Paul van Nguyen

A COMPARISON OF THREE MONTHS OF ANTICOAGULATION WITH EXTENDED ANTICOAGULATION FOR A FIRST EPISODE OF IDIOPATHIC VENOUS THROMBOEMBOLISM

BACKGROUND Patients who have a first episode of venous thromboembolism in the absence of known risk factors for thrombosis (idiopathic thrombosis) are often treated with anticoagulant therapy for three months. Such patients may benefit from longer treatment, however, because they appear to have an increased risk of recurrence after anticoagulant therapy is stopped. METHODS In this double-blind study, we randomly assigned patients who had completed 3 months of anticoagulant therapy for a first episode of idiopathic venous thromboembolism to continue receiving warfarin, with the dose adjusted to achieve an international normalized ratio of 2.0 to 3.0, or to receive placebo for a further 24 months. Our goal was to determine the effects of extended anticoagulant therapy on rates of recurrent symptomatic venous thromboembolism and bleeding. RESULTS A prespecified interim analysis of efficacy led to the early termination of the trial after 162 patients had been enrolled and followed for an average of 10 months. Of 83 patients assigned to continue to receive placebo, 17 had a recurrent episode of venous thromboembolism (27.4 percent per patient-year), as compared with 1 of 79 patients assigned to receive warfarin (1.3 percent per patient-year, P<0.001). Warfarin resulted in a 95 percent reduction in the risk of recurrent venous thromboembolism (95 percent confidence interval, 63 to 99 percent). Three patients assigned to the warfarin group had nonfatal major bleeding (two had gastrointestinal bleeding and one genitourinary bleeding), as compared with none of those assigned to the placebo group (3.8 vs. 0 percent per patient-year, P=0.09). CONCLUSIONS Patients with a first episode of idiopathic venous thromboembolism should be treated with anticoagulant agents for longer than three months.

Influence of thrombophilia on risk of recurrent venous thromboembolism while on warfarin: results from a randomized trial

We sought to determine whether thrombophilic defects increase recurrent venous thromboembolism (VTE) during warfarin therapy. Six hundred sixty-one patients with unprovoked VTE who were randomized to extended low-intensity (international normalized ratio [INR], 1.5-1.9) or conventional-intensity (INR, 2.0-3.0) anticoagulant therapy were tested for thrombophilia and followed for a mean of 2.3 years. One or more thrombophilic defects were present in 42% of patients. The overall rate of recurrent VTE was 0.9% per patient-year. Recurrent VTE was not increased in the presence of factor V Leiden (hazard ratio [HR], 0.7; 95% CI, 0.2-2.6); the 20210G>A prothrombin gene mutation (HR, 0); antithrombin deficiency (HR, 0); elevated factor VIII (HR, 0.7; 95% CI, 0.1-5.4); elevated factor XI (HR, 0.7; 95% CI, 0.1-5.0), or elevated homocysteine (HR, 0.7; 95% CI, 0.1-5.3), but showed a trend to an increase with an antiphospholipid antibody (HR, 2.9; 95% CI, 0.8-10.5). Compared with patients with no thrombophilic defects, the rate of recurrence was not increased in the presence of one (HR, 0.7; 95% CI, 0.2-2.3) or more than one (HR, 0.7; 95% CI, 0.2-3.4) defect. We conclude that single or multiple thrombophilic defects are not associated with a higher risk of recurrent VTE during warfarin therapy.

Calcium, phosphoinositide, and 1,2-diacylglycerol responses of blood vessels of deoxycorticosterone acetate-salt hypertensive rats to endothelin-1.

In previous studies a decreased responsiveness to endothelin-1 (ET-1) of conduit arteries and resistance vessels of deoxycorticosterone acetate (DOCA)-salt hypertensive rats was found in comparison with uninephrectomized controls. Decreased isometric force, number of receptors, and inositol phosphate accumulation were reported in the DOCA-salt animals. In the present study effects of ET-1 on cytosolic free calcium, inositol phosphates, and 1,2-diacylglycerol were investigated in blood vessels of DOCA-salt hypertensive rats. Basal cytosolic free calcium, measured with the fluorescent dye fura-2, was 201±41 nmol/l in mesenteric arteries of DOCA-salt rats and 45±9 nmol/l in uninephrectomized controls (p < 0.01). The maximal response of cytosolic free calcium (to 30 nmol/l ET-1) was 176±22% of the basal value for DOCA-salt and 242±6% for uninephrectomized rats (p < 0.05). The concentration giving 50% of the maximum response was 9.0 and 6.5 nmol/l for DOCA-salt rats and controls, respectively. Inositol phosphate production after stimulation with 100 nmol/l ET-1 in the presence of LiCl was lower by at least 30% (p < 0.01) in both aorta and mesenteric arteries of DOCA-salt hypertensive versus control rats. Basal levels of diacylglycerol in aorta were similar in DOCA-salt rats and in controls and did not respond to a 100 nmol/l ET-1 stimulation in the DOCA-salt rats, in contrast to the increase found in the control uninephrectomized rats (p < 0.05). Thus, the diminished response to ET-1 of DOCA-salt rat arteries may be due to a lower density of ET-1 receptors, resulting in a blunted signal transduction, as reflected by decreased responses of inositol phosphate, cytosolic free calcium, and diacylglycerol.

