Impact of Anticoagulation Clinic Intervention on Patient Centred Outcomes in a Tertiary Care Hospital

Abstract

Introduction: Vitamin K Antagonists (VKAs) have been in use for more than 50 years. They have remained as mainstay therapy in the prevention of thromboembolic events in atrial fibrillation, mechanical heart valves and venous thromboembolism. Despite many years of clinical experience with VKAs, the quality of anticoagulation achieved in routine clinical practice is suboptimal. Aim: To study the effects of structured Anticoagulation Clinic (ACC) interventions on patient centred outcomes in subjects taking VKAs. Materials and Methods: A retrospective study was conducted among patients taking VKAs enrolled in ACC. A total of 169 patients receiving VKAs for at least six months with 4 INR (International Normalised Ratio) values and completed 12 months of follow-up were analysed. Anticoagulation related quality measures like Time in the Therapeutic Range (TTR), Percentage of International Normalised Ratios in the therapeutic Range (PINRR) and clinical outcomes like stroke, systemic embolic events and bleeding was analysed at the time of enrolment and compared with those during ACC care. Results: Among 352 patients enrolled in ACC, 169 patients were eligible for analysis. The mean age of the study population was 55.62±13.77 years. Atrial fibrillation (59%) was the most common indication for VKA therapy. Hypertension (66.3%) was the most common co-morbidity. Mean TTRs were significantly higher in the ACC care when compared with the pre-ACC care at 12 months follow-up (77.58±8.85% vs 51.01±16.7%, p<0.0001). There was a significant improvement in TTRs as early as three months of ACC intervention (73.18±13.56%). At the time of enrolment, 21.9% of patients had individual TTRs (i-TTR) >70% which increased to 70.4% at 12 months of follow-up. INR testing was done more frequently in ACC care. Adverse clinical events were higher in pre-ACC care than ACC care (4.7% vs 2.4%, p>0.05). Major bleeding and thromboembolic events were higher in pre-ACC care than ACC care (1.8% vs. 0.6% and 2.4% vs. 0.6% respectively). Conclusion: ACC services helps in achieving better quality of anticoagulation control as measured by time in therapeutic range translating into better clinical outcomes.