Pericardial Fluid Accumulates microRNAs That Regulate Heart Fibrosis after Myocardial Infarction.

Pericardial fluid (PF) has been suggested as a reservoir of molecular targets that can be modulated for efficient repair after myocardial infarction (MI). Here, we set out to address the content of this biofluid after MI, namely in terms of microRNAs (miRs) that are important modulators of the cardiac pathological response. PF was collected during coronary artery bypass grafting (CABG) from two MI cohorts, patients with non-ST-segment elevation MI (NSTEMI) and patients with ST-segment elevation MI (STEMI), and a control group composed of patients with stable angina and without previous history of MI. The PF miR content was analyzed by small RNA sequencing, and its biological effect was assessed on human cardiac fibroblasts. PF accumulates fibrotic and inflammatory molecules in STEMI patients, namely causing the soluble suppression of tumorigenicity 2 (ST-2), which inversely correlates with the left ventricle ejection fraction. Although the PF of the three patient groups induce similar levels of fibroblast-to-myofibroblast activation in vitro, RNA sequencing revealed that PF from STEMI patients is particularly enriched not only in pro-fibrotic miRs but also anti-fibrotic miRs. Among those, miR-22-3p was herein found to inhibit TGF-ß-induced human cardiac fibroblast activation in vitro. PF constitutes an attractive source for screening diagnostic/prognostic miRs and for unveiling novel therapeutic targets in cardiac fibrosis.

Interleukin-6, infection and cardiovascular outcomes in acute heart failure: Findings from the EDIFICA registry.

AIMS: Interleukin-6 (IL-6) is upregulated in response to infectious and inflammatory triggers and independently predicts all-cause mortality in acute heart failure (AHF). However, the association of IL-6 with cardiovascular outcomes and its interplay with C-reactive protein and infection, a major precipitating factor in AHF, remains poorly understood. METHODS AND RESULTS: The association between IL-6 and clinical outcomes (180 days) in AHF was evaluated using a cohort of 164 patients from the EDIFICA registry. Median IL-6 levels at admission were 17.4 pg/mL. Patients in the higher admission IL-6 tertile presented with lower blood pressure and more congestion, were diagnosed more frequently with infection, and had a longer hospital stay. Higher IL-6 levels were associated with increased risk of HF rehospitalization (hazard ratio per log2 3.69, 95% confidence interval (CI) 1.26-10.8, p =.017) and the composite of HF rehospitalization or cardiovascular death (hazard ratio per log2 3.50; 95% CI 1.28-9.57; p =.014), independently of major AHF prognosticators, including B-type natriuretic peptide and renal function. However, no independent associations were found for all-cause rehospitalization or mortality. Despite a moderate correlation of IL-6 with C-reactive protein (CRP) levels (R = .51), the latter were not associated with clinical outcomes in this population. CONCLUSIONS: IL-6 levels associate with higher rate of cardiovascular events in AHF, independently of classical prognosticators and evidence of infection, outperforming CRP as an inflammatory outcome biomarker.

A systematic review and meta-analysis of randomized controlled studies comparing off-pump versus on-pump coronary artery bypass grafting in the elderly.

