Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal stem-cell disorders characterized by ineffective hematopoiesis and risk of progression to acute myeloid leukemia. Increased apoptosis and suppressed functions of peripheral blood natural killer (NK) cells have been described in MDS patients, but only limited information is available on the phenotypic and functional integrity of NK cells in the bone marrow. In a cohort of 41 patients with distinct clinical subtypes of MDS, we here show that NK cells in the bone marrow show decreased surface expression of the activating receptors DNAM-1 and NKG2D. Notably, decreased receptor expression correlated with elevated bone marrow blast counts and was associated with impaired NK-cell responsiveness to stimulation with the K562 cell line, or co-activation by NKG2D or DNAM-1 in combination with the 2B4 receptor. Furthermore, antibodymasking experiments revealed a central role for DNAM-1 in NK cell-mediated killing of freshly isolated MDS blasts. Thus, given the emerging evidence for NK cell-mediated immune surveillance of neoplastic cells, we speculate that reduced expression of DNAM-1 on bone marrow NK cells may facilitate disease progression in patients with MDS.

Aims To describe the time trends of in-hospital and out-of-hospital bleeding parallel to the development of new treatments and ischaemic outcomes over the last 20 years in a nationwide myocardial infarction (MI) population. Methods and results Patients with acute MI (n = 371 431) enrolled in the SWEDEHEART registry from 1995 until May 2018 were selected and evaluated for in-hospital bleeding and out-of-hospital bleeding events at 1 year. In-hospital bleeding increased from 0.5% to a peak at 2% 2005/2006 and thereafter slightly decreased to a new plateau around 1.3% by the end of the study period. Out-of-hospital bleeding increased in a stepwise fashion from 2.5% to 3.5 % in the middle of the study period and to 4.8% at the end of the study period. The increase in both in-hospital and out-of-hospital bleeding was parallel to increasing use of invasive strategy and adjunctive antithrombotic treatment, dual antiplatelet therapy (DAPT), and potent DAPT, while the decrease in in-hospital bleeding from 2007 to 2010 was parallel to implementation of bleeding avoidance strategies. In-hospital re-infarction decreased from 2.8% to 0.6% and out-of-hospital MI decreased from 12.6% to 7.1%. The composite out-of-hospital MI, cardiovascular death, and stroke decreased in a similar fashion from 18.4% to 9.1%. Conclusion During the last 20 years, the introduction of invasive and more intense antithrombotic treatment has been associated with an increase in bleeding events but concomitant there has been a substantial greater reduction of ischaemic events including improved survival.

Background Bleeding risk stratification in acute coronary syndrome is of highest clinical interest but current risk scores have limitations. We sought to develop and validate a new in‐hospital bleeding risk score for patients with acute myocardial infarction. Methods and Results From the nationwide SWEDEHEART (Swedish Web‐System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies) register, 97,597 patients with acute myocardial infarction enrolled from 2009 until 2014 were selected. A full model with 23 predictor variables and 8 interaction terms was fitted using logistic regression. The full model was approximated by a model with 5 predictors and 1 interaction term. Calibration, discrimination, and clinical utility was evaluated and compared with the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) and CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Ad verse Outcomes With Early Implementation of the ACC /AHA Guidelines) scores. Internal and temporal validity was assessed. In‐hospital major bleeding, defined as fatal, intracranial, or requiring surgery or blood transfusion, occurred in 1356 patients (1.4%). The 5 predictors in the approximate model that constituted the SWEDEHEART score were hemoglobin, age, sex, creatinine, and C‐reactive protein. The ACTION and CRUSADE scores were poorly calibrated in the derivation cohort and therefore were recalibrated. The SWEDEHEART score showed higher discriminative ability than both recalibrated scores, overall ( C ‐index 0.80 versus 0.73/0.72) and in all predefined subgroups. Decision curve analysis demonstrated consistently positive and higher net benefit for the SWEDEHEART score compared with both recalibrated scores across all clinically relevant decision thresholds. The original ACTION and CRUSADE scores showed negative net benefit. Conclusions The 5‐item SWEDEHEART score discriminates in‐hospital major bleeding in patients with acute myocardial infarction and has superior model performance compared with the recalibrated ACTION and CRUSADE scores.