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Johns Hopkins News Tips from the American Heart Association Scientific Sessions, Nov. 15-19, Chicago - 11/19/2014

Johns Hopkins News Tips from the American Heart Association Scientific Sessions, Nov. 15-19, Chicago

Release Date: November 19, 2014

Absence of Calcium Buildup in the Arteries Spells Low Risk for Heart Disease, Stroke Over 10 Years

Results of a 10-year multicenter study of more than 3,900 middle-aged and older adults add new, stronger evidence that lack of calcium deposits in the arteries portends a very low risk of heart attack and stroke over the long term — a finding that could play a prominent role in treatment decisions for patients with borderline risk profiles.

Findings of the study, known as the Multi-Ethnic Study of Atherosclerosis and led by investigators at Johns Hopkins, are scheduled for presentation Nov. 16 at the annual scientific sessions meeting of the American Heart Association in Chicago.

Specifically, the research showed that people with no visible artery calcification — already known to be at low risk for heart attacks and strokes in the short term — remain at low risk for up to a decade or so. Subtle but important differences emerged between people with no calcium inside their arteries and those with small but detectable deposits. The latter group, the research found, had twice the cardiovascular risk of people with plaque-free arteries. Of the 3,923 participants in the study, 3,415 had no calcium buildup inside their arteries, or a coronary calcium score of zero, while 508 had small calcium deposits, or a low calcium score, between 1 and 10. Analysis showed 123 heart attacks and strokes among all participants during the 10-year follow-up, at an overall risk rate of 3.3 per 1,000 years. However, when the investigators compared those with no calcium deposits against those with minimal calcium buildup, they found the risk nearly doubled among people with low calcium scores. When researchers analyzed the effect of additional risk factors, they found that even though smoking, age and high blood pressure drove up the risk of heart attack and stroke among all participants, people with zero calcium scores still remained at relatively low risk. High cholesterol levels further fueled cardiovascular risk among those with small calcium deposits but did not alter risk among those with plaque-free arteries.

 “Our results show that lack of calcification is a reliable and potent predictor of minimal cardiovascular risk for up to 10 years, even in the presence of other risk factors, such as cholesterol, age or hypertension,” says study lead investigator Parag Joshi, M.D., a cardiology fellow at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease. “We hope these insights can help augment the traditional risk-gauging algorithm, which doesn’t always give straightforward answers and leaves many patients and clinicians in a gray zone of uncertainty.”

The traditional risk-scoring system factors in a person’s cholesterol levels, smoking, gender and age, as well as the presence of other medical conditions known to fuel cardiac risk, including high blood pressure and diabetes.

“Our findings underscore the notion that coronary calcium is not merely a more accurate predictor of ardiac risk than traditional risk factors but also a direct measure of actual blood vessel damage,” says Khurram Nasir, M.D., M.P.H., assistant professor at the Ciccarone Center for the Prevention of Heart Disease and director of the High Risk Cardiovascular Disease Clinic and Center for Wellness and Prevention Research at Baptist Health South Florida. “We hope our findings could eventually help clinicians tailor therapy with greater precision.”

Calcium scoring is based on the presence and degree of calcification seen on CT scan images of the heart’s four major arteries and the carotid artery, which supplies blood to the brain. Calcium deposits signal hardening and narrowing of the arteries, but exactly how and why calcium builds up inside the vessels is not completely understood. Many experts believe that calcium accumulates atop pre-existent fatty plaque as a way to contain and stabilize tiny fat particles from breaking off and causing heart attacks and strokes. Thus, more calcium deposits typically indicate more advanced arterial disease.

Other Johns Hopkins investigators involved in the research included Michael Blaha, M.D., M.P.H.; Roger Blumenthal, M.D.; and Joao Lima, M.D. The other participating institutions included the University of California, the Minneapolis Heart Institute, the University of Washington, Baptist Hospital of Miami, and Brigham and Women’s Hospital.


Being in Good Shape Reduces Death Risk from First Heart Attacks

People in good physical shape are far more likely to survive the immediate aftermath of a first heart attack than those in worse physical fitness, according to the results of Johns Hopkins-led research scheduled for presentation on Wednesday, Nov. 19, at the annual scientific sessions meeting of the American Heart Association in Chicago.

