Intermediate and nonclassical monocytes show heterogeneity in patients with different types of acute coronary syndrome.

This study was performed to gain further insight in the heterogeneity of monocytes in the different categories of acute coronary syndrome (ACS), especially between patients with unstable angina pectoris, ST-elevation myocardial infarction (STEMI), and non-ST-elevation myocardial infarction (NSTEMI). For this purpose, blood samples were collected in the acute phase from patients presenting with an ACS. These samples were examined with multiparameter flow cytometry to identify the different monocyte subsets and to analyze the expression of monocyte-associated molecules. Leukocytes, as well as an absolute number of monocytes, showed a clear and significant increase in patients with STEMI. This increase was seen in all subtypes of monocytes. The classical monocytes (CD14++CD16-) of patients with an NSTEMI had a significantly increased CD11b expression when compared to the control group, while these cells showed a decreased expression pattern in STEMI patients. This increased CD11b-expression was also seen in the intermediate monocytes of NSTEMI, while it was almost completely downregulated on the intermediate monocytes of STEMI. Finally, CX3CR1, which is almost exclusively expressed on intermediate and nonclassical monocytes, showed a significant decrease in expression in patients with STEMI. In conclusion, intermediate and nonclassical monocytes have a different immunophenotypic pattern in patients with STEMI versus NSTEMI. These differences reflect the pro-inflammatory state of the monocytes in NSTEMI and can be used as target molecules for novel therapeutic strategies to diminish the migration of proinflammatory monocytes into the myocardial tissue. © 2017 International Society for Advancement of Cytometry.

Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study.

BACKGROUND: Validated diagnostic algorithms in patients with suspected pulmonary embolism are often not used correctly or only benefit subgroups of patients, leading to overuse of computed tomography pulmonary angiography (CTPA). The YEARS clinical decision rule that incorporates differential D-dimer cutoff values at presentation, has been developed to be fast, to be compatible with clinical practice, and to reduce the number of CTPA investigations in all age groups. We aimed to prospectively evaluate this novel and simplified diagnostic algorithm for suspected acute pulmonary embolism. METHODS: We did a prospective, multicentre, cohort study in 12 hospitals in the Netherlands, including consecutive patients with suspected pulmonary embolism between Oct 5, 2013, to July 9, 2015. Patients were managed by simultaneous assessment of the YEARS clinical decision rule, consisting of three items (clinical signs of deep vein thrombosis, haemoptysis, and whether pulmonary embolism is the most likely diagnosis), and D-dimer concentrations. In patients without YEARS items and D-dimer less than 1000 ng/mL, or in patients with one or more YEARS items and D-dimer less than 500 ng/mL, pulmonary embolism was considered excluded. All other patients had CTPA. The primary outcome was the number of independently adjudicated events of venous thromboembolism during 3 months of follow-up after pulmonary embolism was excluded, and the secondary outcome was the number of required CTPA compared with the Wells' diagnostic algorithm. For the primary outcome regarding the safety of the diagnostic strategy, we used a per-protocol approach. For the secondary outcome regarding the efficiency of the diagnostic strategy, we used an intention-to-diagnose approach. This trial is registered with the Netherlands Trial Registry, number NTR4193. FINDINGS: 3616 consecutive patients with clinically suspected pulmonary embolism were screened, of whom 151 (4%) were excluded. The remaining 3465 patients were assessed of whom 456 (13%) were diagnosed with pulmonary embolism at baseline. Of the 2946 patients (85%) in whom pulmonary embolism was ruled out at baseline and remained untreated, 18 patients were diagnosed with symptomatic venous thromboembolism during 3-month follow-up (0·61%, 95% CI 0·36-0·96) of whom six had fatal pulmonary embolism (0·20%, 0·07-0·44). CTPA was not indicated in 1651 (48%) patients with the YEARS algorithm compared with 1174 (34%) patients, if Wells' rule and fixed D-dimer threshold of less than 500 ng/mL would have been applied, a difference of 14% (95% CI 12-16). INTERPRETATION: In our study pulmonary embolism was safely excluded by the YEARS diagnostic algorithm in patients with suspected pulmonary embolism. The main advantage of the YEARS algorithm in our patients is the absolute 14% decrease of CTPA examinations in all ages and across several relevant subgroups. FUNDING: This study was supported by unrestricted grants from the participating hospitals.

