LVADs for HF: Is it time to abandon heart transplantation?
Heart transplant is the gold standard option for heart failure (HF) patients when all other options fail, says a cardiologist and heart failure specialist at the recent APSC 2017 Congress, with excellent long-term outcomes.
“We’ve heard a lot of inspirational stories, from a Hollywood actress, to an athlete who climbed the highest peaks of the world including Mount Kilimanjaro and Mount Fuji, and many others who are living spectacular lives after a life-saving heart surgery,” said Dr Steve Shaw, a cardiologist from the Wythenshawe Hospital in Manchester, UK.
Nearly 90 percent of those patients will live an average of 10 years with a new heart. “If we look at the ISHLT [International Society for Heart and Lung Transplantation] survival data for heart transplant patients across the world, the outcomes are spectacular as it shows the average survival is about 12 years,” said Shaw.
Aside from the excellent long-term survival and minimal activity limitation postheart transplantation, another advantage of the procedure is that it can be utilized in a vast range of conditions including biventricular failure and restrictive cardiomyopathy.
Nevertheless, the paucity of heart donors translate to more patients in the waiting list and more patients dying without finding a suitable heart.
Closing the transplant shortfall
“When we look at the distribution of heart transplants around the world, there is real disparity. The vast majority of heart transplants were performed in Europe (32.30 percent) and the US (55.80 percent), and yet in terms of population, Europe and US together account for only about 18 percent of the world population,” said Shaw.
In Asia, heart transplantation for advanced HF remains very low and the number of heart transplants that would be required of the Asian population is 13,200 per year, a figure that is impossible to achieve. [J Heart Lung Transplant 2017;36:13-18]
The supply of heart transplantation could not meet the demand. Timing of transplantation can also be unpredictable in some patients who are very sick and need therapy quickly, said Shaw. In some countries, the quality of organ donors can be variable. There also lies the burden of posttransplant care because of polypharmacy, immunosuppression, and frequent endomyocardial biopsy within the first year of surgery. “Putting everything together, we do have limitations to heart transplantation.”
With big strides in technology, ventricular assist devices (VADs) are taking an important place not only as a bridge to transplant but as a destination (lifetime) therapy for patients with refractory HF who are not eligible for transplantation.
LVADs: A viable alternative?
In patients not listed for transplant, left ventricular assist device (LVAD) therapy may help extend life and substantially improve quality of life. “Timing of surgery is under control, there is quick turnaround time, and immunosuppression is not needed. The device is suitable both for transplant-eligible and -ineligible patients,” said Shaw.
In Asia, LVADs are predominantly used as a bridge to transplant. In India where heart transplantation is still in its infancy, LVADs are used mostly as a destination therapy. In Singapore, destination therapy is being carried out as a pilot programme with special funding; the youngest patient to receive an implant was only 14 years of age. [J Heart Lung Transplant 2017;36:13-18]
In Asia, the axial flow device HeartMate II is the most widely used and a recent report demonstrated a remarkable 4-year survival at 88 percent in this region, said Shaw. However, in the MOMENTUM trial, implantation of the new fully magnetically levitated centrifugal-flow pump HeartMate III in patients with advanced HF was associated with better outcomes at 6 months vs the HeartMate II. There was no incidence of pump thrombosis, haemolysis, or pump malfunction with the newer device. Rates of death or disabling stroke and gastrointestinal bleeding were similar between the two devices. [N Eng J Med 2017;376:440-450]
Implantable LVADs will continue to evolve into smaller and more durable devices. With further improvements, major complications such as thrombosis, infection, and bleeding may be better managed.
Is it time to abandon heart transplantation? “No, I see both LVADs and heart transplantation as complimentary to each other rather in competition with each other at this time. We don’t have long-term survival data yet with the newest LVADs, but undoubtedly both are wonderful treatments that improve survival and quality of life of HF patients.”
Now the challenge for cardiologist surgeons is in identifying patients who could benefit from LVADs and from heart transplants. “The best option really depends on the specifics of the patient,” Shaw concluded.