Localization of group II and III metabotropic glutamate receptors at pre- and postsynaptic sites of inner hair cell ribbon synapses

Glutamate is the major excitatory neurotransmitter in the CNS binding to a variety of glutamate receptors. Metabotropic glutamate receptors (mGluR1 to mGluR8) can act excitatory or inhibitory, depending on associated signal cascades. Expression and localization of inhibitory acting mGluRs at inner hair cells (IHCs) in the cochlea are largely unknown. Here, we analyzed expression of mGluR2, mGluR3, mGluR4, mGluR6, mGluR7, and mGluR8 and investigated their localization with respect to the presynaptic ribbon of IHC synapses. We detected transcripts for mGluR2, mGluR3, and mGluR4 as well as for mGluR7a, mGluR7b, mGluR8a, and mGluR8b splice variants. Using receptor-specific antibodies in cochlear wholemounts, we found expression of mGluR2, mGluR4, and mGluR8b close to presynaptic ribbons. Super resolution and confocal microscopy in combination with 3-dimensional reconstructions indicated a postsynaptic localization of mGluR2 that overlaps with postsynaptic density protein 95 on dendrites of afferent type I spiral ganglion neurons. In contrast, mGluR4 and mGluR8b were expressed at the presynapse close to IHC ribbons. In summary, we localized in detail 3 mGluR types at IHC ribbon synapses, providing a fundament for new therapeutical strategies that could protect the cochlea against noxious stimuli and excitotoxicity

Factors associated with safe early discharge after transcatheter aortic valve implantation

  Background: As transcatheter aortic valve implantation (TAVI) becomes more straightforward, a larger proportion of patients will be well enough to be discharged early. This study sought to charac­terise the clinical features that allowed patients to be discharged early after TAVI and to evaluate the safety of an early discharge policy. Methods: All patients undergoing TAVI at the above cited center from August 2007 to March 2015 were included in this study. Baseline characteristics, in-hospital outcomes, re-admissions and mortality were compared. Results: Three hundred thirty-seven TAVIs were performed during the study period, and 18 died in-hospital (18/337, 5.3%). Of the remaining patients, 56 were discharged within 3 days of the index procedure (‘early discharge group’ 56/319, 17.5%). There was no difference between the early discharge and late discharge group in terms of Valve Academic Research Consortium-2 (VARC-2) criteria out­comes, all-cause re-admission rates and the need for permanent pacemaker implantation. Mortality at 1 year was better among the early discharge group (3.6% vs. 15.6%, p = 0.014); a reflection of baseline clinical differences. Conclusion: Early discharge of clinically selected TAVI patients is safe and appropriate. Lower logistic EuroSCORE, smaller delta creatinine and not developing any complications are factors associated with early discharge. (Cardiol J 2018; 25, 1: 14–23

SOURCE 3: 1-year outcomes post-transcatheter aortic valve implantation using the latest generation of the balloon-expandable transcatheter heart valve

AIMS: Transcatheter aortic valve implantation (TAVI) has developed from a procedure for patients with aortic stenosis inoperable or high risk for surgery, into a treatment option even for intermediate risk elderly patients. This development has been facilitated by the clinical learning curve and constant improvements of transcatheter heart valves used. We present total 1-year results of SOURCE 3, the European post-approval multicentre registry of the latest generation balloon expandable SAPIEN 3TM (Edwards Lifesciences, Irvine, CA, USA). METHODS AND RESULTS: Participating centres have submitted their consecutive experience with the SAPIEN 3, dependent on patients consent. Data were prospectively collected and all end point-related outcomes adjudicated according to VARC-2 definitions by an independent committee. Between July 2014 and October 2015, in total 1946 patients (mean age 81.6\u2009\ub1\u20096.7\u2009years, 52% male) were enrolled in 80 centres from 10 European countries. At 1\u2009year, all-cause mortality was 12.6%, cardiovascular mortality 8.0%, stroke 3.1%, disabling stroke 1.4%, and rate of new pacemakers 13.2%. Causes of death were 62.0% cardiovascular and 38.0% non-cardiovascular, with heart failure (13.4%) and pulmonary complications (12.7%) being the main reasons for fatal outcomes. Multivariable analysis identified New York Heart Association Class IV and renal insufficiency as predictors of mortality, while higher BMI's improved survival. Severe (zero) and moderate paravalvular leakage (2.6%) was rare at 1\u2009year. CONCLUSION: In SOURCE 3, we observe a low complication rate and mortality at 1\u2009year. Given the low incidence of higher degree paravalvular leakages, this variable did no longer affect outcome. Clinicaltrial.gov number: NCT02698956

