Advances in LVAD DesignImproving Reliability and Minimizing Risk of Stroke & ThrombosisSteve Reichenbach, PhDSenior Director, Technology DevelopmentThoratec Corporation

J100-1111

Key Objectives In LVAD Design—Implications For HeartMate II®

Maximize reliability

Minimize stroke complications and thrombus formation

Minimize infection risk

Reduce device size

Reduce anticoagulation requirements

Enable return to highly active lifestyle

HeartMate II LVAS6,000 Implants Worldwide

HeartMate II—Designed For Extended Reliability

Elegant design and configuration

Precision engineering

Design targeting more than 10 years of support

30 years of clinical experience reflected in the design

More than 6,000 HeartMate II patients implanted worldwide

Longest ongoing patient supported more than 6 years and 60 patients more than 4 years

Redundant circuitry of the percutaneous lead and system controller provides backup if there is a problem with the primary source

Lithium-ion batteries provide a full work day of support (10–14 hours) on a single charge and are designed to last up to 3 years before replacement

Reliability of percutaneous lead design continuously refined through extensive clinical trial data and feedback over thousands of implants

HeartMate II—Designed For Extended Reliability

HeartMate II—Designed For Highly Washed Flow Path And Low Rates Of Stroke & Pump Thrombosis

Rotor speed typically set between 8,000 and 10,000 RPM and capable of pumping up to 10 liters of blood per minute.

A single moving part combined with open flow paths help to optimize the blood flow.

Flow dynamics designed to maximize washing and minimize the risk of thrombus stasis formation and stroke.

Flow design maintains integrity of blood cells.

HeartMate II—Designed For Low Rates Of Stroke And Pump Thrombosis Over Extended Periods

Blood-immersed ruby bearings designed for ultra long-life—analysis of explanted pumps indicates an excess of 17 years with an average expected life of 60 years.*

No bearing failures in the 6,000 worldwide patient experience.

High-precision bearing / cup design enables plasma to serve as lubricant while dissipating heat, avoiding damage to red blood cells and preventing thrombus formation.

*Reichenbach SH. Negligible bearing wear in explanted HeartMate II LVADs following clinical support for up to 4 years. Paper presented at: Annual Meeting of the International

Society for Rotary Blood Pumps 2010; October 14–16, 2010; Berlin, Germany.

Benefits Of Textured Surfaces

Most LVADs have been designed with smooth interior surfaces in an effort to minimize sites for thrombus nucleation yet the frequency of thromboembolic complications associated with LVADs has been reported to be as high as 29%.

Thoratec began evaluating textured surfaces for LVAD applications more than 3 decades ago and refined its application over that period.

Textured surfaces in select areas of the device encourage a dense, adherent pseudo-neointima, thereby eliminating the direct interface between prosthetic material and blood elements, reducing the risk of thromboembolic complications.

Rose EA, Lewis HR, Oz MC, et al. Artificial circulatory support with textured interior surfaces: a counterintuitive approach to

minimizing thromboembolism. Circulation. 1994;90:87-91.

Zapanta CM, Griffith JW, Hess GD, et al. Microtextured materials for circulatory support devices: preliminary studies.

ASAIO J. 2006;52(1):17-23.

Textured Surfaces

Rose et al. found that despite the low levels in anticoagulation (including patients with no anticoagulation regimen), only 3.5% of patients had thromboembolic complications with the first-generation HeartMate that incorporated Thoratec’s customized texturing process.

The study concluded that this specific application of sintered titanium surfaces can be used for prolonged periods with limited TE complications despite minimal anticoagulation.

Due to the benefits observed with the use of textured surfaces in the first-generation HeartMate, they have been incorporated into the HeartMate II design.

HeartMate II uses customized texturing that has been refined and proven throughout decades of clinical experience.

HeartMate II—Designed For Low Rates Of Stroke And Pump Thrombosis Over Extended Periods

HeartMate II Inflow Conduit

Rose EA, Lewis HR, Oz MC, et al. Artificial circulatory support with textured interior surfaces: a counterintuitive approach to

minimizing thromboembolism. Circulation. 1994;90:87-91.

Flex section consists of a knitted polyester graft that is reinforced and covered with a silicone sleeve.

Flexibility allows for relative movement between the native left ventricle and the LVAD:

Maintains an open flow path

Accommodates reverse remodeling of the heart over time while maintaining cannula position inside left ventricle

Prevents misalignment against ventricular wall

Helps avoid “suckdown” events

Suction detection algorithm:

Detects suction events and automatically adjusts pump speed

Intended to prevent suckdown events which subsequently might cause ventricular arrhythmias, flow interruption, or damage to the left ventricle

Inflow Conduit

Flex Section

HeartMate II—Designed For Low Rates Of Stroke & Pump Thrombosis Over Extended Periods

Low Rates of Stroke and Pump Thrombosis With The HeartMate II

Boyle AJ, Russell SD, Teuteberg JJ, et al. Low thromboembolism and pump thrombosis with the HeartMate II left ventricular assist device: analysis of outpatient anticoagulation.

J Heart Lung Transplant. 2009;28:881-7.

In 331 patients discharged on support:

2.4% had ischemic stroke

0.9% had pump thrombosis

2.1% suffered from hemorrhagic stroke

Low Rates Of Stroke & Pump Thrombosis With The HeartMate II

Boyle AJ, Russell SD, Teuteberg JJ, et al. Low thromboembolism and pump thrombosis with the HeartMate II left ventricular assist device: analysis of outpatient anticoagulation.

J Heart Lung Transplant. 2009;28:881-7.

HeartMate II Bridge-to-TransplantationClinical Trial Experience

This study also concluded that the INR range should target between 1.5 to 2.5 to minimize the risk of hemorrhagic events.

No pump replacements through the first 6 months of HeartMate II support

Low ischemic and hemorrhagic stroke rates

HeartMate II Left Ventricular Assist System [instructions for use] #105747. Pleasanton, Calif. Thoratec Corp; October, 2010.

Low Rates Of Stroke & Pump Thrombosis With The HeartMate II

HeartMate II Bridge-to-TransplantationCommercial Study Experience

HeartMate II provides efficacy and reliability through simplicity of design with a single moving part, open blood flow paths, durable bearings and compliant inflow conduit to accommodate reverse remodeling of the heart.

HeartMate II has the lowest published rates of stroke and pump thrombosis of any continuous-flow LVAD.*

HeartMate II has the lowest published anticoagulation regimen for continuous-flow LVAD therapy.*

HeartMate II offers excellent reliability, proven in more than 6,000 implanted patients worldwide.

HeartMate II—Proven Technology

Boyle AJ, Russell SD, Teuteberg JJ, et al. Low thromboembolism and pump thrombosis with the HeartMate II left ventricular assist device: analysis of outpatient anticoagulation. J Heart

Lung Transplant. 2009;28:881-7.Slaughter MS, Pagani FD, Rogers JG, et al. Clinical management of continuous-flow left

ventricular assist devices in advanced heart failure. J Heart Lung Transplant. 2010;29:S1-39.

* Based on published data from multicenter experience and separate studies, which may involve different patient populations and other variables. Please refer to the HeartMate II Instructions for Use about indications, contraindications, adverse events, warnings, and precautions (http://www.thoratec.com/medical-professionals/resource-library/ifus-manuals/heartmate-ll-lvad.aspx#levelFour).