INTRODUCTION: Comparison of short and mid-term outcomes between off-pump CABG (OPCAB) and on-pump CABG (ONCAB) in patients older than 65 throughout a meta-analysis of randomized clinical trials (RCTs). EVIDENCE ACQUISITION: A literature search was conducted using 3 databases. RCTs reporting mortality outcomes of OPCAB versus ONCAB among the elderly were included. Data on myocardial infarction, stroke, re-revascularization, renal failure and composite endpoints after CABG were also collected. Random effects models were used to compute statistical combined measures and 95% confidence intervals (CI). EVIDENCE SYNTHESIS: Five RCTs encompassing 6221 patients were included (3105 OPCAB and 3116 ONCAB). There were no significant differences on mid-term mortality (pooled HR: 1.02, 95%CI: 0.89-1.17, P=0.80) and composite endpoint incidence (pooled HR: 0.98, 95%CI: 0.88-1.09, P=0.72) between OPCAB and ONCAB. At 30-day, there were no differences in mortality, myocardial infarction, stroke and renal complications. The need for early re-revascularization was significantly higher in OPCAB (pooled OR: 3.22, 95%CI: 1.28-8.09, P=0.01), with a higher percentage of incomplete revascularization being reported for OPCAB in trials included in this pooled result (34% in OPCAB vs. 29% in ONCAB, P<0.01). CONCLUSIONS: Data from RCTs in elderly patients showed that OPCAB and ONCAB provide similar mid-term results. OPCAB was associated with a higher risk of early re-revascularization. As CABG on the elderly is still insufficiently explored, further RCTs, specifically designed targeting this population, are needed to establish a better CABG strategy for these patients.

Multiple versus single arterial grafting in the elderly: a meta-analysis of randomized controlled trials and propensity score studies.

INTRODUCTION: The benefit of adding a second arterial conduit is still controversial, mainly in specific subgroups. We conducted a meta-analysis of randomized controlled trials (RCTs) and propensity score (PS) studies comparing survival and early results in elderly patients who underwent coronary artery bypass grafting (CABG) with multiple (MAG) versus single arterial grafting (SAG). EVIDENCE ACQUISITION: MEDLINE, Web of Science and Cochrane Library were used to find relevant literature (1960-April 2020). Survival at a ≥1-year follow-up and early outcomes were evaluated. Outcomes were collected from matched samples or PS adjusted analysis: hazard ratio (HR) along with their variance, frequencies or odds ratios. Random effect models were used to compute combined statistical measures and 95% confidence intervals (CI) through generic inverse variance method (time-to-event) or Mantel-Haenszel method (binary events). EVIDENCE SYNTHESIS: Eleven PS cohorts and 1 RCT comprising >18,800 patients older than 70 (>6200 MAG and >12,500 SAG) were included in this meta-analysis. MAG was associated with lower long-term mortality (pooled HR: 0.81, 95% CI: 0.72-0.91, P<0.01, I2=64%) in the absence of higher risk of early mortality (pooled OR: 0.74, 95% CI: 0.44 to 1.25, P=0.27, I2=0%). In a meta-regression, MAG survival advantage was more pronounced in studies with a higher MAG usage rate (ß=-0.0052, P=0.021). CONCLUSIONS: Current evidence suggests that advanced age should not limit MAG's use considering its benefits in long-term survival. Of note, an individualized patient selection for this approach is warranted.

Chronic Sildenafil Therapy in the ZSF1 Obese Rat Model of Metabolic Syndrome and Heart Failure With Preserved Ejection Fraction.

Although decreased protein kinase G (PKG) activity was proposed as potential therapeutic target in heart failure with preserved ejection fraction (HFpEF), randomized clinical trials (RCTs) with type-5 phosphodiesterase inhibitors (PDE5i) showed neutral results. Whether specific subgroups of HFpEF patients may benefit from PDE5i remains to be defined. Our aim was to test chronic sildenafil therapy in the young male ZSF1 obese rat model of HFpEF with severe hypertension and metabolic syndrome. Sixteen-week-old ZSF1 obese rats were randomly assigned to receive sildenafil 100 mg·Kg-1·d-1 dissolved in drinking water (ZSF1 Ob SIL, n = 8), or placebo (ZSF1 Ob PL, n = 8). A group of Wistar-Kyoto rats served as control (WKY, n = 8). Four weeks later animals underwent effort tests, glucose metabolism studies, hemodynamic evaluation, and samples were collected for aortic ring preparation, left ventricular (LV) myocardial adenosine triphosphate (ATP) quantification, immunoblotting and histology. ZSF1 Ob PL rats showed systemic hypertension, aortic stiffening, impaired LV relaxation and increased LV stiffness, with preserved ejection fraction and cardiac index. Their endurance capacity was decreased as assessed by maximum workload and peak oxygen consumption (V˙O2) and respiratory quotient were increased, denoting more reliance on anaerobic metabolism. Additionally, ATP levels were decreased. Chronic sildenafil treatment attenuated hypertension and decreased LV stiffness, modestly enhancing effort tolerance with a concomitant increase in peak, ATP levels and VASP phosphorylation. Chronic sildenafil therapy in this model of HFpEF of the young male with extensive and poorly controlled comorbidities has beneficial cardiovascular effects which support RCTs in HFpEF patient subgroups with similar features.

