Left Ventricular Assist Devices N John Castro, M.D. Cardiac SurgeonCentracare Heart and Vascular Center Saint Cloud, Minnesota
1) Consultant-Surgeon INOVATE HF Trial2) LVADS not part of my practice for 17 months 1) University of Minnesota
1952: World’s first successful open-heart surgery 1954: World’s first successful open-heart surgery using cross-circulation 1955: development of world’s first functional heart-lung machine
Approximately how many people in the US are in Heart Failure?
Heart failure affects over 5.3M patients in the United States 1 300,000-800,000 Americans have advanced heart failure. 2 Over 280,000 patients die of heart failure each year 11 Lloyd-Jones D, Adams R, Carnethon M, et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heartdisease and stroke statistics 2009 update: a report from the American Heart Association Statistics Committee and Stroke Stati sticsSubcommittee. Circulation. 2009;119(3):480-6.2 Adams KF, Zannad F. Clinical definition and epidemiology of advanced heart failure. Am Heart J 1998;135:S204-S215.
Class Patient Symptoms • No limitation of physical activity I Mild • No undue fatigue, palpitation or dyspnea A • Slight limitation of physical activity II Mild • Comfortable at rest • Less than ordinary activity results in fatigue, palpitation, or dyspnea B • Marked limitation of physical activity • III Moderate Comfortable at rest • C Less than ordinary activity results in fatigue, palpitation, or dyspnea • Unable to carry out any physical activity without discomfort IV • D Severe Symptoms of cardiac insufficiency at rest • Physical activity causes increased discomfortCriteria Committee of the New York Heart Association, 1964.
Data on file, Thoratec Corporation.Rose EA, et al. Long-term mechanical left ventricular assistance forend-stage heart failure. N Engl J Med. 2001 Nov 15;345(20):1435-43.
Heart Failure Expected to Become More Common as Population AgesOutlook for Heart Failure: Five-year Technology and BusinessAssessment. The Advisory Board; 2007.
Approximately, 2200 hearts are donated each year and it is on the decline. NOW LET’S COMPARE: 600,000 Class IV Heart Failure Patients vs. 2,200 Heart Donations
Remains the most effective Tx for end- stage heart disease, although donor shortage limits its use 1-year survival: 86% (2002) 5-year survival: 71% 10-year survival: 46%Vitali E, Colombo T, et al. Surgical therapy in advanced heart failure.Am J Cardiol 2003;91(suppl):88F-94FTaylor et al. J Heart Lung Transplant 2003;22:616.American Heart Association. Heart Disease and Stroke Statistics-2009Update.
• A VAD is a mechanical circulatory device that is used to partially or completely replace the function of a failing heart• Goal of device: to direct blood away from the failing ventricle (Left and/or Right) and provide flow to the circulation (Systemic and/or Pulmonary)
Pulsatile pumps mimic the natural pulsing action of the heart ▪ These pumps are also known as volume displacement pumps Continuous flow pumps use either centrifugal pumps or axial flow pumps ▪ Both types have a central rotor containing permanent magnets. Controlled electric currents apply forces to the magnets, which in turn cause the rotors to rotate
Pump (VAD) ▪ Internal or external placement Wearable or portable control system Power source ▪ AC power or battery power that is outside of the body The pump can vary in method of operation, size and placement
A rotary continuous- flow device in parallel with the native left ventricle Left ventricle to ascending aorta Percutaneous driveline Electrically powered Batteries & line power Fixed speed operating mode Home discharge
Smaller size 60% Smaller than HeartMate I (XVE) No requirement for venting ― 40% reduction in the size of percutaneous lead Enhanced patient comfort Silent, vibration-free operation Ease of surgical implantation ― Standard sternotomy vs. extended midline excision ― Smaller preperitoneal pocket Designed for extended durability
More than 10000 patients worldwide have now beenimplanted with the HeartMate II LVAS. Patients supported ≥ 2 years: 1108 Patients supported ≥ 5 years: 332 Patients supported ≥ 6 years: 8 Patients supported ≥ 7 years: 1 As of Sept 2011 *Based on clinical trial and device tracking data
1937 Vladmir Demikhov implanted the first artificial heart in a dog 1949 Glenn successfully bypassed the heart of a dog for over an hour using a machine he made out of an erector set, assorted odds and ends and dime store finds
The modern era of mechanical circulatory support began in 1953 with the work of Gibbon, the first surgeon to use CPB successfully
First successful use of an LVAD for postcardiotomy heart failure
Texas Heart Institute implanted a Total Artificial Heart. Patient lived 64 hours before successful transplant
First use of an LVAD as a bridge to transplant in a 21 year old post MVR/AVR. Patient received a heart transplant 5 days later. The pumps was interposed between the apex of the left ventricle and the infrarenal abdominal aorta (ALVAD).
