Chronic pain causes Tau-mediated hippocampal pathology and memory deficits.

Persistent pain has been recently suggested as a risk factor for dementia. Indeed, chronic pain is frequently accompanied by maladaptive brain plasticity and cognitive deficits whose molecular underpinnings are poorly understood. Despite the emerging role of Tau as a key regulator of neuronal plasticity and pathology in diverse brain disorders, the role of Tau has never been studied in the context of chronic pain. Using a peripheral (sciatic) neuropathy to model chronic pain in mice-spared nerve injury (SNI) for 4 months-in wildtype as well as P301L-Tau transgenic mice, we hereby demonstrate that SNI triggers AD-related neuropathology characterized by Tau hyperphosphorylation, accumulation, and aggregation in hippocampus followed by neuronal atrophy and memory deficits. Molecular analysis suggests that SNI inhibits autophagy and reduces levels of the Rab35, a regulator of Tau degradation while overexpression of Rab35 or treatment with the analgesic drug gabapentin reverted the above molecular changes leading to neurostructural and memory recovery. Interestingly, genetic ablation of Tau blocks the establishment of SNI-induced hippocampal morphofunctional deficits supporting the mediating role of Tau in SNI-evoked hippocampal pathology and memory impairment. These findings reveal that exposure to chronic pain triggers Tau-related neuropathology and may be relevant for understanding how chronic pain precipitates memory loss leading to dementia.

Peak left atrial longitudinal strain is associated with all-cause mortality in patients with ventricular functional mitral regurgitation.

PURPOSE: Chronic mitral regurgitation promotes left atrial (LA) remodeling. However, the significance of LA dysfunction in the setting of ventricular functional mitral regurgitation (FMR) has not been fully investigated. Our aim was to assess the prognostic impact of peak atrial longitudinal strain (PALS), a surrogate of LA function, in patients with FMR and reduced left ventricular ejection fraction (LVEF). METHODS: Patients with at least mild ventricular FMR and LVEF < 50% under optimized medical therapy who underwent transthoracic echocardiography at a single center were retrospectively identified in the laboratory database. PALS was assessed by 2D speckle tracking in the apical 4-chamber view and the study population was divided in two groups according to the best cut-off value of PALS, using receiver operating characteristics (ROC) curve analysis. The primary endpoint-point was all-cause mortality. RESULTS: A total of 307 patients (median age 70 years, 77% male) were included. Median LVEF was 35% (IQR: 27 - 40%) and median effective regurgitant orifice area (EROA) was 15mm2 (IQR: 9 - 22mm2). According to current European guidelines, 32 patients had severe FMR (10%). During a median follow-up of 3.5 years (IQR 1.4 - 6.6), 148 patients died. The unadjusted mortality incidence per 100 persons-years increased with progressively lower values of PALS. On multivariable analysis, PALS remained independently associated with all-cause mortality (adjusted hazard ratio 1.052 per % decrease; 95% CI: 1.010 - 1.095; P = 0.016), even after adjustment for several (n = 14) clinical and echocardiographic confounders. CONCLUSION: PALS is independently associated with all-cause mortality in patients with reduced LVEF and ventricular FMR.

Pectoralis major muscle quantification by cardiac MRI is a strong predictor of major events in HF.

