Self-monitoring of oral anticoagulation: systematic review and meta-analysis of individual patient data.

BACKGROUND: Uptake of self-testing and self-management of oral anticoagulation [corrected] has remained inconsistent, despite good evidence of their effectiveness. To clarify the value of self-monitoring of oral anticoagulation, we did a meta-analysis of individual patient data addressing several important gaps in the evidence, including an estimate of the effect on time to death, first major haemorrhage, and thromboembolism. METHODS: We searched Ovid versions of Embase (1980-2009) and Medline (1966-2009), limiting searches to randomised trials with a maximally sensitive strategy. We approached all authors of included trials and requested individual patient data: primary outcomes were time to death, first major haemorrhage, and first thromboembolic event. We did prespecified subgroup analyses according to age, type of control-group care (anticoagulation-clinic care vs primary care), self-testing alone versus self-management, and sex. We analysed patients with mechanical heart valves or atrial fibrillation separately. We used a random-effect model method to calculate pooled hazard ratios and did tests for interaction and heterogeneity, and calculated a time-specific number needed to treat. FINDINGS: Of 1357 abstracts, we included 11 trials with data for 6417 participants and 12,800 person-years of follow-up. We reported a significant reduction in thromboembolic events in the self-monitoring group (hazard ratio 0·51; 95% CI 0·31-0·85) but not for major haemorrhagic events (0·88, 0·74-1·06) or death (0·82, 0·62-1·09). Participants younger than 55 years showed a striking reduction in thrombotic events (hazard ratio 0·33, 95% CI 0·17-0·66), as did participants with mechanical heart valve (0·52, 0·35-0·77). Analysis of major outcomes in the very elderly (age ≥85 years, n=99) showed no significant adverse effects of the intervention for all outcomes. INTERPRETATION: Our analysis showed that self-monitoring and self-management of oral coagulation is a safe option for suitable patients of all ages. Patients should also be offered the option to self-manage their disease with suitable health-care support as back-up. FUNDING: UK National Institute for Health Research (NIHR) Technology Assessment Programme, UK NIHR National School for Primary Care Research.

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. METHODS: We developed a Bayesian Markov model comparing the costs and quality-adjusted life years (QALYs) accrued to patients receiving oral anticoagulation therapy through self-management or physician management for atrial fibrillation or for a mechanical heart valve. Five health states were defined: no events, minor hemorrhagic events, major hemorrhagic events, thrombotic events and death. Data from published literature were used for transition probabilities. Canadian 2003 costs were used, and utility estimates were obtained from various published sources. RESULTS: Self-management resulted in 3.50 fewer thrombotic events, 0.78 fewer major hemorrhagic events and 0.12 fewer deaths per 100 patients than physician management. The average discounted incremental cost of self-management over physician management was found to be 989 dollars (95% confidence interval [CI] 310 dollars-1655 dollars) per patient and the incremental QALYs gained was 0.07 (95% CI 0.06-0.08). The cost-effectiveness of self-management was 14,129 dollars per QALY gained. There was a 95% chance that self-management would be cost-effective at a willingness to pay of 23,800 dollars per QALY. Results were robust in probabilistic and deterministic sensitivity analyses. INTERPRETATION: This model suggests that self-management is a cost-effective strategy for those receiving long-term oral anticoagulation therapy for atrial fibrillation or for a mechanical heart valve.

Clinical impact of point-of-care vs laboratory measurement of anticoagulation.

Patients using anticoagulation point-of-care (POC) monitors are advised to periodically test these systems against laboratory methods to monitor performance. The international normalized ratio (INR), however, can vary between test systems owing to different instrument-reagent combinations. In a randomized study evaluating warfarin self-management, we compared INR measured by patients on a POC monitor (ProTime, International Technidyne Corporation, Edison, NJ) with those obtained at a hospital laboratory within 1 hour Ninety-one paired INR determinations from 55 patients met inclusion criteria. Clinical agreement in which POC and laboratory INR were within or outside the target INR range occurred in 56 (62%) of 91 cases (kappa = 0.35). The mean (SD) difference between POC and laboratory INR was 0.44 (0.61). Six pairs differed by 1 or more INR units, 3 at study initiation resulting in POC monitor replacement. The accuracy of INR self-testing with ProTime was acceptable. The small failure rate of INR agreement might be clinically important, suggesting the need for external quality control systems.

Patient self-management of oral anticoagulation: a review.

Self-management of warfarin is an evolving strategy that involves self-testing of the international normalized ratio using a point-of-care device and adjustment of warfarin dosage by the patient using a dosage-adjustment nomogram. There is mounting evidence from clinical trials that self-management of warfarin is feasible and is potentially superior to conventional management by physicians in maintaining anticoagulation control. Some advantages of this strategy are convenience, rapid availability of results with timely adjustment of warfarin dosages, increased patient responsibility for their own therapy and enhanced patient satisfaction. Access to point-of-care instruments may prove particularly valuable for patients without ready access to laboratories, frequent travellers who are often away from their home laboratory for extended periods of time and those who experience difficulties with venous blood collection. Self-management may be considered for carefully selected and properly trained individuals. Information from several ongoing clinical trials will aid in determining the value of anticoagulation self-management with respect to complication rates and economic outcomes.

Switching from abciximab to eptifibatide for percutaneous coronary interventions: a local analysis (SWAP study).

