WASHINGTON — Short-term use of a percutaneous ventricular assist device during high-risk surgery or in cases of near-death heart failure can help support patients long enough for them to recover or receive additional treatment, Reynolds M. Delgado III, M.D., said at the annual conference of the American Society for Artificial Internal Organs.
Dr. Delgado and his colleagues at the Texas Heart Institute have used the TandemHeart in four different scenarios as:
▸ A supportive device during high-risk percutaneous transluminal coronary angioplasty in nine patients.
▸ A bridge to recovery in two patients with acute cardiogenic shock.
▸ Circulatory support in five patients during high-risk cardiac surgery (coronary artery bypass and/or mitral valve surgery).
▸ A bridge to an implanted left ventricular assist device (LVAD) in seven patients.
Blood flow in the TandemHeart, made by CardiacAssist Inc., follows a path from a cannula in the femoral vein that pierces the intraatrial septum and takes oxygenated blood from the left atrium back to a continuously flowing extracorporeal pump (attached to the patient's leg), which distributes the blood through a cannula in one or both femoral arteries.
“The tricky part of this procedure is the transseptal cannulation; putting this venous catheter across the septum requires some special skill. A subset of cardiologists are able to do this—perhaps 10% or less,” said Dr. Delgado, medical director of mechanical assist devices in heart failure at the institute, located at St. Luke's Episcopal Hospital, Houston.
None of the high-risk percutaneous transluminal coronary angioplasty patients were candidates for surgery. They had high-risk coronary anatomy and were at risk for imminent death without intervention. The investigators successfully performed the procedure without complications in eight of these nine patients; one patient had a perforated left atrium. Overall, eight patients were discharged from the hospital with good long-term outcomes while one patient died of multiorgan failure after surgery, said Dr. Delgado, a cardiologist. Dr. Delgado reported that he was an investigator on a previous trial sponsored by CardiacAssist but has no financial conflicts of interest with the company.
Both cardiogenic shock patients successfully underwent the implantation procedure. After 7 days, one patient successfully recovered from heart failure due to acute myocarditis. The other patient initially suffered an acute MI and then cardiac arrest just prior to implantation of the TandemHeart; the patient died despite successful implantation.
Of five patients who underwent high-risk cardiac surgery, all had successful implantation, but one patient with coagulopathy and multiorgan failure died of major intraoperative bleeding.
Seven patients were successfully bridged from the TandemHeart to an LVAD. However, four of these patients did not survive long term with an LVAD, primarily because of multiorgan failure that existed prior to the implantation of the TandemHeart.
On average, the 23 patients in the study were aged 68 years and were on percutaneous ventricular assist device support for 2.8 days; 20 patients were male.