Download Evolution of Mechanical Circulatory Support

Evolution of Mechanical Circulatory Support –
From the Balloon Pump to the Destination
Ventricular Assist Device
Charles Hoopes MD
Jason Alexander Gill Professor in Thoracic Surgery
Section Chief, Heart and Lung Transplant/Mechanical Circulatory Support
Director, UK Comprehensive Transplant Center
University
of Kentucky
An Equal Opportunity University

Lexington, KY
Evolution of Mechanical Circulatory Support –
From the Balloon Pump to the Destination
Ventricular Assist Device
Objectives:
Discuss the history of mechanical circulatory support devices
from the balloon pump to the first artificial hearts and
destination VADs.
Describe the evolution of the mechanical assist device from
early conception to today’s current technology in successful
treatment of advanced heart therapy.
Describe the clinical implications for implantation of devices
and recovery and what issues future devices may solve.
I have no financial disclosures
I have no financial relationship with any of
the technologies discussed
I will not discuss any off label use of current technologies
Charles Hoopes MD
Jason Gill Professor in Thoracic Surgery
Section Chief, Cardiopulmonary Transplant/Mechanical Circulatory Support
Director, UK Transplant Center
An Equal Opportunity University

University
of Kentucky
Conceptual eras of mechanical circulatory support..
1812 Le Gallois “parts of the body may be preserved by external perfusion”
Etienne-Jules Marey (Paris,1881) – physician, inventor
.. the 1st “artificial heart
Guillotined head of a dog in perfusion experiments of
Brukhonenko and Tchetchuline. This preparation relied on
gas exchange from a second donor dog's lungs.
Diaphragm-like pumps pumped blood into the recipient
dog's carotid arteries. Dog heads perfused in this manner
remained functional for a few hours. (Reprinted from
Brukhonenko S, Tchetchuline S. Experiences avec la tete
isolee du chien.1.Technique et conditions des experiences.
J Physiol Pathol Gen 1929;27:42)
..a “biological oxygenator”
Intellectual origins of “mechanical assist” and “circulatory support”…
“Experimentally, it is possible to completely replace
the heart with an artificial heart, and animals have
been known to survive as long as 36 hours. This idea,
I am sure, could be reached to full fruition if we had
more funds to support more work, particularly in the
bioengineering area”
DeBakey (1963) Senator Lister Hill’s Subcommittee on
Health
May 1965
“..surgeons at Baylor hailed the Jackson transplant. The
Baylor surgeons say there are two solutions for support of
the failing heart..transplants from humans or animals and
artificial hearts. The Baylor group is concentrating its
efforts on developing an artificial heart.”
Associated Press, 25 Jan 1964
In Jan of 1964 James Hardy consented the sister
of Boyd Rush – a 68 yo comatose deaf mute with
ischemic heart failure and lower extremity gangrene
– for “the insertion of a suitable heart transplant if
such should be available. Rush decompensated and
was placed on cardiopulmonary bypass. In the
absence of a viable donor Hardy transplanted the
heart of a 45 kg chimpanzee. The heart provided
hemodynamic support for 90 minutes…
Physiologic basis…
“..mechanical pumping of blood to
viscera previously inadequately
perfused … reducing the
workload and oxygen consumption
of the myocardium”
Ann Review Med 1966
Evolution of Mechanical Circulatory Support…
1936
1965
1969
1981
1982
1968
As socio-political history…
Evolution of Mechanical Circulatory Support…
HeartWare
Artificial Hearts
FDA Categories of Use in US
Thoratec
(safety and efficacy)

Post-Cardiotomy
Abiomed
Thoratec PVAD
Biomedicus
Roller pumps
ECMO
PMA
IDE

Bridge to Transplant  Bridge to Recovery
Novacor LVAD
Thoratec PVADs
HeartMate XVE LVAD
HeartMate XVE
HeartMate IP
HeartMate IP
Thoratec PVADs
Novacor
CardioWest Total Heart
MicroMed
Thoratec IVADs
Jarvik
Jarvik LVAD
MicroMed LVAD
HeartMate II
MicroMed (Peds)

