Differences in Androgen Receptor Expression in Human Heart Tissue in Various Types of Cardiomyopathy and in Aortic Valve Stenosis.

Background: Sex-specific differences in heart disease outcomes are influenced by the levels of the steroid hormones, estrogen and testosterone. While the roles of estrogen receptors in cardiac disease are well-studied in animals and humans, respective research on androgen receptors (AR) is limited. Here we investigate AR protein and mRNA expression in human myocardium of various cardiac diseases. Methods: AR expression was analyzed by western blotting in myocardium from human non-failing hearts (NF, n = 6) and patients with aortic stenosis (AS, n = 6), hypertrophic cardiomyopathy (HCM, n = 7), dilated cardiomyopathy (DCM, n = 7), and ischemic cardiomyopathy (ICM, n = 7). Using an AR45-specific antibody, a subsequent western blot assessed samples from male and female patients with HCM (n = 10) and DCM (n = 10). The same sample set was probed for full-length AR and AR45 mRNA expression. Immunohistochemistry (IHC) localized AR in myocardium from HCM and AS hearts. Results: Full-length AR was notably enriched in AS and HCM hearts compared to ICM, DCM, and NF. Similarly, AR45 was more abundant in HCM than in DCM. In contrast to the pattern observed for AR protein, full-length AR mRNA levels were lower in HCM compared to DCM, with no discernible difference for the AR45 isoform. Although gender differences in AR expression were not detected in western blots or qRT-PCR, IHC showed stronger nuclear AR signals in males than in females. Conclusions: Our findings indicate disease-specific regulation of AR mRNA and/or AR protein in cardiac hypertrophy, underscoring a potential role in this cardiac pathology.

Mechanistic role of the CREB-regulated transcription coactivator 1 in cardiac hypertrophy.

The sympathetic nervous system is the main stimulator of cardiac function. While acute activation of the ß-adrenoceptors exerts positive inotropic and lusitropic effects by increasing cAMP and Ca2+, chronically enhanced sympathetic tone with changed ß-adrenergic signaling leads to alterations of gene expression and remodeling. The CREB-regulated transcription coactivator 1 (CRTC1) is activated by cAMP and Ca2+. In the present study, the regulation of CRTC1 in cardiomyocytes and its effect on cardiac function and growth was investigated. In cardiomyocytes, isoprenaline induced dephosphorylation, and thus activation of CRTC1, which was prevented by propranolol. Crtc1-deficient mice exhibited left ventricular dysfunction, hypertrophy and enlarged cardiomyocytes. However, isoprenaline-induced contractility of isolated trabeculae or phosphorylation of cardiac troponin I, cardiac myosin-binding protein C, phospholamban, and ryanodine receptor were not altered, suggesting that cardiac dysfunction was due to the global lack of Crtc1. The mRNA and protein levels of the Gαq GTPase activating protein regulator of G-protein signaling 2 (RGS2) were lower in hearts of Crtc1-deficient mice. Chromatin immunoprecipitation and reporter gene assays showed stimulation of the Rgs2 promoter by CRTC1. In Crtc1-deficient cardiomyocytes, phosphorylation of the Gαq-downstream kinase ERK was enhanced. CRTC1 content was higher in cardiac tissue from patients with aortic stenosis or hypertrophic cardiomyopathy and from two murine models mimicking these diseases. These data suggest that increased CRTC1 in maladaptive hypertrophy presents a compensatory mechanism to delay disease progression in part by enhancing Rgs2 gene transcription. Furthermore, the present study demonstrates an important role of CRTC1 in the regulation of cardiac function and growth.

Periodontal Bacterial DNA and Their Link to Human Cardiac Tissue: Findings of a Pilot Study.

