Development and validation of a bleeding risk prediction score for patients with mitral valve stenosis and atrial fibrillation or mechanical heart valves receiving long-term warfarin therapy.

AIMS: This study aimed to develop and validate a new bleeding risk score to predict warfarin-associated major bleeding for patients with mitral valve stenosis with atrial fibrillation (MSAF) or mechanical heart valves (MHV). METHODS: A multicentre, retrospective cohort study was conducted at 3 hospitals in Thailand. Adult patients with MSAF or MHV receiving warfarin for ≥3 months during 2011-2015 were identified. Data collection and case validation were performed electronically and manually. Potential variables were screened using the least absolute shrinkage and selection operator. Multivariate logistic regression analysis using stepwise backward selection was used to construct a risk score. Predictive discrimination of the score was evaluated using the C-statistic. Calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test. RESULTS: There were 1287 patients (3903.41 patient-year of follow-up), with 192 experiencing bleeding (4.92 event/100 patient-year) in the derivation cohort. A new bleeding risk score termed, the HEARTS-60 + 3 score (hypertension/history of bleeding; external factors, e.g., alcohol/drugs [aspirin or nonsteroidal anti-inflammatory drugs]; anaemia/hypoalbuminaemia; renal/hepatic insufficiency; time in therapeutic range of <60%; stroke; age ≥60 y; target international normalized ratio of 3.0 [2.5-3.5]), was developed and showed good predictive performance (C-statistic [95% confidence interval] of 0.88 [0.85-0.91]). In the external validation cohort of 832 patients (2018.45 patient-year with a bleeding rate of 4.31 event/100 patient-year), the HEARTS-60 + 3 score showed a good predictive performance with a C-statistic (95% confidence interval) of 0.84 (0.81-0.89). CONCLUSION: The HEARTS-60 + 3 score shows a potential as a bleeding risk prediction score in MSAF or MHV patients.

Anticoagulation control of pharmacist-managed collaborative care versus usual care in Thailand.

OBJECTIVE: There has been a lack of evidence of the effects of pharmacist-managed warfarin therapy (PMWT) in developing countries (e.g. Southeast Asian countries) where the patients' characteristics, genetic make-up, clinical practice and healthcare system are different from the Western world. This study aimed to compare the anticoagulation control and clinical outcomes associated with warfarin therapy provided by PMWT to usual care (UC) in the Thai population. SETTING: A 1,000-bed tertiary-care hospital in Nakornratchasima province of Thailand. METHOD: A quasi-experimental study comparing PMWT and UC in patients receiving long-term warfarin therapy. For PMWT group, clinical pharmacists optimised the warfarin therapy and suggested recommendations (e.g. dose adjustment, safer alternative drugs, and follow-up time) to physicians. The UC group received the standard care. MAIN OUTCOME MEASURE: Time in therapeutic range (TTR), both actual- and expanded-TTR, bleeding and thromboembolic complications, and physician' acceptance of pharmacist suggestions. RESULTS: Of 433 patients enrolled, 220 and 213 were in the PMWT and UC groups respectively. At baseline, patient's characteristics of both groups were comparable. At the end of follow-up period, patients in the PMWT group had significantly higher actual-TTR (48.3% vs. 40.1%; P < 0.001) and expanded-TTR (62.7% vs. 53.9%; P < 0.001) compared to those in the UC group. Rates of major bleeding were 4.4 vs 4.5 events per 100 person-years for the PMWT and UC groups, respectively. Pharmacists performed 284 interventions with an acceptance rate of 80.3% from physicians. CONCLUSION: Pharmacist-managed warfarin therapy resulted in a significantly better anticoagulation control. This study showed that a collaborative approach in anticoagulation management can be successfully implemented in a developing country. Implementation of such care model in other developing countries should be considered.