Gastric microbiome profile throughout gastric carcinogenesis: beyond helicobacter.

BACKGROUND: Gastric dysbiosis has been hinted as a potential cause of gastric cancer. However, changes in microbiome throughout the major stages of gastric carcinogenesis remain mostly unknown. OBJECTIVE: To describe gastric microbiome at different stages, analysing for the first time dysbiosis specifically in patients with early gastric cancer (EGC). METHODS: Cross-sectional study including patients (n = 77) with endoscopically and histologically confirmed normal stomachs (controls; n = 25), advanced atrophic gastritis with intestinal metaplasia (IM; n = 18) and EGC (n = 34). Endoscopic biopsies from antrum and corpus (n = 154) were analyzed. Next-generation sequencing was performed characterizing microbial communities down to the species level based on full-length 16SrRNA gene profiling. RESULTS: Significant differences were found in the microbiome profile between the groups. Firmicutes were more frequent (p = .012) and Proteobacteria were less frequent (p = .04) both in the IM and EGC when comparing to controls. Relative frequency of Helicobacter pylori, when present, was much higher in the controls (83%) when comparing to the other groups (IM 1%, EGC 27%; p = .006), being the dominant bacteria only in the controls. Dysbiosis was present already and more significantly at the IM stage, with two bacteria progressively increasing from controls to IM then to cancer: Gemella from 1.48 to 3.9% (p = .014); and Streptococcus from 19.3 to 33.7% (p = .04), being the EGC dominant bacteria. CONCLUSIONS: Our results confirm Helicobacter pylori dominancy in non-atrophic stomachs and progressive dysbiosis throughout gastric carcinogenesis. Gemella but particularly Streptococcus is significantly increased in patients with EGC. Specific modulation of these bacteria may change gastric cancer risk.

Nicotinamide for the treatment of heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF) is a highly prevalent and intractable form of cardiac decompensation commonly associated with diastolic dysfunction. Here, we show that diastolic dysfunction in patients with HFpEF is associated with a cardiac deficit in nicotinamide adenine dinucleotide (NAD+). Elevating NAD+ by oral supplementation of its precursor, nicotinamide, improved diastolic dysfunction induced by aging (in 2-year-old C57BL/6J mice), hypertension (in Dahl salt-sensitive rats), or cardiometabolic syndrome (in ZSF1 obese rats). This effect was mediated partly through alleviated systemic comorbidities and enhanced myocardial bioenergetics. Simultaneously, nicotinamide directly improved cardiomyocyte passive stiffness and calcium-dependent active relaxation through increased deacetylation of titin and the sarcoplasmic reticulum calcium adenosine triphosphatase 2a, respectively. In a long-term human cohort study, high dietary intake of naturally occurring NAD+ precursors was associated with lower blood pressure and reduced risk of cardiac mortality. Collectively, these results suggest NAD+ precursors, and especially nicotinamide, as potential therapeutic agents to treat diastolic dysfunction and HFpEF in humans.

The Degree of Cardiac Remodelling before Overload Relief Triggers Different Transcriptome and miRome Signatures during Reverse Remodelling (RR)-Molecular Signature Differ with the Extent of RR.