SOURCE 3 Registry Design and 30-Day Results of the European Postapproval Registry of the Latest Generation of the SAPIEN 3 Transcatheter Heart Valve

BACKGROUND: The SOURCE 3 Registry (SAPIEN Aortic Bioprosthesis European Outcome) is a European multicenter, observational registry of the latest generation of transcatheter heart valve, the SAPIEN 3 (Edwards Lifesciences, Irvine, CA). Its purpose is to document outcomes of clinical safety and performance after European approval was given. METHODS: Here, we present the 30-day outcome of the SOURCE 3 Registry. All data are self-reported, and all participating centers have committed to support their consecutive experience with the SAPIEN 3 transcatheter heart valve, dependent on patient consent, before the start of the study. Adverse events are defined with Valve Academic Research Consortium 2 criteria and adjudicated by an independent clinical events committee. RESULTS: A total of 1950 patients from 80 centers in 10 countries were enrolled between July 2014 and October 2015. Of those, 1947 patients underwent transcatheter aortic valve implantation (TAVI) with the SAPIEN 3 (mean age, 81.6 +/- 6.6 years; 48.1% female). Main comorbidities included coronary artery disease (51.5%), renal insufficiency (27.4%), diabetes mellitus (29.5%), chronic obstructive pulmonary disease (16.0%), and a mean logistic EuroSCORE of 18.3 +/- 13.2. Transfemoral access was used in 87.1% (n=1695); nontransfemoral, in 252 patients. Conscious sedation was used in 59.9% of transfemoral procedures, and in 50% of patients, TAVI was performed without aortic balloon valvuloplasty. Implantation success (1 valve in the intended location) was 98.3%. Conversion to conventional surgery (0.6%) and use of cardiopulmonary bypass (0.7%) were rare. Adverse events were low, with site-reported 30-day all-cause mortality of 2.2%, cardiovascular mortality of 1.1%, stroke of 1.4%, major vascular complications of 4.1%, life-threatening bleeding of 5%, and post-TAVI pacemaker implantation of 12%. Moderate or greater paravalvular regurgitation was observed in 3.1% of reporting patients. CONCLUSIONS: Results from the SOURCE 3 Registry demonstrate contemporary European trends and good outcomes of TAVI in daily practice when this third-generation TAVI device is used.Peer reviewe

Local versus general anesthesia for transcatheter aortic valve implantation (TAVR) – systematic review and meta-analysis

BACKGROUND: The hypothesis of this study was that local anesthesia with monitored anesthesia care (MAC) is not harmful in comparison to general anesthesia (GA) for patients undergoing Transcatheter Aortic Valve Implantation (TAVR). TAVR is a rapidly spreading treatment option for severe aortic valve stenosis. Traditionally, in most centers, this procedure is done under GA, but more recently procedures with MAC have been reported. METHODS: This is a systematic review and meta-analysis comparing MAC versus GA in patients undergoing transfemoral TAVR. Trials were identified through a literature search covering publications from 1 January 2005 through 31 January 2013. The main outcomes of interest of this literature meta-analysis were 30-day overall mortality, cardiac-/procedure-related mortality, stroke, myocardial infarction, sepsis, acute kidney injury, procedure time and duration of hospital stay. A random effects model was used to calculate the pooled relative risks (RR) with 95% confidence intervals. RESULTS: Seven observational studies and a total of 1,542 patients were included in this analysis. None of the studies were randomized. Compared to GA, MAC was associated with a shorter hospital stay (-3.0 days (-5.0 to -1.0); P = 0.004) and a shorter procedure time (MD -36.3 minutes (-58.0 to -15.0 minutes); P <0.001). Overall 30-day mortality was not significantly different between MAC and GA (RR 0.77 (0.38 to 1.56); P = 0.460), also cardiac- and procedure-related mortality was similar between both groups (RR 0.90 (0.34 to 2.39); P = 0.830). CONCLUSION: These data did not show a significant difference in short-term outcomes for MAC or GA in TAVR. MAC may be associated with reduced procedural time and shorter hospital stay. Now randomized trials are needed for further evaluation of MAC in the setting of TAVR

