Epidemiology of venous thromboembolism in patients with liver diseases: a systematic review and meta-analysis

Abstract

The risk of venous thromboembolism (VTE) may be increased in patients with liver diseases. A systematic review and meta-analysis were conducted to analyze the epidemiology of VTE in such patients. All relevant studies were searched via the PubMed, EMBASE, and Cochrane Library databases. The incidence and prevalence of VTE were pooled using random-effect models. Subgroup analyses were conducted according to the type of VTE [deep vein thrombosis (DVT), pulmonary embolism (PE)], type of liver disease (liver cirrhosis alone/unclassified liver diseases or non-cirrhotics), region in which the study was performed (USA/Europe/Asia), number of total observed patients with liver diseases (>1,000/<1,000 patients), study quality (high/low), and methods for identifying the cases (ICD codes/clinical charts). Of 4,843 papers initially identified, 20 were included. The incidence of VTE varied from 0.33 to 6.32 % in 14 studies with a pooled value of 1 % (95 % confidence interval (CI) 0.7-1.3 %). The pooled incidence of DVT and PE was 0.6 % (95 % CI 0.4-0.8 %) and 0.28 % (95 % CI 0.13-0.49 %), respectively. The prevalence of VTE varied from 0.6 to 4.69 % in six studies with a pooled value of 1.0 % (95 % CI 0.7-1.2 %). The pooled prevalence of DVT and PE was 0.7 % (95 % CI 0.6-0.9 %) and 0.36 % (95 % CI 0.13-0.7 %), respectively. The heterogeneity was statistically significant in the main and subgroup meta-analyses. In conclusion, about 1 % of patients with liver diseases develop or are diagnosed with VTE during their hospitalizations. However, the epidemiological data are very heterogeneous among studies.

Venous thromboembolism in patients with liver diseases

“…The pooled proportion is unaffected by diagnosis (liver cirrhosis or unclassified liver diseases), whereas studies involving fewer than 1000 patients show a slightly higher incidence and prevalence compared to those involving more than 1000 patients, likely due to an enhanced possibility of selection bias [17]. Additional data analyzed by Qi et al [17] present evidence that in the majority of studies, the risk of VTE is increased in CLD patients by approximately 1.7-to 2-fold with respect to the controls, as previously reported [8]. The 1.7-fold increase in risk of VTE in cirrhotic patients has been recently confirmed in a nationwide study [18].…”

“…Qi et al [17] acknowledge the limitations of their study, including the significant heterogeneity found in nearly all meta-analyses. However, they confirm that a non-trivial proportion of CLD patients are prone to an increased thrombotic risk; this calls for studies aimed at the investigation of the risk stratification of patients according to the presence of patient-or disease-linked factors, and the opportunity of thromboprophylaxis in this setting.…”

“…In the present issue of Intern Emerg Med, Qi et al [17] conducted a systematic review and meta-analysis of all relevant studies published on the epidemiology of VTE in patients with CLD. Notably, they carried out an exhaustive search for relevant papers and they were able to include 20…”

“…Institute of Hematology, Catholic University, Rome, Italy e-mail: valerio.destefano@rm.unicatt.it papers, whereas the aforementioned reviews analyzed 6-12 studies [8,[14][15][16]; more importantly, the studies added by Qi et al [17] to their review cover over 600,000 patients with CLD, significantly increasing the sample size and the depth of analysis. However, five of the overall included studies were published in abstract or letter forms, so that information was limited.…”

“…However, five of the overall included studies were published in abstract or letter forms, so that information was limited. An additional strength of the review of Qi et al [17] is the employment of a meta-analytical procedure to evaluate the available data. In all, the pooled rate of VTE in patients with CLD is 1 %, with about one-third of the cases complicated by pulmonary embolism.…”