Left ventricular assist device as bridge to heart transplantation – lessons learned with the MicroMed DeBakey axial blood flow pump

Abstract

Objective: The MicroMed DeBakey left ventricular assist device (LVAD) axial blood flow pump was used as bridge to heart transplantation (HTx) in patients with terminal heart failure. The aim was to evaluate this novel mechanical circulatory support system in regard to overall outcome. Methods: Prospective study in 15 HTx candidates (mean age 40^7 years) with terminal heart failure and maximal medical treatment due to ischemic cardiomyopathy (CMP, n ¼ 5), dilated CMP ðn ¼ 3Þ, restrictive CMP ðn ¼ 2Þ, unclassified CMP ðn ¼ 1Þ, metabolic CMP ðn ¼ 1Þ, valvular CMP ðn ¼ 1Þ and congenital CMP ðn ¼ 2Þ. All patients were implanted with a MicroMed DeBakey LVAD. A rescue procedure was necessary in eight critical patients, while seven underwent elective LVAD implantation. Procedures were performed via median sternotomy, in normotherm femoro-femoral CPB (mean duration 59^1 min). Oral Marcoumar q (INR 2.0-3.0) and Aspirin q (100 mg daily) were started as soon as possible. Patients were discharged into a specialized rehabilitation clinic from which it was possible to release them home after a few weeks. Results: Successful implantation and discharge from ICU (mean stay 10^7 days) was possible in 11 patients. Seven were transplanted (mean support 50.7 days) and one is awaiting HTx (support .310 days) in the comfort of his home (NYHA I). Survival was 100% among the transplanted patients. Of the seven elective implants, five, and of the eight rescue procedures three patients underwent successful HTx. Four patients died early, while three patients died late on pump support due to intracranial hemorrhage (n ¼ 2, 73 and 76 days) and chest infection (n ¼ 1, 124 days). All survivors were discharged from hospital, with significant decrease in NYHA class (mean 3.8-2.4 ðn ¼ 11Þ). Treadmill testing showed increased exercise tolerance, from 35 to 71 W ðn ¼ 4Þ. Plasma BNP values (mean 950-162 ng/l ðn ¼ 4Þ) and pulmonary resistance (mean 316 -194.5 dyne s/cm 5 ðn ¼ 3Þ) decreased significantly during LVAD support. Conclusions: The MicroMed DeBakey LVAD is simple to implant; outpatient treatment is safe and efficient. Patients' condition and pulmonary resistances normalize within 6 weeks, making previously considered inoperable patients amenable for HTx. HTx can be performed in low-risk situation, allowing better donor -recipient matching and improving overall outcome. q

Normalization of high pulmonary vascular resistance with LVAD support in heart transplantation candidates☆

“…All patients were operated on electively under cardio pulmonary bypass with cannulation of femoral artery and vein and on the beating heart, as previously reported [4].…”

“…Details of this series, such as outcome, anticoagulation and clinical follow-up have recently been published by our team [4].…”

“…It renders reasonable quality of life while significantly increasing life expectancy [1,2]. Due to the shortage of donor organs and medical contraindications to heart transplantation, mechanical circulatory support (MCS) such as left ventricular assist devices (LVAD) have shown to be very beneficial as a bridge to transplantation [3,4]. Furthermore as an alternative to heart transplantation in terminal heart failure, the REMATCH trial has established LVADs as such [5][6][7].…”

Numerical Simulation of LVAD Inflow Cannulas with Different Tip

“…Some LVADs can prolong HF patients' lives for more than two years [1][2][3][4][5]. Now, most LVADs are equipped with complete accessories such as designed inflow and outflow cannulas to ensure that the LVADs can work safely and longer.…”

Cardiac Electronic Implantable Devices in the Treatment of Heart Failure

“…The development of new technology in LVAD devices has seen the evolution of LVAD designs from the first generation LVADs which were larger since they were designed to be pulsatile since a steady supply of blood to muscles, brain and other organs was initially thought to be harmful to the second generation LVADs which are non-pulsatile and therefore smaller and easier to implant hence resulting in reduced postsurgical bleeding and a reduced risk of infection [115][116][117]. Third generation LVAD devices are currently in the design stage and are considered to have many improvements over the second generation devices including the use of magnetic levitation to propel blood Heart, Lung and Circulation Cardiac Electronic Implantable Devices in the treatment of Heart Failure 2012;21:338-351 within the device and the incorporation of transcutaneous energy transmission features.…”