The Novel Cardiac Myosin Activator Danicamtiv Improves Cardiac Systolic Function at the Expense of Diastolic Dysfunction In Vitro and In Vivo: Implications for Clinical Applications.

Recent cardiotropic drug developments have focused on cardiac myofilaments. Danicamtiv, the second direct myosin activator, has achieved encouraging results in preclinical and clinical studies, thus implicating its potential applicability in the treatment of heart failure with reduced ejection fraction (HFrEF). Here, we analyzed the inotropic effects of danicamtiv in detail. To this end, changes in sarcomere length and intracellular Ca2+ levels were monitored in parallel, in enzymatically isolated canine cardiomyocytes, and detailed echocardiographic examinations were performed in anesthetized rats in the absence or presence of danicamtiv. The systolic and diastolic sarcomere lengths decreased; contraction and relaxation kinetics slowed down with increasing danicamtiv concentrations without changes in intracellular Ca2+ transients in vitro. Danicamtiv evoked remarkable increases in left ventricular ejection fraction and fractional shortening, also reflected by changes in systolic strain. Nevertheless, the systolic ejection time was significantly prolonged, the ratio of diastolic to systolic duration was reduced, and signs of diastolic dysfunction were also observed upon danicamtiv treatment in vivo. Taken together, danicamtiv improves cardiac systolic function, but it can also limit diastolic performance, especially at high drug concentrations.

Omecamtiv mecarbil evokes diastolic dysfunction and leads to periodic electromechanical alternans.

Omecamtiv mecarbil (OM) is a promising novel drug for improving cardiac contractility. We tested the therapeutic range of OM and identified previously unrecognized side effects. The Ca2+ sensitivity of isometric force production (pCa50) and force at low Ca2+ levels increased with OM concentration in human permeabilized cardiomyocytes. OM (1 µM) slowed the kinetics of contractions and relaxations and evoked an oscillation between normal and reduced intracellular Ca2+ transients, action potential lengths and contractions in isolated canine cardiomyocytes. Echocardiographic studies and left ventricular pressure-volume analyses demonstrated concentration-dependent improvements in cardiac systolic function at OM concentrations of 600-1200 µg/kg in rats. Administration of OM at a concentration of 1200 µg/kg was associated with hypotension, while doses of 600-1200 µg/kg were associated with the following aspects of diastolic dysfunction: decreases in E/A ratio and the maximal rate of diastolic pressure decrement (dP/dtmin) and increases in isovolumic relaxation time, left atrial diameter, the isovolumic relaxation constant Tau, left ventricular end-diastolic pressure and the slope of the end-diastolic pressure-volume relationship. Moreover, OM 1200 µg/kg frequently evoked transient electromechanical alternans in the rat in vivo in which normal systoles were followed by smaller contractions (and T-wave amplitudes) without major differences on the QRS complexes. Besides improving systolic function, OM evoked diastolic dysfunction and pulsus alternans. The narrow therapeutic window for OM may necessitate the monitoring of additional clinical safety parameters in clinical application.

Predictors of Hospital Mortality in Patients with Acute Coronary Syndrome Complicated by Cardiogenic Shock.

As demonstrated by earlier studies, pre-hospital triage with trans-telephonic electrocardiogram (TTECG) and direct referral for catheter therapy shows great value in the management of out-of-hospital chest pain emergencies. It does not only improve in-hospital mortality in ST-segment elevation myocardial infarction, but it has also been identified as an independent predictor of higher in-hospital survival rate. Since TTECG-facilitated triage shortens both transport time and percutaneous coronary intervention (PCI)-related procedural time intervals, it was hypothesized that even high-risk patients with acute coronary syndrome (ACS) and cardiogenic shock (CS) might also benefit from TTECG-based triage. Here, we decided to examine our database for new triage- and left ventricular (LV) function-related parameters that can influence in-hospital mortality in ACS complicated by CS. ACS patients were divided into two groups, namely, (1) hospital death patients (n = 77), and (2) hospital survivors (control, n = 210). Interestingly, TTECG-based consultation and triage of CS and ACS patients were confirmed as significant independent predictors of lower hospital mortality risk (odds ratio (OR) 0.40, confidence interval (CI) 0.21-0.76, p = 0.0049). Regarding LV function and blood chemistry, a good myocardial reperfusion after PCI (high area at risk (AAR) blush score/AAR LV segment number; OR 0.85, CI 0.78-0.98, p = 0.0178) and high glomerular filtration rate (GFR) value at the time of hospital admission (OR 0.97, CI 0.96-0.99, p = 0.0042) were the most crucial independent predictors of a decreased risk of in-hospital mortality in this model. At the same time, a prolonged time interval between symptom onset and hospital admission, successful resuscitation, and higher peak creatine kinase activity were the most important independent predictors for an increased risk of in-hospital mortality. In ACS patients with CS, (1) an early TTECG-based teleconsultation and triage, as well as (2) good myocardial perfusion after PCI and a high GFR value at the time of hospital admission, appear as major independent predictors of a lower in-hospital mortality rate.