For the study, the investigators looked at a group of more than 2,000 middle-aged and older adults who had just suffered a first heart attack. The researchers then analyzed the results of exercise stress tests the patients had undergone several years prior to their heart attacks. An exercise stress test measures how well the heart and lungs respond to increasing levels of physical exertion while a person is walking on a treadmill at progressively higher speed and elevation. Based on their past treadmill performance, the investigators divided the subjects into four fitness categories — those with low, moderate, high and very high exercise capacity.

Overall, 11 percent of the 2,086 people in the study died within a month of suffering a first heart attack, but important differences emerged when the investigators looked at heart attack deaths by fitness level. The death rate among people with low levels of physical fitness was 14 percent, compared with 6 percent among those at very high levels of physical fitness. The death rate among those with moderate physical fitness was 11 percent, and it was 7 percent among those with high exercise capacity.

In other words, people with good or very good exercise capacity were nearly twice more likely to survive within a month of suffering a heart attack than those with poor fitness levels.

Fitness levels, the researchers say, predicted heart attack mortality independently of other factors known to fuel heart attack risk, including age, smoking, obesity, diabetes, high blood pressure and high cholesterol.

“We have known for quite some time that physical fitness improves cardiac performance and reduces the risk for heart attack in the first place, but our findings now suggest that being in good shape can also dramatically reduce the risk of dying if one should suffer a heart attack,” says senior investigator Michael Blaha, M.D., M.P.H., director of clinical research at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease.

Calcium Buildup in the Arteries: Not Just a Problem for the Heart

The presence of calcium deposits in the arteries of the heart has recently emerged as a powerful predictor of cardiovascular disease risk, but new research from Johns Hopkins suggests these calcium plaques may spell greater trouble. The findings, scheduled for presentation on Monday, Nov. 17 at the annual scientific meeting of the American Heart Association in Chicago, suggest that calcium buildup also portends elevated risk for cancer, lung disease, hip fractures and chronic kidney disease.

“Our findings support the notion that coronary calcium is a marker of biologic aging and may provide useful insight about a person’s risk for a wide range of age-related conditions well beyond heart disease,” says lead investigator Cathy Handy, M.D., M.P.H., an internal medicine resident in the Johns Hopkins University School of Medicine.

A person’s calcium score is based on the presence and degree of calcification visible on CT scan images of the arteries of the heart. Although calcium deposits signal hardening and narrowing of the arteries, how and why it builds up inside the blood vessels is not entirely understood. But many experts believe calcium accumulates inside blood vessels over many years as a byproduct of vessel aging and damage, Handy says.

In their multi-center study, Handy and colleagues tracked the development of new disease among more than 6,800 people, aged 45 to 84 over a period of 10 years. All participants were free of heart disease and cancer at the beginning of the study. The researchers compared the rate of new disease between participants with no calcium deposits in their arteries against those with very high calcium buildup, defined as a score above 400. The score is calculated based on the amount and visual density of calcium in the heart’s arteries as seen on a CT scan — the higher the density, the greater the degree of calcification.

People with heavy calcium buildup were 1.6 times as likely to develop cancer, almost twice as likely to develop kidney disease and pneumonia, and more than three times as likely to develop chronic obstructive pulmonary disease and suffer hip fractures.

“People whose arteries were free of calcium deposits had a notably reduced risk of age-related diseases and may, in fact, illustrate the very essence of healthy aging,” says senior investigator Michael Blaha, M.D., M.P.H., an assistant professor at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease.

Obesity More Likely to Lead to Heart Failure than to Other Types of Heart Disease

Obese people are more likely to develop heart failure than other types of cardiovascular disease, including heart attacks and strokes, according to results of a study led by investigators at Johns Hopkins and scheduled for presentation on Tuesday, Nov. 18 at the annual scientific sessions meeting of the American Heart Association in Chicago.

Specifically, obese people had heart failure risk twice as high as the risk for heart attacks and strokes, the study found. Even though obese people had markedly higher risk for all types of cardiovascular damage compared with people of normal weight, their heart failure risk was far more pronounced, the investigators say.