Permanent
HeartMate
Novacor
MicroMed
Abiocor
Arrow Lionheart
Abiomed
18 Legal systems
8 Off label systems
Off label
HDE
As medical technology…
Evolution of Mechanical Circulatory Support…
Historical context
oxygenators and pumps, biological and mechanical
Application (why are you doing this and what do you want)
“moratorium of decision” (non-durable )
“bridge to recovery” (non-durable and durable)
“bridge to transplant” (non-durable and durable)
“destination therapy” (durable)
Deployment (how do we do it and when do we try)
Problems (general, device specific, and evolving)
As clinical medicine…
Historical “truisms” in mechanical circulatory support (MCS)…
Deployment of MCS technologies in the context of medical futility
results in futile deployment of technology… MCS is capable of resuscitation, not
reanimation
MCS technology restores hemodynamics (>86%) but may not
alter survival depending upon the specifics of deployment
“Unnecessary surgery” performed well has excellent outcomes…
device technology should be deployed based upon clinical trajectory and
the natural history of the disease process
Physiology always trumps engineering..
MCS can support patients awaiting good clinical decision making but
is ineffective in supporting bad clinical decisions
3 October 1930
“..at 8AM respirations ceased and the
blood pressure could not be obtained.
Within 6 min and 30 sec Dr. Churchill
opened the chest, incised the pulmonary
artery, extracted a large pulmonary embolus,
and closed the incised wound..”
JH Gibbon
“the idea occurred to me if it were possible to remove continuously some of the
blue blood from the patient’s swollen veins, put oxygen into the blood and allow
carbon dioxide to escape from it, and then to inject continuously the now red
blood back into the patients arteries, we might have saved her life. We would have
bypassed the obstructing embolus and performed part of the work of the patients
heart and lungs outside the body.”
Gibbon JH Jr (1939) The maintenance of life during
experimental occlusion of the pulmonary artery followed
by survival. Surg Gynecol Obstet 69:604
The original “TandemHeart”…
Dennis et al (1962) Ann Surg 156:623
The Percutaneous Ventricular Assist Device
in Severe Refractory Cardiogenic Shock
Cardiogenic shock: SBP<90mmHg, CI<2 L/min,
inadequate end organ perfusion with IABP/pressor support
88 ischemic, 37 non-ischemic (9 myocarditis)
pLVAD (TandemHeart): SVO2>70%, MAP>60mmHg, AoV
DOS 5.8 days…MSOF(n=31),CVA(n=8)
Cardiac index, l/(min·m2)
SBP, mm Hg
DBP, mm Hg
MAP, mm Hg
HR, beats/min
SVO2, %
PCWP, mm Hg
PAP mm Hg
Lactic acid, mg/dl
LDH, U/dl
pH
Urine output, ml/day
Hemoglobin
Pre pLVAD
Post pLVAD
0.52 (0.8)
75 (15)
30 (20)
45 (20)
105.
49 (11.5)
31.52
39.16
24.5 (74.25)
602 (630)
7.22 0.14
70.3
11
3.0 (0.9)
100 (15)
65 (20)
81 (15)
118.0
69.29 (10)
17.29
26.70
11.0 (12)
416.5 (335)
7.44 0.06
1200
10.25
Kar et al (2011) JACC 57:688
“Pumping improved two patients' circulatory status;
one survived. Two patients died before pumping
could begin; in another, an abdominal aortic
aneurysm prevented insertion of the pump…
Kantrowitz et al (1968) JAMA 203:135
RETROSPECTIVE ANALYSIS OF 286 PATIENTS
REQUIRING CIRCULATORY SUPPORT WITH
THE INTRAAORTIC BALLOON PUMP
Johnson et al (1977) Cardiovasc Dis 4(4):428–436.
Device function must match patient need…
preservation of end organ perfusion (survival)
and capacity for functional myocardial recovery
The timing of implantation is critical to patient
survival…
Mechanical circulatory support (MCS) as a
clinical program, not an isolated procedure
“From 1972 through 1974, we
implanted the pump in 34
patients. Of those patients, only
2 (1 in 1973 and 1 in 1974)
survived until explantation, and
only 1 (the patient in 1974)
survived to discharge. Yet the
intraaortic balloon pump remains
essentially unchanged today, and
survival rates of 70% to 80% can
be expected when the device is
implanted in appropriately
selected patients … This
experience emphasizes the danger
of premature randomized studies,
