Lysed Erythrocyte Membranes Promote Vascular Calcification.

BACKGROUND: Intraplaque hemorrhage promotes atherosclerosis progression, and erythrocytes may contribute to this process. In this study we examined the effects of red blood cells on smooth muscle cell mineralization and vascular calcification and the possible mechanisms involved. METHODS: Erythrocytes were isolated from human and murine whole blood. Intact and lysed erythrocytes and their membrane fraction or specific erythrocyte components were examined in vitro using diverse calcification assays, ex vivo by using the murine aortic ring calcification model, and in vivo after murine erythrocyte membrane injection into neointimal lesions of hypercholesterolemic apolipoprotein E-deficient mice. Vascular tissues (aortic valves, atherosclerotic carotid artery specimens, abdominal aortic aneurysms) were obtained from patients undergoing surgery. RESULTS: The membrane fraction of lysed, but not intact human erythrocytes promoted mineralization of human arterial smooth muscle cells in culture, as shown by Alizarin red and van Kossa stain and increased alkaline phosphatase activity, and by increased expression of osteoblast-specific transcription factors (eg, runt-related transcription factor 2, osterix) and differentiation markers (eg, osteopontin, osteocalcin, and osterix). Erythrocyte membranes dose-dependently enhanced calcification in murine aortic rings, and extravasated CD235a-positive erythrocytes or Perl iron-positive signals colocalized with calcified areas or osteoblast-like cells in human vascular lesions. Mechanistically, the osteoinductive activity of lysed erythrocytes was localized to their membrane fraction, did not involve membrane lipids, heme, or iron, and was enhanced after removal of the nitric oxide (NO) scavenger hemoglobin. Lysed erythrocyte membranes enhanced calcification to a similar extent as the NO donor diethylenetriamine-NO, and their osteoinductive effects could be further augmented by arginase-1 inhibition (indirectly increasing NO bioavailability). However, the osteoinductive effects of erythrocyte membranes were reduced in human arterial smooth muscle cells treated with the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide or following inhibition of NO synthase or the NO receptor soluble guanylate cyclase. Erythrocytes isolated from endothelial NO synthase-deficient mice exhibited a reduced potency to promote calcification in the aortic ring assay and after injection into murine vascular lesions. CONCLUSIONS: Our findings in cells, genetically modified mice, and human vascular specimens suggest that intraplaque hemorrhage with erythrocyte extravasation and lysis promotes osteoblastic differentiation of smooth muscle cells and vascular lesion calcification, and also support a role for erythrocyte-derived NO.

Novel echocardiographic prognostic markers for cardiac tamponade in patients with large malignant pericardial effusions: A paradigm shift from flow to tissue imaging.

BACKGROUND: With this study, we sought to investigate the prognostic value of echocardiographic tissue imaging markers in predicting tamponade among patients with large malignant pericardial effusion compared to routinely used echocardiographic signs. METHODS: A total of 96 consecutive patients with large malignant pericardial effusion, not in clinical cardiac tamponade, underwent an echocardiographic examination and were prospectively assessed for 1 month. Clinically evident cardiac tamponade was considered as the study endpoint. The prognostic performance of tricuspid valve annular plane systolic excursion (TAPSE) and peak systolic annular velocity at the lateral margin of the tricuspid valve annulus (STV ) was assessed and compared to routinely used imaging signs. RESULTS: During follow-up, 37 patients (39%) developed clinically evident cardiac tamponade. TAPSE (area under the curve [AUC] 0.958) and STV (AUC 0.948) had excellent predictive accuracy for tamponade. Multivariate analysis showed that TAPSE (Hazard ratio [HR] 3.03; 95% CI 1.60-5.73, P=.001) and STV (HR 1.17; 95% CI 1.05-1.29, P=.005) remained independent significant predictors of cardiac tamponade. Reclassification analysis and decision curve analysis showed additive prognostic value and adjunct clinical benefit of these markers when added to a recently published triage pericardiocentesis score. CONCLUSION: Echocardiographic tissue imaging markers such as TAPSE and STV are characterized by an excellent prognostic ability for development of cardiac tamponade and better prognostic value compared to routine echocardiographic signs in patients with large malignant pericardial effusion. Incorporating these markers to a recent triage pericardiocentesis score resulted in additional prognostic value and increased clinical benefit.