This study aims to provide new insights into transcriptome and miRome modifications occurring in cardiac reverse remodelling (RR) upon left ventricle pressure-overload relief in mice. Pressure-overload was established in seven-week-old C57BL/6J-mice by ascending aortic constriction. A debanding (DEB) surgery was performed seven weeks later in half of the banding group (BA). Two weeks later, cardiac function was evaluated through hemodynamics and echocardiography, and the hearts were collected for histology and small/bulk-RNA-sequencing. Pressure-overload relief was confirmed by the normalization of left-ventricle-end-systolic-pressure. DEB animals were separated into two subgroups according to the extent of cardiac remodelling at seven weeks and RR: DEB1 showed an incomplete RR phenotype confirmed by diastolic dysfunction persistence (E/e' ≥ 16 ms) and increased myocardial fibrosis. At the same time, DEB2 exhibited normal diastolic function and fibrosis, presenting a phenotype closer to myocardial recovery. Nevertheless, both subgroups showed the persistence of cardiomyocytes hypertrophy. Notably, the DEB1 subgroup presented a more severe diastolic dysfunction at the moment of debanding than the DEB2, suggesting a different degree of cardiac remodelling. Transcriptomic and miRomic data, as well as their integrated analysis, revealed significant downregulation in metabolic and hypertrophic related pathways in DEB1 when compared to DEB2 group, including fatty acid ß-oxidation, mitochondria L-carnitine shuttle, and nuclear factor of activated T-cells pathways. Moreover, extracellular matrix remodelling, glycan metabolism and inflammation-related pathways were up-regulated in DEB1. The presence of a more severe diastolic dysfunction at the moment of pressure overload-relief on top of cardiac hypertrophy was associated with an incomplete RR. Our transcriptomic approach suggests that a cardiac inflammation, fibrosis, and metabolic-related gene expression dysregulation underlies diastolic dysfunction persistence after pressure-overload relief, despite left ventricular mass regression, as echocardiographically confirmed.

Multiple versus single arterial grafting in coronary artery bypass grafting: A meta-analysis of randomized controlled trials and propensity score studies.

OBJECTIVES: We conducted a meta-analysis of randomized controlled trials (RCTs) and propensity score (PS) studies comparing survival and major adverse cardiac and cerebrovascular events (MACCEs) of patients who underwent coronary artery bypass grafting (CABG) with multiple (MAG) versus single arterial grafting (SAG). METHODS: MEDLINE, Web of Science and Cochrane Library were used to find relevant literature (1960-2018). Survival at a follow-up ≥1 year, MACCEs and early outcomes were evaluated. Time-to-event outcomes were collected through hazard ratio (HR) along with their variance, and the other endpoints using frequencies from matched sample or adjusted odds ratios. Random effect models were used to compute combined statistical measures and 95% confidence intervals (CI) through generic inverse variance method (time-to-event) or Mantel-Haenszel method (binary events). RESULTS: Twenty-nine PS cohorts and 8 RCTs comprising 122,832 patients (52,178 MAG and 70,654 SAG) were included in this meta-analysis. MAG was associated with lower early mortality (OR: 0.82, 95%CI: 0.71-0.95, p = .007), long-term mortality (HR: 0.76, 95%CI: 0.73-0.78, p < .001) and MACCEs (HR: 0.85, 95%CI: 0.79-0.91, p < .001). Increased risk of sternal wound complications (SWC) was only observed when the bilateral internal mammary artery configuration was used for MAG (OR MAG BIMA: 1.96, 95%CI: 1.37-2.81, p < .001). CONCLUSION: Although the BIMA configuration increases the risk of SWC, MAG improves both early and long-term survival as well as MACCEs in CABG.

In Vitro Assessment of Cardiac Function Using Skinned Cardiomyocytes.

