Varicose veins are associated with an increased risk of mitral valve regurgitation: a nationwide population-based cohort study

Background: Varicose veins (VV) and mitral valve regurgitation (MR) are both common diseases. The aim was to investigate whether VV are associated with an increased risk of MR. Methods: We conducted a nationwide cohort study to assess the association between VV and risk of developing MR. Drawn from the Taiwan National Health Insurance Research Database (NHIRD), the records of 56,898 patients with VV (the VV cohort) and 56,898 propensity score-matched patients without VV (the non-VV cohort) in the years 2007 to 2015 were identified. Follow-up duration was calculated from the date of entry in the cohort until the occurrence of a first MR diagnosis, death, or the end of the observation period (December 31, 2015), whichever occurred first. Hazard ratios (HRs) and accompanying 95% confidence intervals (CIs) derived from the Cox proportional hazards model were used to estimate the association between VV and MR risks. Results: After multivariable adjustment, VV was associated with an increased risk of MR (adjusted HR, 1.63; 95% CI: 1.52-1.74). Notably, significant associations between VV and MR risk were evident in both genders and in all age groups. A trend of significant increase of MR risk was also observed with increasing frequency of annual clinical visits for VV. Within the VV cohort, the subgroup of MR presence had higher incidences of atrial fibrillation, heart failure, valve-related surgeries, and mortality (P<0.001). Conclusions: This population-based cohort study revealed that VV was associated with an increased risk of MR in a Taiwanese population. Vigilance of MR existence should be emphasized in patients of VV due to its potentially poor long-term outcomes.