Opium as a risk factor for early-onset coronary artery disease: Results from the Milano-Iran (MIran) study.

The spreading of opium use poses new health related concerns. In some areas of Asia its use is believed to protect from cardiovascular disorders, such as coronary artery disease (CAD). However, whether opium use has an association with CAD is unclear. We aimed to investigate the association between non-medical opium use and CAD. We set up a case-control analysis, i.e., the Milano-Iran (MIran) study by enrolling consecutive young patients who underwent a coronary angiography at the Tehran Heart Center, between 2004 and 2011. Incident cases with CAD were contrasted with controls for opium use. Relative risks were calculated in terms of odds ratios (ORs) by logistic regression models adjusted for age, sex, cigarette smoking, body mass index, hypertension, hyperlipidaemia, and diabetes. Interaction analyses were performed between opium and major cardiovascular risk factors. 1011 patients with CAD (mean age 43.6 years) and 2002 controls (mean age 54.3 years) were included in the study. Habitual opium users had a 3.8-fold increased risk of CAD (95%CI 2.4-6.2) compared with non-users. The association was strongest for men, with a fully adjusted OR of 5.5 (95%CI 3.0-9.9). No interaction was observed for the combination of opium addiction and hypertension, or diabetes, but an excess in risk was found in opium users with hyperlipidaemia (OR 16.8, 95%CI 8.9-31.7, expected OR 12.2), suggesting supra-additive interaction. In conclusion, despite common beliefs, we showed that non-medical opium use is associated with an increased risk of CAD, even when other cardiovascular risk factors are taken into account.

How I treat gastrointestinal bleeding in congenital and acquired von Willebrand disease.

Gastrointestinal (GI) bleeding is distinctive of severe von Willebrand disease (VWD), generally arising in older patients; in most cases, blood transfusion and hospitalization are required. The presence of arteriovenous malformations is often described when endoscopic examinations are performed. Patients with congenital type 3, 2A, and 2B are those most frequently affected by this symptom, possibly due to the loss of high-molecular-weight multimers of von Willebrand factor (VWF). GI bleeding can also occur in patients affected by acquired von Willebrand syndrome. Endoscopic examination of the GI tract is necessary to exclude ulcers and polyps or cancer as possible causes of GI bleeding. In congenital VWD, prophylaxis with VWF/factor VIII concentrates is generally started after GI-bleeding events, but this therapy is not always successful. Iron supplementation must be prescribed to avoid chronic iron deficiency. Possible rescue therapies (high-dose statins, octreotide, thalidomide, lenalidomide, and tamoxifen) were described in a few case reports and series; however, surgery may be necessary in emergency situations or if medical treatment fails to stop bleeding. In this article, we present several clinical cases that highlight the clinical challenges of these patients and possible strategies for their long-term management.

Effect of emicizumab on global coagulation assays for plasma supplemented with apixaban or argatroban.

Emicizumab is a bi-specific humanized monoclonal antibody mimicking the factor (F) VIII cofactor activity in mediating the activation of FX by FIXa. Recent observations showed that emicizumab when added to pooled normal plasma (PNP), hemophilic plasma or PNP added with unfractionated heparin is able to interfere with coagulation assays. To further explore the mechanisms of assay interference we investigated the effect of emicizumab on global coagulation assays for the PNP added with two direct oral anticoagulants, apixaban or argatroban. Aliquots of PNP were added with purified apixaban or argatroban at a concentration of 500 ng/mL and emicizumab at concentrations ranging from 0 to 100 µg/mL. Plasma samples were then tested for the activated partial thromboplastin time (APTT) and for thrombin generation (the latter for the apixaban plasma only). Emicizumab at a 25-50 µg/mL shortened the APTT of the PNP with or without apixaban or argatroban. The extent of correction was greater for the apixaban or argatroban plasma and amounted to 35% or 42%, respectively. The parameters of thrombin generation (lag-time and time-to-peak) for the PNP supplemented with apixaban were shortened by 30% or 25%, respectively and the endogenous thrombin potential and the peak-thrombin were marginally affected. Emicizumab attenuates in vitro the anticoagulant activity of the PNP induced by apixaban or argatroban as documented by the correction of prolonged APTT and velocity of thrombin generation (i.e., lag-time and time-to-peak). Whether the above effects have any relevance in vivo is unknown.

Thrombin generation and other coagulation parameters in a patient with homozygous congenital protein S deficiency on treatment with rivaroxaban.

Rivaroxaban, which targets factor Xa and does not reduce proteins C/S, was chosen to treat a 6-year-old girl with homozygous protein S (PS) deficiency who developed skin necrosis while on warfarin. Owing to the lack of experience with rivaroxaban in children, the girl was started with 5 mg once-daily, which was gradually increased to 40 mg daily. The increasing dosage was driven by the need to avoid recurrence of skin necrosis. During dose-escalation, four pharmacokinetics assays were carried out measuring drug plasma concentrations and their effect on hemostatic parameters. We report the laboratory work-up, with special reference to parameters of thrombin-generation. Rivaroxaban concentrations by HPLC were correlated with those by the anti-factor Xa assay (r(2) = 0.92, p < 0.01), but there was an overestimation by HPLC. Thrombin-generation parameters, such as the area under the curve (referred to as ETP), peak-thrombin, and velocity-index, when measured after addition of thrombomodulin, showed unexpected changes: ETP decreased, but peak-thrombin and velocity-index increased. Similar patterns were obtained in a PS-depleted plasma and in plasma from patients with heterozygous PS deficiency, but not in plasma from controls. In conclusion, these preliminary results suggest that PS may be a determinant of velocity and peak-thrombin, but not of the total amount of thrombin generated.

Anticoagulant treatment with rivaroxaban in severe protein S deficiency.

We report a case of a 6-year-old girl with severe protein S deficiency due to a homozygous mutation and recurrent episodes of skin necrosis. She developed purpura fulminans at birth and a catheter-related venous thrombosis complicated by massive pulmonary embolism at the sixth day of life. Long-term oral anticoagulant therapy with a vitamin K-antagonist was started with a therapeutic range of the international normalized ratio of prothrombin time between 2.0 and 3.0. Unfortunately, this common range was not sufficient because recurrent episodes of warfarin-induced skin necrosis developed if the international normalized ratio was <4.0. Vitamin K antagonists decrease plasma level of vitamin K-dependent coagulation proteins, including the natural anticoagulant protein C. In our patient, the hypercoagulable state due to warfarin-induced reduction of protein C, other than severe protein S deficiency, outweighed the anticoagulant efficacy of the inhibition of procoagulant factors II, VII, IX, and X. The switch of anticoagulant therapy from warfarin to rivaroxaban, a direct inhibitor of activated factor X that does not inhibit other vitamin K-dependent proteins, resulted in the disappearance of skin necrosis at 1 year of follow-up. Rivaroxaban may be considered as a valid anticoagulant alternative in patients with severe inherited protein S deficiency and warfarin-induced skin necrosis.