Perioperative use of iloprost in cardiac surgery patients diagnosed with heparin-induced thrombocytopenia-reactive antibodies or with true HIT (HIT-reactive antibodies plus thrombocytopenia): An 11-year experience.

Thrombocytopenia and thromboembolism(s) may develop in heparin immune-mediated thrombocytopenia (HIT) patients after reexposure to heparin. At the Onassis Cardiac Surgery Center, 530 out of 17,000 patients requiring heart surgery over an 11-year period underwent preoperative HIT assessment by ELISA and a three-point heparin-induced platelet aggregation assay (HIPAG). The screening identified 110 patients with HIT-reactive antibodies, out of which 46 were also thrombocytopenic (true HIT). Cardiac surgery was performed in HIT-positive patients under heparin anticoagulation and iloprost infusion. A control group of 118 HIT-negative patients received heparin but no iloprost during surgery. For the first 20 patients, the dose of iloprost diminishing the HIPAG test to ≤5% was determined prior to surgery by in vitro titration using the patients' own plasma and donor platelets. In parallel, the iloprost "target dose" was also established for each patient intraoperatively, but before heparin administration. Iloprost was infused initially at 3 ng/kg/mL and further adjusted intraoperatively, until ex vivo aggregation reached ≤5%. As a close correlation was observed between the "target dose" identified before surgery and that established intraoperatively, the remaining 90 patients were administered iloprost starting at the presurgery identified "target dose." This process significantly reduced the number of intraoperative HIPAG reassessments needed to determine the iloprost target dose, and reduced surgical time, while maintaining similar primary clinical outcomes to controls. Therefore, infusion of iloprost throughout surgery, under continuous titration, allows cardiac surgery to be undertaken safely using heparin, while avoiding life-threatening iloprost-induced hypotension in patients diagnosed with HIT-reactive antibodies or true HIT.

Incidence and peri-operative risk factors for development of acute kidney injury in patients after cardiac surgery: A prospective observational study.

BACKGROUND: Patients admitted to intensive care unit (ICU) after cardiac surgery develop acute kidney injury (AKI) immediately post-operation. We hypothesized that AKI occurs mainly due to perioperative risk factors and may affect outcome. AIM: To assess peri-operative risk factors for AKI post cardiac surgery and its relationship with clinical outcome. METHODS: This was an observational single center, tertiary care setting study, which enrolled 206 consecutive patients, admitted to ICU after cardiac surgery. Patients were followed-up until ICU discharge or death, in order to determine the incidence of AKI, perioperative risk factors for AKI and its association with outcome. Univariate and multivariate logistic regression analysis was performed to assess predictor variables for AKI development. RESULTS: After ICU admission, 55 patients (26.7%) developed AKI within 48 h. From the logistic regression analysis performed, high EuroScore II (OR: 1.18; 95%CI: 1.06-1.31, P = 0.003), white blood cells (WBC) pre-operatively (OR: 1.0; 95%CI: 1.0-1.0, P = 0.002) and history of chronic kidney disease (OR: 2.82; 95%CI: 1.195-6.65, P = 0.018) emerged as independent predictors of AKI among univariate predictors. AKI that developed AKI had longer duration of mechanical ventilation [1113 (777-2195) vs 714 (511-1020) min, P = 0.0001] and ICU length of stay [70 (28-129) vs 26 (21-51) h, P = 0.0001], higher rate of ICU-acquired weakness (16.4% vs 5.3%, P = 0.015), reintubation (10.9% vs 1.3%, P = 0.005), dialysis (7% vs 0%, P = 0.005), delirium (36.4% vs 23.8%, P = 0.001) and mortality (3.6% vs 0.7%, P = 0.046). CONCLUSION: Patients present frequently with AKI after cardiac surgery. EuroScore II, WBC count and chronic kidney disease are independent predictors of AKI development. The occurrence of AKI is associated with poor outcome.

Mineralocorticoid Receptor Pathway Is a Key Mediator of Carfilzomib-induced Nephrotoxicity: Preventive Role of Eplerenone.

