Background: Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction mediated by platelet-activating antibodies that target complexes of platelet factor 4 and heparin. Patients are at markedly increased risk of thromboembolism. Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about diagnosis and management of HIT. Methods: ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment. Results: The panel agreed on 33 recommendations. The recommendations address screening of asymptomatic patients for HIT, diagnosis and initial management of patients with suspected HIT, treatment of acute HIT, and special situations in patients with acute HIT or a history of HIT, including cardiovascular surgery, percutaneous cardiovascular intervention, renal replacement therapy, and venous thromboembolism prophylaxis. Conclusions: Strong recommendations include use of the 4Ts score rather than a gestalt approach for estimating the pretest probability of HIT and avoidance of HIT laboratory testing and empiric treatment of HIT in patients with a low-probability 4Ts score. Conditional recommendations include the choice among non-heparin anticoagulants (argatroban, bivalirudin, danaparoid, fondaparinux, direct oral anticoagulants) for treatment of acute HIT.

D-dimer assays are commonly used in clinical practice to exclude a diagnosis of deep vein thrombosis or pulmonary embolism. More recently, they have been also been used to guide patients with unprovoked venous thromboembolism (VTE) when faced with the decision to continue or stop anticoagulation after initial treatment is complete. D-dimer assays vary widely with respect to the antibody used, method of capture, instrumentation required, and calibration standard. These differences have an important influence on the operating characteristics of the assays. Consequently, the evidence available in the literature for one assay cannot simply be extrapolated to another. In this review, we will outline the general properties of D-dimer assays, discuss the concept of raising the D-dimer threshold used in diagnosis of VTE according to pretest probability and age, and provide clinical perspective on the role of D-dimer testing in the diagnosis and prognosis of VTE.

A negative result on a quantitative latex d -dimer assay safely eliminates the need for further testing in patients with low or moderate pretest probability of DVT.

interval, 2.71-2.81) compared with never smokers. This was despite the fact that 44% of the baseline smokers who responded to the 8-year resurvey had stopped smoking at that point. Mortality was tripled, largely irrespective of age, in those still smoking at the 3-year resurvey (rate ratio, 2.97; 2.88-3.07). The 12-year mortality was doubled (rate ratio, 1.98; 1.91-2.04) even for women smoking fewer than 10 cigarettes daily at baseline. Of the 30 most common causes of death, 23 were increased significantly in smokers. Excess mortality was mainly from diseases caused by smoking. Among ex-smokers who stopped permanently at ages 25 to 34 or at ages 35 to 44 years, the respective relative risks were 1.05 (95% confidence interval, 1.00-1.11) and 1.20 (1.14-1.26) for all-cause mortality and 1.84 (1.45-2.34) and 3.34 (2.76-4.03) for lung cancer mortality.Comment: Please see also the report by Jha P et al providing similar data from the United States, also featured in this Abstract Section of the Journal. The data are remarkably similar between the two countries. In particular, it is important to note that although some excess mortality remains among long-term ex-smokers, it is only about 3% and 10% of excess mortality among continued smokers. If the data in this study were combined with the 2010 U.K. national death rates, it would indicate 53% of smokers and 22% of never smokers die before age 80 years with an 11year life-span difference in favor of the never smokers.