This document discusses mechanical circulatory support devices for advanced heart failure, including intra-aortic balloon pumps (IABP) and ventricular assist devices (VADs). It describes the physiology and indications for IABP, including how it increases coronary perfusion and reduces left ventricular afterload. It also discusses VADs, describing both pulsatile and non-pulsatile devices, components, classifications based on period of use and pumping mechanism. Patient selection criteria for VADs include being refractory to medical therapy, having a life expectancy less than 2 years without support, and being ineligible for heart transplant.

1. MECHANICAL CIRCULATORY
SUPPORTS IN ADVANCED
HEART FAILURE
Dr SHALINI GARG
SR II DM CARDIOLOGY

3. 100
75
50
25
0
I II III IV
1
10
NYHA CLASS
AnnualSurvivalRate
Hospitalizations/year
.1
Deceased
Adapted from Bristow, MR Management of Heart Failure, Heart Disease: A Textbook of Cardiovascular Medicine,
6th edition, ed. Braunwald et al.
Class III
 25% of HF Patients
 Frequent
hospitalizations
 Worsening symptoms
despite drug therapy
 Significant opportunity
for new therapies
Survival Rate
Hospitalizations
Natural History of Heart Failure

4. Stages of Heart Failure

5. Addressing Heart Failure in 2013
Katz AM
Heart Failure

8. 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

9. INTERMACS Level Pre-Implant
for 1092 Primary LVAD (June 2006–March 2009)
1 Critical cardiogenic shock
2 Progressive decline
3 Stable but inotrope dependent
4 Recurrent advanced HF
5 Exertion intolerant
6 Exertion limited
7 Advanced NYHA III
Kirklins et al INTERMACS 2. JHLT 2010

10. Short term Device options
Bridge to recovery
Bridge to decision
IABP
ECMO
Tandem Heart
Impella
AbioMed 5000
Centrimag
Circulation 112 (3): 438

11. Intraaortic Balloon Pump (IABP)

12. Basic principles of counterpulsation
Counterpulsation is a term that describes balloon inflation in
diastole and deflation in early systole. Balloon inflation causes
‘volume displacement’ of blood within the aorta, both
proximally and distally. This leads to a potential increase in
coronary blood flow and potential improvements in systemic
perfusion by augmentation of the intrinsic ‘Windkessel effect’,
whereby potential energy stored in the aortic root during
systole is converted to kinetic energy with the elastic recoil of
the aortic root.

13. IABP inflates with aortic valve closure:
Provides pressurized pulse of blood against
closed aortic valve, increasing coronary perfusion
IABP deflates immediately prior to aortic valve opening:
Reduces LV afterload

14. IABP: Physiology
• Inflation at aortic valve closure:
• Increases aortic diastolic blood pressure
• Increases diastolic coronary perfusion
• Net neutral effect on cerebral perfusion
• Increases C.O./“runoff” to subdiaphragmatic organs
• Deflation prior to systole:
• Reduces impedance to LV ejection (afterload)
• Reduces myocardial oxygen consumption

15. IABP: Physiology
• 2 main beneficial effects:
– 1) Augmented coronary perfusion
– 2) Reduced LV afterload/Increased CO

16. IABP: Physiology
• 2 main beneficial effects:
1) Augmented coronary perfusion
• Only in normal coronary arteries
• No augmentation beyond severe stenoses pre PCI
• Augmentation beyond severe stenoses post PCI
2) Reduced LV afterload/Increased CO

17. IABP: Physiology
• 2 main beneficial effects:
– 1) Augmented coronary perfusion
– 2) Reduced LV afterload/Increased CO
• Most important of 2 main effects when severe coronary
stenoses present

18. Hemodynamic Effects of IABP
Aorta ↓systolic pressure, ↑diastolic pressure
Left ventricle ↓systolic pressure, ↓end-diastolic
pressure, ↓volume, ↓wall tension
Heart ↓afterload, ↓preload, ↑cardiac output
Blood flow ↑→ coronary blood flow

