Mayo Clinic in Arizona pioneers use of cardiac mechanical assist devices
Total mechanical heart
Posteroanterior chest X-ray view of patient with total mechanical heart
Lateral chest X-ray view of patient with total mechanical heart
Cardiac transplantation offers patients with end-stage congestive heart failure a new lease on life. Unfortunately, donor availability continues to limit this lifesaving option. The development of mechanical ventricular assist devices (VADs) has provided alternative opportunities to these patients, either as bridge-to-transplant or as destination therapy. Importantly, many patients are able to leave the hospital and enjoy increased mobility.
"Patients with acute cardiogenic shock are some of the most difficult patients to manage, with hemodynamic instability frequently complicated by life-threatening arrhythmias," according to Robert L. Scott, M.D., medical director of the heart failure and transplantation program in the Division of Cardiovascular Diseases at Mayo Clinic in Arizona.
While these patients benefit from the intensive and comprehensive care provided by tertiary care centers, many are too unstable for transport. Infrequent use of VADs by many hospitals makes it financially difficult to maintain devices in inventory and a challenge for medical and surgical personnel to maintain competency.
Doctors at Mayo Clinic in Arizona have overcome this barrier by developing an emergency transport team, based on the SWAT team approach pioneered by law enforcement. This highly specialized, multidisciplinary team was developed by Francisco A. Arabia, M.D., chair of the Division of Cardiovascular and Thoracic Surgery at Mayo Clinic in Arizona and surgical director of cardiac transplantation. The team is deployed to local and regional hospitals requesting stabilization and transport assistance.
"We may assist with medical management, and we are equipped to implant appropriate VADs at the referring hospital in order to stabilize the patient for transport," says Dr. Arabia. Support devices include right ventricular assist devices, left ventricular assist devices, biventricular assist devices and extracorporeal membrane oxygenation. Transport typically occurs within 48 hours via a specially equipped ambulance.
Since Mayo Clinic in Arizona began implanting VADs in 2005, almost 300 devices have been implanted by both the emergency transport team and the cardiac transplant program. Eleven different types of circulatory support devices are available, including the total mechanical heart, to support cardiac function, depending on the type and degree of heart failure. To date, the longest time a patient has been on VAD support is 1,595 days, or approximately 4.4 years.
Technological improvements have resulted in smaller and lighter devices powered by portable battery packs compatible with near-normal lifestyles. In May 2010, Mayo Clinic in Arizona was the first center in the United States to dismiss a patient home on a total artificial heart to await heart transplant, which he received in January 2011.
The Joint Commission, in its most recent evaluation, gave high marks to the VAD program. Certification for all services was granted, calling the program at Mayo Clinic in Arizona "the poster child for VAD programs nationally."