Dr. William DeVries implanted the Jarvik 7 in Barney Clark for destination therapy. He lived for 112 days
1984 First Successful Bridge-to-Transplant - Thoratec VADCalifornia Pacific Med Ctr, San Francisco
More than 9,000 patients worldwide have now beenimplanted with the HeartMate II LVAS. Patients supported ≥ 1 year: 3263 Patients supported ≥ 2 years: 1220 Patients supported ≥ 3 years: 436 Patients supported ≥ 4 years: 151 Patients supported ≥ 5 years: 40 Patients supported ≥ 6 years: 13 Patients supported ≥ 7 years: 1 *Based on clinical trial and device tracking data On file with Thoratec As of Jan 2012
> 9,000 Patients Implanted Pivotal Trial Commercial Pilot Trial Experience n=1315* n=53 *as treated n>8000 (+114 XVEs) Bridge to Transplant Destination Therapy n=490 n=825 BTT Approvals DT Approvals CE Mark: Nov. 2005 Mark: Nov. 2005 CE FDA: Apr. 2008 Health Canada: May 2009 2010 FDA: Jan. Health Canada: Nov 2010On file with ThoratecAs of Jan 2012
HM II with controller and batteries HM I HM II Weight (gm) 1250 280 HM I Volume (ml) 450 63 Noise Audible Silent Moving parts Many OneHM II Maximal flow 10 10 (l/min)* Clinical 1.5 Est. > 5 Durability (yr) * at mean pressure=100 mm Hg
Thoratec Laboratories Corp Thoratec VAD Clinical Trial IVAD Clinical TrialFounded1976 Electron / ThermoCardio Systems IncThermo First LVAD Clinical Trial HeartMate IP HeartMate VE REMATCH Trial Thoratec-TCI HeartMate II Trial Merger 2001 1980 1990 2000 2010 =FDA Approvals
Bristow MK. Management of heart failure. In: Braunwauld E, ed. HeartDisease: a Textbook of Cardiovascular Medicine. Vol 1. 6th ed.Philadelphia: W.B. Saunders Company, 2001:635-651
When Should the MCS Discussion Begin?Jessup M, Brozena S. N Engl J Med 2003;348:2007-18.
Bridge to Transplantation ▪ Non-reversible left heart failure ▪ Imminent risk of death ▪ Candidate for cardiac transplantation Destination Therapy ▪ NYHA Class IIIB or IV heart failure ▪ Optimal medical therapy 45 of last 60 days ▪ Not candidate for cardiac transplantation
Post Approval Study 90% 6-Month Survival 85% 1-Year SurvivalStarling, Naka, Boyle JACC, in press 2010
• 90% of patients were transplanted, recovered or had ongoing support at 6 months• Operative 30-day survival was 96%• Survival was superior to that which has been previously reported with LVAD usage
Early Trial vs Mid Trial Average Support Duration 100 Early trial = 2.0 ± 1.6 years (longest: 5.5 years) 90 Mid trial = 1.5 ± 1.0 years (longest: 3.4 years) 80 74 ± 3% Mid trial (N=281) 64 ± 3% 70 Percent Survival 68 ± 4% 60 Early trial (N=133) 58 ± 4% 50 40 P(log-rank) = 0.134 30 P(adjusted for BSA) = 0.162 20 At Risk: 10 281 215 188 167 94 133 95 82 69 62 0 0 6 12 18 24 Time (Months) * P value adjusted for body surface areaPark, S. presented at AHA 2010, Chicago
Background Survival in Destination Therapy Trials2• Initial HeartMate II Destination Therapy (DT) trial demonstrated significant improvements in outcomes compared to randomized patients with pulsatile LVADs1 – 68% survival at 1 year – 58% survival at 2 years• Over 500 additional DT patients have been enrolled under continued access protocol (CAP) 1 Slaughter MS, Rogers JG, Milano CA et al: Advanced heart failure treated with continuous-flow left ventricular assist device. N Engl J Med. 2009 Dec 3;361(23):2241-51. 2 Fang JC: Rise of Machines – Left Ventricular Assist Devices as Permanent Therapy for Advanced Heart Failure N Engl J Med. 2009 Dec 3;361(23):2282-84. Source: Park SJ, AHA 2010