Remarkably, the elevated risk for heart failure persisted even when researchers accounted for the effects of high blood pressure, diabetes and cholesterol, all known to cause heart damage. On the other hand, the higher risk for heart attack and stroke was almost entirely explained by these well-known risk factors, the researchers say. That finding, the team says, suggests that obesity itself precipitates heart failure independently of other disease-causing factors.

“The notion that obesity affects cardiac health is hardly new, but how exactly the extra weight leads to different kinds of heart disease has remained somewhat of a mystery,” says lead investigator Chiadi Ndumele, M.D., M.H.S., assistant professor in the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease. “Our findings suggest that obesity fuels different types of cardiac pathology differently, interfering much more with the ability of the heart muscle to contract and relax properly than with other cardiovascular functions.”

Heart failure is marked by a stiff or weakened heart muscle that reduces the heart’s ability to pump blood. Heart attacks are generally caused by blood clots or fatty plaque obstruction inside the arteries of the heart, while strokes stem from blood clots inside the arteries that feed blood to the brain.

The study followed more than 13,700 men and women, aged 45 to 64, for more than 20 years. Compared with people of normal weight, severely obese people — those with body mass indices greater than 35 — were four times more likely to develop heart failure, more than twice as likely to develop coronary artery disease, or heart attack, and nearly twice as likely to suffer strokes.

Other Johns Hopkins investigators involved in the research included Kunihiro Matsushita, Mariana Lazo, Roger Blumenthal, Gary Gerstenblith, Elizabeth Selvin and Josef Coresh.

Other institutions involved in the study included Brigham and Women’s Hospital, Baylor College of Medicine, Michael E. DeBakey Veterans Affairs Medical Center in Houston and the University of Minnesota.
 

Calcium Deposits in the Arteries Portend Erectile Dysfunction Years Down the Road

Erectile dysfunction is common among men with established heart disease, but the results of a new Johns Hopkins-led study show the condition may manifest itself only after years of silent cardiovascular damage — one marked by high levels of calcium buildup inside their arteries and that is easily detectible with a CT scan of the heart.

Specifically, researchers found that men with heavy calcium buildup in their arteries — even when free of any heart disease symptoms — were 43 percent more likely to report erectile dysfunction years down the road.  Erectile dysfunction, which is characterized by reduced blood flow to the penis and inability to achieve or sustain erections, stems from the same process that causes stiffening and hardening in the arteries of the heart.

Findings of the multi-center study, scheduled for presentation on Tuesday, Nov. 18, at the annual scientific sessions of the American Heart Association in Chicago, highlight the importance of screening asymptomatic high-risk patients as an opportunity to ward off both cardiovascular disease and erectile dysfunction before either has manifested itself clinically, the research team says.

“Primary care physicians and cardiologists who care for men at risk for heart disease should be vigilant about new or progressive erectile dysfunction, which often signals the worsening of cardiovascular damage and the onset of overt heart disease,” says senior investigator Michael Blaha, M.D., M.P.H., director of clinical research at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease.

“Just as importantly, however, clinicians should counsel and, if necessary preemptively treat, symptom-free men with high calcium scores to avert the onset of full-blown erectile dysfunction and heart disease,” Blaha adds.  

For the study, investigators followed nearly 1,900 heart disease-free men, ages 55 through 64, over nine years. The participants underwent cardiac CT scans to measure the presence and amount of calcium buildup inside the arteries of the heart. Calcium deposits inside the major blood vessels are a direct measure of blood vessel hardening and portend high cardiovascular risk. In addition, participants underwent ultrasound imaging to measure the stiffness of their aortas and carotid arteries. The aorta is the body’s largest blood vessel, while the carotid arteries are critical in supplying blood to the brain. Participants also had a test to compare blood pressure in their lower legs to the blood pressure in their arms — an indicator of how well the arteries carry blood to the farthest sites of the body. Irregularities on any of the tests were linked to higher risk for subsequent erectile dysfunction. However, high amounts of calcium buildup, defined as a score of 100 or above, were the most accurate predictor of erectile problems years later, the research showed.