In this article, we describe the steps required to isolate a single permeabilized ("skinned") cardiomyocyte and attach it to a force-measuring apparatus and a motor to perform functional studies. These studies will allow measurement of cardiomyocyte stiffness (passive force) and its activation with different calcium (Ca2+)-containing solutions to determine, amongst others: maximum force development, myofilament Ca2+-sensitivity (pCa50), cooperativity (nHill) and the rate of force redevelopment (ktr). This method also enables determination of the effects of drugs acting directly on myofilaments and of the expression of exogenous recombinant proteins on both active and passive properties of cardiomyocytes. Clinically, skinned cardiomyocyte studies highlight the pathophysiology of many myocardial diseases and allow in vitro assessment of the impact of therapeutic interventions targeting the myofilaments. Altogether, this technique enables the clarification of cardiac pathophysiology by investigating correlations between in vitro and in vivo parameters in animal models and human tissue obtained during open heart or transplant surgery.

Early dual antiplatelet therapy versus aspirin monotherapy after coronary artery bypass surgery: survival and safety outcomes.

BACKGROUND: There is currently conflicting evidence regarding outcomes of dual antiplatelet therapy (DAPT) in patients following coronary artery bypass grafting (CABG). We aim to compare the survival and safety outcomes of DAPT versus aspirin (ASA) within a 24h window after CABG. METHODS: Single-center retrospective cohort study on consecutive patients undergoing 1st isolated CABG surgery in 2010. Survival analysis (median follow-up 9 years) was performed using Kaplan-Meier curves and multivariable Cox regression using propensity score (PS) as a covariate along with DAPT. Bleeding was assessed through red blood cells' (RBC) transfusion, re-exploration of thorax and drainage. RESULTS: We included 351 patients (251 were DAPT). Kaplan-Meier curves showed similar cumulative survival between groups (9y: 75% DAPT vs. 67% ASA, Log-rank P=0.103), as well as the PS adjusted analysis (HR DAPT: 0.93, 95% CI: 0.57-1.51). We found no differences in early mortality (2 DAPT and 1 ASA). Total median cell-saver transfusion (300 mL vs. 250 mL) and the re-exploration of thorax due to bleeding (1.6% vs. 4%) showed no statistical significance either. On the other hand, postoperative total median chest tube drainage was higher in the ASA group (1220 mL DAPT vs. 1320 mL ASA, P=0.034). There was also a lower frequency of DAPT patients requiring RBC transfusions (≥3 units 4.8% vs. 13%, P=0.009, respectively). Redo-CABG was performed in 3 patients (2 DAPT vs. 1 ASA) during follow-up. CONCLUSIONS: Compared with ASA, DAPT showed a non-significant impact on long-term survival and demonstrated to be a safe option. Further studies are needed to provide recommendations on the therapeutical strategy following CABG.

Update on pathophysiology and preventive strategies of anthracycline-induced cardiotoxicity.

Anthracycline chemotherapy has a prominent role in treating many forms of cancer. Unfortunately, cardiotoxic side effects represent a serious limitation to their use, with doxorubicin being the leading drug of the group. Indeed, anthracycline-induced cardiomyopathy is an important public health concern because it may not be detected for many years and remains a lifelong threat. Even after decades of investigation, neither the exact mode of action of anthracyclines nor the pathways leading to their side effect are fully understood. It is increasingly important to establish collaboration between oncologists and cardiologists to improve the management of cancer patient receiving anthracyclines. This article reviews the clinical course, pathogenesis, cardiac monitoring and new concepts in diagnosing and preventing anthracycline-induced cardiotoxicity.

Early myocardial changes induced by doxorubicin in the nonfailing dilated ventricle.

