"The current outcomes with HeartMate II have already changed the field. We published a paper last year that showed there was no difference between LVADs and transplant in costs and outcomes at 1 year (Ann. Thorac. Surg. 2011;91:1330-4)," said Dr. Mark S. Slaughter, professor of surgery and chief of thoracic and cardiovascular surgery at the University of Louisville (Ky.). Between that and the competitive mortality benefit from LVADs "we need to rethink the role of transplant. In appropriately selected patients, we can achieve outstanding long-term results with limited adverse events."
In their 2011 paper, Dr. Slaughter and his associates put the pending change more bluntly: "As outcomes for continuous-flow LVADs and heart transplantation converge, the therapy of heart transplantation could emerge as salvage therapy for major device-related complications or dysfunction or progressive right heart failure as opposed to the default option for all patients who are eligible for transplant."
Despite their huge promise, some experts have lingering concerns about the current generation of continuous-flow LVADs that make them reluctant to say that heart transplant has unquestionably stepped down from its pedestal as the gold standard treatment for patients with severe, end-stage heart failure.
Dr. James K. Kirklin
"There is no question that [current continuous-flow LVADs] are very good technology. But whether they are great technology remains to be proven," said Dr. James K. Kirklin, professor of surgery and director of the division of cardiothoracic surgery at the University of Alabama at Birmingham. "We still have important concerns about things like drive-line infections and thromboembolic complications. Neither rate is terribly high, but they are high enough to be a problem if you apply LVADs to patients who are doing okay. We still have important doubts about whether we can really mimic the quality of life" achieved by transplant, he said in an interview.
LVAD placement also poses an operative risk, which may be as high as 10%, said Dr. David Taylor, a cardiologist and advanced heart failure specialist at the Cleveland Clinic. "If the risk was 2% or 3%, I’d say do it, but a risk closer to 10% makes you hesitate.
"There are a lot of really sick, elderly patients with heart failure who could unquestionably benefit from an LVAD. But as soon as you push the envelope [by treating sicker patients] you increase mortality. A large group of heart failure patients are very ill with chronic disease and feel terrible, and these are the patients where you’d see the greatest benefit, but we can’t afford to do that. We can’t afford to allocate this resource to patients with a 30% mortality risk, because that would limit our ability to extend it to other patients," Dr. Kirklin said in an interview.
"Most patients appreciate an LVAD and like it, but they still look forward to getting a transplant," said Dr. Stephen H. Bailey, director of cardiothoracic surgery at Allegheny General Hospital in Pittsburgh. "In July 2012, while the margin between LVAD and transplant is narrowing, transplant is still the gold standard for definitive treatment. Most patients still favor transplant, but that might change. It’s not quite there yet that an LVAD is equal to a transplant for the long term. It also requires getting rid of the drive line. That would be a game changer. It would also help if we could reduce gastrointestinal bleeds, but that is more of a nuisance."
Part of the bleeding problem comes from anticoagulation treatment to prevent clots from forming in the LVAD, but another facet is an acquired Von Willebrand factor deficiency caused by absent pulsatile blood flow, Dr. Bailey said. Early clinical results suggest that allowing the heart to beat every few seconds, by adjusting the LVAD’s continuous flow rate, can minimize the acquired deficiency.
Which INTERMACS Level?
The most widely used gauge physicians and surgeons have for assessing LVAD candidates is their level in a seven-step sequence created by INTERMACS (the Interagency Registry for Mechanically Assisted Circulatory Support), which subdivides a patient’s descent from advanced New York Heart Association class III heart failure through the strata of class IV disease. (See table.) The most severe INTERMACS stage, level 1 patients (also known as "crash and burn") are those in cardiogenic shock. During the past year or two, about 16% of U.S. LVAD recipients have been level 1 patients, a percentage that should ideally drop much closer to zero, experts say.