What is the magnitude of absolute survival Conclusions benefit with LVAD DT therapy?• Trend towards improving survival – Fewer deaths from hemorrhagic stroke• Significant reductions in adverse events: – Hemorrhagic stroke >50% reduction – Device related infections >35% reduction – Sepsis >25% reduction• Both QoL measures (KCCQ and MLWHF) demonstrated significant improvement over baseline valuesSource: Park SJ, AHA 2010
80 Centers For Medicare and Medicaid ServicesCertified Destination Therapy Facilities (as of April 2010) Denotes a CMS-certified Destination Therapy facility. Number of facilities = 80 Source: CMS website www.cms.hhs.gov/coverage/lvadfacility.asp
Qualifies for a heart transplant, but… Likely to have a long wait time History of malignancy High PRA levels Pulmonary hypertension Crash & Burn Destination Therapy
Stage D Refractory Heart Failure On the max tolerated doses of medical Tx Recurrent hospitalizations for HF Peak VO2 < 14 Dependent on IV inotropic therapy Seattle HF Model Predicts survival at 1 year
Chronic HF with acute hemodynamic compromise Acute Myocardial Infarction with cardiogenic shock Myocarditis Inability to wean from cardiopulmonary bypass
On maximum inotropic support and/or IABP Systolic BP < 80 and either: PCW > 20 Cardiac Index < 2.0 In need of immediate mechanical circulatory support and may not survive transfer
Conclusions• Trend towards improving survival – Fewer deaths from hemorrhagic stroke• Significant reductions in adverse events: – Hemorrhagic stroke >50% reduction – Device related infections >35% reduction – Sepsis >25% reductionSource: Park SJ, AHA 2010
Unique Features of the HeartWare Pump• No abdominal surgery or pump • Accurate flow estimation pocket • Log files enable flow and power• Fits in the pericardial space waveform analysis• Anatomically fits smaller patients • Novel impeller design enables excellent hemodynamics• Less surgery; potentially minimizes blood transfusions
University of Minnesota Experience Continuous Flow Devices 180 160 140 120 DTNumber 100 80 BTT 60 40 20 0 170 33 10 HeartMate II Ventrassist HeartWare
Readmissions with CF LVADs• Total days of hospital readmission were 1117 days• Mean duration per readmission at 6.81 days.• Reasons for readmission: • Elective procedures 19 (11.6%) • Heart failure 17 (10.4%) • GI bleeding 16 (9.8%) • Driveline infection 13 (7.9%) • Other 17 (10.4%)
Refining Timing of Implant May require 24-48 hours of preop support Hemodynamic monitoring Drug therapy focusing on right atrial pressure and renal function Preop IABP Normalize coagulation parameters Consider ultrafiltration
HeartMate II Left ®Ventricular Assist System Surgical Implant Procedure
Median sternotomy Cardiopulmonary bypass No cross clamp required Preperitoneal vs. Intra-abdominal placement Create apical core site and suture the sewing ring in position Anastomose outflow graft to ascending aorta Tunnel percutaneous lead & create percutaneous lead exit site with skin punch
Issue Possible Solution and Comments AI must be corrected. Mild AI may progress to moderate following LVAD implant with reduction in LV pressure Aortic Insufficiency Aortic leaflets can be partially oversewn Replace with a bioprosthetic valve1 Mitral Regurgitation Generally does not require repair Mitral Stenosis MV replacement with bioprosthethic valve 3+ to 4+ TR, consider annuloplasty repair (ring or modified Tricuspid Insufficiency De Vega reinforced with multiple pledgets) Aortic valve: consider replacement with a bioprosthetic Mechanical Prosthetic valve Valves Mitral valve: generally does not require replacement; consider anticoagulation1Feldman CM, Silver MA, Sobieski MA, Slaughter MS. Management of aortic insufficiency with continuous flow LVADs: bioprosthetic valvereplacement. J Heart Lung Transplant. In press, 2006.
