A Method to Determine the Optimal Intensity of Oral Anticoagulant Therapy

Rosendaal, F.R.; Cannegieter, Suzanne C.; Meer, F. J. M. Van Der; Briët, E.

doi:10.1055/s-0038-1651587

Cited by 1,809 publications

(1,443 citation statements)

References 6 publications

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“…15 Time in target range for each patient was assessed by the percentage of interpolated INR values within the target range of 2.0-3.0. The anticoagulation control was considered moderate when percentage time of INR in target range was more than 60%, and good when the percentage was 475%.…”

Section: Resultsmentioning

confidence: 99%

“…The incidence of ischaemic stroke, myocardial infarction and bleeding events were reported according to the INR value among patients who were taking warfarin. Incidence rates of ischaemic stroke and different bleeding complications (major and minor bleeding, bleeding requiring hospitalization and intracranial haemorrhage) for each specific level of INR were calculated by applying the following equation: 15 Number of events occurred at an INR level/number of total patientyears spent at the same INR level.…”

Section: Resultsmentioning

confidence: 99%

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Safety and efficacy of oral anticoagulation therapy in Chinese patients with concomitant atrial fibrillation and hypertension

Siu

Yue

et al. 2010

J Hum Hypertens

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Limited evidence is available on the safety and efficacy of anticoagulants in non-valvular atrial fibrillation (AF) patients with concomitant hypertension. We investigated the safety and efficacy of 476 consecutive anticoagulated Chinese outpatients with non-valvular AF and hypertension. Occurrence of ischaemic stroke and major bleeding, and international normalized ratio (INR) values during these events were recorded. There was no significant difference in anticoagulation control between patients with or without hypertension. INRspecific incidence rates of the events were calculated, which showed no excessive risk for ischaemic stroke (2.5 vs 1.6% per year, P ¼ 0.22) or major bleeding (3.9 vs 3.2% per year, P ¼ 0.29) in non-valvular AF patients with or without hypertension. In multivariate analysis, congestive heart failure, smoking and high CHADS2 score were independent predictors for ischaemic stroke, whereas use of antiplatelet agents was an independent predictor for bleeding. It can be noted that hypertension was not associated with ischaemic stroke or major bleeding. Hypertensive patients who achieved target blood pressure control (o130/80 mm Hg) had a lower ischaemic stroke (0.9 vs 3.1% per year, P ¼ 0.01), but similar bleeding risk compared with those not achieving target blood pressure. Our findings demonstrate the effects of hypertension on the outcomes of warfarin therapy; further investigation is needed to clarify whether more aggressive antihypertensive therapy could result in better outcomes in hypertensive patients with non-valvular AF.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Safety and efficacy of oral anticoagulation therapy in Chinese patients with concomitant atrial fibrillation and hypertension

Siu

Yue

et al. 2010

J Hum Hypertens

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“…A software programme was used for the assessment of the quality of anticoagulation by determining the percentage time spent at different INR levels [10]. All overanticoagulation episodes (defined as INR ≥ 6.5) in asymptomatic patients were recorded and treated with 2 mg vitamin K1 per os administration.…”

Section: Methods Patientsmentioning

confidence: 99%

Risk of bleeding in very old atrial fibrillation patients on warfarin: Relationship with ageing and CHADS2 score

Poli

Antonucci

Marcucci

et al. 2007

Thrombosis Research

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Aims: In atrial fibrillation (AF) patients, age z75 years is one of the major risk factors for stroke. However, it is not clear if an upper limit for the indication to OAT exists. Methods and results: For this reason, we performed a prospective study on 290 AF patients on OAT aged z75 years (median age 82 years, total follow-up period 814 pt/ years) followed by our Anticoagulation Clinic. Seventeen major bleeding events were recorded (rate 2.1 × 100 pt/years), 11 of which cerebral (1.35 × 100 pt/years). The occurrence of major bleedings was associated with history of previous TIA or stroke [OR 3.4 (1.1-12.5), p = 0.01] and with diabetes .7) p = 0.01]. We found a trend to a progressive increase in the rate of bleeding risk with the increase of the CHADS 2 score: patients with score 4-6 showed a rate of 3.4 × 100 pt/years with respect to 1.5 × 100 pt/years of patients with lower score. Number Needed to Harm (NNH) was calculated in relation to different classes of age (75-89, 80-84, z85 years) and to CHADS 2 score. For patients in CHADS 2 score 1-3 NNH remained stable across the different age classes. Instead for patients in CHADS 2 score 4-6, NNH varied among the 3 groups of ages, reaching a value of 10 in patients ≥ 85 years. Conclusion: Our data suggest that: 1) in AF patients older than 75 years with CHADS 2 score 1-3 the risk of bleeding is low, 2) in AF patients N85 years with CHADS 2 4-6 the risk of bleeding is high so that the use of OAT should be highly individualised.

