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Update on Long-term Ventricular Assist Devices Basel Ramlawi,MD, MMSc, FACS, FACC, FRCSC Co-Director, Methodist Aortic Network Cardiothoracic Surgery & Transplantation Methodist DeBakey Heart Center The Methodist Hospital Houston, TX

Basel Ramlawi, MD Bramlawi@TMHS.ORG


Heart Failure – Incidence / Stats • US Figures: – – – – –

400,000 new cases/year 5 Million living with HF diagnosis Most common diagnosis in patients > 65yrs. Annual cost $60 billion. Incidence increasing.

• In the last 20 years: – Death by MI has decreased by 30% – Death by heart failure has doubled

• Prognosis – 50% mortality within 5 years – NYHA III or IV  40% survival at 1 year.


First Ventricular Assist Device

• Product of Total Artificial Heart Program (Est. 1963) • Temporizing Measure Only


Heart Replacement Need


NUMBER OF HEART TRANSPLANTS REPORTED BY YEAR

2005 J Heart Lung Transplant 2005;24: 945-982


Ventricular Assist Devices


Surgical Intervention: VADs 

Post-Cardiotomy Recovery  Mechanical support for patients who are unable to be weaned from the cardio/pulmonary by-pass pump

Bridge-to-Transplantation  Mechanical support of the heart for patients awaiting transplant  Improve post-transplant outcomes

Bridge-to-Recovery  Mechanical support allowing patients to recover sufficient myocardial function to allow device explantation

Destination Therapy (DT)  Mechanical support for patients who are ineligible for cardiac transplantation due to age, malignancy or co-morbidities


Early Generation LVADs • Thoratec HeartMate(I) XVE

– REMATCH Study Group( N Engl J Med, 2001)

• Novacor LVAD

– InTrEPID Trial (J Am Coll Cardio,2007)

• Thoratec (Implantable Ventricular Assist Device) – IVAD Study Group (J Thorac Cardiovasc Surg,2007)


HeartMate XVE Pneumatic Displacement Pump

HeartMate II Axial Flow Pump


NEJM 2009


Improvement in Quality of Life


Patient Selection for LVAD Therapy Inotrope dependent? Hemodynamic criteria? “Optimal”

“Too Late”

{

{

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“Too Early” Disease progression

Death

Non-inotrope dependent? Acute, Catastrophic Event


Basel Ramlawi, MD Bramlawi@TMHS.ORG


Basel Ramlawi, MD Bramlawi@TMHS.ORG


Basel Ramlawi, MD Bramlawi@TMHS.ORG


Basel Ramlawi, MD Bramlawi@TMHS.ORG


Basel Ramlawi, MD Bramlawi@TMHS.ORG


Basel Ramlawi, MD Bramlawi@TMHS.ORG


Surgical Implant Procedure Pump Pocket


HM II Surgical Implant Procedure – Aortic Anastomosis


HM II Surgical Implant Procedure Aortic Anastomosis


Surgical Implant Procedure Inflow Conduit Placement • Point posteriorly toward mitral valve • Should not point toward septum or free wall – Partial occlusion of inflow conduit, leading to poor filling of the LVAD and possible thromboembolic complications


HM II Surgical Implant Procedure - LV Coring


HM II Surgical Implant Procedure - Apical Sewing Ring


HM II Surgical Implant Procedure Percutaneous Lead Placement


HM II Surgical Implant Procedure - De-airing


Continuous Flow, Rotary Pumps  Smaller size – – – –

60% Smaller than XVE 35 mm diameter 70 mm long 400 grams

 No requirement for venting ― 40% reduction in the size of percutaneous driveline

 Patient comfort  Quiet  Ease of surgical implantation ― Standard sternotomy ― Smaller pre-peritoneal pocket


HeartMate II LVAS • Design – Valveless – Only one moving part, the rotor – Blood immersed bearings designed for minimization of blood damage – All motor drive and control electronics are outside of the implanted blood pump

• Two piece outflow conduit • Speed range: 6,000 to 15,000 rpm • Flow range: 3 – 10 L/min


Pump Rotor and Stators Flow

Outflow Stator

Inflow Stator

Rotor Outflow Bearing

Inflow Bearings


VAD Complications Bleeding

Embolism

Infection

MOF


Right-Heart Support w/ CentriMag RVAD


Driveline Infections


NEJM 2009


3rd Generation VADs Centrifugal Flow


The HeartWare Ventricular Assist System (3rd generation) ®

HVAD™ miniaturized implantable blood pump • 50cc, 140g, 2” outside diameter • Full circulatory support device designed for patients with a BSA >1.2m2 • Advanced Impeller is the only moving part  Hybrid magnetic / hydrodynamic suspension  Contact-less system

• Two motors designed to provide power redundancy • Thin (4.2 mm), flexible driveline constructed with pacemakers conductor wires


Pericardial Placement of HVAD™ Pump


• Ischemic Stroke 8% Hemorrhagic stroke 3%


Heartware DT Trial Primary Endpoint: The primary endpoint is stroke-free survival at 2 years.

Secondary endpoints:

1. Incidence of bleeding, per INTERMACS definition 2. Incidence of major infections, per INTERMACS definition 3. Time to death 4. Incidence of all device failures and device malfunctions per INTERMACS definition 5. Health Status improvement, as measured by KCCQ and EuroQol EQ-5D 6. Functional status improvement, as measured by NYHA and 6-minute walk


Jarvik 2000 Blood Pump Motor

Outflow Impeller

Inflow


EvaHeart LVAS


Options for Biventricular Failure •Heart Transplantation •LVAD and temporary RVAD •Long term BiVAD (extracorporeal) •Syncardia Total Artificial Heart


Thoratec pVADs biventricular solution


The SynCardia Total Artificial Heart • 79% bridge-to-human-heart transplant rate (Highest of any heart device) •

Over 900 implants account for more than 210 patient years on the Total Artificial Heart

Pneumatically powered through drivelines that connect to a driver


The SynCardia Total Artificial Heart replaces both Human Ventricles


Creatinine (mg/dL) Total Bilirubin (mg/dL)

3.0 2.5 2.0 1.5 1.0 0.5 0

5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0

Recovery Kidney

Out of Bed

100% 80% 60% 40% 20%

-1

2

5

8

11 14 35 56 77

0%

2

Time (days)

4

7

14

21

Days on Study

100%

Walking > 100 Feet

80%

Liver

60% 40% 20%

-1

2

5

8

11 14 35 56 77

Time (days)

0%

2

4

7

14

Days on Study

21


Circulite Synergy – Partial Support Device 4 L/min flow


Conclusions •

Long Term LVAD support (DT) rapidly gaining acceptance

Patient referral often “too late”

HMII LVAD still “gold standard” for BTT and DT

Investigational devices and future pump designs look promising

Syncardia TAH option for biventricular failure as bridge to transplant


What is coming? • Minimally-invasive implantation refinements • Apical anastomotic devices • Improved peripherals and monitoring


VAD Wish list • Infection  Totally Implantable – Trans-cutaneous Energy Conduction

• Bleeding  No anti-coagulation • Stroke  Minimal Thrombo-embolism • Malfunction  Durable / No friction • Small Size  Potential for BiV Support  Comfort  Minimally Invasive


Thank you

SHA24/043002  

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