Karen Shalansky

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.

Comparison of a Weight-Based Heparin Nomogram with Traditional Heparin Dosing to Achieve Therapeutic Anticoagulation

Optimum anticoagulation with heparin within the first 24 hours of a thrombotic event is critical in preventing a recurrence. We believed that traditional nonweight‐based heparin dosing at our institution resulted in delayed anticoagulation. A weight‐based heparin nomogram was therefore created and compared to traditional heparin dosing in patients with a diagnosis of acute deep vein thrombosis or pulmonary embolism. Fifty historical control patients were compared to 50 consecutive patients treated prospectively using the weight‐based nomogram. The primary outcome assessed was time to achieve therapeutic anticoagulation, defined as an activated partial thromboplastin time (aPTT) of 46–70 seconds (1.5–2.5 times the control aPTT). The weight‐based nomogram achieved an aPTT above the therapeutic threshold more rapidly than the control group (10.7 hrs nomogram vs 33.3 hrs control group, p < 0.004). Similarly, the proportion of patients who exceeded the therapeutic threshold at the first aPTT measurement, at 24 hours, and at 48 hours was significantly higher in the nomogram group. There was no difference in the frequency of bleeding complications or recurrent thrombotic events between the two groups. The initial nomogram was revised for patients weighing more than 80 kg owing to a greater frequency of excessive anticoagulation in these patients. Subsequent analysis of 29 patients using the modified nomogram revealed sustained efficacy and a reduced number of supratherapeutic aPTTs. We concluded that a weight‐based heparin nomogram is superior to traditional therapy in achieving rapid therapeutic anticoagulation without an increase in adverse outcomes.

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.

Outpatient Self-Management of Warfarin Therapy: A Pilot Study

Self‐testing and adjusting of warfarin dosages by patients is an evolving strategy for management of oral anticoagulation. We performed this open, prospective, 3‐month pilot study to assess the feasibility of conducting a large, randomized trial comparing self‐managed with physician‐managed anticoagulation. Ten competent patients with planned anticoagulation for at least 3 months were provided education on warfarin therapy and trained to use an individualized warfarin nomogram. International normalized ratios (INRs) were determined weekly for 12 weeks and reported with warfarin dosages to the investigator for the first 8 weeks only. Eight patients elected to use a home monitor (ProTime) to measure INRs. Patients maintained 76.5% (range 50–91.7%) of INRs within the target range. In 119 dosage adjustment decisions, there were only 3 errors (2.5%). No bleeding or thrombotic complications occurred. To confirm concordance, initial and final INRs were measured concurrently by the ProTime monitor and laboratory. The mean absolute difference for 16 paired INR determinations was 0.33 (range 0.02–0.9). All patients expressed satisfaction and a desire to continue with self‐management. This pilot study provides support for conducting a prospective, large‐scale, randomized trial.

Management of Anemia in Erythropoietin-Resistant Hemodialysis Patients

BACKGROUND: Human recombinant erythropoietin (rHuEPO) is administered to patients with end-stage renal disease for treatment of anemia. OBJECTIVE: To assess the impact of a structured team approach to anemia management in rHuEPO-resistant hemodialysis patients. METHODS: This was an 8-month prospective, open-label, quality-improvement initiative. Nineteen patients in a 160-bed hemodialysis unit receiving rHuEPO doses >300 units/kg/wk were defined as rHuEPO-resistant. Hemoglobin (Hb), iron indices, parathyroid hormone, folate, B12, aluminum, and reticulocyte counts were determined at baseline. The former 3 parameters were followed every 6, 12, and 26 weeks, respectively. Vascular access flow was regularly assessed via ultrasonic dilution methodology. Target Hb was 12.0–13.5 g/dL. All factors potentially contributing to rHuEPO resistance were assessed and, if possible, treated every 6 weeks by a dedicated anemia team. Downward rHuEPO dosage adjustments of 12.5–25% to the closest 1000 units were considered if underlying causes of rHuEPO resistance could not be identified or reversed, or if the Hb rose beyond the target level. RESULTS: Dysfunctional vascular access and iron deficiency were the predominant treatable factors associated with rHuEPO resistance. At 8 months, mean rHuEPO dosage decreased significantly from 469 to 319 units/kg/wk (p < 0.001) and mean Hb increased significantly from 10.6 to 11.6 g/dL (p = 0.023). Eight-month cost savings approximated

Ampicillin-Induced Maculopapular versus Urticarial Rash

45 000 (CDN

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

). CONCLUSIONS: A structured team approach to the management of rHuEPO-resistant patients was successful in significantly lowering rHuEPO dosage with improvement in serum Hb at a substantial cost savings.

Patient self-management of oral anticoagulation: A review

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