19. IABP: Indications
• Cardiogenic shock:
Post cardiotomy,
Ass. with acute MI,
Mechanical complications of MI
• In ass. with CABG
Pre op : Pt with severe LV dysfunction
Pt with intractable ischemic arrythmias
Post op: Post Cardiotomy cardiogenic shock
• In ass. With non surgical revascularization.
– Hemodynamically unstable infarct patients
– High risk PCI : severe LV dysfunction, complex CAD
• Stabilization of Cardiac Transplant recipient before insertion of
VAD
• Post Infarction Angina
• Ventricular Arrythmias related to Ischemia

20. IABP: Contraindications
Contraindications FOR IABP
Absolute Relative
Aortic regurgitation Uncontrolled sepsis
Aortic dissection Abdominal aortic aneurysm
Chronic end-stage heart disease with no
anticipation of recovery
Tachyarrhythmias
Severe peripheral vascular disease

21. Technique of insertion and operation
The IABP device has two major components:
(i) a double-lumen 8.0–9.5 French catheter with a 25–50 ml
balloon attached at its distal end
(ii) a console with a pump to drive the balloon.
The balloon is made of polyethylene and is inflated with gas
driven by the pump. Helium is often used because its low
density facilitates rapid transfer of gas from console to the
balloon. It is also easily absorbed into the blood stream in case
of rupture of the balloon

22. The appropriate balloon size is selected on the basis of pt’s height
PATIENT’S HEIGHT BALLOON VOLUME
< 152 cms 25 cc
152 – 163 cms 34 cc
164 – 183 cms 40 cc
> 183 cms 50 cc
The diameter of the balloon, when fully expanded should not exceed 80–90%
of the diameter of the patient’s descending thoracic aorta.

23. • Once vascular access is obtained, the balloon catheter is
inserted and advanced, usually under fluoroscopic guidance,
into the descending thoracic aorta, with its tip ~ 2 to 3 cm
distal to the origin of the left subclavian artery (at the level of
the carina).
• Intraoperatively, balloon placement can be ascertained using
transoesophageal echocardiography.
• The outer lumen of the catheter is used for delivery of gas to
the balloon and the inner lumen can be used for monitoring
systemic arterial pressure.

24. • The console is programmed to identify a trigger for balloon
inflation and deflation. The most commonly used triggers are
the ECG waveform and the systemic arterial pressure
waveform.
• The balloon inflates with the onset of diastole, which
corresponds with the middle of the T-wave. The balloon
deflates at the onset of LV systole and this corresponds to the
peak of the R-wave.
• Poor ECG quality, electrical interference, and cardiac
arrhythmias can result in erratic balloon inflation.

25. When intra-aortic balloon pumping is begun, the assist
interval is set on 1:2 (the IAB inflates and deflates every
other systole). This is done so that landmarks can be
identified and the effects of inflation and deflation can be
compared to the baseline hemodynamic status. Later on the
Assist ratio can be changed to 1:1.

28. PDP/AUG should be higher than the PSP/SYS unless:
• Balloon is positioned too low
• severe cases of hypo volemia
• balloon is too small for patient’s aorta
• low SVR
• improper timing
• catheter partially kinked, in sheath, not unwrapped

29. Criteria for Assessment of Effective IAB Therapy on the
Arterial Pressure Waveform
1 ) Inflation occurs at the dicrotic notch.
2) Inflation slope is parallel to the systolic upstroke and is a straight line.
3) Peak Diastolic augmentation should be greater than the unassisted
systolic peak.
4) An end-diastolic dip in pressure is created with balloon deflation.
5) Two assisted pressures (systolic and diastolic) should be lower than the
unassisted pressures .

30. Timing is set and changed using two separate controls that
move the timing markers to the left and right. The inflate
control is moved to the left to adjust the inflate time to occur
earlier and to the right to occur later. The deflate control
operates in a similar manner: moved to the left for earlier
deflation, to the right for later deflation.

