AREAS COVERED: A review of articles that evaluated the cost of prescribing conventional (e.g. vitamin K antagonists) and NOACs (e.g. direct thrombin inhibitors and direct factor Xa inhibitors) in older adults.
EXPERT COMMENTARY: While the use of NOACs significantly increases the cost of the initial treatment for thromboembolic disorders, they are still considered cost-effective relative to warfarin since they offer reduced risk of intracranial haemorrhagic events. The optimum anticoagulation with warfarin can be achieved by providing specialised care; clinics managed by pharmacists have been shown to be cost-effective relative to usual care. There are suggestions that genotyping the CYP2C9 and VKORC1 genes is useful for determining a more appropriate initial dose and thereby increasing the effectiveness and safety of warfarin.
METHODS: A retrospective cohort study of 200 patients on dabigatran and warfarin from January 2009 till September 2016 was carried out. Data were collected for 100 patients on dabigatran and 100 patients on warfarin.
RESULTS: The mean follow-up period was 340.7±322.3 days for dabigatran group and 410.5±321.2 days for warfarin group. The mean time in therapeutic range (TTR) was 52±18.7%. The mean CHA2DS2 -VASc score for dabigatran group was 4.4±1.1 while 5.0±1.5 for warfarin group. None in dabigatran group experienced ischemic stroke compared to one patient in warfarin group (p=0.316). There was one patient in dabigatran group suffered from ICH compared to none in warfarin group (p=0.316). Four patients in warfarin group experienced minor bleeding, while none from dabigatran group (p=0.043).
CONCLUSION: Overall bleeding events were significantly lower in dabigatran group compared to warfarin group. In the presence of suboptimal TTR rates and inconveniences with warfarin therapy, non-vitamin-K antagonist oral anticoagulants (NOAC) are the preferred agents for stroke prevention in elderly Asian patients for nonvalvular AF.
METHODS: In this non-interventional study involving 49 sites across five countries in Southeast Asia and South Korea, 379 stable NVAF patients who switched from VKA therapy to dabigatran during routine clinical practice were recruited and followed up for 6 months. Treatment convenience and satisfaction were evaluated using Perception on Anticoagulant Treatment Questionnaire-2 (PACT-Q2). Through post hoc analysis, factors associated with improved treatment convenience scores at visit 2 were described.
RESULTS: Treatment convenience and satisfaction significantly improved after switching from VKAs to dabigatran at visit 2 and visit 3 (convenience: p<0.001 each vs baseline; satisfaction: p=0.0174 (visit 2), p=0.0004 (visit 3) compared with baseline). Factors predictive of higher (>80th percentile) response on treatment convenience were female sex, younger age (<75 years), higher baseline stroke risk, higher creatinine clearance and absence of concomitant hypertension, stroke or gastrointestinal diseases.
CONCLUSION: Dabigatran was associated with a significant improvement in treatment convenience and satisfaction after switching from VKAs when used for stroke prevention in NVAF patients from Southeast Asia and South Korea.
METHODS: This is a prospective case-control study. We registered 80 patients and 60 healthy controls from Jan 2009 to Dec 2013. Complete blood counts, prothrombin time, activated partial thromboplastin time, protein C, protein S, antithrombin, serum ferritin, liver enzymes; HbsAg and Anti- HCV were evaluated.
RESULT: There were 42 males and 38 females with mean age of 12.30±5.50 years. The mean protein C, protein S and antithrombin in patients and control were 58.25±22.5 versus 110.67±22.60, 67.90±19.58 versus 98.70±21.54 and 89.73±18.09 versus 104.0±10.98 (p<0.001) respectively. Protein C was predominantly deficient in 65% followed by protein S and antithrombin in 35% and 20% respectively. Protein C deficiency divulged positive correlation with protein S deficiency (p = 0.035) and antithrombin deficiency with hemoglobin of ≤8gm% (p<0.0025). No significant correlation of prothrombotic markers was established with maternal characteristics, hepatic dysfunction, hepatitis and serum ferritin.
