Left ventricular assist devices (LVADs) are mechanical pumps that are used to support heart function in patients with heart failure. There are several indications for LVAD support including bridging patients to cardiac transplantation, bridging to decision about transplantation eligibility, as destination (permanent) therapy for those ineligible for transplantation, and bridging to potential heart recovery. LVADs improve symptoms and survival in advanced heart failure patients and can allow some to recover enough to no longer require support or become eligible for transplantation. Newer continuous flow LVAD designs have improved outcomes compared to older pulsatile devices.

1. LEFT VENTRICULAR ASSIST
DEVICES

2. INDICATIONS
• Bridge to cardiac transplantation
• Bridge to decision
• As destination (or permanent) therapy,
• As a bridge to recovery of heart function.

3. BRIDGE TO TRANSPLANTATION
• LVADs are inserted into patients who have worsening New York Heart Association (NYHA) Class III or IV
HF often despite inotropic plus intra-aortic balloon pump support
• LVADs life-saving in these deteriorating patients who might otherwise die before a donor heart becomes
available, but they can also improve secondary organ function prior to transplantation, reduce
pulmonary hypertension, and enable improvement in nutritional status, all of which are associated with
improved post-transplant survival.

4. BRIDGE TO DECISION
• Many patients receive an LVAD before a final decision regarding transplantation eligibility has been able
to be reached (use of which has been termed "bridge to decision" or BTD).

5. DESTINATION THERAPY
• As survival rates with LVAD support have improved, the use of these devices as permanent (rather than
"bridge" therapy) has evolved and expanded considerably .
• DT refers to this long-term use of LVADs as an alternative to transplantation in patients with end-stage
HF who are considered to be ineligible for transplantation

6. BRIDGE TO RECOVERY
• There is now evidence that LVAD unloading can promote recovery of myocardial function
• The strategy of device implantation to promote recovery of myocardial function is known as "bridge to
recovery." Usually, however, the device is not implanted specifically as a "bridge to recovery" but as DT
or BTT and then if sufficient myocardial recovery has been deemed to have occurred on testing of the
underlying cardiac function explantation of the pump considered.

7. DESTINATION THERAPY VS. BRIDGE TO TRANSPLANTATION
Long-term placement
Destination Therapy (DT)
• Not a heart transplant candidate
• NYHA IV
• LVEF <25%
• Maximized medical therapy >45
of 60 days; IABP for 7 days; OR 14
days
• Functional limitation with a peak
oxygen consumption of less than
or equal to 14 ml/kg/min
• Life expectancy < 2 years
Bridge to Transplantation (BTT)
• Patient is approved and currently
listed for transplant
• NYHA IV
• Failed maximized medical therapy

8. THINGS TO CONSIDER BEFORE PLACING ANY TYPE OF VAD
SUPPORT
• Are there any contraindications to VAD support?
• End-stage lung, liver, or renal disease
• Metastatic disease
• Medical non-adherence or active drug addiction
• Active infectious disease
• Inability to tolerate systemic anticoagulation (recent CVA, GI bleed, etc.,)
• Moderate to severe RV dysfunction for some LVADs
• What are our other issues in this particular patient?
• What are the patient’s goals? What are our goals?
• What happens if we don’t meet our goals?

9. INTERMACS SCORE
Interagency Registry for Mechanically Assisted Circulatory Support
Long-Term LVAD
Ideal candidates are
INTERMACS classes 3-
4
Short-Term LVAD
Candidates are
INTERMACS classes 1-
2
Not a LVAD Candidate
INTERMACS 1 or those
with multisystem organ failure

10. DEVICE
• FIRST GENERATION DEVICES
 pulsatile positive displacement pumps
 HeartMate I device
 Thoratec paracorporeal ventricular assist device
 Novacor

11. HEARTMATE I DEVICE
• The HeartMate I (HM I) was inserted in over 5000 patients
• REMATCH trial
• It has a pusher-plate actuator that is powered pneumatically or electrically.
• A cannula is placed in the apex of the left ventricle and blood flows through a Dacron conduit through a
porcine valve to the pump and is returned into a Dacron outflow graft through another porcine valve
inserted in the ascending aorta.
• The HeartMate I contains a unique blood pumping surface consisting of titanium microspheres and a
fibrillar textured inner surface that promoted the formation of a "pseudointima" that resists
thrombogenesis. Thus, the only antithrombotic therapy needed was aspirin

12. • The HeartMate I underwent several design improvements and evolved from the pneumatic to the
vented electric (VE) to the XVE

14. THORATEC PARACORPOREAL VENTRICULAR ASSIST
DEVICE
• The Thoratec paracorporeal ventricular assist device (PVAD) has been inserted in over 3000 patients.
• It has the advantage that it can be used as an LVAD, RVAD, or two together as a BIVAD
• Alternating positive and negative air pressure generated by a console or portable pneumatic driver
produces a beat rate of 40 to 110 bpm and a flow rate of 1.3 to 7.2 L/min

15. • The PVAD is positioned outside the body (paracorporeal) on the anterior abdominal wall with cannulas
crossing into the chest wall. Patients supported by this pump require warfarin (goal INR 2.5 to 3.5) plus
aspirin therapy.

17. NOVACOR
• The Novacor LVAD was implanted in over 1600 patients for durations of up to 6.1 years, but has been
discontinued after trials showing a high rate of stroke.

