Objective: Warfarin therapy is crucial to prevent thromboembolism in patients with valvular heart disease and prosthesis. For valvular heart surgery, it is still controversial to either bridging with heparin or no bridging of warfarin prior to the procedure. In clinical practice at the Queen Sirikit Heart Center, Khon Kaen University, no bridging therapy is the main treatment. The present study aimed to evaluate the prevalence of thromboembolism and predictors for bleeding complications in the high risk patients who underwent valvular heart surgery with warfarin interruption.
Materials and Methods: The present study was a retrospective cohort study and conducted at The Queen Sirikit Heart Center, Thailand. The present study period was between January 1st, 2015 and December 31st, 2015. The inclusion criteria were adults with high risk for thromboembolism who underwent valvular heart surgery and stop taking warfarin before surgery for three to five days. The main outcome was evidence of any thromboembolism or bleeding events at 90 days after surgery. Prevalence of thromboembolism and predictors for post-operative bleeding were analyzed.
Results: During the study period, there were 416 patients met the study criteria. Of those, 24 patients (5.76%) were in high-risk group. There were two patients (8.33%) had thromboembolism events: ischemic stroke. Among 24 patients who had warfarin interruption, 11 patients (45.83%) had bleeding events. Baseline characters and laboratory results of those with and without bleeding were comparable. There was no one significant factor between both groups: Bleed MAP score. The bleeding group had significantly higher score of 1 and 2 than the non-bleeding group (63.64% vs. 0% for score of 1 and 27.27% vs. 0% for score of 2; p<0.001).
Conclusion: Thromboembolism and bleeding in high risk patients who underwent valvular heart surgery with the non-bridging regimen were 8.33% and 45.83%. Bleed MAP score is suggestive for postoperative bleeding in this setting.

Keywords: Prevalence; Predictors; Valvular heart disease; Warfarin; Thromboembolism; Bleeding