Although structural and functional heart “recovery” sometimes follows implantation of a left ventricular assist device (LVAD) in patients with end-stage heart failure (HF), allowing pump removal, such cases are rare in practice and the supportive medical therapy and monitoring isn’t standardized.
But what if there were a protocol for aiming patients with an LVAD specifically toward the goal of myocardial recovery followed by pump explantation, one featuring an especially aggressive drug regimen to promote reverse remodeling? Many more patients, potentially, might receive a pump with bridge to recovery as the intent and eventually have their devices removed, propose researchers who published their experience with such a strategy October 26 in Circulation.
About half of 40 adult patients who had received HeartMate II (Thoratec, now Abbott) axial-flow pumps at six major LVAD centers participating in the prospective Remission from Stage D Heart Failure (RESTAGE-HF) study were able to have their pumps explanted after following the protocol.
Their rate of survival free from transplantation or another LVAD implantation was about 90% 1 year after explantation and 77% 3 years after.
The heart recovery rate after LVAD explantation exceeds what has been previously reported, and such recoveries were achieved at all participating centers, “a key component for its broader application,” the group writes. “This suggests that the explant rate after LVAD could be much higher if this strategy were more widely used, and supports promoting and testing systematically for recovery after LVAD implantation.”
The findings build on a recent published experience in which 18 patients with LVADs explanted on a similar protocol achieved results at cardiopulmonary exercise testing comparable to those in 97 healthy control participants.
The current protocol’s key elements included optimization of the LVAD speed, or rate of continuous flow, for as much ventricular unloading as safely possible; a drug regimen designed to intensify the reverse remodeling process; close echocardiographic follow-up, the scans obtained at reduced pump speeds to capture native contractile function; and functional testing as needed.
The drug regimen, initiated with uptitration once the patient is implanted and weaned off inotropic agents, is so aggressive it wouldn’t normally be tolerated in a patient with HF not on mechanical circulatory support, observed lead author Emma Birks, PhD, MBBS, University of Kentucky, Lexington, for theheart.org | Medscape Cardiology.
Initially, ventricular unloading on the LVAD itself rests the heart and sets the stage for recovery, so it’s important that the pump be set to a speed that optimizes that process, Birks explained. The other crucial element is the intensive use of conventional HF medications, which at standard dosages the patients no longer tolerated. “They dropped their blood pressure and affected their kidneys,” she said.
But as soon as the pump is engaged, “all of a sudden they’re supported, the kidneys are better. So you can not only use the drugs, we use them at huge doses.”
The regimen, started and uptitrated as soon as the newly implanted patient weans off inotropic agents, features carvedilol, digoxin, spironolactone, an ACE inhibitor (lisinopril),