The Three R’s of Returning to a Healthy Heart
Soon after Joey Bellettiere was born with an enlarged heart, he was brought to CHOP for treatment. Although the newborn was stabilized, his parents were told he might eventually need a heart transplant. This prediction almost came to fruition when, at 19, he started having significant breathing problems that he had never before experienced. Within six months, Bellettiere was at HUP, learning that the left ventricular assist device (LVAD) he needed to survive was being studied as a possible bridge to recovery. Was he interested in participating in this trial? “It was a no brainer.”
Bellettiere received the LVAD in October 2009. Little by little, the device did less of the work as his heart took over more of the pumping process. By March 2011, his heart was deemed strong enough to remove the device. Today “I feel better than ever,” he said. “I can walk, I can run, without getting out of breath.”
From Implant to Explant: What’s Involved
In patients with heart failure, the heart enlarges as an adaptive response to injury. This allows it to keep pumping enough blood through the body, at least temporarily. As Eduardo Rame, MD, medical director of Mechanical Circulatory Support, explained, a normal heart regularly ejects – or pumps – about half of its 40-milliliter volume. Because a damaged heart might pump only 10 percent of its volume, it might need to enlarge to 200 ml to continue this ejection pace. However, it’s not sustainable. “The heart requires a tremendous amount of energy per day – more than any other organ – to circulate that much blood,” Rame said. “It simply can’t continue doing that much work at that size.”
With an LVAD augmenting the blood flow, a patient’s heart can rest and begin the slow process of reverse remodeling, ie, shrinking back to its normal size. Prior to implant, the patient’s heart failure medications are maximized to further help the reversal process. “The LVAD may be a platform that allows them to better tolerate these meds,” Rame said.
Routine echocardiograms chart the heart’s changes while the speed of the LVAD is slowly decreased. Echos are the primary imaging modality because they can be done repeatedly with no damage to internal organs. MRIs cannot be used on patients with these implanted devices.
The echocardiogram provides detailed information during the turndown, including the heart’s size and function level, how the right ventricle handles the increased blood flow, and a measure of the flow through the aortic valve. According to James Kirkpatrick, MD, of Cardiovascular Medicine, “The LVAD bypasses the aortic valve, but if the heart starts to function as it should, more of the blood starts going out the aortic valve, rather than through the LVAD.”
The echo also shows any leakage of the mitral valve, which would occur if the blood went backwards into the left atrium. Most important, if a patient does start to experience symptoms during the turndown, “ the echo will tell us why,” Kirkpatrick said.
Eventually, if the patient continues to tolerate the turndowns, the LVAD’s speed is down to a point where the patient is getting very little support from the device. If all gathered data – including the echos and stress tests -- show evidence the heart has recovered, the LVAD will be explanted (removed).
While no surgical procedure is without risks, removing the LVAD is a fairly simple procedure, said Y. Joseph Woo, MD, director of Penn’s Cardiac Transplantation and Mechanical Circulatory Support Program. The LVAD is removed from the heart and the holes in the heart where the LVAD was connected are repaired. “The entire procedure takes about two hours.”
“The sooner the heart starts to get better, the more successful the patient will be long term, ” Rame said, adding that if a patient’s heart has not recovered within six to nine months of implanting the LVAD, “this strategy is not working.”
Studies in Europe, where the bridge-to-recovery strategy has been used for years, show that, when the LVAD is removed, well over 90 percent of patients have had no recurrence of heart failure for more than two years – and others have gone well beyond five years. Rame said that younger patients with a short duration of heart failure have the greatest chance of recovery.
“We don’t know if a patient’s heart will continue to work on its own or might eventually still need a transplant or even another LVAD. But postponing a transplant for years in someone young is a significant benefit,” said Judy Marble, outpatient coordinator in the Mechanical Assist Device Program.
Rame agreed. “The longer you can put off a transplant, the better. In the majority of cases, patients who receive one at an early age will probably need another during their lifetime.”
The Future is Open
Cardiac-assist technology for heart failure has progressed enormously in the last several years and will continue to do so. As the number of patients who need a transplant continues to outnumber available donor hearts, devices such as the LVAD – and other approaches using the LVAD – continue to be vital to saving these patients.
Woo is part of a multi-site trial in which patients receive stem cells when the LVAD is implanted “to help regenerate the heart along with the device.” Rame said other experimental therapies at Penn are examining the use of gene therapy to replete factors in the heart “that we believe and know to be deficient.”
In addition, the next generation of these devices “will be smaller and more efficient,” Woo said.
While today’s VADs are still powered by a cable through the skin, “in the future, we may be able to implement a new way of charging the device, much like cell phone charger pads.”
So far, Penn’s bridge-to-recovery team has explanted five patients, including Bellettieri, and continues to monitor them closely. “Our longtime goal,” Rame said, “is to give our patients a survival free from heart failure and from mechanical assist device.”
Joey Bellettiere underwent regular stress tests to measure his heart’s increasing strength as the LVAD speed was reduced. Clinical coordinator Judy Marble turned down his VAD to the minimal possible support and monitored him for any symptoms of heart failure.
LVAD illustration reprinted with the permission of Thoratec Corporation
Regular echocardiograms, such as the one performed by Lise Fishman, RDCS, technical director/manager of the Echo Lab, provided detailed information during the turndown, including the heart's size and function level, and a measure of the flow through the aortic valve.
Restage Heart Failure Trial
The Restage Heart Failure Trial is designed for Class 4 non-ischemic heart failure patients with a diagnoses for less than five years. As part of the trial, a Heart Mate II LVAD is implanted and all medical therapies maximized to see if the heart will recover. A series of LVAD turndowns would then test the heart for recovery. The VAD would be explanted if the heart demonstrated sufficient recovery.
For more information call Judy Marble, nurse coordinator, at 215-662-2802.