Early Surgery for Aortic Stenosis Saves Lives


Ed Susman

Mr. Susman is a freelance medical writer based in Florida, USA. He travels worldwide to report from medical conferences, writing regularly for wire services, internet websites, and medical journals such as the Journal of the National Cancer Institute and AIDS.

For comments, edwardsusman@cs.com

PHILADELPHIA, Pennsylvania – During routine testing, doctors will sometimes find an unexpected heart murmur in their patients – which is later identified as a severe aortic stenosis. The dilemma has been whether to surgically repair a problematic heart valve in these asymptomatic patients, or wait until symptoms emerge.

Researchers suggested here at the annual scientific sessions of the American Heart Association that surgery as soon as feasible – within 2 months of the finding, will save lives, reducing the risk of death from operative mortality of death from cardiovascular causes by 81 percent.

After a median follow-up of 4 years in the RECOVERY (Randomized Comparison of Early Surgery vs Conventional Treatment in Very Severe Aortic Stenosis) trial, 1 patient in the early surgery group experienced the endpoint compared with 11 patients treated conservatively [HR 0.09 (95 percent CI 0.01-0.67, P=0.003)], said Duk-Hyun Kang, MD, PhD, professor of medicine at Asan Medical Center, Seoul, Republic of Korea.

Death from any cause occurred in 5 patients in the early surgery group compared with 15 patients from the conservative treatment group over the course of the trial, Dr. Kang said in his oral, late-breaker presentation. “Usually these asymptomatic patients are identified because their doctors detect heart murmurs,” Dr. Kang said. “It usually happens during a routine physical or they are being checked for another reason.”

The research team randomized 73 patients to early surgery, and surgery was performed in 69 patients. They assigned 72 patients to conservative care but 3 patients opted for early surgery, so the conservative care group included 69 patients as well.

Over the course of the 9 years that the trial recruited patients plus 4 years of follow-up, 92 percent of the patients in the conservative care group eventually underwent surgery, Dr. Kang reported. The cumulative incidence of sudden death was 4 percent at 4 years and 14 percent at 8 years in the conservative group; it was 1 percent at 4 years and 1 percent at 8 years in the group that underwent early surgery. There were no operative deaths in either group of patients.

In the early surgery group, half the patients were treated with mechanical valve replacement; and the others were treated with a biologic prosthesis.

“Although aortic valve replacement is the only effective therapy for symptomatic severe aortic stenosis, optimal timing for valve replacement has been controversial,” Kang said.

Non-diabetics benefit from diabetes drug

Heart failure patients with reduced ejection fraction appear to benefit significantly when the diabetes drug dapagliflozin (Farxiga) is added to their treatment regimens – even if they do not have diabetes, researchers reported in another trial.

Among people taking dapagliflozin in the DAPA-HF trial, the reduction of the composite primary endpoint of cardiovascular death, heart failure hospitalization and urgent heart failure visit was reduced by 27 percent among patients who were not diagnosed with diabetes compared to placebo (HR 0.73 [95 percent CI 0.60-0.88]), reported John McMurray, MD, professor of cardiology at the British Heart Foundation Cardiovascular Research Centre at the University of Glasgow.

In his late-breaker presentation. Dr. McMurray noted that among diabetics in the DAPA-HF trial, there was a 25 percent reduction in primary endpoint events (HR 0.75 [95 percent CI 0.63-0.90]) among diabetic patients compared with placebo.

“When added to standard therapy, dapagliflozin reduced the risk of worsening heart failure events and cardiovascular death, and improved symptoms, in patients with heart failure with reduced ejection fraction, bot with and without type 2 diabetes,” he said.

“The relative and absolute risk reductions in death and hospitalization were substantial, clinically important and consistent in patients with and without type 2 diabetes,” he said.

In the composite of death and heart failure hospitalizations, patients on dapagliflozin who were diagnosed with diabetes achieved a 23 percent reduction in the endpoint (HR 0.77 [95 percent CI 0.63-0.94)] compared with placebo, while there was a 27 percent reduction in the risk of experiencing the endpoint (HR 0.73 [95 percent CI 0.59-0.91]) among patients with reduced ejection fraction who did not have diabetes, McMurray illustrated.