Effect of Sacubitril/Valsartan on circulating catecholamine levels during a 6-month follow-up in heart failure patients. Timeo Danaos et dona ferentes?

We assessed the effect of Sacubitril/Valsartan on circulating catecholamine levels in patients with HF in an observational cohort study. We included 108 consecutive HF patients attending our HF Outpatients Clinic who were eligible to Sacubitril/Valsartan according to the PARADIGM-HF inclusion and exclusion criteria. We furthermore included 58 stable HF patients under optimal medical therapy as a control group. Norepinephrine and epinephrine were measured with immunoradiometric assays at baseline, at 3- and at 6-month time follow-up. Compared to baseline levels there was no change at three months in epinephrine (p = 0.177) or norepinephrine (p = 0.815) concentrations. At 6 months norepinephrine remained unchanged (p = 0.359). However, at 6 months we observed a significant increase in epinephrine levels compared to baseline [66 pg/mL (37-93) vs 38 pg/mL (18-74), p < 0.001]. In the control group no change was observed in epinephrine levels compared to baseline (p = 0.838). This study is the first to report on the effect of the new drug Sacubitril/Valsartan on circulating catecholamine levels in HF patients. Our data show a significant increase in epinephrine levels during a 6 month follow up in stable HF patients.

Application of 17 Contrast-Induced Acute Kidney Injury Risk Prediction Models.

INTRODUCTION: Contrast-induced acute kidney injury (CI-AKI) is a frequent complication of percutaneous coronary interventions (PCI). Various groups have developed and validated risk scores for CI-AKI. Although the majority of these risk scores achieve an adequate accuracy, their usability in clinical practice is limited and greatly debated. OBJECTIVE: With the present study, we aimed to prospectively assess the diagnostic performance of recently published CI-AKI risk scores (up to 2018) in a cohort of patients undergoing PCI. METHODS: We enrolled 1,247 consecutive patients (80% men, mean age 62 ± 10 years) treated with elective or urgent PCI. For each patient, we calculated the individual CI-AKI risk score based on 17 different risk models. CI-AKI was defined as an increase of ≥25% (liberal) or ≥0.5 mg/dL (strict) in pre-PCI serum creatinine 48 h after PCI. RESULTS: CI-AKI definition and, therefore, CI-AKI incidence have a significant impact on risk model performance (median negative predictive value increased from 85 to 99%; median c-statistic increased from 0.516 to 0.603 using more strict definition criteria). All of the 17 published models were characterized by a weak-to-moderate discriminating ability mainly based on the identification of "true-negative" cases (median positive predictive value 19% with liberal criterion and 3% with strict criterion). In none of the models, c-statistic was >0.800 with either CI-AKI definition. Novel, different combinations of the >35 independent variables used in the published models either by down- or by up-scaling did not result in significant improvement in predictive performance. CONCLUSIONS: The predictive ability of all models was similar and only modest, derived mainly by identifying true-negative cases. A new approach is probably needed by adding novel markers or periprocedural characteristics.

Long-term impact of acute kidney injury on prognosis in patients with acute myocardial infarction.

BACKGROUND: Little evidence exists regarding the long-term impact of acute kidney injury (AKI) during index hospitalisation for acute myocardial infarction (AMI). We prospectively assessed the long-term prognostic significance of the occurrence of in-hospital AKI in a multicentre cohort of patients admitted with AMI. METHODS: Data were obtained from 518 AMI patients with a median follow-up of 5.6 (IQR 4.6-6.5) years. Patients were followed up regarding the occurrence of death, major adverse cardiovascular events (MACE), and any deterioration in kidney function. RESULTS: From the study cohort, 84 patients (16%) had developed AKI at discharge during index hospitalisation. 96 patients died during follow-up, MACE occurred in 90 patients, and 30 patients showed evidence of deterioration in kidney function. Patients with AKI at hospital discharge had a three-fold increased mortality risk (HR 3.2, 95% CI 2.1-4.8; P < 0.001). This association was independent of possible confounding by variables that could influence prognosis (HR 1.9 95% CI 1.1-3.2; P = 0.028) evident only up to three years during follow-up. During long-term follow-up, patients with AKI during their index hospitalisation had a significantly (P = 0.027) higher incidence of MACE (26%) than those who did not develop AKI (15%). Patients with AKI had a higher incidence of deteriorating kidney function (10%) than those without AKI (5%) during follow-up, but this difference was not significant (P = 0.124). CONCLUSIONS: Our findings emphasise in addition to the need for appropriate long term follow-up in such patients, an increased mortality and morbidity during the first three years after the index event.

