Left Ventricular Assist Device (LVAD)

General Considerations

• Surgically implanted, mechanical circulatory assist device in patients with severe and medically refractory heart failure
• Originally, these devices were used as a bridge to cardiac transplantation
• LVAD are now used as a permanent alternative to heart transplantation (known as destination therapy)
• It is estimated that 250,000 patients in US are in refractory heart failure and there are approximately 2,100 donor hearts available each year

Clinical Findings

• Centers for Medicare & Medicaid Services guidelines for LVAD eligibility
  • End-stage heart failure patients who are not candidates for heart transplantation
  • Patients have received but failed to respond to optimal medical treatment for 45 of the last 60 days
  • Patients must have an LV ejection fraction of < 25%
  • Patients must have demonstrated functional limitation

Imaging Findings

• The device described here is the HeartMateÒ (See image below)
• Implantation requires a median sternotomy and cardiopulmonary bypass
• The pump is implanted in the preperitoneal space or peritoneal cavity below the heart (A)
  • It is a continuous flow pump with no pulsatile action; therefore the patient who receives such a device will have no palpable pulse
• The inflow cannula is anastomosed to the tip of the left ventricle (B)
• The outflow cannula is attached to the ascending aorta (C)
• The controller (D) and battery (E) is worn externally, rechargeable and allows tether-free operation for about 3 hours
  • The unit can also run on AC power

MedGadget

Complications

• Neurologic complications such as stroke, transient ischemic attack and toxic encephalopathy
• Sepsis is the most common complication either from infection of the device or from other parts of the body
• Device failure increases with time
• Not necessarily related to the device itself. Other complications include
  • Right heart failure
  • Multiorgan failure

Prognosis

• 1- and 2-year survival rates after LVAD implantation in the post-REMATCH era were 56% and 33%
• The probability of device exchange or fatal device failure was 17.9% and 72.9% at 1 and 2 years, respectively