37. LATE DEFLATION
Waveform characteristics
• assisted aortic end-diastolic pressure
may be equal to the unassisted aortic
end-diastolic pressure;
•rate of increase of assisted systole is
prolonged
•diastolic augmentation may appear
widened.
Physiological effects
• afterload reduction is essentially
absent
• increased MVO2 consumption
because of the left ventricle ejecting
against a greater resistance and a
prolonged isovolumetric contraction
phase
•IAB may impede LV ejection and
increase the afterload

38. 1. Inflation -- Just Prior to the Dicrotic Notch (DN)
If > 40ms before—EARLY INFLATION
If dicrotic notch exposed—LATE INFLATION
2. Deflation:-- BAEDP < PAEDP
BAEDP = Balloon Aortic End Diastolic Pressure
PAEDP = Patient Aortic End Diastolic Pressure
If BAEDP is higher—LATE DEFLATION may be occuring
3. Deflation:
Assisted Systole (APSP/ASYS) < Peak Systole (PSP/SYS)
SYS/PSP = Peak Systolic Pressure
ASYS/APSP = Assisted Peak Systolic Pressure
If both pressures are equal—EARLY DEFLATION can be suspected

39. BALLOON PRESSURE WAVEFORM
During a cycle of inflation/deflation, helium is rapidly moved in and
out of the balloon. The environment within the balloon and the
surrounding forces that affect balloon behavior all contribute to a
predictable pattern of gas flow and pressure. The gas pressure
characteristics are converted into a waveform. This transduced
waveform can tell us much about the interaction of the balloon within
the patient’s aorta.

42. • Initial under fill of the intra-aortic
balloon
• Leak
• Auto-fill failure
• Balloon disconnected
Auto-vent failure
 Possible vacuum malfunction
Kinked Line
Kinked catheter.

43. Weaning from the Intra-Aortic Balloon Pump
There are two methods of weaning which may be used independently
or in conjunction with one another. Weaning can be accomplished by
decreasing the frequency and/or volume of balloon inflation.
 Weaning by decreasing the frequency is accomplished by
decreasing the frequency of assistance from one balloon inflation per
cardiac cycle to 1:2, 1:3, 1:4, and 1:8.
 Weaning can also be accomplished by decreasing the volume
delivered to the balloon.
Do not reduce the volume delivered to the balloon less than 2/3 the
capacity of the balloon, i.e. a 40cc balloon should not have the
volume reduced to less than 28cc.

44. IABP: Complications
Complications associated with IABP
Transient loss of peripheral pulse
Limb ischaemia
Thromboembolism
Compartment syndrome
Aortic dissection
Local vascular injury—false aneurysm, haematoma, bleeding from the wound
Infection
Balloon rupture (can cause gas embolus)
Balloon entrapment
Haematological changes, for example thrombocytopenia, haemolysis
Malpositioning causing cerebral or renal compromise
Cardiac tamponade

45. IABP: Complications
Risk Factors
• Odds Ratios for Major complications with IABP
therapy:
– PVD: 2.0
– Female Gender: 1.7
– Small BSA: 1.5
– Advanced age: 1.3
(Little Old Ladies!!!)

46. Ventricular Assist Device (VAD)
Long-Term LVAD
Implanted surgically
with the intention of
support for months to
years
Short-Term LVAD
Utilized for urgent/
emergent support over
the course of days to
weeks
A mechanical circulatory device used to
partially or completely replace the function of
either the left ventricle (LVAD); the right
ventricle (RVAD); or both ventricles (BiVAD)

47. Ventricular Assist Devices
• There are several many
different VADs. All VADs have
the following four parts:
– An inflow cannula which takes
blood from the ventricular to the
pump
– A pump
– An outflow cannula that takes the
pumped blood to the ascending
aorta
– A power source for the pump

48. • They are powered by external power sources that connect
to the implanted pump via a percutaneous lead (driveline)
that exits the body on the right abdomen.
• Pump output flow can be pulsatile or nonpulsatile.

49. Components of a Ventricular Assist Device

50. Classification of Ventricular Assist Devices
 On the basis of period of use:
a) Temporary, b) Permanent
 On the basis of impaired ventricle:
a) LVAD, b) RVAD, c) Bi-VAD
 On the basis of Pumping mechanism:
a) Pulsatile b) Non pulsatile
 On the basis of suspension of rotors:
a) Bearing suspension
b) Electromagnetic or Hydrodynamic suspension.