Clinical overt cardiac cachexia is a late ominous sign in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF). The main goal of this study was to assess the feasibility and prognostic significance of muscle mass quantification by cardiac magnetic resonance (CMR) in HF with reduced LVEF. HF patients with LVEF < 40% (HFrEF) referred for CMR were retrospectively identified in a single center. Key exclusion criteria were primary muscle disease, known infiltrative myocardial disease and intracardiac devices. Pectoralis major muscles were measured on standard axial images at the level of the 3rd rib anteriorly. Time to all-cause death or HF hospitalization was the primary endpoint. A total of 298 HF patients were included (mean age 64 ± 12 years; 76% male; mean LVEF 30 ± 8%). During a median follow-up of 22 months (IQR: 12-33), 67 (22.5%) patients met the primary endpoint (33 died and 45 had at least 1 HF hospitalization). In multivariate analysis, LVEF [Hazard Ratio (HR): 0.950; 95% Confidence Interval (CI): 0.917-0.983; p = 0.003), NYHA class I-II vs III-IV (HR: 0.480; CI: 0.272-0.842; p = 0.010), creatinine (HR: 2.653; CI: 1.548-4.545; p < 0.001) and pectoralis major area (HR: 0.873; 95% CI: 0.821-0.929; p < 0.001) were independent predictors of the primary endpoint, when adjusted for gender and NT-pro-BNP levels. Pectoralis major size measured by CMR in HFrEF was independently associated with a higher risk of death or HF hospitalization. Further studies to establish appropriate age and gender-adjusted cut-offs of muscle areas are needed to identify high-risk subgroups.

In vitro and in vivo evaluation of novel chromeno[2,3-d]pyrimidinones as therapeutic agents for triple negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and the limited therapeutic options show poor efficacy in patients, associated to severe side effects and development of resistance. Considering that chromene-based scaffolds proved to be attractive candidates for cancer therapy, herein we prepared new chromeno[2,3-d]pyrimidinone derivatives by a simple two step procedure, starting from the reaction of cyanoacetamide and a salicylaldehyde. A cell viability screening in several breast cancer cell lines allowed to identify two promising compounds with IC50 values in the low micromolar range for TNBC cells. These chromenes inhibited cell proliferation, induced cell cycle arrest and triggered cell death through apoptosis. In vivo studies revealed a safe profile in invertebrate and vertebrate animal models and confirmed their capacity to inhibit tumor growth in the CAM model, inducing significant tumor regression after 4 days of treatment. The two compounds identified in this study are promising drug candidates for TNBC treatment and valuable hits for future optimization, using the versatile synthetic platform that was developed.

Assessment of myocardial strain patterns in patients with left bundle branch block using cardiac magnetic resonance.

Recently, a classification with four types of septal longitudinal strain patterns was described using echocardiography, suggesting a pathophysiological continuum of left bundle branch block (LBBB)-induced left ventricle (LV) remodeling. The aim of this study was to assess the feasibility of classifying these strain patterns using cardiovascular magnetic resonance (CMR), and to evaluate their association with LV remodeling and myocardial scar. Single center registry included LBBB patients with septal flash (SF) referred to CMR to assess the cause of LV systolic dysfunction. Semi-automated feature-tracking cardiac resonance (FT-CMR) was used to quantify myocardial strain and detect the four strain patterns. A total of 115 patients were studied (age 66 ± 11 years, 57% men, 28% with ischemic heart disease). In longitudinal strain analysis, 23 patients (20%) were classified in stage LBBB-1, 37 (32.1%) in LBBB-2, 25 (21.7%) in LBBB-3, and 30 (26%) in LBBB-4. Patients at higher stages had more prominent septal flash, higher LV volumes, lower LV ejection fraction, and lower absolute strain values (p < 0.05 for all). Late gadolinium enhancement (LGE) was found in 55% of the patients (n = 63). No differences were found between the strain patterns regarding the presence, distribution or location of LGE. Among patients with LBBB, there was a good association between strain patterns assessed by FT-CMR analysis and the degree of LV remodeling and LV dysfunction. This association seems to be independent from the presence and distribution of LGE.

Glucocorticoid receptor-dependent therapeutic efficacy of tauroursodeoxycholic acid in preclinical models of spinocerebellar ataxia type 3.

