Performance of five different bleeding-prediction scores in patients with acute pulmonary embolism.

Bleeding-prediction scores may help guiding management of patients with pulmonary embolism (PE), although no such score has been validated. We aimed to externally validate and compare two bleeding-prediction scores for venous thromboembolism to three scores developed for patients with atrial fibrillation in a real-world cohort of PE patients. We performed a prospective observational cohort study in 448 consecutive PE patients who were treated with heparins followed by vitamin-K-antagonists. The Kuijer, RIETE, HEMORR2HAGES, HAS-BLED and ATRIA scores were assessed at baseline. All patients were followed for the occurrence of major bleeding over a 30-day period. The accuracies of both the overall, original 3-level and newly defined optimal 2-level outcome of the scores were evaluated and compared, both for the 30-day period as well as for bleeding occurring in versus after the first week of treatment. 20 of 448 patients suffered major bleeding resulting in a cumulative incidence of 4.5 % (95 % CI 2.5-6.5). The predictive power of all five scores for bleeding was poor (c-statistics 0.57-0.64), both for the 3-level and 2-level score outcomes. No individual score was found to be superior. The HAS-BLED score had a good c-statistic for bleedings occurring after the first week of treatment (0.75, 95 % CI 0.47-1.0). Current available scoring systems have insufficient accuracy to predict overall anticoagulation-associated bleeding in patients treated for acute PE. To optimally target bleeding-prevention strategies, the development of a high quality PE-specific risk score is urgently needed.

Increased proatherogenic monocyte-platelet cross-talk in monocyte subpopulations of patients with stable coronary artery disease.

BACKGROUND: Monocytes and platelets are important cellular mediators of atherosclerosis. Human monocytes can be divided into CD14(++) CD16(-) , CD14(++) CD16(+) and CD14(+) CD16(++) cells, which differ in their functional properties. The aim of this study was to examine monocyte subset distribution, monocyte-platelet aggregate (MPA) formation and expression of CCR5, the receptor of the platelet-derived chemokine CCL5, and to determine whether these parameters are altered in individuals with coronary atherosclerosis. METHODS: Peripheral blood cells from 64 healthy blood donors (HBDs) and 60 patients with stable coronary artery disease (CAD) were stained with antibodies against CD14, CD16, CD42b and CCR5 and analysed by flow cytometry. Circulating CCL5 levels were determined using an enzyme-linked immunosorbent assay. RESULTS: In patients with CAD, the relative proportion of the CD14(++) CD16(-) monocyte subset was elevated (P < 0.05) and of the CD14(+) CD16(++) subset was reduced (P < 0.001) compared with the HBD group. Furthermore, MPA formation significantly increased in patients with CAD in all three monocyte subsets. In both study groups, the majority of CCR5(+) cells was detected in CD14(++) CD16(+) monocytes (P < 0.001 versus CD14(++) CD16(-) and CD14(+) CD16(++) ), although the CCR5(+) monocyte number was reduced in patients with CAD (CD14(++) CD16(-) /CD14(+) CD16(++) , P < 0.001; CD14(++) CD16(+) , P < 0.05) compared with the HBD group, particularly in those who were not taking statins. Ex vivo incubation of monocytes from HBDs with plasma from patients with CAD also decreased CCR5(+) expression (P < 0.05 versus plasma from HBDs). Serum CCL5 levels were similar in both groups. CONCLUSIONS: The increased monocyte-platelet cross-talk in patients with CAD might have contributed to atherosclerosis progression. The decreased CCR5(+) monocyte numbers in patients with CAD could have resulted from CCR5(+) cell recruitment into atherosclerotic lesions or CCR5 downregulation in response to circulating factors.

BMI-independent inverse relationship of plasma leptin levels with outcome in patients with acute pulmonary embolism.

OBJECTIVE: The adipocytokine leptin is an independent cardiovascular risk factor and exerts prothrombotic effects, both in arterial and venous thrombosis. We therefore investigated the relationship between leptin levels and clinical outcome in patients with acute pulmonary embolism (PE). DESIGN: We prospectively studied consecutive patients with confirmed acute PE admitted at the University Hospital of Goettingen (Germany) between 2003 and 2009. SUBJECTS: The study subjects were a total of 264 patients with PE (median age, 68 years; interquartile range, 53-75; 60% women; body mass index (BMI) 27 kg m(-2) (24.1-31.2)). Leptin levels were determined by a commercially available enzyme-linked immunosorbent assay. Patients were followed for an adverse 30-day outcome, that is, death, circulatory collapse with need for catecholamines, intubation or resuscitation, and for long-term survival. RESULTS: The median leptin level was 10.1 ng ml(-1) (3.7-25.2). Patients (n=49; 18.6%) with a complicated 30-day course had significantly lower leptin levels (5.3 ng ml(-1) (1.8-19.7) compared with patients without complications (10.4 ng ml(-1) (4.7-25.5), P=0.02). When leptin was analyzed as a continuous variable, there was a significant 36% increase in the relative risk for early complications for every decrease in the natural logarithm of leptin by one s.d. (odds ratio (OR) 1.36 (1.06-1.76), P=0.017), independently of BMI (BMI-adjusted OR, 1.52 (1.13-2.05), P=0.006). In addition, patients within the lowest leptin tertile had a 2.8- and 2.3-fold increased risk for 30-day-complications, compared with those in the middle (P=0.011) and high tertile (P=0.030), and a worse probability of long-term survival (log-rank; P=0.018). CONCLUSION: Low plasma leptin concentration is a predictor for a complicated course and high mortality in patients with acute PE. This association is independent of known factors affecting leptin levels, including gender and obesity.