Several studies have demonstrated that administration of doxorubicin (DOXO) results in cardiotoxicity, which eventually progresses to dilated cardiomyopathy. The present work aimed to evaluate the early myocardial changes of DOXO-induced cardiotoxicity. Male New Zealand White rabbits were injected intravenously with DOXO twice weekly for 8 wk [DOXO-induced heart failure (DOXO-HF)] or with an equivolumetric dose of saline (control). Echocardiographic evaluation was performed, and myocardial samples were collected to evaluate myocardial cellular and molecular modifications. The DOXO-HF group presented cardiac hypertrophy and higher left ventricular cavity diameters, showing a dilated phenotype but preserved ejection fraction. Concerning cardiomyocyte function, the DOXO-HF group presented a trend toward increased active tension without significant differences in passive tension. The myocardial GSSG-to-GSH ratio and interstitial fibrosis were increased and Bax-to- Bcl-2 ratio presented a trend toward an increase, suggesting the activation of apoptosis signaling pathways. The macromolecule titin shifted toward the more compliant isoform (N2BA), whereas the stiffer one (N2B) was shown to be hypophosphorylated. Differential protein analysis from the aggregate-enriched fraction through gel liquid chromatography-tandem mass spectrometry revealed an increase in the histidine-rich glycoprotein fragment in DOXO-HF animals. This work describes novel and early myocardial effects of DOXO-induced cardiotoxicity. Thus, tracking these changes appears to be of extreme relevance for the early detection of cardiac damage (as soon as ventricular dilation becomes evident) before irreversible cardiac function deterioration occurs (reduced ejection fraction). Moreover, it allows for the adjustment of the therapeutic approach and thus the prevention of cardiomyopathy progression. NEW & NOTEWORTHY Identification of early myocardial effects of doxorubicin in the heart is essential to hinder the development of cardiac complications and adjust the therapeutic approach. This study describes doxorubicin-induced cellular and molecular modifications before the onset of dilated cardiomyopathy. Myocardial samples from doxorubicin-treated rabbits showed a tendency for higher cardiomyocyte active tension, titin isoform shift from N2B to N2BA, hypophosphorylation of N2B, increased apoptotic genes, left ventricular interstitial fibrosis, and increased aggregation of histidine-rich glycoprotein.

Hemodynamic and clinical performance of Solo stentless bioprosthetic aortic valves.

OBJECTIVE: To report the hemodynamic profile and short- and medium-term outcomes of Freedom Solo and Solo Smart stentless aortic valves implanted at our center. METHODS: Between 2009 and 2015, all patients undergoing aortic valve replacement using Solo stentless valves at our center were enrolled. Clinical and echocardiographic follow-up was carried out six months postoperatively. Survival and major events, including structural valve deterioration and non-structural valve dysfunction, endocarditis, reoperation and stroke, were assessed through medical records or telephone interview with the referring cardiologist up to November 2015 (mean and maximum follow-up 39±22 and 78 months, respectively). RESULTS: Patients' (n=345) mean age was 72±8 years, 52% were female and median euroSCORE II was 2.7 (1.5-4.7). There was no intraoperative mortality and in-hospital mortality was 2.6%. Postoperatively, mean transvalvular gradient was 11.9±4.5 mmHg and effective orifice area was 1.9±0.5 cm2. Patient-prosthesis mismatch occurred in 14% but was severe in only one patient. Cumulative survival at six years was 72%. Six patients were reoperated: three due to endocarditis, two for structural prosthesis deterioration and one because of periprosthetic fistula. Five patients suffered stroke, three had medically-treated endocarditis and one had structural valve deterioration but was not considered suitable for reoperation. None of the remainder had structural valve deterioration or non-structural valve dysfunction. CONCLUSIONS: Solo stentless aortic valves are safe to implant, with promising clinical outcomes in short- and medium-term assessment. Moreover, they show an excellent hemodynamic performance: low transvalvular gradients, large effective orifice areas and low incidence of patient-prosthesis mismatch.

Survival after bilateral internal mammary artery in coronary artery bypass grafting: Are women at risk?