Prophylactic, single-drug cardioprotection in a comparative, experimental study of doxorubicin-induced cardiomyopathy.

BACKGROUND: Cardiomyopathy is a common side effect of doxorubicin (DOX) chemotherapy. Despite intensive research efforts in the field, there is still no evidence available for routine cardioprotective prophylaxis to prevent cardiotoxicity in the majority of oncological patients at low risk of cardiovascular disease. We have recently demonstrated the advantages of a prophylactic, combined heart failure therapy in an experimental model of DOX-induced cardiomyopathy. In the current work, we focus on individually applied prophylactic medications studied in the same translational environment to clarify their distinct roles in the prevention of DOX cardiotoxicity. METHODS: Twelve-week-old male Wistar rats were divided into 5 subgroups. Prophylactic ß-blocker (BB, bisoprolol), angiotensin-converting enzyme inhibitor (ACEI, perindopril) or aldosterone antagonist (AA, eplerenone) treatments were applied 1 week before DOX administration, then 6 cycles of intravenous DOX chemotherapy were administered. Rats receiving only intravenous DOX or saline served as positive and negative controls. Blood pressure, heart rate, body weight, and echocardiographic parameters were monitored in vivo. Two months after the last DOX administration, the animals were sacrificed, and their heart and serum samples were frozen in liquid nitrogen for histological, mechanical, and biochemical measurements. RESULTS: All prophylactic treatments increased the survival of DOX-receiving animals. The lowest mortality rates were seen in the BB and ACEI groups. The left ventricular ejection fraction was only preserved in the BB group. The DOX-induced increase in the isovolumetric relaxation time could not be prevented by any prophylactic treatment. A decreased number of apoptotic nuclei and a preserved myocardial ultrastructure were found in all groups receiving prophylactic cardioprotection, while the DOX-induced fibrotic remodelling and the increase in caspase-3 levels could only be substantially prevented by the BB and ACEI treatments. CONCLUSION: Primary prophylaxis with cardioprotective agents like BB or ACEI has a key role in the prevention of DOX-induced cardiotoxicity in healthy rats. Future human studies are necessary to implement this finding in the clinical management of oncological patients free of cardiovascular risk factors.

Levosimendan Efficacy and Safety: 20 Years of SIMDAX in Clinical Use.

Levosimendan was first approved for clinical use in 2000, when authorization was granted by Swedish regulatory authorities for the hemodynamic stabilization of patients with acutely decompensated chronic heart failure (HF). In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitization and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced HF, right ventricular failure, pulmonary hypertension, cardiac surgery, critical care, and emergency medicine. Levosimendan is currently in active clinical evaluation in the United States. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and noncardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute HF arena in recent times and charts a possible development trajectory for the next 20 years.

Heme-Induced Oxidation of Cysteine Groups of Myofilament Proteins Leads to Contractile Dysfunction of Permeabilized Human Skeletal Muscle Fibres.