CONCLUSION: Substantial decrement in prothrombotic markers, primarily protein C, may be implicated in elevated thrombosis; however follow-up data is required to establish definitive thromboembolic events.
PATIENTS AND METHODS: This was a multinational, multicentre, non-interventional study involving 49 sites across 5 countries in South East Asia and South Korea where 934 patients newly diagnosed with NVAF were initiated on either dabigatran (N=591) or VKA (N=343). Data were collected at baseline and over two follow-up visits across 6 months. Treatment satisfaction and patient convenience were evaluated using the Perception on Anticoagulant Treatment Questionnaire-2 (PACT-Q2).
RESULTS: The mean age of the patients was 65.9±10.4 years, and 64.2% were male. Mean CHA2DS2-VASc score was 2.4±1.5, and mean HAS-BLED score was 1.2±0.9. At baseline, patients initiated on dabigatran had higher stroke risk, bleeding risk, creatinine clearance and proportion of patients with concomitant illnesses compared with patients initiated on VKAs. Treatment convenience was perceived to be significantly better with dabigatran versus VKAs at visits 2 and 3 (p=0.0423 and 0.0287, respectively). Treatment satisfaction was significantly better with dabigatran compared with VKAs at visit 3 (p=0.0300).
CONCLUSION: In this study, dabigatran is associated with better patient perception in terms of treatment convenience and satisfaction compared with VKAs when used for stroke prevention in newly diagnosed NVAF patients from South East Asia and South Korea.
TRIAL REGISTRATION NUMBER: NCT02849509.
PLAIN LANGUAGE SUMMARY: Patient satisfaction with dabigatran versus VKAs in South East Asia. Patients with atrial fibrillation are at high risk of stroke and require anticoagulants for stroke prevention. Two such anticoagulants are dabigatran and VKAs. We wanted to compare the extent of satisfaction and treatment convenience among newly diagnosed patients with atrial fibrillation from the South East Asian region when they were given either dabigatran or VKAs. Consenting patients filled out a standardised questionnaire called the PACT-Q2 over three visits after they were started on either dabigatran (591 patients) or VKAs (343 patients). We found that satisfaction and convenience were significantly higher when patients received dabigatran than when they received VKAs.
METHODS: This retrospective cohort study includes adult patients of two tertiary hospitals in Malaysia. Potential study subjects were identified using pharmacy supply database or novel oral anticoagulant (NOAC) registry. Demographics, clinical data and laboratory test results were extracted from the medical records of the patients or electronic databases. The main outcome measure is the occurrence of a bleeding event. Bleeding events were classified into major bleeding, clinically relevant non-major bleeding, or minor bleeding, according to the International Society on Thrombosis and Haemostasis criteria. We consider clinically relevant non-major bleeding events or major bleeding events as clinically relevant bleeding events. An occurrence of any bleeding event was recorded from the initiation of NOAC therapy until the death of a patient, or the date of permanent discontinuation of NOAC use, or the last day of data collection. The predicted rate of dabigatran-induced bleeding events per 100 patient-years was estimated.
RESULTS: During a median follow-up period of 18 months, 73 patients experienced 90 bleeding events. Among these patients, 25 including 4 fatal cases, experienced major bleeding events. The predicted rate per 100 patient-years of follow-up of any bleeding events was 9.0 [95% CI 6.9 to 11.1]; clinically relevant bleeding events 6.0 [95% CI 4.8 to 8.3], and major bleeding events 3.0 [95% CI 1.9 to 4.2]. The independent risk factor for clinically relevant bleeding events is prior bleeding. While prior bleeding or congestive heart failure is linked with major bleeding events.
CONCLUSIONS: The predicted rate for dabigatran-induced major bleeding episodes is low but these adverse events carry a high fatality risk. Preventive measures should target older patients who have prior bleeding or congestive heart failure. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.