Unreliability of Home Blood Pressure Measurement and the Effect of a Patient-Oriented Intervention

BACKGROUND Home blood pressure (BP) measurement (HBPM) is recommended for the diagnosis and follow-up of high BP. It is unclear how this aspect of BP monitoring has evolved over the years and whether interventions could influence patient adherence to HBPM guidelines. METHODS After a questionnaire-based cross-sectional study performed in 2010, a passive, multimodal intervention, focused on improving adherence to HBPM guidelines, was implemented. A second study was conducted in 2014 to measure its effect. RESULTS In 2010 and 2014, 1010 and 1005 patients, respectively, completed the questionnaire. In 2010 and 2014, 82% and 84% of patients, respectively, self-measured their BP. Reporting of HBPM and adherence to recommended procedures was suboptimal. Only 34.0% of patients in 2010 and 31.7% in 2014 brought > 80% of their measurements to their doctor. Only 49.6% in 2010 and 52.9% in 2014 prepared > 80% of the time for HBPM. Only 48.1% in 2010 and 52.1% in 2014 rested for 5 minutes > 80% of the time before HBPM. Only 15% of patients in 2010 and 18% in 2014 were defined as sufficiently compliant with all HBPM procedures. Paired analysis of a subset of 535 patients who participated in the 2010 and 2014 studies showed no clinically significant differences in reliability between the 2 surveys. CONCLUSIONS Adherence to HBPM guidelines was suboptimal in 2010 and still is in 2014 despite a passive, multimodal intervention. Active training in HBPM procedures should be studied. Greater automation could improve HBPM reliability.

Comparison of Different Automated Office Blood Pressure Measurement Devices: Evidence of Nonequivalence and Clinical Implications

BACKGROUND Automated office blood pressure (AOBP) measuring devices are increasingly recommended as preferred blood pressure (BP) diagnostic tools, but it is unclear how they compare and how clinical environments impact their performance. METHODS This prospective randomized factorial parallel 4-group study compared BP estimates by BpTRU (VSM MedTech, Vancouver, BC, Canada) and Omron HEM 907 (Omron Healthcare, Kyoto, Japan) devices in closed vs open areas. Patients diagnosed with hypertension were recruited during office visits. After baseline open-room AOBP measurement with the BpTRU, patients had a second BP measurement with either the BpTRU or HEM 907 in either open or closed areas. Absolute BP levels and differences between the first and second measurements were compared. Diagnostic performance was also assessed. RESULTS Two hundred fifty-eight patients were studied. Their mean age was 66.2 ± 12.0 years, and 62% were men. The mean of first AOBP estimates was 127.4/73.3 mm Hg. Analyses of subsequent measurements revealed no influence of open or closed areas on BP means and diagnostic performance. Conversely, the Omron HEM 907 exceeded BpTRU systolic BP measurements by 4.6 mm Hg (< 0.01) in closed areas and by 3.9 mm Hg (< 0.01) in open areas. The discrepancy between devices was amplified at lower BP levels. CONCLUSIONS Although different areas did not influence BP estimates, the Omron HEM 907 significantly exceeded BpTRU measurements on average and especially at lower BP levels. These differences should be considered when interchanging devices and could have clinical decision impacts in a population of patients treated for hypertension. Our results support the constant use of only 1 device type in a given clinic.

Recurrent arterial and venous thromboemboli as initial presentation of acute promyelocytic leukemia.

We report a case of a 52-year-old Caucasian woman diagnosed with a synchronic arterial and venous thrombosis as an initial presentation of an acute promyelocytic leukemia (APL). After the diagnosis, the patient was treated with all trans-retinoic acid and arsenic chemotherapy concomitant to systemic anticoagulation. This treatment regimen led to a complete remission and absence of relapse of the thrombosis or APL during the follow-up. To our knowledge, this presentation is the second case in the literature. We use this opportunity to emphasize the importance of performing a complete medical evaluation in cases of unusual thromboembolic events.

Lack of Clinical Benefit of Thromboprophylaxis in Patients Hospitalized in a Medical Unit Over a 10-year Span

Background Thromboprophylaxis for hospitalized patients with a high risk of venous thromboembolic events (VTEs) is strongly recommended but is not universally applied on medical units. Outside of randomized trials, there is minimal evidence that the usual medications reduce the incidence of clinically significant VTE. Methods We conducted a retrospective cohort study including all patients admitted into a teaching medical unit during years 2001-2002, 2003-2004, 2005-2006, 2007-2008 and 2009-2010. Inclusion criteria for the analysis were having one or more risk factors for a VTE and no contraindication to thromboprophylaxis. Results Of 2,369 patients reviewed, 1,302 satisfied the inclusion criteria. Between years 2001-2002 and 2009-2010, the proportion of patients receiving thromboprophylaxis increased from 29.2% to 76.4% (P < 0.0001) and the duration of thromboprophylaxis increased from 63% of hospital stay to 84% (P = 0.004). There was no statistically significant association between the number of risk factors and the rate of thromboprophylaxis. Overall, only 32 patients suffered from a VTE with no decrease in VTE incidence between years 2001-2002 and 2009-2010. A total of 107 patients had a bleeding event, and there was no statistically significant change in the incidence of bleeding during our study period. Conclusions In our medical units, we found a statistically significant increase in the use of the thromboprophylaxis practice. However, this was not associated with any statistically significant impact on the VTE incidence. This suggests that patients given thromboprophylaxis could be better selected.

Pure Red Cell Aplasia with Adult Onset Still’s Disease

Adult Onset Stills Disease (AOSD) is a rare inflammatory syndrome mostly seen in young adults. Known for its wide range of clinical manifestations, AOSD often presents with nonremitting systemic signs and symptoms. Many rare case associations have been described with AOSD, but only few with pure red cell aplasia (PRCA). We are presenting a fourth known case of a young female adult with AOSD and PRCA in the literature.