BACKGROUND: The aim of this pilot study was to detect correlations of microbiological DNA, inflammatory proteins, and infection parameters in patients with periodontal disease (PD) and valvular heart disease (VHD). METHODS: A perioperative comprehensive dental examination for the investigation of periodontal status, including sampling of specific subgingival bacteria, was performed in 10 patients with indication for surgery of aortic valve stenosis with or without concomitant myocardial revascularization. Standard protocol biopsies were taken from right atrium (A), left septal myocardium (M), and aortic valve (V). Eleven periodontal pathogens DNA in oral and cardiac tissue samples (A/M/V) were analyzed using polymerase chain reaction. For cardiac tissue samples, Western blot analysis of LPS-binding protein (LBP), immunohistochemical (IHC) detection of LBP-big42, LPS-binding protein receptor (CD14), and macrophages (CD68), as well as inflammation scoring measurement were performed. RESULTS: Periodontitis was present in all patients with severe intensity in 7, moderate in 2 and mild in one patient. Same bacterial DNA was detected in A, M, and V in different distribution, and detection was more often in atrium than in myocardium or valve tissue. Morphological investigation revealed increased extracellular inflammatory cell migration. In IHC markers of LBP, CD68 and CD14 showed positive findings for all patients in atrium and myocardium. CONCLUSION: Our results demonstrate the presence of oral bacterial DNA in human cardiac tissue, as well as inflammatory markers potentially indicating connection of PD and VHD. Further investigation is necessary to confirm these preliminary data.

ABCA3 Phenotype in Non-Small Cell Lung Cancer Indicates Poor Outcome.

BACKGROUND: ATP-binding cassette transport protein A3 (ABCA3) is expressed in non-small cell lung cancer (NSCLC). We hypothesize that high-level ABCA3 expression may have a negative prognostic impact in patients with NSCLC. METHODS: In 89 patients with NSCLC and curative intended surgery, we analyzed postoperative immunohistochemistry staining of primary tumors (anti-ABCA3) and clinicopathological parameters. We used a unidimensional four point score (FPS) system for intensity assessment and, furthermore, a combined bidimensional scoring of intensity and quantity resulting in the positive index (PI). RESULTS: Former or never-smokers were more likely to have intermediate or strong ABCA3 unidimensional expression (FPS) compared with current smokers (p < 0.01). Patients >65 years of age had a higher probability of intermediate/strong ABCA3 expression (FPS) than younger patients (p < 0.05). In PI measurement, there were no significant correlations between ABCA3 and clinicopathological parameters. Patients with high-level PI had a significantly worse disease-free survival as well as overall survival than patients with low-level PI (p < 0.05). CONCLUSIONS: High-level PI of ABCA3 in NSCLC showed poor disease-free and overall survival in this patient cohort, potentially indicating the relevance of ABCA3 in lung cancer. This observation needs to be validated in larger series.

Robotic versus thoracoscopic thymectomy: The current evidence.

BACKGROUND: The purpose of this study was to analyze all relevant comparative studies comparing robot-assisted minimally invasive thymectomy (RATS) and video-assisted thoracic surgery thymectomy (VATS) in terms of surgical and short-term outcomes. METHODS: A systematic search for articles describing robot-assisted and video-assisted thymectomy and addressing surgical outcomes, operation time, length of hospitalization, intra-operative blood loss, conversion to sternotomy and post-operative complications was performed using the medical databases. RESULTS: Of the 478 studies from preliminary screening, five articles were included. By pooling these studies, we found no significant differences between the RATS and VATS (odds ratio 1.24 (95% CI 0.51, 3.03; p = 0.63)).There were no significant differences in comparison of conversion rates, operation time (26.29 min (95% CI -2.57, 55.35; p = 0.07)) and length of hospitalization (-1.58 days (95% CI -4.78, 1.62; p = 0.33)). There was a slightly higher blood loss in the RATS group. CONCLUSION: Our meta-analysis did not detect any statistically significant differences in surgery outcomes between the two groups.

Supra-aortic interventions for endovascular exclusion of the entire aortic arch.