which can expose technology to
errors that are manmade rather
than inherent.”
OH Frazier (2005) Tex Heart
Inst J 32:60
“Escalation therapy” criteria and MCS application…and deployment
Hemodynamic instability:
CI<1.8, CPO<0.53, PCWP>18
FiO2/PaO2<300, “high” inotropy
CPO: MAP x CO/451
0.53
Cardiac power is the strongest hemodynamic
correlate of mortality in cardiogenic shock:
A report from the SHOCK trial registry
Fincke (2004) JACC 44:340
Ben Roe and the UCSF “artificial heart” circa 1970
post LVAD
Left ventricular assist vs.
biventricular replacement…
Durable vs non-durable applications
Heartware (impellar)
Syncardia TAH
Heartmate II (axial flow)
AbioCor TAH
Evolution of implantable mechanical cardiac assist technologies……
I
II
III
The complexity of mechanical circulatory support technologies represents…
epidemiology…a significant clinical need…cardiogenic shock is
highly morbid and frequently lethal (>55%)
absence of a common effective therapy… anecdotal experience
not supported by clinical trials pkVO2
12-16 ml/kg/min
variability of clinical application…
1.
2.
3.
4.
5.
6.
7.
Critical cardiogenic shock
Progressive decline
Stable inotrope dependent
Recurrent advanced disease
Exercise intolerant
Exercise limited
Advanced NYHA class III
“Crash
and burn”
will get
bridge to
durable
device
Inotrope dependent
Ongoing RCT in low
risk pts with
pkVO2 12-16
ml/kg/min
Risk factors for death in patients with an implantable
mechanical circulatory support device:
older patient age at the time of implant
(relative risk [RR] = 1.41, p < 0.001);
assignment to INTERMACS Level 1 category
characterized by cardiogenic shock with life-threatening
hypoperfusion (RR = 1.59, p = 0.02);
indicators of severe right ventricular failure, such as ascites and
hyperbilirubinemia, which are clinically evident at the time
of implant
Pagani et al (2009) J Heart Lung Transpl
INTERMACS
Competing Outcomes –
Level 1: Critical Cardiogenic Shock (n=186)
0.9
0.8
0.7
0.6
Transplanted 40%
0.5
0.4
Dead 29%
0.3
0.2
Alive 26%
Recovery 5%
0.1
0.0
0
1
2
3
4
5
6
7
8
9
10 11 12
Months after Device Implant
Competing Outcomes –
Level 3: Stable but Inotrope Dependent (n=35)
Proportion of patients
1.0
0.9
0.8
0.7
Alive
0.6
0.5
0.4
Transplanted
0.3
0.2
Dead
0.1
0.0
0
1
2
3
4
5
6
7
8
9
10 11 12
Months after Device Implant
1.0
Proportion of patients
Proportion of patients
1.0
Competing Outcomes –
Level 2: Progressive Decline (n=148)
0.9
0.8
0.7
0.6
0.5
Transplanted
0.4
Alive
0.3
0.2
Dead
0.1
0.0
0
1
2
3
4
5
6
7
8
9
10 11 12
Months after Device Implant
Evolution of mechanical circulatory support…ventricular assist devices
Moratorium of decision
Bridge to recovery
Bridge to transplant
Destination (CMS)
Are VADs an operation…or part
of an integrated heart failure
program?
Slaughter M (2010) Will destination
therapy be limited to large transplant
centers? Texas Heart Inst J 37(5):562
The evolution of mechanical cardiopulmonary support …
the “learning curve”
No device has ever saved or killed a patient …
good physicians using good devices have done
both
No device program has everything … effective
device programs have everything they need
Device technology accomplishes nothing but
facilitates everything
LVAD induced remodeling: Basic science and clinical implications for recovery
* biomarkers of recovery
(genetic,structural,metabolic)
* therapeutic intervention (pre,post,and peri)
* etiology of CHF (sequential tissue)
May ‘08
Inotrope dependent
Leftward shift of the EDPVR
(structural “reverse remodeling”)
Time dependent reduction in heart size
(EDP of 30 mmHg, V30)
Dec ‘08
Dec ‘08
LVAD
Regression of cellular hypertrophy
BNP
1400
1200
1000
800
600
400
200
0
inotropes
Feb ‘09
s/p LVAD
Preexplant(12)
LVAD
pod1
Explant pod1
Explant pod7(103)
LVAD induced remodeling: Basic science and clinical implications for recovery
May ‘08
Inotrope dependent
Leftward shift of the EDPVR (structural “reverse
remodeling”)
Dec ‘08
‘08
LVAD
Feb ‘09
s/p LVAD
Time dependent reduction in heart size
(EDP of 30 mmHg, V30)
Regression of cellular hypertrophy