Heart-type fatty acid-binding protein for risk assessment of chronic thromboembolic pulmonary hypertension.

Heart-type fatty acid-binding protein (H-FABP) is a reliable marker of myocardial injury and was recently identified as a predictor of outcome in acute pulmonary embolism. The aim of the present study was to investigate the prognostic value of H-FABP in chronic thromboembolic pulmonary hypertension (CTEPH). In total, 93 consecutive patients with CTEPH were studied. During long-term follow-up (median duration 1,260 days, interquartile range (IQR) 708-2,460 days), 46 (49%) patients had an adverse outcome, defined as CTEPH-related death, lung transplantation or persistent pulmonary hypertension after pulmonary endarterectomy (PEA). Baseline H-FABP levels in plasma ranged from 0.69-24.3 ng x mL(-1) (median (IQR) 3.41 (2.28-4.86) ng x mL(-1)). Cox regression analysis revealed a hazard ratio of 1.10 (95% confidence interval 1.04-1.18) for each increase of H-FABP by 1 ng x mL(-1), and continuous elevations of H-FABP emerged as an independent predictor of adverse outcome by multivariable analysis. PEA was performed in 52 patients and favourably affected the long-term outcome. Kaplan-Meier analysis revealed that patients with baseline H-FABP concentrations >2.7 ng x mL(-1), the median value of the biomarker in the surgically treated population, had a lower probability of event-free survival after PEA. Heart-type fatty acid-binding protein is a promising novel biomarker for risk stratification of patients with chronic thromboembolic pulmonary hypertension.

[Acute ST-elevation myocardial infarction: is primary PCI superior to thrombolysis?]. / Akuter Myokardinfarkt mit persistierender ST-Elevation. Primäre PCI oder Lyse?

Thrombolysis is an established treatment of acute myocardial infarction with persistent ST elevation (STEMI). Thrombolytic agents are most effective in patients who can be treated within two hours of symptom onset. On the other hand, the efficacy of mechanical recanalization (PCI) was consistently shown to be superior to thrombolysis regardless of the duration of symptoms. Recent studies further suggest that it may be preferable for small hospitals to rapidly transfer patients with acute STEMI to a PCI center rather than perform on-site thrombolysis. Therefore, this novel strategy is principally recommended in the updated guidelines of German and international cardiac societies. However, it is emphasized that the transfer-related delay of treatment should not exceed 60-90 minutes.

The leptin receptor system of human platelets.

Obesity is associated with elevated levels of leptin in the blood. Elevated leptin is a risk factor for thrombosis in humans, and leptin administration promotes platelet activation and thrombosis in the mouse. The current study examines the effect of leptin on human platelets, and provides initial insights into the nature of the leptin receptor on these platelets. Leptin potentiated the aggregation of human platelets induced by low concentrations of ADP, collagen and epinephrine. However, the response varied significantly between donors, with platelets from some donors (approximately 40%) consistently responding to leptin (responders) and those from other donors (approximately 60%) never responding (non-responders). Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed that platelets from both groups only express the signaling form of the leptin receptor, and that responder platelets express higher levels of this receptor than non-responders. Ligand-binding assays demonstrate specific, saturable binding of leptin to platelets from both groups with apparent K(d) values of 76 +/- 20 nM for responders and 158 +/- 46 nM for non-responders. Thus, the decreased sensitivity of non-responder platelets to leptin does not result from the absence of the signaling form of this receptor, but may reflect differences in its level of expression and/or affinity for leptin. These preliminary studies demonstrate that platelets are a major source of leptin receptor in the circulation, and suggest that leptin-responsive individuals may have a higher risk for obesity-associated thrombosis than non-responsive individuals.

External validation of a simple non-invasive algorithm to rule out chronic thromboembolic pulmonary hypertension after acute pulmonary embolism.

PURPOSE: International guidelines do not provide strong recommendations on the duration and intensity of follow-up after acute pulmonary embolism (PE), nor on screening-programs for chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to address this gab by performing an external validation of the easy "CTEPH rule-out-criteria" based on a normal NT-proBNP level and the absence of 3 ECG characteristics. METHODS: 134 patients underwent clinical follow-up 6months after PE. Predefined transthoracic echocardiographic (TTE) criteria were used to categorize patients as "PH unlikely" or "PH possible/likely". The latter patients underwent further (invasive) diagnostic procedures to confirm and classify the diagnosis of pulmonary hypertension. NT-proBNP and ECGs, both assessed at the day of echocardiography, were evaluated post-hoc. RESULTS: Sixty-three patients (47%) scored none of the "CTEPH rule-out criteria" positive, of whom 61 had normal TTE (97%). Twenty-five patients (19%) were categorized by TTE as "PH possible/likely"; of those, 6 were diagnosed with CTEPH. The sensitivity of rule-out criteria for CTEPH was 100% (95%CI 56-100%; 6/6 patients identified), and for "PH possible/likely" on TTE 92% (95%CI 74-99%; 23/25 patients identified): 2 asymptomatic patients with estimated systolic pulmonary arterial pressure of 36mmHg and 38mmHg, respectively, who remained stable during further 2-year follow-up, were not identified. Inter-observer agreement for the adjudication of the ECG characteristics was excellent (kappa-statistic 0.97). CONCLUSIONS: In this external validation cohort, we confirmed the diagnostic accuracy and reproducibility of the "CTEPH rule-out criteria". These results provide a solid ground for future outcome trials applying this algorithm.