Does previous warfarin treatment effect complications and outcome in hospitalised patients with community-acquired pneumonia?

Aim :To assess whether established warfarin treatment affects outcome in hospitalised patients with community-acquired pneumonia(CAP). Methodology:This retrospective study included adults with confirmed CAP clinically and on CXR. A total of 30 patients on warfarin were compared to 30 controls (not on warfarin). These were matched for time of presentation, age (+/-2 years), gender and co-morbidities. The co-morbidities included diabetes mellitus, ischaemic heart disease, congestive cardiac failure, chronic lung disease, chronic kidney and liver disease and immunosuppression. Outcome was assessed in terms of CURB65 score, complications (empyema, lung abscess, pleural effusion, respiratory failure, sepsis), length of hospital stay and 30-day mortality. Results:A total of 60 CAP patients (30 on warfarin, 30 controls) were included with a mean age of 78.4+/-8.7 in the warfarin group and 78.9+/-8.4 in the control group. Patients on anticoagulation had higher CURB65 scores (3 to 5) on admission at 27% compared to the 17% of the control group. The patients on warfarin had less complications (10 warfarin versus 17 control), decreased hospital stay (median 6 days versus 7 days, p =0.84), decreased mortality as in-patients and at 30 days (7 on warfarin versus 11 controls). Conclusion:Hospitalised CAP patients on established home warfarin treatment, despite presenting with more severe pneumonia on CURB65 score, had less pneumonia complications, decreased hospital stay and 30-day mortality. A large randomised control trial may help establish whether inpatient anticoagulation will help improve outcome in hospitalised patients with this common respiratory condition.