Preperitoneal PlacementPotential Advantages: Potential Issues: Patients with: Previous abdominal Pocket hematoma surgery Exit site drainage Short torso Infection (pocket and Easier explant or exchange exit site) Reduced Risk of: Wound dehiscence Bowel and gastric Skin erosion over erosion pump Visceral adhesion Bowel obstruction Diaphragmatic hernia
Retractor Placement Inverted CPB Cannulation Right atrial single 2 stage or bi-caval Aortic
Steps to minimize CPB time: Outflow graft anastomosis Pump pocket & placement Percutaneous lead tunneling Adjusting inotropic and afterload-reducing drugs prior to CPB can help maximize RV function and reduce PVR while optimizing systemic perfusion pressure
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
Maximize distance between the pump pocket and exit site 1 to 2 cm of velour exteriorized Gentle loop leaving some internal slack for accidential tugs
Trendelenburg position Needle in outflow graft Back bleed from aorta and replace clamp on graft Reduce CPB flow and de-air heart Use TEE to check for air in LV and aorta Remove LV vent if used Reduce CPB flow by half and ventilate
Make sure following alarms are active: Pump Off Pump Disconnected Low Flow Remove tunneling bullet & connect percutaneous lead to system controller Initiate pump flow at 6,000 rpm and vent through needle Remove needle and clamp, terminate CPB and then increase pump speed
Maintain speeds >9,000 rpm to maximize flow through the pump Use TEE to determine optimum speed RV function Position of septum LV unloading Aortic valve opening Presence & degree of TR, MR, AI
Repeat bubble study with the LV unloaded Previously undetected PFO may be unmasked Some centers visually inspect the interatrial septum to rule out PFO11 Heath MJ, Dickstein ML. Perioperative management of the left ventricular assist device recipient. Prog Cardiovasc Dis. 2000;43(1):47-54.
Evaluate & repair tricuspid valve if necessary Avoid RV volume overload – maintain CVP < 16 to 18 mm Hg. CVP ≤ 10 mm Hg, volume may improve flow Moderate RV dysfunction Milrinone, epinephrine, or vasopressin ↑ PVR: Inhaled Nitric Oxide or Flolan1-3 Avoid high LVAD speeds that cause leftward septal shift Leaving sternum open for 24 hours may reduce CVP > 16 mm Hg Temporary RVAD Moderate to high inotropic, pressor support CI < 2.0 L/min/m2 CVP > 16 mm Hg1 Augoustides JG, Ochroch EA. Pro: inhaled prostaglandin as a pulmonary vasodilator instead of nitric oxide. J Cardiothorac Vasc Anesth. 2005;19(3):400-402.2 De Wet CJ, Affleck DG, Jacobsohn E, et al. Inhaled prostacyclin is safe, effective, and affordable in patients with pulmonary hypertension, right heart dysfunction, and refractory hypoxemia after cardiothoracic surgery. J Thorac Cardiovasc Surg. 2004;127(4):1058-1067.3 Dickstein ML. Con: inhaled prostaglandin as a pulmonary vasodilator instead of nitric oxide. J Cardiothorac Vasc Anesth. 2005;19(3):403-405.
Noon – 1 pm on the 1st Tuesday of the month Led by Ann Rudnicki, R.N. Opportunity for LVAD, or potential LVAD patients to have an opportunity to meet people in a similar situation Share fears, anxieties, experiences Ask each other questions, get advice
Product Design Benefits • Potential for reduced anti- coagulation, thrombus, and bleeding • Ability to induce pulsatility • Low power consumption • Compact design – intrathoracic Ultra-Compact, Fully Mag-Lev VAD placement• Full support (10L / min) in ultra- compact size• Incorporates critical HeartMate family design elements (e.g. large gaps, textured surfaces)• Intrathoracic placement; centrifugal flow
Product Design Benefits • Dramatic size reduction – Rapid, less invasive implant – Versatile cannulation options • Meets needs of expanded patient pool – Earlier-stage patients – RVAD / BiVAD population • Low power consumption – Potential for smaller external batteries and components• Leverages core HeartMate II technology• Versatile platform, capable of providing partial and full support (1-8 L/min)