Spinocerebellar ataxia type 3 (SCA3) is an adult-onset neurodegenerative disease caused by a polyglutamine expansion in the ataxin-3 (ATXN3) gene. No effective treatment is available for this disorder, other than symptom-directed approaches. Bile acids have shown therapeutic efficacy in neurodegenerative disease models. Here, we pinpointed tauroursodeoxycholic acid (TUDCA) as an efficient therapeutic, improving the motor and neuropathological phenotype of SCA3 nematode and mouse models. Surprisingly, transcriptomic and functional in vivo data showed that TUDCA acts in neuronal tissue through the glucocorticoid receptor (GR), but independently of its canonical receptor, the farnesoid X receptor (FXR). TUDCA was predicted to bind to the GR, in a similar fashion to corticosteroid molecules. GR levels were decreased in disease-affected brain regions, likely due to increased protein degradation as a consequence of ATXN3 dysfunction being restored by TUDCA treatment. Analysis of a SCA3 clinical cohort showed intriguing correlations between the peripheral expression of GR and the predicted age at disease onset in presymptomatic subjects and FKBP5 expression with disease progression, suggesting this pathway as a potential source of biomarkers for future study. We have established a novel in vivo mechanism for the neuroprotective effects of TUDCA in SCA3 and propose this readily available drug for clinical trials in SCA3 patients.

Transition from Animal-Based to Human Induced Pluripotent Stem Cells (iPSCs)-Based Models of Neurodevelopmental Disorders: Opportunities and Challenges.

Neurodevelopmental disorders (NDDs) arise from the disruption of highly coordinated mechanisms underlying brain development, which results in impaired sensory, motor and/or cognitive functions. Although rodent models have offered very relevant insights to the field, the translation of findings to clinics, particularly regarding therapeutic approaches for these diseases, remains challenging. Part of the explanation for this failure may be the genetic differences-some targets not being conserved between species-and, most importantly, the differences in regulation of gene expression. This prompts the use of human-derived models to study NDDS. The generation of human induced pluripotent stem cells (hIPSCs) added a new suitable alternative to overcome species limitations, allowing for the study of human neuronal development while maintaining the genetic background of the donor patient. Several hIPSC models of NDDs already proved their worth by mimicking several pathological phenotypes found in humans. In this review, we highlight the utility of hIPSCs to pave new paths for NDD research and development of new therapeutic tools, summarize the challenges and advances of hIPSC-culture and neuronal differentiation protocols and discuss the best way to take advantage of these models, illustrating this with examples of success for some NDDs.

Parameters of the mitral apparatus in patients with ischemic and nonischemic dilated cardiomyopathy.

The mitral valve apparatus is a complex structure consisting of several coordinating components: the annulus, two leaflets, the chordae tendineae, and the papillary muscles. Due to the intricate interplay between the mitral valve and the left ventricle, a disease of the latter may influence the normal function of the former. As a consequence, valve insufficiency may arise despite the absence of organic valve disease. This is designated as functional or secondary mitral regurgitation, and it arises from a series of distortions to the valve components. This narrative review describes the normal anatomy and the pathophysiology behind the mitral valve changes in ischemic and non-ischemic dilated cardiomyopathies. It also explains the value of a complete multiparametric assessment of this structure. Not only must an assessment include quantitative measures of regurgitation, but also various anatomical parameters from the mitral apparatus and left ventricle, since they carry prognostic value and are predictors of mitral valve repair success and durability.

Repair of a gigantic ascending aortic pseudoaneurysm - A challenging approach.

Aortic pseudoaneurysms can be a potentially fatal, yet rare, complication of heart surgery. Surgery is indicated but is high risk during sternotomy. Therefore, careful planning is required. We report the case of a 57-year-old patient who underwent heart surgery twice in the past and who presented with an ascending aortic pseudoaneurysm. A successful repair of the pseudoaneurysm was performed under deep hypothermia, left ventricular apical venting, periods of circulatory arrest and endoaortic balloon occlusion.

LGE prevalence and patterns in severe aortic stenosis: When "junctional" means the same.