19. • SECOND GENERATION DEVICES
 Continuous flow devices, including the second generation devices (axial flow pumps)
 Continuous flow pumps account for 100 percent of patients receiving DT since 2010 and more than 95 percent
of patients receiving primary MCS implants
 HeartMate II
 Jarvik 2000
 Berlin Heart INCOR

20. HEARTMATE II
• Continuous flow axial blood pump with an internal rotor with helical blades that curve around a central
shaft
• The pump weighs 350 g and it is approximately 7 cm in length and 4 cm at its largest diameter. It can
generate up to 10 L/min of flow at a pressure of 100 mmH

21. • The axial flow design and absence of blood sac eliminates the need for venting of pulsatile volume
(required for the first generation of implantable pumps), thus reducing the size of the percutaneous
drive lead and also eliminating the need for internal one-way valves.
• Blood flows through an inflow cannula from the apex of the LV to the pump and returns back through
an outflow cannula to the ascending aorta.

23. JARVIK 2000
• Continuous flow axial blood pump that has an intraventricular position, with the whole pump sitting
within the LV cavity
• The pump weighs 85 g, measures 2.4 cm in diameter, and is 5.5 cm long.
• The pump can generate up to a maximum of 7 L/min of flow.

24. • The single moving component is the impeller located in the center of the titanium housing. A brushless
direct-current motor, contained within the housing, creates the electromagnetic force necessary to
rotate the impeller.
• Blood flow is directed through the outlet graft by stator blades located near the pump outlet and it
returns to either the ascending or descending aorta

27. BERLIN HEART INCOR
• Continuous flow axial flow pump marketed in Europe but not in the US.
• Blood passes into the INCOR it first passes an inducer that directs laminar flow onto the impeller, which
is suspended by a magnetic bearing and floats free of contact with other parts.
• The impeller operates at speeds between 5000 and 10,000 rotations per minute.
• Blood is then directed to a stationary diffuser that has specially aligned blades that reduce the
rotational effect of the blood flow and thus builds additional pressure which assists in the transport of
blood through the outflow cannula to the aorta.

29. • THIRD GENERATION PUMPS
 centrifugal pumps that have been designed for their long durability, compact size, optimization of blood flow
through the device to minimize the risk of thrombus formation and hemolysis, and simplified surgical
implantation.
 HeartWare
 HeartMate 3

31. HEARTWARE
• Continuous flow centrifugal third generation pump
• It was approved by the FDA as a bridge to transplantation in November 2012 and as destination therapy
in September 2017.
• HeartWare has only one moving part, the impeller, and no mechanical bearings.
• Because the HeartWare pump has no bearings and runs at lower rpm, it is likely to have long durability.
It is much smaller than earlier devices and easier to surgically implant

32. • The pump weighs 140 g and has an external diameter of 53 mm. The impeller spins at rates between 1800
and 4000 rpm and generates up to 10 L/min of blood flow.
• Implantable directly adjacent to the heart in the pericardial space due to its small total size, equivalent to
50 cc
• The impeller is suspended within the pump housing through a combination of passive magnets and a
hydrodynamic thrust bearing.
• This hydrodynamic suspension is achieved by a gentle incline on the upper surfaces of the impeller blades.
• When the impeller spins, blood flows across these inclined surfaces, creating a "cushion" between the
impeller and the pump housing.
• The inflow cannula is integrated with the device itself, ensuring proximity between the heart and the
pumping mechanism which facilitates implantation and ensures optimal blood flow characteristics.
• The impeller has a wide blade to help minimize risk of pump induced hemolysis or thrombus.

35. HEARTMATE 3
• The HeartMate 3 is a fully magnetically levitated centrifugal-flow device that is inserted into the apex of
the left ventricle
• The rotor spins at rates of 3000 to 9000 rpm and generates up to 10 L/min of blood flow.
• The mass of the HeartMate 3 is 475 g, including the motor (535 g), the inflow cannula, recovery section,
outflow graft, bend relief, and all connecting hardware.
• it incorporates rapid changes in rotor speed to create an intrinsic artificial pump pulse (asynchronous
with the native heart beat) to reduce stasis in the pump

38. BIVENTRICULAR SUPPORT
Total artificial heart
• A pulsatile total artificial heart that continues to be used clinically in over 50 centers worldwide
• The SynCardia TAH is the only TAH system to receive FDA, CE, and Canadian Health approval for clinical
implantation
• The size of the artificial heart has restricted its use to patients with a large enough body habitus to
accommodate positioning within the thoracic cavity.
• To be eligible for use of the SynCardia TAH, the patients must have a body-surface area of >1.7 or a
distance of ≥10 cm from the 10th anterior vertebral body to the inner table of the sternum on computed
tomographic scanning (CT).

39. • The SynCardia TAH weighs 160 g and consists of two artificial ventricles, each made of semi-rigid polyurethane
housing with four flexible polyurethane diaphragms separating the blood chambers from the air chambers
• The diaphragms enable the artificial ventricle to fill and then eject blood when compressed by air from the
external console. Mechanical valves, mounted in the inflow (27 mm) and outflow (25 mm) ports of each
artificial ventricle, control the direction of blood flow.
• The maximum dynamic stroke volume of each ventricle is 70 mL, which enables generation of a flow rate up to
9.5 L per minute.
• Each artificial ventricle driveline conduit is tunneled through the chest wall.
• The right and left artificial ventricles are attached to seven-foot pneumatic drivelines that connect to the back
of the external console.

40. • The external console weighs 180 kg and includes a monitoring computer that provides noninvasive
diagnostic and monitoring information to the user, including device rates, dynamic stroke volumes,
calculated cardiac outputs, drive pressure, flow waveforms, and trending information. Device status and
patient related alarms (eg, low cardiac output) are also displayed on the console.