Factor XIa and Thrombin Generation Are Elevated in Patients with Acute Coronary Syndrome and Predict Recurrent Cardiovascular Events.

OBJECTIVE: In acute coronary syndrome (ACS) cardiac cell damage is preceded by thrombosis. Therefore, plasma coagulation markers may have additional diagnostic relevance in ACS. By using novel coagulation assays this study aims to gain more insight into the relationship between the coagulation system and ACS. METHODS: We measured plasma thrombin generation, factor XIa and D-dimer levels in plasma from ACS (n = 104) and non-ACS patients (n = 42). Follow-up measurements (n = 73) were performed at 1 and 6 months. Associations between coagulation markers and recurrent cardiovascular events were calculated by logistic regression analysis. RESULTS: Thrombin generation was significantly enhanced in ACS compared to non-ACS patients: peak height 148±53 vs. 122±42 nM. There was a significantly diminished ETP reduction (32 vs. 41%) and increased intrinsic coagulation activation (25 vs. 7%) in ACS compared to non-ACS patients. Furthermore, compared to non-ACS patients factor XIa and D-dimer levels were significantly elevated in ACS patients: 1.9±1.1 vs. 1.4±0.7 pM and 495(310-885) vs. 380(235-540) µg/L. Within the ACS spectrum, ST-elevated myocardial infarction patients had the highest prothrombotic profile. During the acute event, thrombin generation was significantly increased compared to 1 and 6 months afterwards: peak height 145±52 vs. 100±44 vs. 98±33 nM. Both peak height and factor XIa levels on admission predicted recurrent cardiovascular events (OR: 4.9 [95%CI 1.2-20.9] and 4.5 [1.1-18.9]). CONCLUSION: ACS patients had an enhanced prothrombotic profile, demonstrated by an increased thrombin generation potential, factor XIa and D-dimer levels. This study is the first to demonstrate the positive association between factor XIa, thrombin generation and recurrent cardiovascular events.

Associations Between Thrombin Generation and the Risk of Cardiovascular Disease in Elderly Patients: Results From the PROSPER Study.

BACKGROUND: Hypercoagulability may be an important contributor to the pathophysiology of atherosclerosis and atherothrombosis. As thrombin fulfills a central role in coagulation and links to several cellular mechanisms involved in arterial disease, we hypothesized that thrombin generation is associated with cardiovascular events in elderly patients. METHODS: We studied the relationship between plasma thrombin generation and incident coronary heart disease (CHD) and stroke in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). From this multicenter prospective cohort, 4,932 samples of subjects (70-82 years) with pre-existing vascular disease or risk factors were available for thrombin generation measurements. RESULTS: Within the 3.2 years of follow-up incident stroke and CHD was observed in 227 and 545 subjects, respectively. Baseline thrombin generation was significantly decreased in subjects with incident stroke compared with subjects without: normalized peak height 71.1±40.8% versus 82.3±44.9%, p = .0002, and normalized endogenous thrombin potential 79.1±23.3% versus 87.0±24.8%, p < .0001 (mean and SDs). Thrombin generation was independently and inversely associated with stroke risk: hazard ratio 0.71 (95%CI: 0.60-0.85), 0.68 (95%CI: 0.58-0.79), for normalized peak height and normalized endogenous thrombin potential, respectively (all p < .001). In subjects with incident CHD, thrombin generation was comparable to subjects without a coronary event. Only an increased normalized peak height was significantly associated with incident CHD (hazard ratio 1.17 [95% CI: 1.06-1.28], p = .002). CONCLUSIONS: We demonstrate that a delayed and decreased thrombin generation is a strong and independent predictor for stroke in elderly people at increased risk of vascular disease. However, no convincing consistent association could be demonstrated between thrombin generation and incident CHD.