OBJECTIVE: Our aim was to analyze the outcomes of endovascular exclusion of the entire aortic arch (proximal landing in zone 0, distal landing in zone III or beyond, after Ishimaru) in which complete surgical debranching of the supra-aortic vessels (I), endovascular supra-aortic revascularization (chimney, fenestrated, or branched grafts) with partial surgical debranching (II), or total endovascular supra-aortic revascularization (III) was additionally performed. METHODS: Publications describing endovascular repair of the aortic arch (2000-2016) were systematically searched and reviewed. RESULTS: From a total of 53 relevant studies including 1853 patients, only 1021 patients undergoing 35 different total aortic arch procedures were found eligible for further evaluation and included in group I, II, or III (429, 190, and 402 patients, respectively). Overall early mortality was higher in group I vs groups II and III (P = .001; 1 - ß = 95.6%) but exceeded in group III (18.6%) and group II (14.0%) vs group I (8.0%; P = .044; 1 - ß = 57.4%) for diseases involving zone 0. Mortality was higher in all subgroups treated for zone 0 disease compared with corresponding subgroups treated for zone I to zone III disease. The incidence of cerebral ischemic events was increased in groups I and II vs group III (7.5% and 11% vs 1.7%; P = .0001) and correlated with early mortality (R2 = .20; P = .033). The incidence of type II endoleaks and endovascular reintervention was similar between groups and correlated with each other (R2 = .37; P = .004). Type Ia endoleak occurred more often in groups II and III than in group I (7.1% and 12.1% vs 5.8%; P = .023) and correlated with midterm mortality (R2 = .53; P = .005). Retrograde type A dissection was low in all groups, whereas aneurysm growth was higher in group III (2.6%, 4.2%, 10.7%; P = .002), correlating with midterm mortality (R2 = .311; P = .009). Surgical revision slightly correlated with surgical complications (R2 = .18; P = .044) but not with mortality (R2 = .10; P = .214). CONCLUSIONS: Because early mortality was significantly higher in patients receiving endovascular treatment for proximal aortic disease, endovascular-based approaches proved to be feasible alternatives to hybrid surgical procedures, especially when they were performed for aneurysms located in the distal aortic arch. Whereas cerebral ischemia accompanies both surgical and endovascular involvement of the supra-aortic vessels, endoleaks and aneurysm growth remain hallmarks of endovascular supra-aortic repair. Because surgical revision had no impact on mortality, complete surgical debranching may become the option of choice for patients with good life expectancy suffering from proximal aortic arch disease, whereas total endovascular procedures could be particularly advantageous in patients with short life expectancy and distal aortic arch disease.

Heart Transplantation in a Toddler with Cardiac Kawasaki Disease.

Kawasaki disease is very rare in Western Europe. The disease may involve coronary arteries. A 2-year-old boy diagnosed with Kawasaki disease had had seizure-like symptoms. Further evaluation revealed recurrent myocardial ischemia and myocardial infarction. Due to extraordinary extension of the coronary disease, myocardial revascularization was not feasible and the toddler underwent successful heart transplantation after 97 days on waiting list.

A minimally invasive approach for open surgical thoracoabdominal aortic replacement: experimental concept for a novel surgical procedure.

Objectives: We aimed to develop a simple, reliable, and timesaving technique for the therapy of thoracoabdominal aortic (TAA) aneurysms that are not suitable for endovascular repair. Methods: In this pilot study, we sought to combine the advantages of classic open vascular procedure with the use of endoscopic surgical tools and small skin incisions to develop a minimally invasive approach for TAA replacement. The following procedures were used: endoscopic exposure and closure of the lower intercostal arteries; small posterolateral thoracotomy and left retroperitoneal incisions to expose the anastomotic regions of the aorta; partial anticoagulation; passive bypass and sequential aortic clamping; tunnelling of the graft through the native aortic lumen (endoaneurysmorrhaphy) and open performance of vascular anastomosis. Results: Five mixed-breed dogs (25-35 kg) underwent minimally invasive TAA replacement. All animals survived the operation without blood transfusion (lowest Hb = 5.5 mg/dl). Total operation time was 364 ± 46.3 min. Clamping times were 17.6 ± 3.2 min for proximal anastomosis, 33.2 ± 2.48 min for visceral patch and 11 ± 2.3 min for distal anastomosis. The pull-through procedure of graft through the native aorta was performed during the visceral clamp time. Conclusions: Surgical replacement of the TAA through small transverse incisions of the thoracic and abdominal wall is feasible and allows open performance of all vascular anastomosis with no leakage at any anastomotic site. Further experimental studies and clinical implementation are needed to establish the safety and long-term outcome of minimally invasive TAA replacement as a possible primary therapeutic tool for complex aneurysms that are not suitable for endovascular treatment and require open surgical repair.