BACKGROUND: Most observational studies support long-term survival benefit after bilateral internal mammary artery (BIMA) compared with single internal mammary artery (SIMA) coronary artery bypass grafting (CABG) but data on females is scarce. We compared survival and safety of BIMA versus SIMA CABG between males and females at our tertiary care center. METHODS: Single-center retrospective cohort including consecutive patients with at least 2 left-coronary system (LCS) vessel disease who underwent isolated CABG with at least 1 IMA conduit and a minimum of 2 conduits targeting the LCS in 2004-2013. All-cause mortality was the primary outcome, secondary outcomes were early mortality and reoperation due to sternal wound complications (SWC). Kaplan-Meier analysis after inverse probability weighting using propensity score (IPW) was used to compare BIMA and SIMA CABG amongst genders. Results were confirmed in subgroup analysis. RESULTS: BIMA CABG was performed in 39% out of 2424 eligible procedures and in 27% of 460 females. No differences were found in survival after BIMA and SIMA CABG (median and maximum follow-up of 5.5 and 12 years, respectively) but a statistical interaction was observed with gender (P < 0.001). Females who underwent BIMA CABG showed higher mortality (weighted HR in females subset: 3.16; 95% CI: 1.56-6.29, P = 0.001). BIMA CABG showed a higher incidence of reoperation due to SWC (IPW adjusted model OR: 1.74; 95% CI: 1.16-2.60) that was mostly ascribable to males (weighted OR in males: 3.10; 95% CI: 1.74-5.51, P < 0.001). CONCLUSIONS: Females may experience higher mortality after BIMA CABG which should be further explored.

Complex roads from genotype to phenotype in dilated cardiomyopathy: scientific update from the Working Group of Myocardial Function of the European Society of Cardiology.

Dilated cardiomyopathy (DCM) frequently affects relatively young, economically, and socially active adults, and is an important cause of heart failure and transplantation. DCM is a complex disease and its pathological architecture encounters many genetic determinants interacting with environmental factors. The old perspective that every pathogenic gene mutation would lead to a diseased heart, is now being replaced by the novel observation that the phenotype depends not only on the penetrance-malignancy of the mutated gene-but also on epigenetics, age, toxic factors, pregnancy, and a diversity of acquired diseases. This review discusses how gene mutations will result in mutation-specific molecular alterations in the heart including increased mitochondrial oxidation (sarcomeric gene e.g. TTN), decreased calcium sensitivity (sarcomeric genes), fibrosis (e.g. LMNA and TTN), or inflammation. Therefore, getting a complete picture of the DCM patient will include genomic data, molecular assessment by preference from cardiac samples, stratification according to co-morbidities, and phenotypic description. Those data will help to better guide the heart failure and anti-arrhythmic treatment, predict response to therapy, develop novel siRNA-based gene silencing for malignant gene mutations, or intervene with mutation-specific altered gene pathways in the heart.This article is part of the Mini Review Series from the Varenna 2017 meeting of the Working Group of Myocardial Function of the European Society of Cardiology.

Stretch-induced compliance: a novel adaptive biological mechanism following acute cardiac load.

Aims: The heart is constantly challenged with acute bouts of stretching or overload. Systolic adaptations to these challenges are known but adaptations in diastolic stiffness remain unknown. We evaluated adaptations in myocardial stiffness due to acute stretching and characterized the underlying mechanisms. Methods and results: Left ventricles (LVs) of intact rat hearts, rabbit papillary muscles and myocardial strips from cardiac surgery patients were stretched. After stretching, there was a sustained >40% decrease in end-diastolic pressure (EDP) or passive tension (PT) for 15 min in all species and experimental preparations. Stretching by volume loading in volunteers and cardiac surgery patients resulted in E/E' and EDP decreases, respectively, after sustained stretching. Stretched samples had increased myocardial cGMP levels, increased phosphorylated vasodilator-stimulated phosphoprotein phosphorylation, as well as, increased titin phosphorylation, which was reduced by prior protein kinase G (PKG) inhibition (PKGi). Skinned cardiomyocytes from stretched and non-stretched myocardia were studied. Skinned cardiomyocytes from stretched hearts showed decreased PT, which was abrogated by protein phosphatase incubation; whereas those from non-stretched hearts decreased PT after PKG incubation. Pharmacological studies assessed the role of nitric oxide (NO) and natriuretic peptides (NPs). PT decay after stretching was significantly reduced by combined NP antagonism, NO synthase inhibition and NO scavenging, or by PKGi. Response to stretching was remarkably reduced in a rat model of LV hypertrophy, which also failed to increase titin phosphorylation. Conclusions: We describe and translate to human physiology a novel adaptive mechanism, partly mediated by titin phosphorylation through cGMP-PKG signalling, whereby myocardial compliance increases in response to acute stretching. This mechanism may not function in the hypertrophic heart.