51. Krishnamani, R. et al. (2010) Emerging ventricular assist devices for long-term
cardiac support
Nat. Rev. Cardiol. doi:10.1038/nrcardio.2009.222

52. Pulsatile Devices
• Ventricle-like pumping sac device.
– Blood enters via the inflow cannula and fills a flexible pumping
chamber.
– Electric motor or pneumatic (air) pressure collapses the chamber
and forces blood into systemic circulation via the outflow cannula.
• Can be LVAD, RVAD, or BiVAD
• First-generation devices (in use since early 1980s)
• Patients will have a palpable pulse and a measurable blood pressure.
Both are generated from the VAD output flow.
• Pulsatile VADs emulated the real contraction phenomenon of
ventricles while Advanced VADs use continuous flow mechanisms

53. FEATURES
• is a short-term uni- or
biventricular support
system .
• comprised of two 100 mL
polyurethane blood sacs.
• the inlet and outlet
portions of which are
guarded by polyurethane
valves
The Abiomed BVS 5000i
NEWER ADVANCES IN HEART FAILURE
DEVICE THERAPY

54. HeartMate XVE
• Has a titanium-alloy
external housing, with
inflow and outflow conduits
that use porcine xenograft
valves.
• Internal blood-contacting
surface is made of textured
titanium that results in the
development of a pseudo-
neointima on which
thrombus formation is
greatly reduced, thereby
decreasing the need for
anticoagulation.
NEWER ADVANCES IN HEART FAILURE
DEVICE THERAPY

55. Non-Pulsatile Devices
• Continuous-flow devices
Impeller (spinning turbine-like rotor blade) propels blood
continuously forward into systemic circulation.
Axial flow: blood leaves the pump in the same direction as
it enters (boat motor propeller).

58. Key features of nonpulsatile VAD
• Most implanted devices are LVADs only.
• Are quite and cannot be heard outside of the patient’s body.
Assess VAD status by auscultation over the apex of the LV. The
VAD should have a continuous, smooth humming sound.
• The Patient may have a weak, irregular, or non-palpable pulse
• The Patient may have a narrow pulse pressure and may not be
measurable with automated blood pressure monitors. This is
due to the continuous forward outflow from the VAD.
• The Mean Arterial Pressure is the key in monitoring
hemodynamics. Ideal range is 65-90 mmHg.

59. Heartware HVAD

64. Patient Selection: Who benefits from a
VAD

65. Recommendations in pt with severe Heart
Failure ineligible for transplant

66. Mechanical Circulatory Support
VAD
RECOVERY
BRIDGE TO TRANSPLANT
CANDIDACY
DESTINATION
THERAPY
TRANSPLANT

67. Mechanical Circulatory Support
INDICATION NOMENCLATURE DEFINITION
Bridge to transplantation Patient is listed for heart transplantation
Bridge to candidacy
Patient initially deemed ineligible for heart
transplantation because of comorbidity
(cardiorenal syndrome or pulmonary
hypertension), which improves during
mechanical support
Bridge to recovery
Patient with a potentially reversible cause
of cardiac decompensation (acute
myocarditis, postcardiotomy syndrome,
peripartum cardiomyopathy)
Bridge to decision
Patient in whom the potential for
transplantation or recovery is yet unclear
Destination therapy
Patient in whom recovery or
transplantation is not feasible

68. Indications for Use:Pulsatile vs. Continuous
Flow
• Pulsatile Devices
– PVAD
– IVAD
– Heartmate XVE
LVAD
• Continuous Flow
– Heartmate II LVAD
– Heartware HVAD
FDAApproved Devices for Bridge
to Transplant
PVAD/IVAD
Heartmate XVE LVAD
Heartmate II LVAD
Heartware HVAD
FDAApproved Device for
Destination Therapy
Heartmate XVE LVAD
Heartmate II LVAD

