A new HPF specimen carrier adapter for the use of high-pressure freezing with cryo-scanning electron microscope: two applications: stearic acid organization in a hydroxypropyl methylcellulose matrix and mice myocardium .

Cryogenic transmission electron microscopy of high-pressure freezing (HPF) samples is a well-established technique for the analysis of liquid containing specimens. This technique enables observation without removing water or other volatile components. The HPF technique is less used in scanning electron microscopy (SEM) due to the lack of a suitable HPF specimen carrier adapter. The traditional SEM cryotransfer system (PP3000T Quorum Laughton, East Sussex, UK; Alto Gatan, Pleasanton, CA, USA) usually uses nitrogen slush. Unfortunately, and unlike HPF, nitrogen slush produces water crystal artefacts. So, we propose a new HPF specimen carrier adapter for sample transfer from HPF system to cryogenic-scanning electronic microscope (Cryo-SEM). The new transfer system is validated using technical two applications, a stearic acid in hydroxypropyl methylcellulose solution and mice myocardium. Preservation of samples is suitable in both cases. Cryo-SEM examination of HPF samples enables a good correlation between acid stearic liquid concentration and acid stearic occupation surface (only for homogeneous solution). For biological samples as myocardium, cytoplasmic structures of cardiomyocyte are easily recognized with adequate preservation of organelle contacts and inner cell organization. We expect this new HPF specimen carrier adapter would enable more SEM-studies using HPF

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Prevention of Atrial Fibrillation After Atrial Flutter Ablation With Ramipril (from the PREFACE Study)

International audienceThe clinical efficacy of the inhibitors of the renin-angiotensin-aldosterone system (RAAS) as an upstream therapy for atrial fibrillation (AF) prevention is controversial. No study has itemized so far the role of RAAS inhibitors in AF prevention after atrial flutter (AFL) ablation. This trial aims to investigate the effect of ramipril compared with placebo on AF occurrence in patients hospitalized for AFL ablation without structural heart disease. The Prevention of Atrial Fibrillation by Inhibition Conversion Enzyme (ICE) After Radiofrequency Ablation of Atrial Flutter (PREFACE) trial was a prospective, multicenter, randomized, double-blind, double-dummy trial depicting the AF occurrence during a 12-month follow-up as the primary end point. A total of 198 patients hospitalized for AFL ablation were enrolled in the trial and randomized to placebo or ramipril 5 mg/day. Patients were followed up during 1 year after AFL ablation using 1-week Holter electrocardiogram at 3, 6, 9, and 12 months. The intention-to-treat population encompassed 97 patients in the ramipril group and 101 patients in the placebo group. The primary end point, such as AF occurrence during the 1-year follow-up, was not different between the 2 groups (p = 0.96). Secondary end points, including the occurrence of supraventricular arrhythmia (p = 0.50), heart failure, stroke, and death, were not different between the 2 groups. Safety outcome parameters, including serious adverse events leading to treatment disruption (p = 0.10), hypotension, impairment of renal function, and elevated serum potassium level, also were not different between the 2 groups. In conclusion, RAAS inhibition using ramipril does not reduce AF occurrence in patients facing AFL ablation during the 1-year follow-up

Heart transplantation as a rescue strategy for patients with refractory electrical storm

International audienceBackground: Heart transplantation (HT) can be proposed as a therapeutic strategy for patients with severe refractory electrical storm (ES). Data in the literature are scarce and based on case reports. We aimed at determining the characteristics and survival of patients transplanted for refractory ES.Methods: Patients registered on HT waiting list during the following days after ES and eventually transplanted, from 2010 to 2021, were retrospectively included in 11 French centers. The primary endpoint was in-hospital mortality.Results: 45 patients were included (82% men; 55.0 (47.8-59.3) years old; 42.2% and 26.7% non-ischemic dilated or ischemic cardiomyopathies, respectively). Among them, 42 (93.3%) received amiodarone, 29 (64.4%) betablockers; 19 (42.2%) required deep sedation, 22 (48.9%) mechanical circulatory support, and 9 (20.0%) had radiofrequency catheter ablation. Twenty-two patients (62%) were in cardiogenic shock. Inscription on wait list and transplantation occurred 3.0 (1.0-5.0) days and 9.0 (4.0-14.0) days after ES onset, respectively. After transplantation, 20 patients (44.4%) needed immediate hemodynamic support by extracorporeal membrane oxygenation (ECMO). In-hospital mortality rate was 28.9%. Predictors of in-hospital mortality were serum creatinine/urea levels, need for immediate post-operative ECMO support, post-operative complications, and surgical re-interventions. One-year survival was 68.9%.Conclusion: ES is a rare indication of HT but may be lifesaving in those patients presenting intractable arrhythmias despite usual care. Most patients can be safely discharged from hospital, although post-operative mortality remains substantial in this context of emergency transplantation. Larger studies are warranted to precisely determine those patients at higher risk of in-hospital mortality