A randomized, parallel group, double-blind study of ticagrelor compared with aspirin for prevention of vascular events in patients undergoing coronary artery bypass graft operation: Rationale and design of the Ticagrelor in CABG (TiCAB) trial: An Investigator-Initiated trial.

BACKGROUND: For patients with coronary artery disease undergoing coronary bypass surgery, acetylsalicylic acid (ASA) currently represents the gold standard of antiplatelet treatment. However, adverse cardiovascular event rates in the first year after coronary artery bypass grafting (CABG) still exceed 10%. Graft failure, which is predominantly mediated by platelet aggregation, has been identified as a major contributing factor in this context. Therefore, intensified platelet inhibition is likely to be beneficial. Ticagrelor, an oral, reversibly binding and direct-acting P2Y12 receptor antagonist, provides a rapid, competent, and consistent platelet inhibition and has shown beneficial results compared with clopidogrel in the subset of patients undergoing bypass surgery in a large previous trial. HYPOTHESIS: Ticagrelor is superior to ASA for the prevention of major cardiovascular events within 1 year after CABG. STUDY DESIGN: The TiCAB trial (NCT01755520) is a multicenter, phase III, double-blind, double-dummy, randomized trial comparing ticagrelor with ASA for the prevention of major cardiovascular events within 12 months after CABG. Patients undergoing CABG will be randomized in a 1:1 fashion to either ticagrelor 90 mg twice daily or ASA 100 mg once daily. The study medication will be started within 24 hours after surgery and maintained for 12 months. The primary end point is the composite of cardiovascular death, myocardial infarction, stroke, and repeat revascularization at 12 months after CABG. The sample size is based on an expected event rate of 13% of the primary end point within the first 12 months after randomization in the control group, a 2-sided α level of .0492 (to preserve the overall significance level of .05 after planned interim analysis), a power of 0.80%, 2-sided testing, and an expected relative risk of 0.775 in the active group compared with the control group and a dropout rate of 2%. According to power calculations based on a superiority design for ticagrelor, it is estimated that 3,850 patients should be enrolled. SUMMARY: There is clinical equipoise on the issue of optimal platelet inhibition after CABG. The TiCAB trial will provide a pivotal comparison of the efficacy and safety of ticagrelor compared with ASA after CABG.

Aneurysm of the pulmonary vein: an unusual cause of stroke.

This clinical report deals with a giant true pulmonary venous aneurysm, which was partially thrombosed. The overall incidence of pulmonary venous aneurysms is unknown, and they are reported only occasionally. We present the case of a previously healthy man with acute onset of ischemic cerebral stroke. The cause was a thrombus in a huge aneurysm of the left superior pulmonary vein. The patient subsequently underwent uncomplicated therapy for stroke, including thrombolysis followed by excision of the giant pulmonary venous aneurysm. As curative therapy we recommend complete resection of this rare entity.

Ca2+/calmodulin-dependent protein kinase II and protein kinase A differentially regulate sarcoplasmic reticulum Ca2+ leak in human cardiac pathology.

BACKGROUND: Sarcoplasmic reticulum (SR) Ca(2+) leak through ryanodine receptor type 2 (RyR2) dysfunction is of major pathophysiological relevance in human heart failure (HF); however, mechanisms underlying progressive RyR2 dysregulation from cardiac hypertrophy to HF are still controversial. METHODS AND RESULTS: We investigated healthy control myocardium (n=5) and myocardium from patients with compensated hypertrophy (n=25) and HF (n=32). In hypertrophy, Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and protein kinase A (PKA) both phosphorylated RyR2 at levels that were not different from healthy myocardium. Accordingly, inhibitors of these kinases reduced the SR Ca(2+) leak. In HF, however, the SR Ca(2+) leak was nearly doubled compared with hypertrophy, which led to reduced systolic Ca(2+) transients, a depletion of SR Ca(2+) storage and elevated diastolic Ca(2+) levels. This was accompanied by a significantly increased CaMKII-dependent phosphorylation of RyR2. In contrast, PKA-dependent RyR2 phosphorylation was not increased in HF and was independent of previous ß-blocker treatment. In HF, CaMKII inhibition but not inhibition of PKA yielded a reduction of the SR Ca(2+) leak. Moreover, PKA inhibition further reduced SR Ca(2+) load and systolic Ca(2+) transients. CONCLUSIONS: In human hypertrophy, both CaMKII and PKA functionally regulate RyR2 and may induce SR Ca(2+) leak. In the transition from hypertrophy to HF, the diastolic Ca(2+) leak increases and disturbed Ca(2+) cycling occurs. This is associated with an increase in CaMKII- but not PKA-dependent RyR2 phosphorylation. CaMKII inhibition may thus reflect a promising therapeutic target for the treatment of arrhythmias and contractile dysfunction.

