IN BRIEF

Study Supports Expanded Use of Ventricular Assist Devices in Children With Complex Congenital Heart Disease

April 29, 2020

New multicenter study shows that the HeartMate3 ventricular assist device is associated with low morbidity and adverse events in pediatric patients with complex CHD.

Ventricular assist devices (VADs), such as the HeartMate3 (HM3) continuous-flow VAD, provide critical heart function support in patients with advanced heart failure. Although design improvements in VADs have reduced complication rates and improved survival, VADs are not yet widely used in children.

“These devices are made for adults. They are meant to go into much larger people and provide a cardiac output for a much larger person,” says Deipanjan Nandi, MD, a cardiologist with the Pediatric & Adult Advanced Cardiac Therapies Program at Nationwide Children’s Hospital.

Also, because of small patient populations, individual pediatric treatment centers are often unable to acquire enough expertise with VADs in their patients.

The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) is composed of 44 pediatric treatment centers. With a focus on quality improvement, ACTION collaboratively shares clinical data, allowing for rapid advancement and implementation of treatments for pediatric cardiac patients. Nationwide Children’s was one of ACTION’s first participants.

A new ACTION study, recently published in Journal of Heart and Lung Transplantation, evaluated the clinical outcomes of 35 pediatric and adult patients (ages 9 to 47 years) with complex congenital heart disease who underwent HM3 implantation. The study reported low mortality and adverse events (AE) rates, suggesting the feasibility of HM3 implantation in children and young adults.

Continuous-flow VADs are an improvement from early pulsatile VADs, which “invited blood to stand still for a fraction of a second for every beat,” says Dr. Nandi.

Continuous-flow VADs have a spinning rotor that continuously moves blood forward. However, blood is constantly being sheared against the rotors. Also, the moving parts can create eddy currents and subsequent clots. Design improvements in the HM3, which was taken to market in 2018, reduced the number of moving parts and shear stress, and incorporated intrinsic pulsatility to prevent clot formation.

The study’s patients were from nine ACTION centers and underwent HM3 implantation between December 2017 and September 2019. Nationwide Children’s contributed three patients to the study.

Notably, nearly 40% of the patients weighed less than 60 kg, which is important because VADs are created with a 70 kg adult in mind, explains Dr. Nandi.

Clinical data analysis revealed that no patients experienced a stroke or pump thrombosis. Some of the reported AEs could be attributed to HM3. For example, four patients each experienced driveline infection and bleeding problems.

Other AEs, including arrythmias and seizures, could not be directly attributed to HM3. Seven patients developed right heart failure; one of these patients required an unplanned right VAD implant. However, this is likely right heart failure revealed by the LVAD, as opposed to being caused by it. The one patient who died had a fatal hypoxic-ischemic encephalopathy.

“Study results demonstrate that we can support children with VADs and use the latest and greatest technology,” says Dr. Nandi. “We can do that comfortably and reproducibly in our patient population.”

Of the three patients from Nationwide Children’s, one has successfully been on device for 18 months without device-related complications.

With the study’s reported safety profile of HM3, VADs could be implanted with more confidence in children, even very sick children, Dr. Nandi adds. These children can survive and thrive after implantation, with improved mental health and quality of life.

Moving forward, ACTION treatment centers will continue their focus on quality improvement. The network currently is developing protocols for VAD imaging and early RHF recognition. They are also using chest CT to design a 3D reconstruction of VADs to improve their fit in children.

 

Reference:

O’Connor MJ, Lorts A, Davies RR, Fynn-Thompson F, Joong A, Maeda K, Mascio CE, McConnel PI, Monge MC, Nandi D, Peng DM, Rosenthal DN, Si M-S, Sutcliffe DL, VanderPluym CJ, Viegas M, Zafar F, Zinn M, Morales DLS. Early experience with the HeartMate 3 continuous-flow ventricular assist device in pediatric patients and patients with congenital heart disease: A multicenter registry analysisJournal of Heart and Lung Transplantation. 2020;S1053-2498(20)31393-0.

Image credit: Nationwide Children’s