Carfilzomib is an irreversible proteasome inhibitor indicated for relapsed/refractory multiple myeloma. Carfilzomib toxicity includes renal adverse effects (RAEs) of obscure pathobiology. Therefore, we investigated the mechanisms of nephrotoxicity developed by Carfilzomib. In a first experimental series, we used our previously established in vivo mouse models of Carfilzomib cardiotoxicity, that incorporated 2 and 4 doses of Carfilzomib, to identify whether Carfilzomib affects renal pathways. Hematology and biochemical analyses were performed, while kidneys underwent histological and molecular analyses. In a second and third experimental series, the 4 doses protocol was repeated for 24 hours urine collection and proteomic/metabolomic analyses. To test an experimental intervention, primary murine collecting duct tubular epithelial cells were treated with Carfilzomib and/or Eplerenone and Metformin. Finally, Eplerenone was orally co-administered with Carfilzomib daily (165 mg/kg) in the 4 doses protocol. We additionally used material from 7 patients to validate our findings and patients underwent biochemical analysis and assessment of renal mineralocorticoid receptor (MR) axis activation. In vivo screening showed that Carfilzomib-induced renal histological deficits and increased serum creatinine, urea, NGAL levels, and proteinuria only in the 4 doses protocol. Carfilzomib decreased diuresis, altered renal metabolism, and activated MR axis. This was consistent with the cytotoxicity found in primary murine collecting duct tubular epithelial cells, whereas Carfilzomib + Eplerenone co-administration abrogated Carfilzomib-related nephrotoxic effects in vitro and in vivo. Renal SGK-1, a marker of MR activation, increased in patients with Carfilzomib-related RAEs. Conclusively, Carfilzomib-induced renal MR/SGK-1 activation orchestrates RAEs and water retention both in vivo and in the clinical setting. MR blockade emerges as a potential therapeutic approach against Carfilzomib-related nephrotoxicity.

Chronic Empagliflozin Treatment Reduces Myocardial Infarct Size in Nondiabetic Mice Through STAT-3-Mediated Protection on Microvascular Endothelial Cells and Reduction of Oxidative Stress.

Aims: Empagliflozin (EMPA) demonstrates cardioprotective effects on diabetic myocardium but its infarct-sparing effects in normoglycemia remain unspecified. We investigated the acute and chronic effect of EMPA on infarct size after ischemia-reperfusion (I/R) injury and the mechanisms of cardioprotection in nondiabetic mice. Results: Chronic oral administration of EMPA (6 weeks) reduced myocardial infarct size after 30 min/2 h I/R (26.5% ± 3.9% vs 45.8% ± 3.3% in the control group, p < 0.01). Body weight, blood pressure, glucose levels, and cardiac function remained unchanged between groups. Acute administration of EMPA 24 or 4 h before I/R did not affect infarct size. Chronic EMPA treatment led to a significant reduction of oxidative stress biomarkers. STAT-3 (signal transducer and activator of transcription 3) was activated by Y(705) phosphorylation at the 10th minute of R, but it remained unchanged at 2 h of R and in the acute administration protocols. Proteomic analysis was employed to investigate signaling intermediates and revealed that chronic EMPA treatment regulates several pathways at reperfusion, including oxidative stress and integrin-related proteins that were further evaluated. Superoxide dismutase and vascular endothelial growth factor were increased throughout reperfusion. EMPA pretreatment (24 h) increased the viability of human microvascular endothelial cells in normoxia and on 3 h hypoxia/1 h reoxygenation and reduced reactive oxygen species production. In EMPA-treated murine hearts, CD31-/VEGFR2-positive endothelial cells and the pSTAT-3(Y705) signal derived from endothelial cells were boosted at early reperfusion. Innovation: Chronic EMPA administration reduces infarct size in healthy mice via the STAT-3 pathway and increases the survival of endothelial cells. Conclusion: Chronic but not acute administration of EMPA reduces infarct size through STAT-3 activation independently of diabetes mellitus.

Levosimendan prevents doxorubicin-induced cardiotoxicity in time- and dose-dependent manner: implications for inotropy.