Heme released from red blood cells targets a number of cell components including the cytoskeleton. The purpose of the present study was to determine the impact of free heme (20-300 µM) on human skeletal muscle fibres made available during orthopedic surgery. Isometric force production and oxidative protein modifications were monitored in permeabilized skeletal muscle fibre segments. A single heme exposure (20 µM) to muscle fibres decreased Ca2+-activated maximal (active) force (Fo) by about 50% and evoked an approximately 3-fold increase in Ca2+-independent (passive) force (Fpassive). Oxidation of sulfhydryl (SH) groups was detected in structural proteins (e.g., nebulin, α-actinin, meromyosin 2) and in contractile proteins (e.g., myosin heavy chain and myosin-binding protein C) as well as in titin in the presence of 300 µM heme. This SH oxidation was not reversed by dithiothreitol (50 mM). Sulfenic acid (SOH) formation was also detected in the structural proteins (nebulin, α-actinin, meromyosin). Heme effects on SH oxidation and SOH formation were prevented by hemopexin (Hpx) and α1-microglobulin (A1M). These data suggest that free heme has a significant impact on human skeletal muscle fibres, whereby oxidative alterations in structural and contractile proteins limit contractile function. This may explain and or contribute to the weakness and increase of skeletal muscle stiffness in chronic heart failure, rhabdomyolysis, and other hemolytic diseases. Therefore, therapeutic use of Hpx and A1M supplementation might be effective in preventing heme-induced skeletal muscle alterations.

Advantages of prophylactic versus conventionally scheduled heart failure therapy in an experimental model of doxorubicin-induced cardiomyopathy.

BACKGROUND: Chemotherapy-induced left ventricular dysfunction represents a major clinical problem, which is often only recognised at an advanced stage, when supportive therapy is ineffective. Although an early heart failure treatment could positively influence the health status and clinical outcome, there is still no evidence of routine prophylactic cardioprotection for the majority of patients without previous cardiovascular history awaiting potentially cardiotoxic chemotherapy. In this study, we set out to investigate whether a prophylactic cardioprotective therapy relative to a conventionally scheduled heart failure treatment is more effective in preventing cardiotoxicity in a rodent model of doxorubicin (DOX)-induced cardiomyopathy. METHODS: Male Wistar rats (n = 7-11 per group) were divided into 4 subgroups, namely negative controls receiving intravenous saline (CON), positive controls receiving intravenous DOX (6 cycles; D-CON), and DOX-treated animals receiving either prophylactic (PRE, started 1 week before DOX) or conventionally applied (POST, started 1 month after DOX) combined heart failure therapy of oral bisoprolol, perindopril and eplerenone. Blood pressure, heart rate, body weight and echocardiographic parameters were monitored in vivo, whereas myocardial fibrosis, capillarisation, ultrastructure, myofilament function, apoptosis, oxidative stress and mitochondrial biogenesis were studied in vitro. RESULTS: The survival rate in the PRE group was significantly improved compared to D-CON (p = 0.0207). DOX increased the heart rate of the animals (p = 0.0193), while the blood pressure (p ≤ 0.0105) and heart rate (p = 0.0029) were significantly reduced in the PRE group compared to D-CON and POST. The ejection fraction remained preserved in the PRE group compared to D-CON or POST (p ≤ 0.0237), while none of the treatments could prevent the DOX-induced increase in the isovolumetric relaxation time. DOX decreased the rate of the actin-myosin cross-bridge cycle, irrespective of any treatment applied (p ≤ 0.0433). The myocardium of the D-CON and POST animals displayed pronounced ultrastructural damage, which was not apparent in the PRE group (p ≤ 0.033). While the DOX-induced apoptotic activity could be reduced in both the PRE and POST groups (p ≤ 0.0433), no treatment was able to prevent fibrotic remodelling or the disturbed mitochondrial biogenesis. CONCLUSION: For attenuating DOX-induced adverse myocardial effects, prophylactic cardioprotection has many advantages compared to a late-applied treatment.

Effect of factor XIII levels and polymorphisms on the risk of myocardial infarction in young patients.

Factor XIII (FXIII) stabilizes and protects the fibrin network. Its role in myocardial infarction (MI) is still to be clarified. To evaluate the association of FXIII levels with MI in young patients and to investigate how the FXIII-A p.Val34Leu, FXIII-B p.His95Arg, and IVS11, c.1952 + 144 C>G (Intron K) polymorphisms influence FXIII levels and MI risk. Patients with ST elevation MI below 40 years of age (MI, n = 119), age-matched clinical controls (CC, n = 101) without MI and coronary artery disease, and healthy controls (HC, n = 120) were investigated for FXIII activity, FXIII-A2B2, FXIII-B concentrations and for the polymorphisms. FXIII activity and FXIII-A2B2 antigen were significantly elevated in MI. FXIII activity and antigen were significantly elevated in Arg95, while decreased in Intron K "G" carriers. Smoking had an independent increasing effect on FXIII activity and FXIII-A2B2 antigen. Intron K C>G polymorphism significantly decreased the risk of MI in patients with elevated fibrinogen. Among the investigated factors Intron K C>G polymorphism and smoking have the most powerful effect on FXIII levels and on the risk of MI in the young. The effect of smoking on coronary thrombus formation may partially be attributed to its FXIII increasing effect.

