Safety of diagnostic coronary angiography during uninterrupted therapeutic warfarin treatment

Long-term warfarin therapy is assumed to increase bleeding and access site complications after coronary angiography and it is often recommended to postpone invasive procedures to reach international normalized ratio (INR) levels <1.8. To assess the safety and feasibility of diagnostic coronary angiography during uninterrupted warfarin therapy, we retrospectively analyzed all consecutive patients (n = 258) on warfarin therapy referred for diagnostic coronary angiography in 2 centers with long experience in uninterrupted warfarin therapy during coronary angiography and in 1 center with a policy of preprocedural warfarin pause. An age- and gender-matched control group (n = 258) with similar disease presentation (unstable or stable symptoms) was collected from each center. Radial access was used in 56% of patients in the warfarin group and in 60% of controls (p = 0.21). There was no difference in access site and bleeding complications (1.9% vs 1.6%) or major adverse cardiovascular and cerebrovascular events (0.4% vs 0.8%) between the warfarin group and their controls. Warfarin was interrupted in 80 patients (31%), and bridging therapy was used in 24 of these patients (30%). INR levels were higher in the uninterrupted warfarin group (2.3 vs 1.9, p <0.001), but the incidence of access site complications was not higher (1.7%) than in patients (n = 80) with a warfarin pause (2.5%) or in patients with pause and bridging therapy (8.3%). Need for blood transfusions (n = 2) occurred only in patients with bridging therapy. Access site complications were more common in the 22 patients with supratherapeutic anticoagulation (INR >3) than in patients with therapeutic periprocedural INR (9.1% vs 1.5%, p <0.05). In conclusion, a simple strategy of performing coronary angiography during uninterrupted therapeutic warfarin anticoagulation is a tempting alternative to bridging therapy and is likely to lead to considerable cost savings.