Intracellular ATP-binding cassette transporter A3 is expressed in lung cancer cells and modulates susceptibility to cisplatin and paclitaxel.

Patients with advanced-stage bronchial cancer benefit from systemic cytostatic therapy, in particular from regimens integrating cisplatin and taxanes. However, eventual disease progression leads to a fatal outcome in most cases, originating from tumor cells resisting chemotherapy. We here show that the intracellular ATP-binding cassette transporter A3 (ABCA3), previously recognized as critical for the secretion of surfactant components from type 2 pneumocytes, is expressed in non-small-cell lung cancer (NSCLC) cells. With some heterogeneity in a given specimen, expression levels detected immunohistochemically in primary cancer tissue were highest in adenocarcinomas and lowest in small cell lung cancers. Genetic silencing of ABCA3 in the NSCLC cell line models A549, NCI-H1650 and NCI-H1975 significantly increased tumor cell susceptibility to the cytostatic effects of both cisplatin (in all cell lines) and paclitaxel (in two of three cell lines). Taken together, ABCA3 emerges as a modulator of NSCLC cell susceptibility to cytostatic therapy.

Cardiogenic shock due to myocardial infarction: diagnosis, monitoring and treatment: a German-Austrian S3 Guideline.

INTRODUCTION: Infarction-related cardiogenic shock (ICS) is usually due to left-ventricular pump failure. With a mortality of 30% to 80%, ICS is the most common cause of death from acute myocardial infarction. The S3 guideline presented here characterizes the current evidence-based treatment of ICS: early revascularization, treatment of shock, and intensive care treatment of multi-organ dysfunction syndrome (MODS) if it arises. The success or failure of treatment for MODS determines the outcome in ICS. METHODS: Experts from eight German and Austrian specialty societies analyzed approximately 3600 publications that had been retrieved by a systematic literature search. Three interdisciplinary consensus conferences were held, resulting in the issuing of 111 recommendations and algorithms for this S3 guideline. RESULTS: Early revascularization of the occluded vessel, usually with a percutaneous coronary intervention (PCI), is of paramount importance. The medical treatment of shock consists of dobutamine as the inotropic agent and norepinephrine as the vasopressor of choice and is guided by a combination of pressure and flow values, or by the cardiac power index. Levosimendan can be given in addition to treat catecholamine-resistant shock. For patients with ICS who are treated with PCI, the current S3 guideline differs from the European and American myocardial infarction guidelines with respect to the recommendation for intra-aortic balloon pulsation (IABP): Whereas the former guidelines give a class I recommendation for IABP, this S3 guideline states only that IABP "can" be used in this situation, in view of the poor state of the evidence. Only for patients being treated with systemic fibrinolysis is IABP weakly recommended (IABP "should" be used in such cases). With regard to the optimal intensive-care interventions for the prevention and treatment of MODS, recommendations are given concerning ventilation, nutrition, erythrocyte-concentrate transfusion, prevention of thrombosis and stress ulcers, follow-up care, and rehabilitation. DISCUSSION: The goal of this S3 guideline is to bring together the types of treatment for ICS that lie in the disciplines of cardiology and intensive-care medicine, as patients with ICS die not only of pump failure, but also (and even more frequently) of MODS. This is the first guideline that adequately emphasizes the significance of MODS as a determinant of the outcome of ICS.

Impact of the learning curve on outcomes after percutaneous mitral valve repair with MitraClip and lessons learned after the first 75 consecutive patients.