Optimized angiotensin-converting enzyme activity assay for the accurate diagnosis of sarcoidosis.

BACKGROUND: Serum angiotensin-converting enzyme (ACE) activity determination can aid the early diagnosis of sarcoidosis. We aimed to optimize a fluorescent kinetic assay for ACE activity by screening the confounding effects of endogenous ACE inhibitors and interfering factors. Genotype-dependent and genotype-independent reference values of ACE activity were established, and their diagnostic accuracies were validated in a clinical study. METHODS: Internally quenched fluorescent substrate, Abz-FRK(Dnp)P-OH was used for ACE-activity measurements. A total of 201 healthy individuals and 59 presumably sarcoidotic patients were enrolled into this study. ACE activity and insertion/deletion (I/D) genotype of the ACE gene were determined. RESULTS: Here we report that serum samples should be diluted at least 35-fold to eliminate the endogenous inhibitor effect of albumin. No significant interferences were detected: up to a triglyceride concentration of 16 mM, a hemoglobin concentration of 0.71 g/L and a bilirubin concentration of 150 µM. Genotype-dependent reference intervals were considered as 3.76-11.25 U/L, 5.22-11.59 U/L, 7.19-14.84 U/L for II, ID and DD genotypes, respectively. I/D genotype-independent reference interval was established as 4.85-13.79 U/L. An ACE activity value was considered positive for sarcoidosis when it exceeded the upper limit of the reference interval. The optimized assay with genotype-dependent reference ranges resulted in 42.5% sensitivity, 100% specificity, 100% positive predictive value and 32.4% negative predictive value in the clinical study, whereas the genotype-independent reference range proved to have inferior diagnostic efficiency. CONCLUSIONS: An optimized fluorescent kinetic assay of serum ACE activity combined with ACE I/D genotype determination is an alternative to invasive biopsy for confirming the diagnosis of sarcoidosis in a significant percentage of patients.

Cardiopoietic cell therapy for advanced ischaemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial.

AIMS: Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort. METHODS AND RESULTS: This multinational, randomized, double-blind, sham-controlled study was conducted in 39 hospitals. Patients with symptomatic ischaemic heart failure on guideline-directed therapy (n = 484) were screened; n = 348 underwent bone marrow harvest and mesenchymal stem cell expansion. Those achieving > 24 million mesenchymal stem cells (n = 315) were randomized to cardiopoietic cells delivered endomyocardially with a retention-enhanced catheter (n = 157) or sham procedure (n = 158). Procedures were performed as randomized in 271 patients (n = 120 cardiopoietic cells, n = 151 sham). The primary efficacy endpoint was a Finkelstein-Schoenfeld hierarchical composite (all-cause mortality, worsening heart failure, Minnesota Living with Heart Failure Questionnaire score, 6-min walk distance, left ventricular end-systolic volume, and ejection fraction) at 39 weeks. The primary outcome was neutral (Mann-Whitney estimator 0.54, 95% confidence interval [CI] 0.47-0.61 [value > 0.5 favours cell treatment], P = 0.27). Exploratory analyses suggested a benefit of cell treatment on the primary composite in patients with baseline left ventricular end-diastolic volume 200-370 mL (60% of patients) (Mann-Whitney estimator 0.61, 95% CI 0.52-0.70, P = 0.015). No difference was observed in serious adverse events. One (0.9%) cardiopoietic cell patient and 9 (5.4%) sham patients experienced aborted or sudden cardiac death. CONCLUSION: The primary endpoint was neutral, with safety demonstrated across the cohort. Further evaluation of cardiopoietic cell therapy in patients with elevated end-diastolic volume is warranted.

