Introduction: In some circumstances left ventricular assist devices (LVAD) can be used to bridge patients with advanced heart failure to myocardial recovery or “remission”. Evaluation of the underlying myocardial function in patients supported with an LVAD is often performed with the pump speed turned down to minimal support for 15 minutes, to simulate unassisted ventricular loading conditions. Longer duration of reduced support and performance of exercise may allow for a more realistic evaluation of myocardial function to assess for recovery. Methods: Nine turn-down exams from 4 patients were analyzed. Subjects were participants in a multi-center prospective non-randomized study of LV recovery with HeartMate II LVAD together with a standardized protocol of pharmacological therapy (REmission from STAGE D Heart Failure (RESTAGE-HF)). LVEF and speckle tracking parameters were measured during full support, at 15 minutes of reduced support (6000 rpm) and again after a 6-min walk test. Averaged radial and circumferential strain, and global circumferential strain were analyzed from papillary muscle level short-axis view using speckle-tracking. Results: LV systolic parameters for each of these patients are shown, (Table). Improvement in LV function was not evident at 15 minutes of reduced support, compared to full support but was evident after the 6-min walk test. Conclusions: After 15 minutes of LVAD turndown, LV systolic parameters did not differ from full support values. Improvement in LV function compared to full support became evident when the protocol was extended to include imaging after a longer period of turndown with the addition of a 6-min walk test.

Speckle tracking echocardiography

Ventricular Function

10.1161/circ.132.suppl_3.12494

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Safety of reduced anti-thrombotic strategies in HeartMate II patients: A one-year analysis of the US-TRACE Study

The Journal of Heart and Lung Transplantation (2015)

Jason N. Katz Robert Adamson Ranjit John Antone Tatooles Kartik S. Sundareswaran

Interquartile range

Regimen

Vitamin K antagonist

10.1016/j.healun.2015.06.018

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HeartMate II Post-marketing Clinical Studies to Further Establish and Expand LVAD Therapy

The VAD Journal (2015)

Faouzi Kallel

The number of patients with end-stage heart failure (HF) benefiting from mechanical circulatory support based therapy is rapidly growing. Over the last 2 decades the therapy has been rapidly evolving particularly since the introduction of continuous flow ventricular assist devices (CF-LVAD) which addressed several limitations of the first generation pulsatile devices. According to the sixth INTERMACS registry annual report, the 12 and 24 months overall actuarial survival of CF-LVAD was 80% and 70% respectively.1 Survival rates remained unchanged over the past 6 years. The adverse events associated with CF-LVAD have been dramatically reduced when compared to rates associated with the previous generation pulsatile flow devices. The burden of adverse events associated with CF-LVAD decreased over the last 6 years and quality of life improvement at 12 and 24 months remained consistent. According to the report, while the proportion of patients implanted while stable on inotropic support has significantly increased in the last era (2011-2013), the expansion into INTERMACS levels 4 and higher remains limited to 20%.

Pulsatile flow

Destination therapy

Artificial heart

10.13023/vad.2015.01

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Reduction in Driveline Infection Rates: Results from the HeartMate II Multicenter Silicone-Skin-Interface (SSI) Registry

The Journal of Heart and Lung Transplantation (2014)

David A. Dean Greg Ewald Antone Tatooles Brett C. Sheridan Robert J. Brewer

Exit site

10.1016/j.healun.2014.01.056

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Preclinical Models for Translational Investigations of Left Ventricular Assist Device‐Associated von Willebrand Factor Degradation

Artificial Organs (2015)

David Restle David M. Zhang George Hung Jessica Howard Faouzi Kallel

Evidence suggests a major role for von Willebrand factor (vWF) in left ventricular assist device (LVAD)-associated bleeding. However, the mechanisms of vWF degradation during LVAD support are not well understood. We developed: (i) a simple and inexpensive vortexer model; and (ii) a translational LVAD mock circulatory loop to perform preclinical investigations of LVAD-associated vWF degradation. Whole blood was obtained from LVAD patients (n = 8) and normal humans (n = 15). Experimental groups included: (i) blood from continuous-flow LVAD patients (baseline vs. post-LVAD, n = 8); (ii) blood from normal humans (baseline vs. 4 h in vitro laboratory vortexer, ∼ 2400 rpm, shear stress ∼175 dyne/cm(2) , n = 8); and (iii) blood from normal humans (baseline vs. 12 h HeartMate II mock circulatory loop, 10 000 rpm, n = 7). vWF multimers and degradation fragments were characterized with electrophoresis and immunoblotting. Blood from LVAD patients, blood exposed to in vitro supraphysiologic shear stress, and blood circulated through an LVAD mock circulatory loop demonstrated a similar profile of decreased large vWF multimers and increased vWF degradation fragments. A laboratory vortexer and an LVAD mock circulatory loop reproduced the pathologic degradation of vWF that occurs during LVAD support. Both models are appropriate for preclinical studies of LVAD-associated vWF degradation.

10.1111/aor.12428

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Citations (28)