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

Above and below: Cannula for ascending aorta (white arrows); pump (blue arrow); LV cannula (red arrows)

For these same photos without the arrows, click here and here
For more information, click on the link if you see this icon

Outcomes of Left Ventricular Assist Device Implantation as Destination Therapy in the Post-REMATCH Era: Implications for Patient Selection. Lietz K, Long JW,. Kfoury AG, Slaughter MS, Silver MA, Milano CA, Rogers JG, Naka Y, Mancini D, Miller LW. MD Circulation. 2007;116:497-505.

Ethical challenges with the left ventricular assist device as a destination therapy. Rizzieri AG, Verheijde JL, Rady MY, McGregor JL. Philosophy, Ethics, and Humanities in Medicine 2008, 3:20doi:10.1186/1747-5341-3-20

HeartMate is a registered trademark of Thoratec Corporation