Outcomes of Left Ventricular Assist Device Implantation in Patients With Uncommon Etiology Cardiomyopathy

International audienceThe impact of uncommon etiology cardiomyopathies on Left-ventricular assist device (LVAD)-recipient outcomes is not very well known. This study aimed to characterize patients with uncommon cardiomyopathy etiologies and examine the outcomes between uncommon and ischemic/idiopathic dilated cardiomyopathy. This observational study was conducted in 19 centers between 2006 and 2016. Baseline characteristics and outcomes of patients with uncommon etiology were compared to patients with idiopathic dilated/ischemic cardiomyopathies. Among 652 LVAD-recipients included, a total of 590 (90.5%) patients were classified as ischemic/idiopathic and 62 (9.5%) patients were classified in the "uncommon etiologies" group. Main uncommon etiologies were: hypertrophic (n = 12(19%)); cancer therapeutics-related cardiac dysfunction (CTRCD) (n = 12(19%)); myocarditis (n = 11(18%)); valvulopathy (n = 9(15%)) and others (n = 18(29%)). Patients with uncommon etiologies were significantly younger with more female and presented less co-morbidities. Additionally, patients with uncommon cardiomyopathies were less implanted as destination therapy compared with ischemic/idiopathic group (29% vs 38.8%). During a follow-up period of 9.1 months, both groups experienced similar survival. However, subgroup of hypertrophic/valvular cardiomyopathies and CTRCD had significantly higher mortality compared to the ischemic/idiopathic or myocarditis/others cardiomyopathies. Conversely, patients with myocarditis/others etiologies experienced a better survival. Indeed, the 12-months survival in the myocarditis/others; ischemic/idiopathic and hypertrophic/CTRCD/valvulopathy group were 77%; 65%, and 46% respectively. In conclusion, LVAD-recipients with hypertrophic cardiomyopathy, valvular heart disease and CTRCD experienced the higher mortality rate

Relation of Body Mass Index to Outcomes in Patients With Heart Failure Implanted With Left Ventricular Assist Devices

International audienceWe aimed at characterizing the impact of low and high body mass index (BMI) on outcomes after left-ventricular assist device (LVAD) surgery and define the predictors of mortality in patients with abnormal BMI (low/high). This study was conducted in 19 centers from 2006 to 2016. Patients were divided based on their baseline BMI into 3 groups of BMI: low (BMI ≤18.5 kg/m²); normal (BMI = 18.5 to 24.99 kg/m²) and high (BMI ≥25 kg/m²) (including overweight (BMI = 25 to 29.99 kg/m²), and obesity (BMI ≥30 Kg/m²)). Among 652 patients, 29 (4.4%), 279 (42.8%) and 344 (52.8%) had a low-, normal-, and high BMI, respectively. Patients with high BMI were significantly more likely men, with more co-morbidities and more history of ventricular/supra-ventricular arrhythmias before LVAD implantation. Patients with abnormal BMI had significantly lower survival than those with normal BMI. Notably, those with low BMI experienced the worst survival whereas overweight or obese patients had similar survival. Four predictors of mortality for LVAD candidates with abnormal BMI were defined: total bilirubin ≥16 µmol/L before LVAD, hypertension, destination therapy, and cardiac surgery with LVAD. Depending on the number of predictor per patients, those with abnormal BMI may be divided in 3 groups of 1-year mortality risk, i.e., low (0 to 1 predictor: 29% and 31%), intermediate (2 to 3 predictors, 51% and 52%, respectively), and high (4 predictors: 83%). In conclusion, LVAD recipients with abnormal BMI experience lower survival, especially underweight patients. Four predictors of mortality have been identified for LVAD population with abnormal BMI, differentiating those a low-, intermediate-, and high risks of death