BACKGROUND: Left ventricular (LV) remodeling in severe aortic valve stenosis (AS) is a complex process that goes beyond hypertrophic response. Reparative/replacement fibrosis is considered irreversible and has recognized value in both risk stratification and prognosis. Currently, cardiac magnetic resonance (CMR) is the gold-standard imaging technique for fibrosis identification through late gadolinium enhancement (LGE) assessment. However, its prevalence and distribution are quite variable among series. Our goal was to assess LGE prevalence and patterns in severe AS. METHODOLOGY: Single-center prospective cohort of 140 patients with severe symptomatic high-gradient AS (mean age 72 ± 8 years; mean valvular transaortic gradient 61 ± 18 mmHg; mean LV ejection fraction by echocardiogram 58 ± 9%) undergoing surgical aortic valve replacement. Those with previous myocardial infarction and/or non-ischemic cardiomyopathy were excluded. All patients performed 1.5 T LGE-CMR prior to surgery. RESULTS: Overall, 103 patients (74%) had non-ischemic LGE (median LGE mass 2.8 g [IQR 0.0-7.8] g), many of them with combined mid-wall and junctional enhancement pattern (36%). LGE was most frequently observed in the mid-basal segments of the interventricular septum. Seventy-four patients (53%) had non-exclusively junctional LGE. Contrary to those with junctional enhancement, patients with non-exclusively junctional LGE had higher LV volumes/mass, worse LV ejection fraction and worse global longitudinal strain. CONCLUSION: Among patients with severe, symptomatic, high-gradient AS, LGE is frequent, primarily affecting the mid-basal interventricular septum. Contrary to junctional LGE, the presence of non-junctional LGE seems to correlate with adverse markers of LV remodeling.

External validation of the unifying concept for the quantitative assessment of functional mitral regurgitation.

PURPOSE: A novel conceptual framework was introduced to enhance the quantitative assessment of functional mitral regurgitation (FMR) and improve risk stratification. However, the data was derived from a single-center cohort and lack external validation. We aimed to validate the proposed algorithm using a different patient population. METHODS: Patients with at least mild FMR and reduced left ventricular ejection fraction (< 50%) were retrospectively identified at a single-center. The cohort was stratified in low, intermediate and high-risk according to the proposed framework, on the basis of effective regurgitant orifice area (EROA) and regurgitant volume (RegVol). Patients within the intermediate-risk group were subsequently reclassified into either the low-risk category (Regurgitant Fraction, RegFrac < 50%) or the high-risk category (RegFrac ≥ 50%) based on their regurgitant fraction. The primary endpoint was all-cause mortality. RESULTS: A total of 572 patients were included. During a median follow-up of 3.8 years there were 254 deaths (44%). On multivariable analysis, the proposed thresholds for FMR severity remained independently associated with all-cause mortality (adjusted hazard ratio: 1.488; 95% confidence interval [CI]: 1.110-2.013; p-value = 0.010). This algorithm demonstrated superior discriminative ability (C-statistic: 0.664) compared to contemporary guidelines (C-statistic: 0.522; p-value for comparison < 0.001). Additionally, it resulted in a significant improvement in the net reclassification index (0.162; p-value < 0.001). CONCLUSIONS: Within our cohort, the application of the proposed concept demonstrated a significant association with a higher risk of all-cause mortality. Moreover, this conceptual framework showcased the potential to improve the accuracy of risk prediction beyond current guidelines.

Influence of Age on the Diagnostic Value of Coronary Artery Calcium Score for Ruling Out Obstructive Coronary Disease in Symptomatic Patients.

