As more patients with advanced heart failure are implanted with left ventricular assist devices (LVADs), the use of echocardiography has also increased in recent years. On July 31, the American Society of Echocardiography (ASE) released the first guidelines for the use of echocardiography in these patients to help provide recommendations for the mechanical circulatory support (MCS) team.
LVADs have been under development for 30 years, but their use had been limited to a few investigational sites where mechanical circulatory support had been developed. The devices were primarily used in patients who were candidates for cardiac transplantation, according to Raymond F. Stainback, MD, FASE, the guidelines committee chairman and medical director of noninvasive cardiac imaging at Texas Heart Institute in Houston.
In 2008, the use of LVADs expanded when the FDA approved a second-generation continuous flow pump. Now, more than 2,000 LVADs are implanted each year, which is similar to the number of annual heart transplants, according to Stainback. In total, more than 30,000 patients throughout the world have received LVADs.
In this analysis, Stainback and his colleagues conducted a literature review and examined published data and expert opinion from high-volume MCS-device implantation centers. They collected LVAD policies and protocols from each site and then reviewed them.
Although Stainback said echocardiography is important in assessing patients who receive LVADs, there was no previous guidance until these guidelines were released. He added that LVAD patients have different physiology compared with non-LVAD patients.
“In some cases, you can image these patients too much and it can overly tax the resources for an echo lab,” Stainback told Cardiovascular Business. “We’ve made some suggestions on how to streamline patient care. On the other hand, we think this can be a complex group of patients that requires special expertise in the echocardiography lab. One of the guidelines’ primary goals is to make sure that all those resources are available and the people working in the lab have adequate knowledge base to care for this new population of patients that we’re seeing in increased numbers.”
The guidelines are limited to the two FDA-approved surgically implanted LVADs: the HeartMate II left ventricular assist system (Thoratec Corp.) and the HVAD ventricular assist system (HeartWare International, Inc.). The HeartMate II was approved in 2008 for bridge to transplantation therapy (BTT) and in 2010 for destination therapy. The HVAD was approved for BTT in 2012. A trial is underway evaluating HVAD for destination therapy.
More than 40 percent of LVAD implants are for destination therapy, whereas there was none before 2010. Today, there are more than 160 sites that implant the devices, and 80 percent of patients survive one year after implantation, while 70 percent are alive after two years.
The ASE guidelines addressed each phase of care related to LVADs: preoperative patient assessment, perioperative imaging, postoperative surveillance, postoperative problem-focused echocardiography and recovery protocols.
“It seems like a long and complex document, but in the end these exams can be relatively straightforward,” Stainback said. “It’s more or less having people that are dealing with LVAD patients be very familiar with potential complications and pitfalls. Part of the guidelines is really just to facilitate communication between the mechanical support team and the echocardiography lab so that they understand exactly the type of information that the echo lab can provide.”