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. 2019 Apr 11;9(1):5909.
doi: 10.1038/s41598-019-42334-3.

Functional Capillary Impairment in Patients With Ventricular Assist Devices

Free PMC article

Functional Capillary Impairment in Patients With Ventricular Assist Devices

Patricia P Wadowski et al. Sci Rep. .
Free PMC article


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/mm2, 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.

Conflict of interest statement

The authors declare no competing interests.


Figure 1
Figure 1
(a) Functional capillary density in chronic heart failure patients with and without VAD support. (b) Total perfused capillary density in chronic heart failure patients with and without VAD support. (c) Ratio of functional capillary density/total perfused capillary density in chronic heart failure patients with and without VAD support. The boundaries of the box show the lower and upper quartiles of data, the line inside the box represents the median. Whiskers are drawn from the edge of the box to the highest and lowest values that are outside the box but within 1.5 times the box length. The outliers are presented as open circles. CHF, chronic heart failure; VAD, ventricular assist device.
Figure 2
Figure 2
Receiver-operating characteristic (ROC) curve for the analysis of the predictive value of (a) functional capillary density: area under the curve (AUC) = 0.78 ± 0.09 (SE), CI 95%: 0.6–0.96, p = 0.007 and (b) total perfused capillary density: AUC = 0.78 ± 0.09 (SE), CI 95%: 0.61–0.96, p = 0.006, (depicted as blue line, respectively) for bleeding events. SE, standard error.

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