BACKGROUND: Glycoprotein IIb/IIIa inhibitors (GPI) are recommended as adjunctive therapy with percutaneous coronary interventions (PCI). Before October 2000, abciximab (AB) was the only GPI available at the authors' institution. Eptifibatide (EP) was added to the formulary in October 2000 and became the preferred agent primarily due to lower cost. OBJECTIVES: To describe the impact of switching from AB to EP in the cardiac catheterization laboratory and compare clinical and practice-related outcomes of these agents following PCI. METHODS: Retrospective chart review was performed on patients who received PCI for all indications except as primary therapy for ST-segment elevation myocardial infarction. The AB group consisted of all consecutive patients within the six months preceding formulary addition of EP in October 2000. A matching number of consecutive patients following this date were included in the EP group. RESULTS: A total of 160 patients were included (80 per group). Use of adjunctive GPI increased from 11% to 25% of PCI within three months of adding EP to the formulary (P<0.001). The composite of in-hospital death, myocardial infarction, recurrent ischemia and repeat revascularization occurred in 12.5% of EP- and 2.5% of AB-treated patients (P<0.025). Minor bleeding was more common in the EP group than in the AB group at 8.8% and 2.5%, respectively (not significant). Premature GPI discontinuation was significantly more common in the EP group (46.3% versus 7.5%, P<0.001). The mean +/- SD length of stay post-PCI was 44.4+/-51.2 h for EP and 25.1+/-12.3 h for AB (P<0.0001). CONCLUSIONS: Adjunctive GPI usage more than doubled following the introduction of EP to the formulary. The present results suggest that EP may be associated with inferior clinical outcomes compared with AB for PCI patients.

A randomized trial of patient self-managed versus physician-managed oral anticoagulation.

BACKGROUND: Self-management (SM) of warfarin by patients is an attractive strategy, particularly if it improves anticoagulation control and can be done safely under minimal physician supervision. OBJECTIVE: To compare the effect of SM with physician-management (PM) on the maintenance of therapeutic anticoagulation. METHODS: A randomized, open-label eight-month trial was performed. Patients 18 years of age and older were eligible if they were receiving warfarin for at least one month before enrolment and required anticoagulation for at least one year to a target international normalized ratio (INR) of 2.0 to 3.0 or 2.5 to 3.5. Exclusion criteria were a known hypercoaguable disorder, mental incompetence, a language barrier or an inability to attend training sessions. Patients randomly assigned to SM tested their INR using a point-of-care device (Pro Time Microcogulation System, International Technidyne Corporation, USA) and adjusted their warfarin doses using a nomogram. Patients randomly assigned to PM received usual care from their general practitioner. The primary outcome was to demonstrate 20% improvement in anticoagulation control by SM. RESULTS: One hundred forty patients were randomly assigned (70 per group). Thirteen patients dropped out of SM early due to an inability to self-manage. Based on intention-to-treat analysis, there was no difference in the proportion of INR in range (SM 64.8% versus PM 58.7%, P=0.23) or time in target range (SM 71.8% versus PM 63.2%, P=0.14). Patients managing their own therapy spent less time below the therapeutic range (15.0% versus 27.3%, P=0.04). There were three major complications of thrombosis or bleeding, all occurring in the PM arm. All patients who completed SM preferred to continue with that strategy. CONCLUSIONS: SM was not significantly better than PM in maintaining therapeutic anticoagulation. SM was feasible and appeared safe in the present study population.

Glycoprotein IIb/IIIa inhibitors in patients with end-stage renal disease.

OBJECTIVE: To determine whether glycoprotein IIb/IIIa inhibitors (GPIs) are effective and safe as adjunctive therapy for percutaneous coronary intervention (PCI) in patients with end-stage renal disease (ESRD). DATA SOURCES: MEDLINE (1966-June 2004), EMBASE (1980-June 2004), and International Pharmaceutical Abstracts (1970-June 2004) were searched, in addition to a manual bibliographic search. DATA SYNTHESIS: Even though GPIs have an established role as adjunctive therapy in PCI, little is known about their use in patients with ESRD. We found 3 reports describing experience with abciximab in this population. Based on the limited information from registries and a retrospective chart review, it is difficult to draw definitive conclusions about the utility of GPIs in ESRD. The decision to use abciximab in this population must be made on an individual case basis. CONCLUSIONS: Studies are needed to evaluate the benefit versus risk of GPI therapy in ESRD.

Evaluation of captopril for the management of hypertension in autonomic dysreflexia: a pilot study.

OBJECTIVE: To evaluate the efficacy of captopril for management of hypertensive urgencies in autonomic dysreflexia. DESIGN: A 1-year, prospective, open-label pilot study. SETTING: Rehabilitation hospital. PATIENTS: Twenty-six consecutive patients older than 15 years with spinal cord injury above T6. INTERVENTIONS: During an autonomic dysreflexia episode, captopril 25mg was administered sublingually if systolic blood pressure (SBP) was at or above 150mmHg despite the use of nondrug measures. If SBP remained elevated 30 minutes after captopril administration, 1 dose of immediate-release nifedipine 5mg was given as rescue by the bite and swallow method and repeated, if necessary, in 15 minutes. MAIN OUTCOME MEASURE: SBP 30 minutes after captopril administration at initial autonomic dysreflexia episode. RESULTS: A total of 33 autonomic dysreflexia episodes were documented, of which 18 episodes in 5 patients were treated with drug therapy. Captopril alone was effective in 4 of 5 initial episodes (80%). Mean SBPs at baseline and 30 minutes after captopril were 178+/-18mmHg and 133+/-28mmHg, respectively. There were no cases of reactive hypotension. The addition of nifedipine successfully reduced SBP in the remaining patient. Of the combined 18 initial and repeat autonomic dysreflexia episodes, 94% were successfully treated with our protocol. CONCLUSION: Captopril appears to be safe and effective for autonomic dysreflexia management.