AIMS: Levosimendan (LEVO) a clinically-used inodilator, exerts multifaceted cardioprotective effects. Case-studies indicate protection against doxorubicin (DXR)-induced cardiotoxicity, but this effect remains obscure. We investigated the effect and mechanism of different regimens of levosimendan on sub-chronic and chronic doxorubicin cardiotoxicity. METHODS AND RESULTS: Based on preliminary in vivo experiments, rats serving as a sub-chronic model of doxorubicin-cardiotoxicity and were divided into: Control (N/S-0.9%), DXR (18 mg/kg-cumulative), DXR+LEVO (LEVO, 24 µg/kg-cumulative), and DXR+LEVO (acute) (LEVO, 24 µg/kg-bolus) for 14 days. Protein kinase-B (Akt), endothelial nitric oxide synthase (eNOS), and protein kinase-A and G (PKA/PKG) pathways emerged as contributors to the cardioprotection, converging onto phospholamban (PLN). To verify the contribution of PLN, phospholamban knockout (PLN-/-) mice were assigned to PLN-/-/Control (N/S-0.9%), PLN-/-/DXR (18 mg/kg), and PLN-/-/DXR+LEVO (ac) for 14 days. Furthermore, female breast cancer-bearing (BC) mice were divided into: Control (normal saline 0.9%, N/S 0.9%), DXR (18 mg/kg), LEVO, and DXR+LEVO (LEVO, 24 µg/kg-bolus) for 28 days. Echocardiography was performed in all protocols. To elucidate levosimendan's cardioprotective mechanism, primary cardiomyocytes were treated with doxorubicin or/and levosimendan and with N omega-nitro-L-arginine methyl ester (L-NAME), DT-2, and H-89 (eNOS, PKG, and PKA inhibitors, respectively); cardiomyocyte-toxicity was assessed. Single bolus administration of levosimendan abrogated DXR-induced cardiotoxicity and activated Akt/eNOS and cAMP-PKA/cGMP-PKG/PLN pathways but failed to exert cardioprotection in PLN-/- mice. Levosimendan's cardioprotection was also evident in the BC model. Finally, in vitro PKA inhibition abrogated levosimendan-mediated cardioprotection, indicating that its cardioprotection is cAMP-PKA dependent, while levosimendan preponderated over milrinone and dobutamine, by ameliorating calcium overload. CONCLUSION: Single dose levosimendan prevented doxorubicin cardiotoxicity through a cAMP-PKA-PLN pathway, highlighting the role of inotropy in doxorubicin cardiotoxicity.

Efficacy and safety of perioperative infusion of levosimendan in patients with compromised cardiac function undergoing open-heart surgery: importance of early use.

OBJECTIVE: Levosimendan is a promising new inotrope. We investigate the proper time for its infusion during or after open-heart surgery to avoid complications related with low-output syndrome and high dosage of inotropes. METHODS: Forty-five consecutive patients were randomised to receive levosimendan in addition to the conventional therapy, its infusion starting in the operating theatre (Group OT) or in the ICU (Group ICU) when low-output syndrome was certified and were consequently dependent on classical inotropic support and IABP. Levosimendan was infused at a rate of 0.1 microg/kg min without loading dose, the infusion being for at least 24h to a maximum 48 h. RESULTS: Levosimendan was well tolerated, with the simultaneous infusion of norepinephrine if required. Its efficacy was identical in both groups with improvement in the haemodynamic and functional status of patients (amelioration of stroke volume, cardiac index and mixed venous blood oxygen saturation, increase of left ventricular ejection fraction by echo study, de-escalation of traditional inotropes, subtraction of IABP and reduction in BNP plasma levels). The ICU stay and hospital stay were significantly decreased in patients of Group OT, compared to patients of Group ICU. Four patients died because of multiple organs dysfunction syndrome (MODS) due to sepsis (all patients of Group ICU). CONCLUSION: Levosimendan is a safe and efficient choice in the management of low-output syndrome during and after open-heart surgery. The shortening of hospitalisation and the trend for better outcome confirm its clear superiority when the infusion starts from the operating theatre.

Attitudes of healthcare professionals involved in cardiology practice towards key points of contemporary guidelines on resuscitation.

Hellenic J Cardiol. 2014; 55: 378-385. At the request of the authors, the name of the second author of this Original Research article has been changed from Athanasios Patialakas to Athanasios Patialiakas.

Intravenous atenolol and esmolol maintain the protective effect of ischemic preconditioning in vivo.

