Splanchnic vein thrombosis-related mortality in the Veneto region (Italy), 2008-2019: Retrospective analysis of epidemiological data

Background Splanchnic vein thrombosis (SVT) is an uncommon manifestation of venous thromboembolism. Historical epidemiological data on SVT-related mortality rate is not available to date. Methods We investigated time trends in SVT-related mortality, 2008–2019, in Veneto, an Italian high-income region of approximatively 5,000,000 inhabitants. SVT-related deaths were identified by the following ICD-10 codes: I81 (portal vein thrombosis), K75.1 (phlebitis of portal vein), K76.3 (liver infarction), K76.5 (hepatic veno-occlusive disease) or I82.0 (Budd-Chiari syndrome). Results During the study period, a total of 557,932 deaths were recorded. SVT was reported in 823 cases; 776 (94%) consisted of portal vein thrombosis. The age-standardized SVT-related mortality rate varied from 1.47 (year 2008) to 1.52 (year 2019) per 100,000 person-years. An increase in the cause-specific annual mortality rate was observed in women (0.56 in 2008 to 1.04 per 100,000 person-years in 2019; average annual percent change +5.7%, 95%CI +3.1; +8.3%). In men, the cause-specific mortality rate moved from 2.53 in 2008 to 2.03 per 100,000 person-years in 2019 (average annual percent change −1.2%, 95%CI -4.0; +1.6%). After conditioning for age and sex, the odds of having a concomitant liver disease were higher for SVT-related deaths (OR 31.6; 95%CI 17.1–37.0) compared with non-SVT-related deaths. This also applies to gastrointestinal cancers (OR 1.28; 95%CI 1.07–1.55), although to a lesser extent. Conclusions We report first epidemiological estimates of SVT-related mortality in a Western country. These values will serve as a reference to weight novel potential factors associated with SVT-related death, putting them into an epidemiological perspective. Summary box What is already known about this subject? Splanchnic vein thrombosis is a rare manifestation of venous thromboembolism, often related to liver diseases. Currently, there is no available data on its impact on the general population in terms of mortality rates. What are the new findings? Splanchnic vein thrombosis-related mortality rate was higher in men than in women and was strongly associated with the presence of liver diseases. In women, the age-standardized splanchnic vein thrombosis-related mortality rate has been increasing since 2008. How might it impact on clinical practice in the foreseeable future? We report first epidemiological estimates of splanchnic vein thrombosis-related mortality rates in a Western country. These values will serve as a reference to weight novel factors or pathologies potentially associated with splanchnic vein thrombosis and interpret them in an epidemiological perspective.