Concerns have been raised about the added diagnostic value of coronary artery calcium score (CACS) of 0 for reducing the likelihood of obstructive coronary artery disease (CAD) in younger patients. Our study aimed to assess the influence of age on the value of CAC = 0 in symptomatic patients who underwent coronary computed tomography angiography (CCTA). We conducted a 2-center retrospective study assessing symptomatic patients with suspected CAD who underwent CACS and CCTA. Pretest probability was calculated according to the Juarez-Orozco method and obstructive CAD was defined as ≥50% luminal stenosis. The diagnostic likelihood ratios and negative predictive values were used to assess the diagnostic value of a CACS of 0 to rule out obstructive CAD. A total of 2,043 patients (mean age 60 ± 11 years, 60% women, 48.5% CACS of 0) were analyzed. The pretest probability of obstructive CAD increased with age, whereas the proportion of patients with a CACS of 0 decreased with age. The added diagnostic value of a CACS of 0 was lower in younger patients (negative likelihood ratios ranging from 0.36 for <50 years to 0.10 for ≥70 years). However, the prevalence of obstructive CAD in patients with a CACS of 0 was low in all age groups. In a cohort of symptomatic patients who underwent CCTA for suspected CAD, the added diagnostic value of a CACS of 0 decreases significantly at younger ages. However, it is offset by their lower pretest probabilities, yielding high negative predictive values independently of age.

Implications of three different testing strategies in the diagnostic approach to patients with stable chest pain and low pretest probability of obstructive coronary artery disease.

INTRODUCTION: The clinical implications of a widespread adoption of guideline recommendations for patients with stable chest pain and low pretest probability (PTP) of obstructive coronary artery disease (CAD) remain unclear. We aimed to assess the results of three different testing strategies in this subgroup of patients: A) defer testing; B) perform coronary artery calcium score (CACS), withholding further testing if CACS â€‹= â€‹0 and proceeding to coronary computed tomography angiography (CCTA) if CACS>0; C) perform CCTA in all. METHODS: Two-center cross-sectional study assessing 1328 symptomatic patients undergoing CACS and CCTA for suspected CAD. PTP was calculated based on age, sex and symptom typicality. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. RESULTS: The prevalence of obstructive CAD was 8.6% (n â€‹= â€‹114). In the 786 patients (56.8%) with CACS â€‹= â€‹0, 8.5% (n â€‹= â€‹67) had some degree of CAD [1.9% (n â€‹= â€‹15) obstructive, and 6.6% (n â€‹= â€‹52) nonobstructive]. Among those with CACS>0 (n â€‹= â€‹542), 18.3% (n â€‹= â€‹99) had obstructive CAD. The number of patients needed to scan (NNS) to identify one patient with obstructive CAD was 13 for strategy B vs. A, and 91 for strategy C vs. B. CONCLUSIONS: Using CACS as gatekeeper would decrease CCTA use by more than 50%, at the cost of missing obstructive CAD in one in 100 patients. These findings may help inform decisions on testing, which will ultimately depend on the willingness to accept some diagnostic uncertainty.

Prevalence and significance of relative apical sparing in aortic stenosis: insights from an echo and cardiovascular magnetic resonance study of patients referred for surgical aortic valve replacement.

AIMS: This study aims to assess the prevalence of relative apical sparing pattern (RASP) in patients with severe symptomatic aortic stenosis (AS), referred for surgical aortic valve replacement (AVR), to evaluate its significance, possible relation to amyloid deposition, and persistence after surgery. METHODS AND RESULTS: Prospective study of 150 consecutive patients [age 73 (interquartile range: 68-77), 51% women], with severe symptomatic AS referred to surgical AVR. All patients underwent cardiac magnetic resonance (CMR) before surgery. RASP was defined by [average apical longitudinal strain (LS)/(average basal LS + average mid LS)] > 1 by echocardiography. AVR was performed in 119 (79.3%) patients. Both Congo red and sodium sulphate-Alcian blue (SAB) stain were used to exclude amyloid on septal myocardial biopsy. LV remodelling and tissue characterization parameters were compared in patients with and without RASP. Deformation pattern was re-assessed at 3-6 months after AVR.RASP was present in 23 patients (15.3%). There was no suspicion of amyloid at pre-operative CMR [native T1 value 1053 ms (1025-1076 ms); extracellular volume (ECV) 28% (25-30%)]. None of the patients had amyloid deposition at histopathology. Patients with RASP had significantly higher pre-operative LV mass and increased septal wall thickness. They also had higher N-terminal pro b-type natriuretic peptide (NT-proBNP) levels [1564 (766-3318) vs. 548 (221-1440) pg/mL, P = 0.010], lower LV ejection fraction (53.7 ± 10.5 vs. 60.5 ± 10.2%, P = 0.005), and higher absolute late gadolinium enhancement (LGE) mass [9.7 (5.4-14.1) vs. 4.8 (1.9-8.6) g, P = 0.016] at CMR. Follow-up evaluation after AVR revealed RASP disappearance in all except two of the patients. CONCLUSION: RASP is not specific of cardiac amyloidosis. It may also be found in severe symptomatic AS without amyloidosis, reflecting advanced LV disease, being mostly reversible after surgery.