[Immunoadsorption in a patient with dilated cardiomyopathy. The first case in Hungary]. / Dilatatív cardiomyopathia immunadszorpciós kezelése. Az elso magyarországi eset kapcsán.

Dilated cardiomyopathy is the main cause of heart transplantation. The etiology is unknown in almost half of the cases. Many cardiac specific antibodies have been identified till now which can cause decreased cardiac function, ventricular tachycardia or sudden heart death. The prognosis of DCM is poor despite the development of medical treatment. Immunoadsorption is hopeful since, with the removal of antibodies, cardiac function and NYHA class can improve and LVAD/heart transplantation-free survival can be prolonged. At the University of Debrecen, Faculty of Medicine, Department of Internal Medicine, Division of Angiology, Intensive Care and Therapeutic Apheresis Unit we performed the first immunoadsorption. Our patient was a 43-year-old man with idiopathic dilated cardiomyopathy, NYHA class IV, a heart transplantation candidate, whose cardiac specific antibody, type IgG was indentified by Western blot. Before the treatment he had ejection fraction of 18%. Discussing with his cardiologists we decided for immunoadsorption therapy. We performed 5 cycles on consecutive days in Intensive Care Unit. After 1 month we detected improvement in exercise capacity. We detected improvement in isovolemic contraction (from 465 mmHg/s to 575 mmHg/s), increased stroke volume (from 49 ml to 66 ml). After 3 months we repeated SPECT investigation which showed improvement in ejection fraction, from 18% to 32%. Orv Hetil. 2018; 159(13): 532-536.

[The Semmelweis University extracorporeal membrane oxygenation program - 5 years' results and perspectives]. / A Semmelweis Egyetem extracorporalis membránoxigenizációs programja ­ az 5 éves Városmajori-eredmények függvényében.

The mechanical circulatory support (MCS) program of the Semmelweis University Heart and Vascular Centre has become established over the last five years. The main requirements of our MCS program to be developed first were the Heart Transplantation and Heart Failure Intensive Care Unit and a well trained medical team. The wide range of mechanical circulatory support devices provides suitable background for the adequate treatment of our patients in all indications. In this review, we present our results related to extracorporeal membrane oxygenation (ECMO) supports performed in the last five years. Between 2012 and 2017, we applied MCS support in 140 cases, among them 111 patients received ECMO support. The leading indications of ECMO support were the following: primary graft failure after heart transplantation (33 cases), postcardiotomy cardiogenic shock (18 patients), acute decompensation of end-stage heart failure (14 patients), acute myocardial infarction complicated with refractory cardiogenic shock (37 patients), cardiogenic shock developed after transcatheter aortic valve implantation (3 patients), malignant arrhythmia due to drug intoxication (1 patient) and acute respiratory distress syndrome (4 cases). The mortality of patients receiving ECMO support was 46%. The analysis of the results of ECMO support needs to change our approach. The mortality results show that we lost the half of our patients. However, the mortality in the conventionally treated patients would have been 100% without ECMO. In fact, we could save the life of half of these patients. Orv Hetil. 2018; 159(46): 1876-1881.

Meta-Analysis of Cell-based CaRdiac stUdiEs (ACCRUE) in patients with acute myocardial infarction based on individual patient data.

RATIONALE: The meta-Analysis of Cell-based CaRdiac study is the first prospectively declared collaborative multinational database, including individual data of patients with ischemic heart disease treated with cell therapy. OBJECTIVE: We analyzed the safety and efficacy of intracoronary cell therapy after acute myocardial infarction (AMI), including individual patient data from 12 randomized trials (ASTAMI, Aalst, BOOST, BONAMI, CADUCEUS, FINCELL, REGENT, REPAIR-AMI, SCAMI, SWISS-AMI, TIME, LATE-TIME; n=1252). METHODS AND RESULTS: The primary end point was freedom from combined major adverse cardiac and cerebrovascular events (including all-cause death, AMI recurrance, stroke, and target vessel revascularization). The secondary end point was freedom from hard clinical end points (death, AMI recurrence, or stroke), assessed with random-effects meta-analyses and Cox regressions for interactions. Secondary efficacy end points included changes in end-diastolic volume, end-systolic volume, and ejection fraction, analyzed with random-effects meta-analyses and ANCOVA. We reported weighted mean differences between cell therapy and control groups. No effect of cell therapy on major adverse cardiac and cerebrovascular events (14.0% versus 16.3%; hazard ratio, 0.86; 95% confidence interval, 0.63-1.18) or death (1.4% versus 2.1%) or death/AMI recurrence/stroke (2.9% versus 4.7%) was identified in comparison with controls. No changes in ejection fraction (mean difference: 0.96%; 95% confidence interval, -0.2 to 2.1), end-diastolic volume, or systolic volume were observed compared with controls. These results were not influenced by anterior AMI location, reduced baseline ejection fraction, or the use of MRI for assessing left ventricular parameters. CONCLUSIONS: This meta-analysis of individual patient data from randomized trials in patients with recent AMI revealed that intracoronary cell therapy provided no benefit, in terms of clinical events or changes in left ventricular function. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01098591.

