Anticoagulation for cirrhosis with portal vein thrombosis: Still a road to be explored

Anticoagulation improves survival in patients with cirrhosis and portal vein thrombosis: The IMPORTAL competing-risk meta-analysisJournal of HepatologyVol. 79Issue 1PreviewPrevious meta-analyses demonstrated the safety and efficacy of anticoagulation in the recanalization of portal vein thrombosis in patients with cirrhosis. Whether this benefit translates into improved survival is unknown. We conducted an individual patient data (IPD) meta-analysis to assess the effect of anticoagulation on all-cause mortality in patients with cirrhosis and portal vein thrombosis. Full-Text PDF The authors received no financial support to produce this manuscript. The authors declare there were no conflicts of interest. Drafting of the manuscript: CXN; critical revision and approval of the final manuscript: CXN, PJS, and ZYY. We have read with considerable interest the meta-analysis conducted by Guerrero et al, which employed a competing-risk model to examine the impact of anticoagulation on all-cause mortality in patients diagnosed with cirrhosis and portal vein thrombosis (PVT).[1]Guerrero A. Campo L.D. Piscaglia F. Scheiner B. Han G. Violi F. et al.Anticoagulation improves survival in patients with cirrhosis and portal vein thrombosis: The IMPORTAL competing-risk meta-analysis.Journal of hepatology. 2023; 79: 69-78Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar It is worth acknowledging the authors' diligent efforts in collecting and analyzing individual patient data for this study, leading to a significant clinical finding. Nevertheless, it is crucial to take into account certain confounding factors before drawing definitive conclusions. Initially, it was observed that patients in the non-anticoagulant treatment group had higher Child-Pugh and MELD scores, along with elevated levels of serum bilirubin. These findings suggest that patients in the non-treatment group may possess compromised liver function and more advanced liver disease. Consequently, it is unsurprising that the prognosis for these individuals was unfavorable. Thus, the implementation of propensity score matching may be deemed appropriate to mitigate potential selection bias. Furthermore, it is important to note that this meta-analysis encompassed a range of anticoagulation strategies, with varying impacts on PVT depending on the specific anticoagulants used and the duration of treatment. A randomized controlled trial has demonstrated a significant increase in the recanalization rate of cirrhotic PVT when utilizing one month of low molecular heparin followed by five months of warfarin (62.5% vs 34.4%, P = 0.024).[2]Zhou T. Sun X. Zhou T. Li Y. Chen X. Cheng B. et al.Efficacy and Safety of Nadroparin Calcium-Warfarin Sequential Anticoagulation in Portal Vein Thrombosis in Cirrhotic Patients: A Randomized Controlled Trial.Clinical and translational gastroenterology. 2020; 11e00228Crossref Scopus (23) Google Scholar However, it is worth mentioning that this study did not yield similar results. Moreover, it is worth considering that certain patients with cirrhosis and PVT may not require anticoagulation therapy. Wang et al. discovered that the rates of PVT recanalization and clinical outcomes were comparable between the group receiving anticoagulation therapy and the control group (83.9% vs. 71.8%, P = 0.252).[3]Wang Z. Jiang M.S. Zhang H.L. Weng N.N. Luo X.F. Li X. et al.Is Post-TIPS Anticoagulation Therapy Necessary in Patients with Cirrhosis and Portal Vein Thrombosis? A Randomized Controlled Trial.Radiology. 2016; 279: 943-951Crossref PubMed Scopus (86) Google Scholar Consequently, there is an immediate need to develop well-designed trials to investigate suitable anticoagulation regimens for diverse populations with cirrhotic PVT. In addition, the PVT condition has the potential to undergo alterations after the completion of anticoagulation therapy. This phenomenon has been documented by Pettinari et al,[4]Pettinari I. Vukotic R. Stefanescu H. Pecorelli A. Morelli M. Grigoras C. et al.Clinical Impact and Safety of Anticoagulants for Portal Vein Thrombosis in Cirrhosis.The American journal of gastroenterology. 2019; 114: 258-266Crossref PubMed Scopus (91) Google Scholar who reported a correlation between the cessation of anticoagulation therapy and the recurrence of PVT. Consequently, it is imperative to include PVT assessment in the follow-up process. If relevant data is accessible, the authors should perform an analysis of the PVT condition after the discontinuation of anticoagulant therapy. Furthermore, considering the absence of a universally acknowledged anticoagulation approach, particularly for individuals classified as Child-Pugh grade C, it would have been advantageous for the authors to conduct subgroup analyses encompassing patients with varying degrees of hepatic functionality. Finally, the total number of participants in each subgroup based on PVT severity (33/0.247 + 64/0.412 + 18/0.147 + 45/0.278 = 573) was 81 higher than the total number presented in Figure 3 (225 + 267 = 492), and the total number of people stratified according to PVT recommencement was also 30 higher than the number presented in the figure. It is recommended that the authors carefully verify the data in the figure. In conclusion, we commend the authors for addressing a clinical concern, but there remain several unresolved issues. Further studies should be conducted, taking into account the potential biases mentioned above.