AIMS: Mitral valve regurgitation plays a significant role in the aetiology and course of heart failure. We investigated the impact of the learning curve on outcomes after percutaneous mitral valve repair with MitraClip. METHODS AND RESULTS: Outcomes of the first 75 consecutive patients treated with MitraClip at our centre were stratified by subsequent treatment periods (25 patients each). Median total procedure time and device time decreased from 180 and 105 min in period 1 to 95 and 55 min in period 3 (P < 0.005 each). There was an excess of total safety events in period 1 (n = 16) that decreased in periods 2 and 3 (n = 6 and 3, P = 0.0003). Acute procedural success [APS; clip successfully placed and mitral regurgitation (MR) grade ≤2+ at discharge] was 80% in periods 1 and 2, but 92% in period 3 (P = 0.46). At 6 months, improvement in durability and completeness of mitral valve repair was evident: 89.4% of patients in period 3 and 65.0% in period 1 had MR ≤2+ at 6 months (P = 0.03). Within 30 days, no patient sustained myocardial infarction or stroke, and mortality was 2.7% for all patients without significant differences regarding periods. Furthermore, while treatment period did not affect mid-term survival and hospitalization for heart failure, failure of APS, STS (Society of Thoracic Surgeons) score ≥15%, and overt right heart failure at baseline predicted increased mortality. CONCLUSION: MitraClip showed a learning curve regarding mid-term durability and completeness of mitral valve repair, and APS predicted mortality. Recently published studies should be interpreted in consideration of these findings.

Prognostic value of chromosomal imbalances in squamous cell carcinoma and adenocarcinoma of the lung.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the most aggressive tumors, with a very low overall survival rate. We investigated surgically resected squamous cell carcinoma (SCC) and adenocarcinoma (AC) to identify chromosomal imbalances and their value for individual prognostication. METHODS: A total of 80 cases, including 55 SCC and 25 AC, were retrospectively analyzed by comparative genomic hybridization. To model the sequential cytogenetic events, an oncogenetic tree model was applied based on maximum likelihood estimation. Clinicopathologic data and follow-up data were correlated with chromosomal imbalances. RESULTS: Fifty-one percent of patients were in stage I, 32% in stage II, and 17% in stage III, without statistically significant differences in staging distribution between SCC and AC. The average number of copy number imbalances was higher in SCC than in AC (9.4±1.2 vs 5.4±1.1; p=0.11). Frequency of chromosomal imbalances at -3p, +3q, -4q, +5q, -5q, +7q, and -13q were significantly different between SCC and AC. Subsequently, oncogenetic tree modeling identified different clusters of chromosomal imbalances for SCC and AC. Appearance of the -3p-cluster in SCC was associated with decreased overall survival independent of clinicopathologic parameters (mean, 42.8±7.5 months vs 80.1±9.1 months, log rank p=0.019), whereas in AC no prognostic value could be identified for specific clusters of chromosomal imbalances. CONCLUSIONS: Although, the limited number of analyzed cases allows a cautious statement on chromosomal imbalances, the oncogenetic tree modeling suggests distinct patterns of cytogenetic evolution for SCC and AC with implications for clinical outcome in SCC.

Comparison of chromosomal aberrations in primary colorectal carcinomas to their pulmonary metastases.

Pulmonary metastases (PM) are frequent in colorectal carcinoma (CRC). However, little is known about the chromosomal imbalances in CRC that accompany metastatic pulmonary disease. We investigated tumor specimens of CRC (n=30) and their corresponding PM by comparative genomic hybridization (CGH). There were no substantial differences in the degree of chromosomal instability between CRC and PM, neither in average number of copy alterations (ANCA; 6.6 ± 0.8 and 7.7 ± 0.9) nor in gains (2.6 ± 0.5 and 2.6 ± 0.4), losses (3.6 ± 0.5 and 4.8 ± 0.6), or amplifications (0.4 ± 0.1 and 0.3 ± 0.1). Basically, similar patterns of chromosomal imbalances could be identified in both CRC and corresponding PM, most frequently including chromosomal gains at 7, 8q, 13q, and 20q, as well as losses at 4, 8p, 18q, and 20p. CRC and corresponding PM differed in frequencies for losses at chromosome arm 5q (3 vs. 26%; P=0.012). Losses at 4q and 11q in CRC were significantly associated with lower 5-year survival rates (80 vs. 24%, P=0.026 and 74 vs. 17%, P=0.007, respectively), and they may represent candidates for adverse prognostic markers in primary CRC.