Cardiovascular Implications of Sphingomyelin Presence in Biological Membranes.

Sphingomyelin (SM) is a type of sphingolipid found within plasma, cellular membranes and plasma lipoproteins. Here we highlight the basic biochemical features of SMs and their role in biological membranes. We further discuss evidence of the association between SM and cardiovascular diseases such as atherosclerosis, valvular disease, heart failure and diabetes mellitus.

Spot urine albumin to creatinine ratio outperforms novel acute kidney injury biomarkers in patients with acute myocardial infarction.

BACKGROUND: Acute kidney injury (AKI) is a frequent complication in patients hospitalized for acute myocardial infarction (AMI), and is associated with in-hospital and long-term morbidity and mortality. We prospectively assessed the diagnostic performance of spot urine albumin to creatinine ratio (uACR) in an adequately sized multicenter cohort of patients admitted to hospital with AMI. We further compared uACR to novel renal injury associated biomarkers regarding their diagnostic ability. METHODS: We enrolled 805 consecutive patients presenting with acute ST-elevation and non-ST elevation AMI. Patients were assessed for presence of AKI at 48h post-admission and at hospital discharge using the Acute Kidney Injury Network (AKIN), the Acute Dialysis Quality Initiative [Risk, Injury and Failure (RIFLE)] criteria and the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Blood and urine sampling for neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), cystatin-C, and uACR assessment was performed during admission. RESULTS: The predictive accuracy of uACR was good (Area Under the Curve (AUC), 0.725; 95% CI 0.676-0.774) and was better compared to urine NGAL (P=0.007), urine (P<0.001) and plasma Cystatin-C (P=0.001). ROC analysis identified concentrations of ≥66.7µg/mg as having the best diagnostic accuracy. The use of uACR exhibited good discriminating ability independent to possible cofounders and additive regarding the use of novel biomarkers. CONCLUSIONS: The use of uACR can easily be applied in the clinical setting, allows for robust risk assessment and offers the potential to improve the management of AMI patients at risk for acute kidney injury.

Development of an easily applicable risk score model for contrast-induced nephropathy prediction after percutaneous coronary intervention: a novel approach tailored to current practice.

BACKGROUND: Several risk factors for contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI) have been identified. The cumulative effect of these risk factors on renal function has been assessed with the development of risk score models in a number of studies. However, concerns were raised that estimates of the risk attributable to individual factors may be unreliable. We sought to develop a simple risk score for developing CIN after PCI irrespective of use of prophylactic measures and also capturing the effect of pre-intervention medication and presence of various co-morbidities. METHODS: Consecutive patients treated with elective or urgent PCI at our cardiac catheterization laboratory were enrolled (derivation cohort n = 488, validation cohort n = 200). CIN was defined as increase ≥ 25% and/or ≥ 0.5 mg/dl in serum creatinine at 48 h after PCI vs baseline. Multivariable logistic regression analysis was then performed to identify independent predictors of CIN (pre-existing renal disease, metformin use, history of previous PCI, peripheral arterial disease and ≥ 300 ml of contrast volume). RESULTS: The incidence of CIN in the development cohort was 10.2% with a significant trend across increasing score values (p < 0.001). The model demonstrated good discriminating power (c-statistic 0.759) and excellent calibration (calibration slope 0.91). The model was validated internally by bootstrapping in 1000 samples (c-statistic 0.753) and in a cohort of 200 patients (c-statistic 0.864) demonstrating stable performance. CONCLUSIONS: The proposed risk score is easily applicable and allows for practically simple risk assessment compared to other published scores while at the same time overcomes drawbacks of previous model designs.