[Ischaemic heart disease in cancer patients. Questions and problems]. / Ischaemiás szívbetegség és tumoros betegségek együttes elofordulása. Kérdések és problémák.

Cardiovascular and oncologic diseases are the causes of more than 50 percent of mortality in Europe. In 2015 oncologic and cardiovascular mortality reached 70 percent in Hungary. Patients who receive anticancer therapies are at a 2- to 7-fold greater long-term risk of acute coronary syndrome; also concomittant oncologic diseases further increase the mortality of myocardial infarction. Unfortunately there is not enough data concerning cardiovascular treatment of oncologic patients because they were excluded from most of the studies and registries. Because there is no clear protocol to treat such patients, only small studies and personal experiences could guide our medical therapies. The role of cardio-oncology is even more important, because due to the new treatments the number of tumor survivors rapidly increases. In the US more than 20 millions survivals are expected by 2025 who were treated by any kind of malignant tumors. It is not surprising that in 2014 the American Society of Cardiology declared cardio-oncology as a special and important field in cardiology, and in 2016 European Society of Cardiology released the first cardio-oncologic guideline. In this review we summarize questions and problems concerning the treatment of oncologic patient with ischaemic heart disease based on resent guidelines, published studies and local protocols. Orv Hetil. 2017; 158(43): 1691-1697.

Renin overexpression leads to increased titin-based stiffness contributing to diastolic dysfunction in hypertensive mRen2 rats.

Hypertension (HTN) is a major risk factor for heart failure. We investigated the influence of HTN on cardiac contraction and relaxation in transgenic renin overexpressing rats (carrying mouse Ren-2 renin gene, mRen2, n = 6). Blood pressure (BP) was measured. Cardiac contractility was characterized by echocardiography, cellular force measurements, and biochemical assays were applied to reveal molecular mechanisms. Sprague-Dawley (SD) rats (n = 6) were used as controls. Transgenic rats had higher circulating renin activity and lower cardiac angiotensin-converting enzyme two levels. Systolic BP was elevated in mRen2 rats (235.11 ± 5.32 vs. 127.03 ± 7.56 mmHg in SD, P < 0.05), resulting in increased left ventricular (LV) weight/body weight ratio (4.05 ± 0.09 vs. 2.77 ± 0.08 mg/g in SD, P < 0.05). Transgenic renin expression had no effect on the systolic parameters, such as LV ejection fraction, cardiomyocyte Ca(2+)-activated force, and Ca(2+) sensitivity of force production. In contrast, diastolic dysfunction was observed in mRen2 compared with SD rats: early and late LV diastolic filling ratio (E/A) was lower (1.14 ± 0.04 vs. 1.87 ± 0.08, P < 0.05), LV isovolumetric relaxation time was longer (43.85 ± 0.89 vs. 28.55 ± 1.33 ms, P < 0.05), cardiomyocyte passive tension was higher (1.74 ± 0.06 vs. 1.28 ± 0.18 kN/m(2), P < 0.05), and lung weight/body weight ratio was increased (6.47 ± 0.24 vs. 5.78 ± 0.19 mg/g, P < 0.05), as was left atrial weight/body weight ratio (0.21 ± 0.03 vs. 0.14 ± 0.03 mg/g, P < 0.05). Hyperphosphorylation of titin at Ser-12742 within the PEVK domain and a twofold overexpression of protein kinase C-α in mRen2 rats were detected. Our data suggest a link between the activation of renin-angiotensin-aldosterone system and increased titin-based stiffness through phosphorylation of titin's PEVK element, contributing to diastolic dysfunction.