Systemic inflammation and oxidative stress contribute to acute kidney injury after transcatheter aortic valve implantation

Background: Acute kidney injury (AKI) is a frequent complication of transcatheter aortic valve implantation (TAVI) and has been linked to preexisting comorbidities, peri-procedural hypotension, and systemic inflammation. The extent of systemic inflammation after TAVI is not fully understood. Our aim was to characterize the inflammatory response after TAVI and evaluate its contribution to the mechanism of post-procedural AKI. Methods: One hundred and five consecutive patients undergoing TAVI at our institution were included. We analyzed the peri-procedural inflammatory and oxidative stress responses by measuring a range of biomarkers (including C-reactive protein [hsCRP], cytokine levels, and myeloperoxidase [MPO]), before TAVI and 6, 24, and 48 hours post-procedure. We correlated this with changes in renal function and patient and procedural characteristics. Results: We observed a significant increase in plasma levels of pro-inflammatory cytokines (hsCRP, interleukin 6, tumor necrosis factor alpha receptors) and markers of oxidative stress (MPO) after TAVI. The inflammatory response was significantly greater after trans-apical (TA) TAVI compared to trans-femoral (TF). This was associated with a higher incidence of AKI in the TA cohort compared to TF (44% vs. 8%, respectively, p &lt; 0.0001). The incidence of AKI was significantly lower when N-acetylcysteine (NAC) was given peri-procedurally (12% vs. 38%, p &lt; 0.005). In multivariate analysis, only the TA approach and no use of NAC before the procedure were independent predictors of AKI. Conclusions: TAVI creates a significant post-procedural inflammatory response, more so with the TA approach. Mechanisms of AKI after TAVI are complex. Inflammatory response, hypoperfusion, and oxidative stress may all play a part and are potential therapeutic targets to reduce/prevent AKI

Contemporary Presentation and Management of Valvular Heart Disease The EURObservational Research Programme Valvular Heart Disease II Survey

Background: Valvular heart disease (VHD) is an important cause of mortality and morbidity and has been subject to important changes in management. The VHD II survey was designed by the EURObservational Research Programme of the European Society of Cardiology to analyze actual management of VHD and to compare practice with guidelines. Methods: Patients with severe native VHD or previous valvular intervention were enrolled prospectively across 28 countries over a 3-month period in 2017. Indications for intervention were considered concordant if the intervention was performed or scheduled in symptomatic patients, corresponding to Class I recommendations specified in the 2012 European Society of Cardiology and in the 2014 American Heart Association/American College of Cardiology VHD guidelines. Results: A total of 7247 patients (4483 hospitalized, 2764 outpatients) were included in 222 centers. Median age was 71 years (interquartile range, 62-80 years); 1917 patients (26.5%) were >= 80 years; and 3416 were female (47.1%). Severe native VHD was present in 5219 patients (72.0%): aortic stenosis in 2152 (41.2% of native VHD), aortic regurgitation in 279 (5.3%), mitral stenosis in 234 (4.5%), mitral regurgitation in 1114 (21.3%; primary in 746 and secondary in 368), multiple left-sided VHD in 1297 (24.9%), and right-sided VHD in 143 (2.7%). Two thousand twenty-eight patients (28.0%) had undergone previous valvular intervention. Intervention was performed in 37.0% and scheduled in 26.8% of patients with native VHD. The decision for intervention was concordant with Class I recommendations in symptomatic patients with severe single left-sided native VHD in 79.4% (95% CI, 77.1-81.6) for aortic stenosis, 77.6% (95% CI, 69.9-84.0) for aortic regurgitation, 68.5% (95% CI, 60.8-75.4) for mitral stenosis, and 71.0% (95% CI, 66.4-75.3) for primary mitral regurgitation. Valvular interventions were performed in 2150 patients during the survey; of them, 47.8% of patients with single left-sided native VHD were in New York Heart Association class III or IV. Transcatheter procedures were performed in 38.7% of patients with aortic stenosis and 16.7% of those with mitral regurgitation. Conclusions: Despite good concordance between Class I recommendations and practice in patients with aortic VHD, the suboptimal number in mitral VHD and late referral for valvular interventions suggest the need to improve further guideline implementation