Gastrointestinal Bleeding as a Complication in Continuous Flow Ventricular Assist Devices: A Systematic Review With Meta-Analysis

Abstract

Background: The use of ventricular assist devices (VADs) has become predominant in this era of medicine. It is commonly used as a bridge to transplant, recovery and as a destination therapy for patients with severe heart failure, who are not responsive to maximum optimal management or ineligible for transplant. However, several complications are known to occur with the use of these devices. In this research, we will compare gastrointestinal bleeding in patients who used centrifugal flow versus axial flow VADs. We hope that the result of this meta-analysis and the review presented provide adequate information to future researchers, physicians and other healthcare professionals who are interested in this topic.

Methods: Published articles evaluated for inclusion were obtained from MEDLINE (PubMed), Cochrane, EBSCO, clinicaltrials.gov, and international clinical trials registry. This research was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Procured articles were reviewed by two independent reviewers. Only randomized control trials and observational studies were used. Quality assessment was done with Cochrane Collaboration's tool (RoB.2 with visualization through robviz) and Newcastle-Ottawa Scale (NOS). Data analysis was carried out with the use of R data analysis tool (version 4.0.0; release date: April 24th, 2020).

Results: At the end of this meta-analysis, the occurrence of gastrointestinal bleeding was not significantly different between both groups; with odds ratio (OR): 0.81; 95% confidence interval (CI): 0.65 - 1.00; P value = 0.05. Between-study variance (Tau-squared) was zero (0), standard error (SE) = 0.06. The degree of heterogeneity measured with I-squared statistic was 0% (minimal). Egger's regression test was not statistically significant, P = 0.93. Symmetry of distribution was observed on the funnel plot. Trim and fill analysis showed no missing studies on the left; SE = 1.68.

Conclusions: The result obtained from this research indicates that the occurrence of gastrointestinal bleeding is not significantly different in both groups of patients, irrespective of the type of continuous flow VAD used. Although, the study sample used in this meta-analysis was limited.

Keywords: Axial flow VADs; Biventricular Assist device; Centrifugal flow VAD; Continuous flow VADs; Extracorporeal Membrane Oxygenation; Gastrointestinal bleeding; VAD.

Figure 1

Multidisciplinary team commonly involved in the care of patients with VADs. VAD: ventricular assist devices.

Figure 2

Classifications of ventricular assist devices.

Figure 3

Schematic representation of ventricular assist device work flow using tethered (AC power source) and untethered connection (DC power source). AC: direct current; AC: alternating current.

Figure 4

The HVAD (HeartWare Corp.) ventricular assist device. Copyright^© 2015 Bonacchi, Harmelin, Bugetti and Sani. Creative commons license CC BY 4.0 (Permission obtained from original authors).

Figure 5

PRISMA flow diagram.

Figure 6

Outcome of RoB.2 quality assessment for all randomized control trials included (visualized with robviz).

Figure 7

Sample distribution across all studies included.

Figure 8

Forest plot showing the effect sizes for all studies included and the pooled effect size (pooled odds ratio) at a confidence level of 95%.

Figure 9

Funnel plot showing the distribution of effect estimates against their standard error (index of precision). The effect estimates are distributed as log odds ratio.