Association Between Platelet Count And The Risk Of Bleeding Among Patients With Nonvalvular Atrial Fibrillation Taking Dabigatran After Radiofrequency Ablation

Objective:This study aimed to investigate the association between platelet count and the risk of bleeding among patients with nonvalvular atrial fibrillation(NVAF)taking dabigatran after radiofrequency ablation.Methods:In this multicenter,prospective and observational study,a total of 576 NVAF patients treated with dabigatran(110 mg bid)after radiofrequency ablation were recruited from 12 centers in China from February 2015 to December 2017.All patients were followed for 3 months.Cox proportional hazards regression analysis was used to evaluate the association between platelet count and the risk of bleeding.Moreover,a Cox proportional hazards regression model with cubic spline functions and smooth curve fitting(the penalized spline method)and a two-piecewise Cox proportional hazards model were used to address the nonlinearity between platelet count and bleeding.Results:During a median follow-up duration of 87 days,50 patients experienced bleeding events.Overall,there was an inverse relationship between the risk of bleeding and platelet count.Low platelet count(<100×10~9/L)were associated with an increased risk of bleeding(hazard ratio(HR),4.05;95%confidence interval(CI):1.32-12.46)compared to higher counts.The adjusted smooth curve showed a nonlinear relationship between platelet count and bleeding events.The inflection point of the platelet count was 105×10~9/L.For platelet counts<105×10~9/L,the HR(95%CI)was0.89(0.84,0.95),and for platelet counts?105×10~9/L,the HR(95%CI)was 1.01(0.95-1.08).Conclusion:Low platelet counts were associated with an increased risk for bleeding among patients with NVAF taking dabigatran after radiofrequency ablation.