Coronary artery calcium score as a gatekeeper for further testing in patients with low pretest probability of obstructive coronary artery disease: A cost-effectiveness analysis.

INTRODUCTION AND OBJECTIVES: Current guidelines recommend not routinely testing patients with chest pain and low pretest probability (PTP <15%) of obstructive coronary artery disease (CAD), but envisage the use of risk modifiers, such as coronary artery calcium score (CACS), to refine patient selection for testing. We aimed to assess the cost-effectiveness (CE) of three different testing strategies in this population: (A) defer testing; (B) perform CACS, withholding further testing if CACS=0, and proceeding to coronary CT angiography (CCTA) if CACS>0; (C) CCTA in all. METHODS: We developed a CE model using data from a two-center cross-sectional study of 1385 patients with non-acute chest pain and PTP <15% undergoing CACS followed by CCTA. Key input data included the prevalence of obstructive CAD on CCTA (10.3%), the proportion with CACS=0 (57%), and the negative predictive value of CACS for obstructive CAD on CCTA (98.1%). RESULTS: Not testing would correctly classify 89.7% of cases and at a cost of €121433 per 1000 patients. Using CACS as a gatekeeper for CCTA would correctly diagnose 98.9% of cases and cost €247116/1000 patients. Employing first-line CCTA would correctly classify all patients, at a cost of €271007/1000 diagnosed patients. The added cost for an additional correct diagnosis was €1366 for CACS±CCTA vs. no testing, and €2172 for CCTA vs. CACS±CCTA. CONCLUSIONS: CACS as a gatekeeper for further testing is cost-effective between a threshold of €1366 and €2172 per additional correct diagnosis. CCTA yields the most correct diagnoses and is cost-effective above a threshold of €2172.

Predictive value of a positive stress single-photon emission computed tomography or stress cardiac magnetic resonance for ruling in obstructive coronary artery disease in a real-world setting.

INTRODUCTION AND OBJECTIVES: Randomized controlled trials comparing stress cardiac magnetic resonance (CMR) and single-photon emission computed tomography (SPECT) suggest similar diagnostic accuracy for detecting obstructive coronary artery disease (CAD). There are few data on whether this remains true in routine clinical practice. The aim of this study was to assess clinical and angiographic characteristics of patients undergoing invasive coronary angiography (ICA) after stress CMR or SPECT, and to compare their positive predictive value with published results from the CE-MARC trial. METHODS: In this retrospective tertiary-center analysis, we included 429 patients undergoing ICA after a positive stress CMR or positive SPECT performed within the previous 12 months. Obstructive CAD was defined as any coronary artery stenosis ≥50% in a vessel compatible with the ischemic territory on stress testing. RESULTS: Of the total 429 patients, 356 (83%) were referred after a positive SPECT, and 73 (17%) after a positive stress CMR. Patients did not differ according to age, cardiovascular risk factors, previous revascularization or left ventricular dysfunction, but patients with SPECT were more frequently male (p=0.046). The prevalence of obstructive CAD was similar in patients with positive SPECT vs. positive stress CMR (76.1% vs. 80.8%, respectively, p=0.385). The positive predictive values of both techniques were similar to those reported in the CE-MARC trial. CONCLUSION: In this tertiary center analysis, stress CMR and SPECT showed similar positive predictive values, comparable to those reported in the CE-MARC trial. This finding supports the emerging adoption of CMR in clinical practice for the diagnosis and management of CAD.

