Assisted Circulation

View TSDA Curriculum Online for this topic

1. Advanced Mechanical Support

Indications

Post-cardiotomy cardiogenic shock

Post-MI cardiogenic shock

Post-transplant graft failure

High-risk PTCA support

Cardiopulmonary resuscitation (CPR)

Hypothermia rewarming

Alternative to transplantation(clinical trials)

2. Circulatory Support

Mechanical cardiac assist

Intra-aortic balloon pump (IABP)

Ventricular assist devices (VAD)

Cardiopulmonary support (CPS, ECMO)

Mechanical cardiac replacement

Total artificial hearts (TAH)

Others

Biologic cardiac assist- cardiomyoplasty

Ventricular remodeling

Pacing

3. Mechanical Circulatory Support- Characterization

Output hemodynamics

Pulsatile

Non-pulsatile

Drive mechanism

Pneumatic; electric (hydraulic, mechanical)

Configuration

TAH, BVAD, RVAD, LVAD

Status/availability

Approved for market, IDE trials, in development

4. Placement position

Orthotopic; heterotopic; extracorporeal

Paracorporal; transcutaneous

Implantability

Fully; partially; not at all

Application/ permanence

Temporary; bridge-to-transplant, cardiogenic shock; bridge-to-recovery

Permanent; alternative-to-transplantation

5. Device Selection for Bridge-to-Transplantation

Criteria	LVAD	RVAD	BVAD	TAH
LV failure	++	--	--	+
RV failure	--	++	--	+
LV & BV failure	--	--	+	+
Unresectable trombus	--	--	--	+
S/P mechanical valve	--	--	--	+
AI (or PI)	--	--	--	+
Irreparable intracardiac shunts	--	--	--	+
Uncorrectable arrhythmias	?	?	+	+
Refractory ischemia, angina	--	--	--	+
Transplant heart rejection	--	--	--	+
Acute MI at cannula site	?	?	?	+
Unresectable cardiac tumor	--	--	--	?

6. Bridge-to-Transplant

Problems

Cardiovascular

Failure on non-supported ventricle

Arrhythmias

Cyanosis/shunting with PFO

Ischemia/angina

Systemic

Hemorrhage

End-organ failure

Infection

Immune sensitization

Compromised quality of life

Device related

Thromboemboli

Obstruction/compression

Improper orientation

Device infection

Device failure

Hemorrhage

Air entrianment/embolus

Hemolysis

Results

65-75% successfully bridged (90+% possible)

90+% of those transplanted are discharged

7. Mechanical Circulatory Support Issues for the future

Technological improvements

Size, biocompatibility, control, reliability, power and durability

Clinical effectiveness

Longevity, quality of life, complications, recovery, expertise

Cost-effectiveness

Of technology and implementation

Societal and ethical concerns

Allocation of resources; patient populations

Permanent Implantation future NEED

By the year 2010

Number or patients: 35,000- 70,000 per year for long-term support

Devices:10,000-20,000 TAH and 25,000-60,000 VAD

By the year 2020

Device reliability exceeds transplant

Number of patient may exceed 200,000 per year

(Ref. Institute of Medicine for NIH, NHLBI)

8. Total Artificial Heart

Results Bridge-to-transplant

	TAH	Control
	N	%	N	%
Pateints	27	--	18	--
Transplanted	25	93	8	44
Discharged home	28	89	7	39
Neurologic-embolic	9	33	--	--

Copeland et al

9. Summary

May be life saving in selected patients with end-stage heart disease

Need for this intervention is increasing with decreasing donor availability

May ultimately become an alternative to transplantation