The lack of aspirin resistance in patients with coronary artery disease.

BACKGROUND: Aspirin resistance established by different laboratory methods is still a debated problem. Using COX1 specific methods no aspirin resistance was detected among healthy volunteers. Here we tested the effect of chronic aspirin treatment on platelets from patients with stable coronary artery disease. The expression of COX2 mRNA in platelets and its influences on the effect of aspirin was also investigated. METHODS: One hundred and forty four patients were enrolled in the study. The direct measurement of COX1 acetylation was carried out by monoclonal antibodies specific to acetylated and non-acetylated COX1 (acCOX1 and nacCOX1) using Western blotting technique. Arachidonic acid (AA) induced TXB2 production by platelets was measured by competitive immunoassay. AA induced platelet aggregation, ATP secretion and VerifyNow Aspirin Assay were also performed. COX2 and COX1 mRNA expression in platelets were measured in 56 patients by RT-qPCR. RESULTS: In 138 patients only acCOX1 was detected, in the remaining six patients nacCOX1 disappeared after a compliance period. AA induced TXB2 production by platelets was very low in all patients including the 6 patients after compliance. AA induced platelet aggregation, secretion and with a few exceptions the VerifyNow Assay also demonstrated the effect of aspirin. Smoking, diabetes mellitus and inflammatory conditions did not influence the results. The very low amount of COX2 mRNA detected in 39 % of the investigated platelets did not influence the effect of aspirin. CONCLUSIONS: No aspirin resistance was detected among patients with stable coronary artery disease. COX2 expression in platelets did not influence the effect of aspirin.

Integrity(®) bare-metal coronary stent-induced platelet and endothelial cell activation results in a higher risk of restenosis compared to Xience(®) everolimus-eluting stents in stable angina patients.

Drug-eluting stenting (DES) has become a reliable tool for coronary stenting; however, its direct effects on platelet and endothelium function differ from those of bare-metal stenting (BMS). This study involved a periprocedural analysis of various biomarkers of cellular activation after elective DES (Xience(®), Abbott Vascular, Santa Clara, CA, USA) or BMS (Integrity(®), Medtronic, Minneapolis, MI, USA). Forty-nine stable angina patients were recruited: 28 underwent BMS, and 21 received everolimus-eluting stents. Samples were collected (i) prior to stenting, (ii) at 24 hours after procedure, and (iii) after 1 month of dual antiplatelet therapy. Platelet activation was analyzed by surface P-selectin positivity in parallel with plasma levels of soluble P-selectin, CD40L and platelet-derived growth factor (PDGF). Endothelial cell (EC) activation was detected by measuring markers of early (von Willebrand factor) and delayed response (VCAM-1, ICAM-1, E-selectin). Patients were followed for 6 months for the occurrence of restenosis or stent thrombosis. Increased platelet activation was sustained regardless of stent type or antiplatelet medication. Concentrations of most EC markers were more elevated after BMS than after DES. No stent thrombosis was seen, but six BMS subjects displayed restenosis with significantly higher sCD40L (779 [397-899] vs. 381 [229-498] pg/mL; p = 0.032) and sICAM-1 (222 [181-272] vs. 162 [153-223] ng/mL; p = 0.046) levels than in those without complication, while DES patients exhibited significantly decreased PDGF (572 [428-626] vs. 244 [228-311] pg/mL; p = 0.004) after 1 month. Nonresponsiveness to antiplatelet drugs did not influence these changes. In conclusion, the degree of platelet and EC activation suggests that Xience(®) DES may be regarded a safer coronary intervention than Integrity(®) BMS, with a lower risk of in-stent restenosis.

How to test the effect of aspirin and clopidogrel in patients on dual antiplatelet therapy?

