Surgically Inducing a Heart Attack may Help Reduce Symptoms in Those with Enlarged Hearts, Scientists say
DALLAS, TX -- Injecting alcohol into the walls of the heart and deliberately inducing a heart attack can ease the symptoms of a genetic enlargement of the heart, report researchers in today's Circulation: Journal of the American Heart Association.
"It is not a procedure that is to be undertaken lightly because it has its hazards. Proper training and experience are necessary," says the study's lead author, William H. Spencer III, MD, of Baylor College of Medicine, Houston.
People who have hypertrophic obstructive cardiomyopathy have hearts that become thicker and stiffer than normal. Their symptoms include fainting, chest pain and shortness of breath to the point where many can't walk at a normal pace on level ground or ascend stairs.
In this study, every person who was treated with the procedure at Baylor had less severe symptoms afterward and in some cases had none at all.
More than a dozen specially-trained medical centers in the United States, Canada, and Great Britain are capable of performing the procedure and are treating patients, says Spencer.
Hypertrophic cardiomyopathy, the most common cause of sudden death in young athletes, occurs in one in 500 in the general population. According to the researchers, about one-third of those with obstructive cardiomyopathy -- one type of hypertrophic cardiomyopathy -- could benefit from this new treatment. Four percent of people with this disease die each year.
Open-heart surgery to cut away the obstruction relieves symptoms and perhaps prolongs life, says Spencer. He adds that this new procedure is considerably less invasive and does not share the risks of surgery.
In this new procedure, developed by Ulrich Sigwart, MD, at the Royal Brampton Hospital in London, ethanol is injected into the ventricular septum, the wall that separates the two chambers of the heart known as the atrium and the ventricle. In these patients, the septum is abnormally overgrown -- hypertrophied -- and obstructs the blood flow from the left ventricle, the main pumping chamber, to the aorta and the body.
Pure ethanol is toxic to the heart muscle, Spencer says. Injecting ethanol into the heart causes a major heart attack that produces scar tissue, which shrinks the obstruction, allowing blood to flow through normally once again.
During the procedure, temporary pacemakers are inserted to keep the heart beating properly.
Spencer says that six months to a year after the procedure, the heart appears as if the obstruction was cut away with a knife. "It is phenomenal. All these people are so much better," he adds.
Why would anyone submit to a heart attack, even under controlled conditions?
"The alternative is open-heart surgery," Spencer says.
In a study at Baylor, 33 patients were treated with this procedure. Their average age was 52. All of them had been treated with drugs, including beta-blockers, calcium antagonists or antiarrhythmic drugs to alleviate their symptoms.
The patients underwent extensive examinations including echocardiograms and blood tests, which helped locate the exact point of obstruction on the heart's septum.
Physicians then slid a balloon catheter into the heart and between 2 and 5 cubic centimeters (cc) of pure ethanol were injected through the balloon for five minutes directly into the blockage. Some complications did occur. All patients had chest pains and multiple premature ventricular beats during the injections, prior to being sedated.
The scientists say all patients reported a significant improvement in symptoms before hospital discharge. Only seven of them needed to continue medication. After six months, five were completely without symptoms, and all reported an improvement. Eleven required permanent pacemakers.
It is too early to tell if the procedure lengthened life, says Spencer. The researchers also say they could not rule out the placebo effect because there was no control group to compare results. While several centers now are treating patients, not all managed healthcare organizations are willing to pay for it, he says.
Centers now performing the procedure and participating in an Internet registry where the surgical results are compiled include: Massachusetts General Hospital, Boston; Duke University Medical Center, Durham, NC; Emory University Medical Center, Atlanta; University of Kentucky Medical Center, Lexington; Cleveland Clinic, Cleveland; the Mid-America Heart Institute, Kansas City; Baylor; the Mayo Clinic; Cedar-Sinai-UCLA, Los Angeles; Sequoia-Stanford University, Palo Alto; the Washington Heart Center, Washington, DC; and St. Louis University Hospital. It is also available at Toronto Hospital as well as two sites in England.