Researchers from Kaiser Permanente in Colorado, US, found that not resuming treatment within 90 days of a GI bleed was linked with an increased risk of thrombosis and death.
In comparison, resuming therapy within 90 days did not increase the risk of bleeds or death from any cause.
Study authors said the findings highlight the 'clinical dilemma' of managing anticoagulant therapy after a GI bleed, which each year affects around 4.5% of patients treated with warfarin.
In the study, 260 out of 442 patients resumed warfarin an average of four days after a GI bleed. Resuming warfarin was found to cut the subsequent risk of thrombosis by 95% and death by 69%.
There were 26 cases of recurrent bleed, one thrombotic event and 15 deaths in the 90 days that followed resumption of treatment.
Among the 182 patients who did not resume warfarin treatment, there were 10 cases of thrombosis and 37 deaths from any cause, although only three of these were attributed to thrombosis.
The researchers concluded: 'Our results provide some guidance regarding optimal timing of warfarin therapy resumption following GI bleed, but clinical judgment remains a critical factor in this difficult decision.'
They said further research would identify the optimal duration of warfarin interruption after a bleed, and the patients for whom a longer stoppage is justified.