Catecholamines bind to alpha- and beta-adrenoreceptors and are capable of preconditioning ischemic myocardium. Our purpose was to investigate the effect of acute either short or prolonged i.v. administration of beta-adrenoreceptor antagonists on ischemic preconditioning in vivo. Fifty-five anesthetized rabbits were divided into 10 groups (n=5-7 per group) and were subjected to 30-min regional ischemia of the heart after ligation of a prominent left coronary artery and 3-h reperfusion after releasing the snare. Ischemic preconditioning was obtained by three cycles of 5-min ischemia separated by 10-min reperfusion. beta-Adrenoreceptor blockade was obtained by the long acting beta-adrenoreceptor antagonist atenolol or by the short acting esmolol, which were given as a short 5-min infusion or as a prolonged 45-min infusion, starting respectively 20 min before and ending 15 min before the beginning of sustained ischemia, or starting 45 min before and ending immediately before the beginning of sustained ischemia. Atenolol was given at a rate of 0.2 mg min(-1) during 5 min or at a rate of 0.088 mg min(-1) as a 45-min infusion. Esmolol was given as an initial dose of 500 microg kg(-1) within 1 min, followed by a 4-min infusion at a rate of 50 microg kg(-1) min(-1) or as an initial dose of 3.4 mg within 1 min, followed by a 44-min infusion at a rate of 0.15 mg min(-1). Blood pressure and heart rate were continuously monitored. The infarcted and risk areas were delineated with the aid of tetrazolium chloride staining and fluorescent Zn-Cd particles. Infarct size was expressed in percent of the area at risk. All the animals without preconditioning developed an infarct size ranging between 36.3+/-2.4% and 49.6+/-7.6% (P=NS) and all the preconditioning groups developed an infarct size ranging between 14.9+/-1.2% and 21.0+/-2.2% (P=NS). All the preconditioning groups, independently of the use of beta-adrenoreceptor antagonists, had a smaller infarct size than the control group, which developed an infarct size of 47.3+/-2.5% (P<0.01). Intravenous atenolol and esmolol, independent of timing and mode of administration, does not seem to interfere with protection afforded by ischemic preconditioning in vivo.

Reduction of myocardial infarct size in rabbits by a novel indole derivative with antioxidant and free radical scavenging properties.

We investigated the cardioprotective efficacy of a new compound, 3-[(1H-1-indolyl)methyl] -4-amino 4,5-dihydro-1H,1,2,4 triazole-5-thione (C6458). The effect of C6458 on the reduction of the infarct size and its protective ability against oxidative damage of the myocardium after ischemia-reperfusion was examined in rabbits that were subjected to 30 min regional ischemia and 2 h reperfusion. C6458 was administered by continuous infusion for 30 min starting at the 10th minute of sustained ischemia and ending at the 10th minute of reperfusion (two doses, 100 and 200 micromol/kg BW). Infarct and risk areas were delineated with Zn2+-Cd2+ particles and triphenyl tetrazolium chloride staining. Antioxidant activity was detected spectrophotometrically by the measurement of malondialdehyde formation. C6458 reduced significantly the level of malondialdehyde in rabbits under ischemia-reperfusion at both doses. Interestingly, at the dose of 200 micromol/kg, the compound decreased the malondialdehyde levels from the 1st minute of reperfusion and significantly reduced infarct size. The free radical scavenging properties of the compound were examined in vitro by determination of the interaction with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable free radical. The ability of the C6458 to scavenge HO* was established by its competition with dimethyl sulfoxide (DMSO) for HO radicals. The compound tested showed a significant effect in the above assays. We conclude that C6458 possesses a protective effect against both damaged myocardium and infarct size in anesthetized rabbits. This beneficial effect may be attributed, at least in part, to its antioxidant and free radical scavenging activity.

Angiotensin II fails to induce preconditioning in vivo--the protective role of myocardial stretch due to pressure overload.