69. • Score of 0-8 is low risk and predict 3 months survival of
87.5% while greater than 19 is very high risk with
survival of 13.7%
• This Risk Score is not validated for Cont. flow device
implanted for destination therapy
RISK FACTORS FOR 3 MONTHS MORTALITY AFTER VAD IMPLANT
RISK FACTORS SCORE
Platelet Count < 148 X 103 per uL 7
Serum Albumin < 3.3 g/dL 5
INR > 1.1 4
Vasodilator treatment 4
Mean PAP < 25mm Hg 3
SGPT > 45 units/ml 2
HCT < 34% 2
BUN > 51U/dL 2
No IV Inotropes 2

70. Anti Coagulation is must
• Optimal INR for cont. flow device is 1.5 to 2.5
• Higher degree of anti coagulation is required in AF, prior
thromboembolic events , known LA or LV thrombi and if there
is low assist device flow rate < 3 l/min.

71. Contraindications
– 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

72. • RV dysfunction is an important source of morbidity and
mortality after LVAD insertion.
• Predictors of post implant RVF are CVP/PCWP > 0.63, BUN >
39 mg/dL, and preop mechanical ventilatory support.
• RV failure is reversible with inotropes or PDEI.
• If RV function does not improve and LVAD flow still
suboptimal (<2.4 L/min/m2 ) with CVP > 16 mm Hg then RVAD
insertion is necessary which can be short term or long term.
• Recent data demonstrates that early planned institution of RV
support can mitigate the potential adverse consequences of
RV dysfunction after LVAD placement.

73. Basic VAD Management
 ALL VADs are:
 Preload-dependent
 EKG-independent
 Afterload-sensitive
 Anticoagulated
 Prone to:
•infection
•bleeding
•thrombosis/stroke
•mechanical malfunction
 Key differences depend on pulsatile vs. non-pulsatile
device

74. Variations of Short-Term VADs
• Impella 2.5 and 5.0
• Tandem Heart
• CentriMag
• ECMO (V-A)

75. Impella 2.5 and 5.0
• Utilized for LV support only; not
appropriate to use with RV failure
• Impella 2.5 can be inserted through
the femoral artery during a standard
catheterization procedure; provides
up to 2.5 L of flow
• Impella 5.0 inserted via femoral or
axillary artery cut down; provides up
to 5L of flow
• The catheter is advanced through the
ascending aorta into the left ventricle
• Pulls blood from an inlet near the tip
of the catheter and expels blood into
the ascending aorta
• FDA approved for support of up to 6
hours

77. Effect of IABP and Impella 2.5 device on
important hemodynamic parameters
NEWER ADVANCES IN HEART FAILURE
DEVICE THERAPY

78. Algorithm for device selection.

79. TandemHeart pVAD
• Used for LV support; not
appropriate in RV failure
• Cannulas are inserted
percutaneously through the
femoral vein and advanced
across the intraatrial septum
into the left atrium
• The pump withdraws
oxygenated blood from the
left atrium and returns it to
the femoral arteries via
arterial cannulas
• Provides up to 5L/min of
flow
• Can be used for up to 14
days

80. CentriMag
• Can be used for LV
and/or RV support
• Cannula are typically
inserted via a
midline sternotomy
• Capable of
delivering flows up
to 9.9 L/min
• Can be used for up
to 30 days

81. ECMO (VA)
• Used for patients with a
combination of acute cardiac
and respiratory failure
• A cannula takes deoxygenated
blood from a central vein or
the right atrium, pumps it past
the oxygenator, and then
returns the oxygenated blood,
under pressure, to the arterial
side of the circulation
• Can be used for days to weeks

83. TOTAL ARTIFICIAL HEART
NEWER ADVANCES IN HEART FAILURE
DEVICE THERAPY

84. Artificial Heart

85. Effects of Chronic Hemodynamic Unloading with
Ventricular Assist Devices
Structural
• Regression of myocyte hypertrophy.
• Reduction in neurohormonal activation
• Normalization in expression of contractile proteins .
• Enhanced electron transport chain respiratory function
• Decreased apoptosis and cellular stress markers
Functional
Provide mechanical circulatory support to restore the circulation of blood
flow to the body.
• Decreases preload
• Decreases cardiac workload
• Increases systemic circulation & tissue perfusion
• Decreases neurohormonal response