Advanced Face Mask Filters Based on PCL Electrospun Meshes Dopped with Antimicrobial MgO and CuO Nanoparticles.

The pandemic situation caused by coronavirus clearly demonstrated the need for alternatives able to protect the respiratory tract and inactivate the infectious agents. Based on this, antibacterial face-mask filters of polycaprolactone (PCL) dopped with magnesium oxide (MgO) and copper oxide (CuO) nanoparticles (NPs) were produced using an electrospinning technique. A morphological analysis of electrospun meshes evaluated the success of nanoparticles' incorporation as well as the average fibers' diameters (481 ± 272 nm). The performance of electrospun nanofibers was also assessed in terms of tensile strength (0.88 ± 0.25 MPa), water vapor permeability (11,178.66 ± 35.78 g·m-2·day-1), stability under wet conditions and antibacterial activity according to the standard guidelines. The filters showed structural stability up to 2 h of washing and improved antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for optimized concentrations of MgO and CuO NPs. Overall, electrospun meshes with antibacterial activity were successfully developed for advanced filtering applications.

Electrospun-Based Membranes as a Key Tool to Prevent Respiratory Infections.

The use of electrospun meshes has been proposed as highly efficient protective equipment to prevent respiratory infections. Those infections can result from the activity of micro-organisms and other small dust particles, such as those resulting from air pollution, that impair the respiratory tract, induce cellular damage and compromise breathing capacity. Therefore, electrospun meshes can contribute to promoting air-breathing quality and controlling the spread of such epidemic-disrupting agents due to their intrinsic characteristics, namely, low pore size, and high porosity and surface area. In this review, the mechanisms behind the pathogenesis of several stressors of the respiratory system are covered as well as the strategies adopted to inhibit their action. The main goal is to discuss the performance of antimicrobial electrospun nanofibers by comparing the results already reported in the literature. Further, the main aspects of the certification of filtering systems are highlighted, and the expected technology developments in the industry are also discussed.

Secondary mitral regurgitation: Maintaining coherence with the American Society of Echocardiography grading guidelines, which proportionality concept best predicts prognosis in the real world?

INTRODUCTION: Proportionality of secondary mitral regurgitation (sMR) may be a key factor in deciding whether a patient may benefit from mitral intervention. The aim of this study was to evaluate the prognostic value of two different concepts of proportionality and assess their ability to improve MR stratification proposed by the American Society of Echocardiography (ASE) guidelines. METHODS: We conducted a retrospective analysis in patients with reduced left ventricular ejection fraction (LVEF) (<50%) and at least mild sMR. Proportionality status was calculated using formulas proposed by a) Grayburn et al. - disproportionate sMR defined as EROALVEDV >0.14; b) Lopes et al. - disproportionate sMR whenever measured EROA>theoretical EROA (determined as 50%×LVEF×LVEDVMitralVTI). Primary endpoint was all-cause mortality. RESULTS: A total of 572 patients (69±12 years; 76% male) were included. Mean LVEF was 33±9%, with a median left ventricular end-diastolic volume of 174 mL [136;220] and a median effective regurgitant orifice area of 14 mm2 [8;22]. During mean follow-up of 4.1±2.7 years, there were 254 deaths. There was considerable disagreement (p<0.001) between both formulas: of 96 patients with disproportionate sMR according to Lopes' criteria, 46 (48%) were considered proportionate according to Grayburn's; and of 62 patients with disproportionate sMR according to Grayburn's, 12 (19%) were considered proportionate according to Lopes' formula. In multivariate analysis, only Lopes' definition of disproportionate sMR maintained independent prognostic value (hazard ratio 1.5; 95% confidence interval 1.07-2.1, p=0.018) and improved the risk stratification of ASE sMR classification. CONCLUSION: Of the two formulas available to define disproportionate sMR, Lopes' model emerged as the only one with independent prognostic value while improving the risk stratification proposed by the ASE guidelines.