BACKGROUND: Angiotensin II (Ang) has been successfully used as a preconditioning analogue in isolated rabbit hearts. It is also known that local concentrations of Ang accelerate ischemic injury in vivo, while activation of stretch receptors protects ischemic hearts. OBJECTIVES: First, to investigate further whether Ang can mimic preconditioning in vivo. Second, to test the hypothesis that there is an activation of stretch receptors, and that the larger infarct from the left atrium Ang compared with that from the intravenous Ang may be associated with the ischemic injury caused by local administration. METHODS: Male rabbits were divided into four groups - a control group, an ischemic preconditioning group with 5 min ischemia, a left atrial group and an intravenous group with 5 min Ang infusion. All animals were subjected to prolonged ischemia and reperfusion. A second series of experiments was also performed with five groups that had a 5 min mechanical obstruction of the aorta (Ao clamp), also used as a preconditioning analogue with or without the stretch receptor blocker gadolinium (Gd). RESULTS: Contrary to what was expected from the ex vivo experiments, Ang failed to mimic preconditioning (infarct size 39.6 6.1%, 13.7 4.1%, 52.2% 6.9% and 31.2 4.8%, respectively for the above groups). Interestingly, however, when Ang was infused intravenously, it produced a significantly smaller infarct compared with that observed after the same dose was infused into the left atrium (P<0.05). The infarct size was 17.0 3.7% in the Ao clamp group, which was an effect completely prevented by Gd (45.8 4.2%, P<0.01). Although Gd did not alter infarct size in the control and ischemic preconditioning groups, it increased infarct size when added to the intravenous Ang group (Gd-intravenous Ang 48.6 3.3%, P<0.05 compared with intravenous Ang). CONCLUSIONS: Ang fails to mimic preconditioning in vivo, but salvage of ischemic myocardium can be emanated from pressure overload.

Attitudes of healthcare professionals involved in cardiology practice towards key points of contemporary guidelines on resuscitation.

INTRODUCTION: Cardiopulmonary resuscitation (CPR) is not always executed in compliance with contemporary guidelines and the quality of CPR may differ among hospitals within the same country or among categories of healthcare providers and medical specialties. The aim of this study was to assess attitudes of cardiology healthcare professionals towards CPR guidelines. METHODS: An anonymous questionnaire was posted online during 2009. Responders were asked about their age, gender, occupation, and training/experience in CPR. Responders' attitudes towards CPR were assessed using 7 questions regarding the accuracy of their opinions about the automated external defibrillator, public defibrillation programs, CPR performance, and therapeutic hypothermia. A score (0 to 7) was formed by assigning grade 1 to answers that accorded with European Resuscitation Council (ERC) guidelines and grade 0 to all other answers. The reliability analysis for this score yielded a Cronbach's alpha of 0.78. RESULTS: There were 544 responders (158 females), median age 34 years (30, 40). Median score was 5 (3, 6). Attending an ERC resuscitation course (beta=0.33, SE beta=0.05, p<0.001), age (beta=-0.15 SE beta=0.05, p=0.002), involvement in >10 CPRs /year (beta=0.19, SE beta=0.05, p<0.001), and being a physician (beta=0.17, SE beta=0.05, p=0.001) were all independent predictors of score. Attendance at an ERC course (OR: 2.7 [1.5 to 4.7]), being a physician (OR: 2 [1.3 to 5]) and involvement in >10 CPRs /year (OR: 1.7 [1.1 to 2.7]) were also independent predictors for attitudes that accorded with contemporary guidelines regarding therapeutic hypothermia. CONCLUSIONS: Attending an ERC resuscitation course, frequent involvement in CPR attempts, younger age, and being a physician were all independent predictors for more positive attitudes towards the guidelines. These factors, with the exception of age, were also associated with positive attitudes towards the implementation of therapeutic hypothermia.

Antioxidant activity of novel indole derivatives and protection of the myocardial damage in rabbits.

Novel indole derivatives containing a triazole moiety (1a-d, 2a-c) were synthesized as lead compounds with interesting pharmacological profiles. Their antioxidant activity was investigated on in vitro non-enzymatic rat hepatic microsomal lipid peroxidation. All compounds showed significant effect in the above assay. The effect depended mainly on the attachment position of the triazole moiety on the indole nucleus. The most potent antioxidant derivatives la, 1c and 1d were tested for their protective ability against the oxidative damage of the myocardium after ischemia-reperfusion, in male rabbits which were subjected to 30 min regional ischemia followed by reperfusion. The tested antioxidant compounds 1a, 1c and 1d were continuously infused for 30 min starting at 10th min of ischemia and lasted at 10th min of reperfusion. The concentration of malondialdehyde (MDA, a marker of lipid peroxidation) and hemodynamic parameters (blood pressure and heart rate) were measured in the baseline, at 20th min of the sustained ischemia, 1st and 20th min of reperfusion. It was found that the examined compounds la, 1c and 1d reduced significantly the level of MDA in rabbits under ischemia-reperfusion and proved to be promising substances for further evaluation of anti-ischemic properties.