Dual antiplatelet therapy with clopidogrel and aspirin is frequently used for the prevention of recurrent ischemic events. Various laboratory methods are used to detect the effect of these drugs administered in monotherapy, however their value in dual therapy has not been explored. Here, we determined which methods used for testing the effect of clopidogrel or aspirin are influenced by the other antiplatelet agent. One arm of the study included 53 ischemic stroke patients being on clopidogrel monotherapy showing effective inhibition of the P2Y12 ADP receptor. Laboratory tests routinely used for the detection of aspirin resistance (arachidonic acid (AA)-induced platelet aggregation/secretion, AA-induced thromboxane B2 (TXB2) production in platelet-rich plasma and VerifyNow Aspirin assay) were carried out on samples obtained from these patients. The other arm of the study involved 52 patients with coronary artery disease being on aspirin monotherapy. Methods used for testing the effect of clopidogrel (ADP-induced platelet aggregation and secretion, flow cytometric analysis of vasodilator-stimulated phosphoprotein (VASP) phosphorylation and a newly developed P2Y12-specific platelet aggregation (ADP[PGE1] test)) were performed on samples obtained from these patients. Clopidogrel monotherapy significantly inhibited AA-induced platelet aggregation and secretion, moreover, AA-induced TXB2 production was also significantly decreased. VASP phosphorylation and AA-induced platelet aggregation showed fair correlation in patients taking clopidogrel only. Clopidogrel did not inhibit the VerifyNow Aspirin test significantly. Aspirin monotherapy influenced ADP-induced platelet aggregation and secretion, but did not have an effect on VASP phosphorylation and on the ADP[PGE1] platelet aggregation test.

Clinical predictors of mortality following rotational atherectomy and stent implantation in high-risk patients: A single center experience.

OBJECTIVES: Our aim was to assess the procedural success and determine the clinical predictors of postprocedure mortality, following rotational atherectomy (RA) and stenting in high-risk patients. BACKGROUND: RA is mainly used to facilitate stenting in complex lesions. Outcomes involving RA and stenting have been investigated, yet high-risk patients have not been adequately described. METHODS: Data of 218 consecutive patients who underwent RA were evaluated in a prospective register. Primary endpoints were the angiographic success and long-term mortality. Secondary endpoints were procedural success, consumption of the angioplasty equipment, and periprocedural major adverse cardiac events. The impact of the relevant angiographic and clinical characteristics on long-term mortality was analyzed using uni- and multivariate Cox regression analysis. RESULTS: Mean age of the patients was 70 ± 8.2 years, diabetes was present in 44%, and chronic renal failure in 29%. Prior myocardial infarction and three-vessel disease amounted to 42.2% and 32.6%, respectively. Altogether, 52.8% of patients underwent RA after a failed, non-RA intervention attempt, and 30.7% of cases presented as acute coronary syndromes. Angiographic success was 100%, and all patients received stents after RA. Periprocedural major adverse cardiac events occurred in five (2.3%) patients. Postprocedural death was investigated, with a mean follow-up of 36 months. Mortality amounted to 37.2%. Multivariate analysis revealed that left ventricular ejection fraction < 50%, glomerular filtration rate < 60 ml/min, cardiogenic shock, and diabetes were the only independent mortality predictors. CONCLUSIONS: We have found that RA and stenting is feasible and viable in an elderly high-risk population, with exceptional procedural success and acceptable long-term results.

Factor XIII B subunit polymorphisms and the risk of coronary artery disease.

The aim of the case-control study was to explore the effect of coagulation factor XIII (FXIII) B subunit (FXIII-B) polymorphisms on the risk of coronary artery disease, and on FXIII levels. In the study, 687 patients admitted for coronary angiography to investigate suspected coronary artery disease and 994 individuals representing the Hungarian population were enrolled. The patients were classified according to the presence of significant coronary atherosclerosis (CAS) and history of myocardial infarction (MI). The F13B gene was genotyped for p.His95Arg and for intron K nt29756 C>G polymorphisms; the latter results in the replacement of 10 C-terminal amino acids by 25 novel amino acids. The p.His95Arg polymorphism did not influence the risk of CAS or MI. The FXIII-B intron K nt29756 G allele provided significant protection against CAS and MI in patients with a fibrinogen level in the upper tertile. However, this effect prevailed only in the presence of the FXIII-A Leu34 allele, and a synergism between the two polymorphisms was revealed. Carriers of the intron K nt29756 G allele had significantly lower FXIII levels, and FXIII levels in the lower tertile provided significant protection against MI. It is suggested that the protective effect of the combined polymorphisms is related to decreased FXIII levels.