Three-dimensional flow characteristics in ventricular assist devices: Impact of valve design and operating conditions

Benk, Christoph; Lorenz, Ramona; Beyersdorf, Friedhelm; Bock, Jelena; Klemm, Rolf; Korvink, Jan G.; Markl, Michael

doi:10.1016/j.jtcvs.2011.01.058

Cited by 9 publications

(8 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Continuous-flow ventricular assist devices (VADs) are increasingly implanted for long-term therapy in patients with advanced heart failure 1 . Though the hemodynamics of the large vessels are greatly improved by VAD in heart failure patients as a result of the mechanical circulatory support, flow pattern changes potentially evoke stasis and the risk of pump thrombosis and stroke 2,3 . In addition, acquired von Willebrand syndrome (AVWS) develops due to altered hemodynamic conditions 4,5 .…”

Section: Introductionmentioning

confidence: 99%

Functional capillary impairment in patients with ventricular assist devices

Wadowski

Steinlechner

Zimpfer

et al. 2019

Sci Rep

View full text Add to dashboard Cite

The implantation of continuous – flow ventricular assist devices (VAD) is suggested to evoke angiodysplasia contributing to adverse events such as gastrointestinal bleeding. We evaluated in vivo capillary density and glycocalyx dimensions to investigate possible systemic microvascular changes in patients with chronic heart failure and VAD support vs. standard medical treatment. Forty-two patients with VAD support were compared to forty-one patients with ischemic and non-ischemic chronic heart failure (CHF) on standard pharmacotherapy and to a group of forty-two healthy subjects in a prospective cross-sectional study. Sublingual microcirculation was visualized using Sidestream Darkfield videomicroscopy and functional and perfused total capillary densities were quantified. Patients with VAD implantation were followed for one year and bleeding events were recorded. Median time after VAD implantation was 18 months. Patients were treated with centrifugal-flow devices (n = 31) or axial-flow devices (n = 11). Median functional capillary density was significantly lower in patients with VAD therapy as compared to CHF patients (196 vs. 255/mm 2 , p = 0.042, adjusted p-value). Functional and total capillary densities were 44% and 53% lower (both p < 0.001) in patients with VAD therapy when compared to healthy subjects. Cox regression analysis revealed loss of capillary density as a significant predictor of bleeding events during one -year follow-up of VAD patients (HR: 0.987, CI (95%): 0.977–0.998, p = 0.021 for functional and 0.992, CI (95%): 0.985–0.999, p = 0.03 for total capillary density). In conclusion, patients with VAD support exhibit capillary density rarefaction, which was associated with bleeding events. If confirmed independently, capillary impairment may be evaluated as novel marker of bleeding risk.

show abstract

Section: Introductionmentioning

confidence: 99%

Functional capillary impairment in patients with ventricular assist devices

Wadowski

Steinlechner

Zimpfer

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Anticoagulation is necessary; however, nonsurgical hemorrhages cannot be attributed to anticoagulation alone. Pathological flow conditions and elevated shear stress occur in VAD patients because of changes in hemodynamics . Therefore, our hypothesis on initiating this prospective observational study (2006–2016) was that acquired von Willebrand syndrome (AVWS) is present in all VAD patients.…”

Section: Introductionmentioning

confidence: 99%

Platelet Secretion Defects and Acquired von Willebrand Syndrome in Patients With Ventricular Assist Devices

Geisen

Brehm

Trummer

et al. 2018

JAHA

Self Cite

View full text Add to dashboard Cite

BackgroundThe number of implanted ventricular assist devices (VADs) has increased significantly recently. Bleeding, the most frequent complication, cannot be solely attributed to anticoagulation therapy. Acquired von Willebrand syndrome (AVWS) caused by increased shear stress is frequent in VAD patients and can increase the bleeding risk. The HeartMate III (HM III) is a novel left VAD featuring potential improvements over the HeartMate II.Methods and ResultsIn this study, we investigated the prevalence and onset of AVWS in 198 VAD patients. To our knowledge, this is the largest cohort of VAD patients whose longitudinal data on AVWS have been collected. We also analyzed whether AVWS is less severe in HM III patients than in HeartMate II patients. Because platelet dysfunction can raise the bleeding risk, we investigated platelet function in a subset of patients. In total, 198 VAD patients and 60 patients with heart transplants as controls were included in this study. The ratio of von Willebrand factor collagen binding capacity to von Willebrand factor:antigen, multimer analyses, and platelet function (especially secretion of α‐ and δ‐granules) were investigated. All 198 VAD patients developed AVWS. As soon as the VAD was explanted, the AVWS disappeared within hours. AVWS was less severe in the HM III patients than in the HeartMate II patients. The HM III patients had fewer bleeding symptoms. In addition, VAD patients exhibited a platelet α‐ and δ‐granule secretion defect.Conclusions AVWS develops in VAD patients and may increase the bleeding risk. The HM III device causes less severe AVWS. Platelet secretion defects should be investigated in VAD patients because they also raise the bleeding risk.Clinical Trial Registration https://www.drks.de/drks_web. Unique identifier: DRKS00000649.

show abstract

“…Pathological flow conditions and elevated shear stress occur in VAD patients because of changes in hemodynamics. 3 Therefore, our hypothesis on initiating this prospective observational study (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016) was that acquired von Willebrand syndrome (AVWS) is present in all VAD patients. AVWS may be one cause of the exacerbated bleeding symptoms, as has been described previously.…”

mentioning

confidence: 99%

Platelet secretion defects and acquired von Willebrand syndrome in patients with Ventricular Assist Devices

et al. 2019

Self Cite

View full text Add to dashboard Cite

Background--The number of implanted ventricular assist devices (VADs) has increased significantly recently. Bleeding, the most frequent complication, cannot be solely attributed to anticoagulation therapy. Acquired von Willebrand syndrome (AVWS) caused by increased shear stress is frequent in VAD patients and can increase the bleeding risk. The HeartMate III (HM III) is a novel left VAD featuring potential improvements over the HeartMate II.Methods and Results--In this study, we investigated the prevalence and onset of AVWS in 198 VAD patients. To our knowledge, this is the largest cohort of VAD patients whose longitudinal data on AVWS have been collected. We also analyzed whether AVWS is less severe in HM III patients than in HeartMate II patients. Because platelet dysfunction can raise the bleeding risk, we investigated platelet function in a subset of patients. In total, 198 VAD patients and 60 patients with heart transplants as controls were included in this study. The ratio of von Willebrand factor collagen binding capacity to von Willebrand factor:antigen, multimer analyses, and platelet function (especially secretion of aand d-granules) were investigated. All 198 VAD patients developed AVWS. As soon as the VAD was explanted, the AVWS disappeared within hours. AVWS was less severe in the HM III patients than in the HeartMate II patients. The HM III patients had fewer bleeding symptoms. In addition, VAD patients exhibited a platelet aand d-granule secretion defect.Conclusions--AVWS develops in VAD patients and may increase the bleeding risk. The HM III device causes less severe AVWS. Platelet secretion defects should be investigated in VAD patients because they also raise the bleeding risk.Clinical Trial Registration--https://www.drks.de/drks_web.

show abstract

Three-dimensional flow characteristics in ventricular assist devices: Impact of valve design and operating conditions

Cited by 9 publications

References 26 publications

Functional capillary impairment in patients with ventricular assist devices

Functional capillary impairment in patients with ventricular assist devices

Platelet Secretion Defects and Acquired von Willebrand Syndrome in Patients With Ventricular Assist Devices

Platelet secretion defects and acquired von Willebrand syndrome in patients with Ventricular Assist Devices

Contact Info

Product

Resources

About