after leaving the hospital improved participation significantly, as did providing a non-medical “navigator” or “coach” while patients were still in the hospital. Hospitals promoting cardiac rehabilitation and more certifications for rehab programs also were effective.
The 10-year death rate for people who participated in cardiac rehabilitation after heart bypass surgery was 50 percent lower than those who did not participate.
5. Breakthroughs in congenital heart disease genetics
Two new papers have significantly increased our understanding of the genetics of congenital heart disease. One identified 400 genes potentially responsible for congenital heart disease, and found that 10 percent of mutations leading to severe congenital heart disease were new and not passed down by a parent. Another study showed for the first time that, mutations within a genetic pathway that regulates early development may be responsible for congenital heart disease, and may also have a link to autism.
6. How intestinal microbes raise the cardiovascular disease risk from red meat
An emerging area of nutrition science is the study of bacteria, or microbes, in the digestive system and how they affect heart disease risk. A 2013 study discovered that microbes in the digestive system may be responsible for red meat elevating two chemicals associated with cardiovascular disease, L-carnitine (a nutrient that can be measured in the blood) and a substance called trimethylamine-N-oxide, or TMAO, produced by bacteria in the digestive tract from L- carnitine, and linked to major cardiac events. Vegans, vegetarians and omnivores (who eat meat and vegetables) were studied. Vegans and vegetarians had less L-carnitine in their blood than omnivores and when they consented to eat meat for the study, their digestive system produced less TMAO than their meat-eating counterparts.
7. Atrial Fibrillation
Atrial fibrillation, an irregular heartbeat that can lead to blood clots, stroke, heart failure and other heart-related complications, affects 2.7 million Americans. One study found that atrial fibrillation also may affect cognitive function.
Warfarin is the most common treatment for atrial fibrillation and proper dosing is critical. Recent analyses have suggested that newer drugs may be as effective as warfarin in preventing strokes, and may reduce the risk of some bleeding complications.
Two studies found that using genetic testing to determine the best dose of warfarin may not be worth the extra testing and cost.
Other studies compared warfarin to newer drugs called novel oral anticoagulants. A meta-analysis compared four of them and found they significantly reduced stroke, bleeding in the brain, and death, although they increased gastrointestinal bleeding.
8. Simplifying the cooling of cardiac arrest patients and extending life support
Resuscitation studies provided guidance on cooling cardiac arrest patients — called therapeutic hypothermia — and on how long to provide life support after they’ve been rewarmed. Cooling patients who have survived sudden cardiac arrest can improve their survival and brain function, and two studies suggest simplifications to the process. The first suggested that cooling before patients reach the hospital did not help their survival or brain function. The second study found no differences in survival or brain function for patients cooled to 33 degrees Celsius vs. 36 degrees Celsius. Incorporating these ideas could save emergency medical services from investing in special equipment and training, and hospitals can more easily lower their patients’ temperatures.
After cooling and rewarming, another study recommends that healthcare providers wait 48-72 hours before withdrawing life support, because patients can still survive with good brain function after 72 hours. Before therapeutic hypothermia is used, most patients are put into a medically induced coma.
9. Endovascular treatment for stroke
Several studies evaluated the use of endovascular treatment of strokes caused by blocked blood vessels supplying the brain. Endovascular treatment either delivers tissue plasminogen activator (tPA) near the blockage in the blood vessel or mechanically restores blood flow in the vessel. Most studies found it led to more blood vessels supplying the brain being open after treatment, but newer studies did not demonstrate that this led to better outcomes for patients than standard drug treatment, intravenous tPA.
One particular study found that brain imaging failed to identify people who might benefit more from endovascular treatment.
Endovascular therapy has also been used after IV tPA to treat patients with moderate to severe ischemic stroke. The largest study to compare this combined approach with IV tPA alone found more open vessels with endovascular therapy, and similar safety outcomes between the approaches, but the trial was stopped early because the combination approach did not change stroke survivors’ functional independence enough to be statistically significant. Investigators have suggested that endovascular therapy might still provide benefit if the relevant vessels could be opened earlier in the course of stroke, and feel more trials are warranted.
10. Niacin doesn’t lower heart risks, may be harmful
In 2013, the largest study of niacin showed that the drug, combined with laropiprant, added to reduce the facial flushing caused by niacin, does not benefit people at risk for heart disease or stroke, and may even be harmful.
Niacin is a B vitamin traditionally used to raise HDL or “good” cholesterol and lower LDL or “bad” cholesterol. The new study of 25,000 people showed the drug combination failed to reduce the chances of non-fatal heart attack or heart-related death, stroke, or the need for angioplasty or bypass surgery.
People taking the drug also had more bleeding, infections, diabetes and related complications, indigestion and diarrhea and itchy skin, compared to those taking a placebo.
Based on these results, patients taking niacin are encouraged to ask their healthcare providers if they should keep taking it.
Study citations available upon request.
The American Heart Association/American Stroke Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and and device corporations are available at www.heart.org/corporatefunding.