Mini-sternotomy versus full sternotomy aortic valve replacement: a single-centre experience.

BACKGROUND: full sternotomy (FS) is the gold standard approach to perform surgical aortic valve replacement (AVR). However, potential advantages of a less traumatic approach fomented the development of so-called minimally invasive procedures, which include upper mini-sternotomy (MS). OBJECTIVE: to compare immediate postoperative clinical results and mid-term mortality after AVR through MS and FS. METHODS: single-centre retrospective study including all patients who underwent isolated AVR through MS between January 1, 2011 and July 31, 2017. These were then matched with patients who underwent the same procedure through FS and by the same surgeons who performed MS, using coarsened exact matching for the variables age, gender, body mass index and diabetes mellitus. Groups were later characterized and compared regarding postoperative results using Qui- -squared and Mann-Whitney tests and regarding mid-term mortality through Kaplan-Meier curves. RESULTS: we included 82 patients (n=41 in each group). Aortic cross clamp [78 vs. 63 minutes, p=0.001] and cardiopulmonary bypass times [107 vs. 90 minutes, p=0.002] were significantly longer in the MS group vs. FS group, respectively. Although without reaching statistical significant difference, a smaller percentage of patients from the MS group required red blood cells transfusions during surgery (39.0% vs. 53.7%, p=0.184). Similar results were found regarding mechanical ventilation, inotropic support, morphine infusion, intensive care unit length of stay and incidence of de novo atrial fibrillation. Cumulative survival at 6 years was 86.7% after MS and 88.5% after FS (p=0.650). CONCLUSIONS: Aortic valve replacement through MS seems to be a safe alternative to the gold standard FS.

Introdução: a esternotomia completa (EC) é a abordagem gold standard da cirurgia de substituição valvular aórtica (SVA). Contudo, as potenciais vantagens de uma abordagem menos traumática promoveram o desenvolvimento de procedimentos minimamente invasivos, incluindo a mini-esternotomia (ME). Objetivo: comparar resultados clínicos no pós-operatório imediato e mortalidade, após SVA por ME e EC. Métodos: estudo retrospetivo unicêntrico incluindo todos os doentes submetidos a SVA isolada por ME, de 1 de janeiro de 2011 a 31 de julho de 2017, emparelhados com doentes submetidos ao mesmo procedimento, pelos mesmos cirurgiões por EC. Utilizou-se o método de emparelhamento coarsened exact matching para as variáveis idade, género, índice massa-corporal e diabetes mellitus. Os grupos foram caracterizados e comparados quanto aos resultados no pós-operatório imediato através de testes Qui-quadrado e Mann-Whitney e quanto à sobrevida através de curvas de Kaplan-Meier. Resultados: foram incluídos 82 doentes (n=41 em cada grupo). Os tempos de clampagem aórtica [78 vs. 63 minutos, p=0,001] e de circulação extracorporal [107 vs. 90 minutos, p=0.002] foram significativamente superiores no grupo ME vs. EC, respetivamente. Embora a frequência de transfusões sanguíneas durante a cirurgia fosse menor no grupo ME, essa diferença não foi estatisticamente significativa (39,0% vs. 53,7%, p=0,184). Os resultados foram semelhantes relativamente ao tempo de ventilação mecânica, suporte inotrópico, infusão de morfina, tempo de permanência em unidade de cuidados intensivos e incidência de fibrilação auricular de novo. A sobrevida cumulativa aos 6 anos foi de 86,7% após ME e 88,5% após EC (p=0,650). Conclusões: a SVA por ME parece ser uma alternativa segura comparativamente ao gold standard EC.