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“…The likelihood of patients changing from one health state to another depended on their time spent below, in and above therapeutic range. 15 Age-specific rates for natural death were derived from life tables from Statistics Canada. 16 At baseline, all patients were assumed to be in the "no events" state.…”

Section: Model Overviewmentioning

confidence: 99%

Cost-effectiveness of self-managed versus physician-managed oral anticoagulation therapy

Regier

Sunderji²,

Lynd³

et al. 2006

Canadian Medical Association Journal

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ResearchL ong-term oral anticoagulation therapy with vitamin K antagonists is prescribed as prophylaxis against strokes and other embolic events in patients with atrial fibrillation or a mechanical heart valve. 1,2 Warfarin therapy, however, is complicated by the variability of its biologic effect, its narrow therapeutic index, and the associated thrombotic or hemorrhagic events in the event of over-or underanticoagulation. 2 It has been shown that improved anticoagulant control can be achieved through frequent monitoring of the international normalized ratio (INR), resulting in improved health outcomes. 3 Monitoring the INR and managing warfarin dosing by a primary care physician is the current clinical standard of practice in Canada. 4 Physician management requires patients to visit a laboratory regularly for INR testing. The laboratory reports the INR to the physician, who subsequently contacts the patient with any required change in dosage. An alternative strategy is patient self-management. Self-management entails the measurement of the INR by the patient using a pointof-care device and, when necessary, self-adjustment of the warfarin dose using a nomogram. 4 Several published trials have compared self-management with physician management or management in an anticoagulation clinic. 4-13 It has been found that patients who self-manage check their INR more frequently and are able to maintain a greater proportion of INRs within the therapeutic range compared with those whose therapy is monitored by a physician or in an anticoagulation clinic. [11][12][13] The results of a recent meta-analysis showed a significant reduction in thromboembolic events (odds ratio [OR] 0.45), major hemorrhagic events (OR 0.65) and all-cause mortality (OR 0.61) for those using a self-management or self-test strategy. 14 The results also showed that self-management compared with self-testing alone reduces the occurrence of thromboembolic events (OR 0.27) and death (OR 0.37). 14 These results, together with the greater initial costs of educating patients to self-manage and of the pointof-care device itself, provide the impetus for a formal costeffectiveness analysis.The objective of this study was to evaluate the incremental cost and health benefits of self-managed versus physicianmanaged chronic oral anticoagulation therapy from the perspective of the Canadian health care payer. A Bayesian approach was adopted to facilitate the incorporation of prior knowledge of transition probabilities and for probabilistic sensitivity analysis. Cost-effectiveness of self-managed versus physician-managed oral anticoagulation therapy Background: Patient self-management of long-term oral anticoagulation therapy is an effective strategy in a number of clinical situations, but it is currently not a funded option in the Canadian health care system. We sought to compare the incremental cost and health benefits of self-management with those of physician management from the perspective of the Canadian health care payer over a 5-year period.

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A Method to Determine the Optimal Intensity of Oral Anticoagulant Therapy

Cited by 1,809 publications

References 6 publications

Safety and efficacy of oral anticoagulation therapy in Chinese patients with concomitant atrial fibrillation and hypertension

Safety and efficacy of oral anticoagulation therapy in Chinese patients with concomitant atrial fibrillation and hypertension

Risk of bleeding in very old atrial fibrillation patients on warfarin: Relationship with ageing and CHADS2 score

Cost-effectiveness of self-managed versus physician-managed oral anticoagulation therapy

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