Adequate time in therapeutic INR range using triple antithrombotic therapy is not associated with long-term cardiovascular events and major bleeding complications after drug-eluting stent implantation.

BACKGROUND: Triple antithrombotic therapy increases the risk of bleeding events in patients undergoing percutaneous coronary intervention (PCI) compared with dual anti-platelet therapy (DAPT). However, whether warfarin control is associated with reduced cardiovascular events and major bleeding events in patients undergoing PCI with triple antithrombotic therapy is uncertain.

METHODS: We investigated 1207 consecutive patients who underwent PCI between 2004 and 2011. Major bleeding complications and major adverse cardiac and cerebrovascular events (MACCE) defined as all-cause death, acute coronary syndrome, target vessel revascularization, and stroke were compared between groups of patients who received either triple antithrombotic therapy or DAPT.

RESULTS: Triple antithrombotic therapy was administered to 95 (7.9%) patients. The mean international normalized ratio of prothrombin time (PT-INR) was 1.8. The target PT-INR level was set between 1.6 and 2.6 and the ratio (%) of time in the therapeutic range (TTR) was calculated. The median TTR was 78.4% (interquartile range, 67.4-87.6%). Kaplan-Meier survival curves showed that warfarin therapy was not associated with MACCE (p=0.89) and major bleeding (p=0.80). Multivariable Cox regression analysis revealed that triple antithrombotic therapy was not an independent predictor of MACCE and major bleeding.

CONCLUSIONS: Triple antithrombotic therapy does not increase the occurrence of MACCE and major bleeding complications, if the warfarin dose is tightly controlled with a lower INR.