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MECHANICAL SUPPORT TO THE FAILING HEART. Professor Davor Miličić, MD, PhD, FESC. Department of Cardiovascular Medicine, Zagreb University School of Medicine, University Hospital Center Zagreb. Epidemiology. Heart failure 23 million people 1-2% total population
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MECHANICAL SUPPORT TO THE FAILING HEART Professor Davor Miličić, MD, PhD, FESC Department of Cardiovascular Medicine, Zagreb University School of Medicine, University Hospital Center Zagreb
Epidemiology • Heart failure • 23 million people • 1-2% total population • >6% people aged over 65 yrs • End stage heart failure: refractory to maximal conventional treatment (drugs, CRT, AICD, ultrafiltration, mortality ≥ 50% within 1 year) • Heart transplantation • ~ 5000/year (ISHLT)
Heart transplantation “Hearttransplantation is anacceptedtreatment for endstage HF. Althoughcontrolledtrials havenotbeenconducted, there is a consensus thattransplantation, providedthroughproperselectioncriteria, significantlyincreasessurvival, exercisecapacity, return to work, andqualityof life comparedwith conventionaltreatment.” ESC guidelines for thediagnosisandtreatmentofthechronicheartfailure, EuropeanHeartJournal 2008; 29:2388-2442
Transplantation is insufficient for treatment all patientswiththeendstage HF • Limited availability of donor hearts • Patients on HTx lists die • Problem of a possibly reversible advanced HF • Problem of patients with temporary contraindication for HTx • Problem of patients with absolute contraindication for HTx • Solution: drugs, VAD
Mechanical myocardial support • IABP • ECMO • VAD • TAH
Goals of mechanical support • Temporary treatment - bridging to: • Transplantation • Recovery • Higher class VAD • Destination therapy
“Mechanical support of the failing heart is today an established therapy option for terminal, end-stage heart failure patients” G.M. Wieselthaler
History • First implantation • VAD (DeBakey 1963) • Artificial heart (Cooley 1969)
Criteria for implantation of VAD • Maximal inotropic support, with/without IABP • Hemodynamic criteria • BPsyst < 80 mmHg with: • CI < 2.0 (2.2) L/min/m2 ili • PCWP > 20 mmHg
Contraindications* • Absolute (?) - multiple previous cardiac surgeries - severe peripheral artery disease • Relative - recent PE - acute GI inflammation or bleeding - cachexia * Harefield & Royal Brompton Hospital, London, UK
Short term Medium term Long term Pulsatile Nonpulsatile VAD: classification
Criteria for VAD selection • Failure of one or two ventricles? • Prediction of mechanical support duration • Anticipation of final outcome • Logistic circumstances
Ultra short term, percutaneous VAD • Tandemheart • Cath lab • Fem. approach • Up to 14 days • Flow 4 L/min
Abiomed Two-chamber Pneumatic Paracorporeal Stroke volume 80 ml Uni or BiVAD Polyurethane valves Mobilization in hospital Application 7 days Short term/Pulsatile VAD
Short term/Nonpulsatile VAD • Levitronix Centrimag • Magnetic levitation • Up to 30 days • Flow up to 9L • Minimal mobilization in hospital
Medium term VAD • Thoratec VAD • Paracorporeal • Pneumatic pulsatile • LVAD, RVAD, BiVAD • Stroke vol. 65 ml • Polyurethane bubbles • Mechanical valves • Application about 6 mo (up to 1.5 yr)
Thoratec VAD • Bridge to HTx (60%) • Bridge to Recovery • viral myocarditis, postpartum cardiomyopathy, heart rejection • Cost → 35000 $ • Complications – bleeding (31%), infections associated with device (18%), thromboembolism (14%) • Thoratec IVAD?
Long term VAD • Novacor LVAS • 55-65% survival to HTx • Average duration of support 85 days (max. 962 days) • Anticoagulation necessary • Embolic CV accidents ~25% • Redesigned cannula(CVA 10%)
Long term/Pulsatile VAD • HeartMate • Increased mobility • Possible hospital discharge • Stroke vol. 83 ml • Preperitoneal location
Advantages Small device Less material contact - higher durability Noiseless Disadvantages Hemolysis at high RPM Intracavitary negative pressure No solution “B” Long term/Nopulsatile VAD
Long term/Nonpulsatile VAD • Centrifugal pumps (axial flow) • Continuously rotating propeller • No proof that lack of pulsatility is harmful
Mechanical Circulatory Support First full implantable, miniaturized axial-pump for clinical application diameter 30,5 mm length 76,2 mm weight 93 g
Centrifugal devices • Jarvik 2000 • HeartMate II • MicroMed DeBakey
FUTURE VS TODAY Current Assist Devices Target Patient Population Treatment Goal Level of Support Placement Procedure Device Implantation Physician Placing Implantation Risks Chronic Non-hospitalized HF patient Quality of life improvement therapy Partial Elective Endovascular IX Cardiologist or CT Surgeon Low End-Stage Hospitalized HF patient Life-saving therapy Full Emergency ALWAYS Surgical CT Surgeon High
Complications • bleeding/thromboembolism • CVA • infection • device failure • ARF • Respiratory insufficiency
Total artificial heart • Heart explantation • Wireless energy transmission • Longest implantation 512 days
Future of Mechanical Circulatory Support VAD-therapy today: -- BRIDGE TO or destinationTx for terminal HF pts -- due to growing experience reasonable outcome -- sophisticated technology provides good long-term results -- individual pump-types for individual patients What can we expect ?? -- next 2 - 5 yrs new pump concepts in clinical application -- new generation pump is predominantly rotary pump -- further improvement of existing pump concepts -- challenge will bring prizes down -- very long lasting VADs for chronic implants -- true alternative to clinical heart transplantation???
Life is like driving a bicycle. To keep your balance you must keep moving. Albert Einstein