Limitations of FKBP12.6-directed treatment strategies for maladaptive cardiac remodeling and heart failure.

Sarcoplasmic reticulum (SR) calcium (Ca) leak can be reduced by enhancing FKBP12.6 binding to SR Ca release channels (RyR2) and expression of a "sticky" FKBP12.6(D37S) mutant may correct reduced binding stoichiometry in RyR2 from failing hearts. Both calcium/calmodulin-dependent protein kinase IIδc (CaMKIIδc) and protein kinase A (PKA) are activated in heart failure and promote SR Ca leak at RyR2. It is possible that FKBP12.6 dissociation from RyR2 may promote remodeling and that interventions to reassociate FKBP12.6 with RyR2 reflect a future therapeutic strategy. We created transgenic (TG) mice expressing FKBP12.6(D37S) and tested their capacity to improve intracellular Ca handling and pathological remodeling in vivo. FKBP12.6(D37S) TG mice were cross-bred with CaMKIIδc TG mice, which are known to exhibit pronounced RyR2 dysfunction and heart failure. We observed a significant improvement of post-rest Ca transients and a higher SR Ca content in FKBP12.6(D37S) TG mice. In double-TG mice, a marked reduction of SR Ca spark frequency indicated reduced SR Ca leak but neither SR Ca transient amplitude, SR Ca content nor morphological or functional parameters improved in vivo. Likewise, FKBP12.6(D37S) TG mice subjected to increased afterload after aortic banding exhibited higher SR Ca load but did not exhibit any improvement in hypertrophic growth or functional decline. Enhancement of FKBP12.6-RyR2 binding markedly reduced RyR2 Ca leak in CaMKIIδc-induced heart failure and in pressure overload. Our data suggest that activation of CaMKIIδc and pressure overload confer significant resistance towards approaches aiming at FKBP12.6-RyR2 reconstitution in heart failure and maladaptive remodeling, although RyR2 Ca leak can be reduced.

Relation between renal dysfunction requiring renal replacement therapy and promoter polymorphism of the erythropoietin gene in cardiac surgery.

Several genetic polymorphisms have been identified to play a role in the occurrence and progression of renal dysfunction after cardiac surgery with cardiopulmonary bypass (CPB). Recently, it was demonstrated that the T allele of SNP rs1617640 in the promoter of the erythropoetin (EPO) gene is significantly associated with proliferative diabetic retinopathy (PDR) and end-stage renal disease (ESRD) due to increased EPO expression. This disease risk-associated gene and its potential pathway mediating severe microvascular complications in T-allele carriers could also play a role on renal dysfunction in patients who underwent cardiac surgery with CPB. We hypothesized that the patients' ability to produce increased EPO concentrations will affect morbidity and mortality after CPB. We conducted a prospective single center study between April 2006 and May 2007. In 481 patients who underwent cardiac surgery with CPB we prospectively examined the SNP rs1617640 in the promoter of the EPO gene by DNA sequencing. The patients were grouped according to their genotype (GG, GT, and TT). The genotype distribution of SNP rs1617640 in the promoter of the EPO gene was 36% (TT), 49% (TG), and 15% (GG). There was no difference in age, body mass index, gender, CPB time, or length of stay in intensive care unit. The hospitalization was irrespective of the patients' genotypes. The baseline creatinine in the TT group was 0.2 points higher than in the other groups; however this was without statistical significance in the multivariate analysis. No significant difference was shown in Euroscore, the Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation Score II, Acute Renal Failure Score, or the Risk, Injury, Failure, Loss of Kidney Function Score. The mortality was equal across the genotypes. However, an association between the TT genotype and acute renal replacement therapy (P=0.03), intra-aortic balloon pump usage (P=0.02), and serum creatine phosphokinase-MB increase (P=0.03) were observed after cardiac surgery. Our analysis suggests that the risk allele (T) of rs1617640 plays a role in the development of renal dysfunction after cardiac surgery with CPB. Patients with the TT risk allele required more frequent acute renal replacement therapy. Since our result is close to the border of significance, this hypothesis should be investigated in larger prospective studies with long-term follow-up to emphasize this polymorphism as a potential risk factor.