He also demonstrated that when patients without diabetes were stratified by HbA1c levels – 5.6 percent of lower, 5.7 percent to 5.9 percent or 6 percent or greater – there was a consistent reduction of between 26 percent to 29 percent in adverse events when compared with placebo.

In discussing the outcome of the DAPAHF substudy, Larry Allen, MD, professor of medicine at the University of Colorado Anschutz Medical Campus, Aurora, said, “Exactly why dapagliflozin works in nondiabetic patients is not really known but may be related to its effect on kidney function. It has a number of effects not only in the kidney but also in the body in terms of neurohormonal antagonism. So it is not surprising to think that we could have effect beyond diabetes.”

Dr. Allen said the evidence of the benefit of drugs in the dapagliflozin class (SGLT2 – sodium glucose co-transporter-2 inhibitors) in other clinical trials had led him to use the drugs in his patients. “So what you are seeing around the community now is that if I have a patient that has diabetes and heart failure, many of us are starting to use these agents in those patients with diabetes,” he said.

In the DAPA-HF trial, Dr. McMurray enrolled 4,744 patients with heart failure characterized by reduced ejection fraction – defined as left ventricular ejection fraction of 40 percent or less — from 20 countries. They were assigned to treatment with placebo or 10 mg dapagliflozin once daily.

Of that group, 2,139 patients were diagnosed with diabetes, and 2606 did not have a diagnosis of diabetes. The patients were about 67 years old and more than 75 percent were men; the vase majority of the patients were diagnosed in New York Heart Association heart failure class II or III. Their mean left ventricular ejection fraction was 31 percent. More of the patients with diabetes (61 percent) had a heart failure etiology of ischemia compared with 51 percent of the patients who did not have diabetes.

Dr. McMurray said dapagliflozin was well tolerated by patients with and without diabetes when compared with patients who were treated with placebo.

“Dapagliflozin offers a new approach to the treatment of heart failure with reduced ejection fraction in patients with and without type 2 diabetes,” he said.

The study was funded by AstraZeneca.

War on vaping

The American Heart Association has opened a war against vaping, dedicating US$20 million to battle electronic cigarettes, nicotine addiction and vaping products aimed at youth.

“It is unfortunate that we need to band together to fight this growing epidemic. It is going to take a big, unparalleled and urgent commitment by national and community level stakeholders if we are going to beat big tobacco,” said Robert Harrington, MD, president of the American Heart Association and chairman of the department of medicine at Stanford University in California.

“We are committing up to $20 million to fund the ‘End the Lies: Youth Vaping Nicotine Research Initiative,’ he said at a press conference. “This is an unprecedented effort to drive scientific discovery and is designed to help end the vaping and nicotine use in this country.”

At the press conference, speakers lashed out at the Food and Drug Administration for a failure to regulate nicotine-laced products such as those produce by JUUL, the electronic cigarette maker that is 35 percent owned by Altria group, formerly Philip Morris Companies. Harrington urged the FDA to “exercise its regulatory authority over these e-cigarettes such as by removing all flavored e-cigarettes, including mint and menthol, from the market and prohibiting flavored tobacco products of any kind.”

Nancy Brown, the chief executive officer of the American Heart Association, noted that the organization has sued the FDA to get the agency to use its authority to regulate the products. The lawsuit is ongoing. “We are horrified to see the uptick of e-cigarette use by youth – estimated to have grown from 1 percent to 27 percent in a decade. Our worst nightmare plus has come true,” she said.

“We thought the FDA was going to do something about smoking and e-cigarettes,” said Regina Benjamin, MD, former surgeon general of the United States, “but the FDA carved it out. We were not prepared for the FDA not doing its job. The result has been disappointing.”

Benjamin said, “As you know, research takes time and we are moving along as fast as we can. We believe that instead of waiting to ban a product when it is proven harmful, we should ban it until it is proven safe.”

While there has been consideration of e-cigarettes as a method of getting people off smoking cigarettes, a known cause of heart disease and cancer, Dr. Benjamin said she has never recommended that her patients trade cigarettes for e-cigarettes.

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