The Structural Basis of Actin Organization by Vinculin and Metavinculin

Vinculin is an essential adhesion protein that links membrane-bound integrin and cadherin receptors through their intracellular binding partners to filamentous actin, facilitating mechanotransduction. Here we present an 8.5-Å-resolution cryo-electron microscopy reconstruction and pseudo-atomic model of the vinculin tail (Vt) domain bound to F-actin. Upon actin engagement, the N-terminal "strap" and helix 1 are displaced from the Vt helical bundle to mediate actin bundling. We find that an analogous conformational change also occurs in the H1' helix of the tail domain of metavinculin (MVt) upon actin binding, a muscle-specific splice isoform that suppresses actin bundling by Vt. These data support a model in which metavinculin tunes the actin bundling activity of vinculin in a tissue-specific manner, providing a mechanistic framework for understanding metavinculin mutations associated with hereditary cardiomyopathies

Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review

The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration

Global Chronic Total Occlusion Crossing Algorithm

The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration.info:eu-repo/semantics/publishedVersio

Transcatheter Aortic-Valve Replacement with a Balloon-Expandable Valve in Low-Risk Patients.

BACKGROUND: Among patients with aortic stenosis who are at intermediate or high risk for death with surgery, major outcomes are similar with transcatheter aortic-valve replacement (TAVR) and surgical aortic-valve replacement. There is insufficient evidence regarding the comparison of the two procedures in patients who are at low risk. METHODS: We randomly assigned patients with severe aortic stenosis and low surgical risk to undergo either TAVR with transfemoral placement of a balloon-expandable valve or surgery. The primary end point was a composite of death, stroke, or rehospitalization at 1 year. Both noninferiority testing (with a prespecified margin of 6 percentage points) and superiority testing were performed in the as-treated population. RESULTS: At 71 centers, 1000 patients underwent randomization. The mean age of the patients was 73 years, and the mean Society of Thoracic Surgeons risk score was 1.9% (with scores ranging from 0 to 100% and higher scores indicating a greater risk of death within 30 days after the procedure). The Kaplan-Meier estimate of the rate of the primary composite end point at 1 year was significantly lower in the TAVR group than in the surgery group (8.5% vs. 15.1%; absolute difference, -6.6 percentage points; 95% confidence interval [CI], -10.8 to -2.5; P<0.001 for noninferiority; hazard ratio, 0.54; 95% CI, 0.37 to 0.79; P = 0.001 for superiority). At 30 days, TAVR resulted in a lower rate of stroke than surgery (P = 0.02) and in lower rates of death or stroke (P = 0.01) and new-onset atrial fibrillation (P<0.001). TAVR also resulted in a shorter index hospitalization than surgery (P<0.001) and in a lower risk of a poor treatment outcome (death or a low Kansas City Cardiomyopathy Questionnaire score) at 30 days (P<0.001). There were no significant between-group differences in major vascular complications, new permanent pacemaker insertions, or moderate or severe paravalvular regurgitation. CONCLUSIONS: Among patients with severe aortic stenosis who were at low surgical risk, the rate of the composite of death, stroke, or rehospitalization at 1 year was significantly lower with TAVR than with surgery. (Funded by Edwards Lifesciences; PARTNER 3 ClinicalTrials.gov number, NCT02675114.)

Racial, ethnic and socioeconomic disparities in patients undergoing left atrial appendage closure.

OBJECTIVE: This manuscript aims to explore the impact of race/ethnicity and socioeconomic status on in-hospital complication rates after left atrial appendage closure (LAAC). METHODS: The US National Inpatient Sample was used to identify hospitalisations for LAAC between 1 October 2015 to 31 December 2018. These patients were stratified by race/ethnicity and quartiles of median neighbourhood income. The primary outcome was the occurrence of in-hospital major adverse events, defined as a composite of postprocedural bleeding, cardiac and vascular complications, acute kidney injury and ischaemic stroke. RESULTS: Of 6478 unweighted hospitalisations for LAAC, 58% were male and patients of black, Hispanic and 'other' race/ethnicity each comprised approximately 5% of the cohort. Adjusted by the older Americans population, the estimated number of LAAC procedures was 69.2/100 000 for white individuals, as compared with 29.5/100 000 for blacks, 47.2/100 000 for Hispanics and 40.7/100 000 for individuals of 'other' race/ethnicity. Black patients were ~5 years younger but had a higher comorbidity burden. The primary outcome occurred in 5% of patients and differed significantly between racial/ethnic groups (p<0.001) but not across neighbourhood income quartiles (p=0.88). After multilevel modelling, the overall rate of in-hospital major adverse events was higher in black patients as compared with whites (OR: 1.60, 95% CI 1.22 to 2.10, p<0.001); however, the incidence of acute kidney injury was higher in Hispanics (OR: 2.19, 95% CI 1.52 to 3.17, p<0.001). No significant differences were found in adjusted overall in-hospital complication rates between income quartiles. CONCLUSION: In this study assessing racial/ethnic disparities in patients undergoing LAAC, minorities are under-represented, specifically patients of black race/ethnicity. Compared with whites, black patients had higher comorbidity burden and higher rates of in-hospital complications. Lower socioeconomic status was not associated with complication rates

Impact of Hospital Procedural Volume on Outcomes After Endovascular Revascularization for Critical Limb Ischemia

Objectives: The aim of this study was to evaluate the interaction between hospital endovascular lower extremity revascularization (eLER) volume and outcomes after eLER for critical limb ischemia (CLI). Background: There is a paucity of data on the relationship between hospital procedural volume and outcomes of eLER for CLI. Methods: The authors queried the Nationwide Readmission Database (2013-2015) for hospitalized patients who underwent eLER for CLI. Hospitals were divided into tertiles according to annual eLER volume: low volume (\u3c100 eLER procedures), moderate volume (100-550 eLER procedures), and high volume (\u3e550 eLER procedures). Stepwise multivariable regression models were used. The main outcomes were in-hospital mortality and 30-day readmission with major adverse limb events, defined as the composite of amputation, acute limb ischemia, or repeat revascularization. Results: Among 145,785 hospitalizations for eLER for CLI, 5,199 (3.6%) were at low-volume eLER hospitals, 27,857 (19.1%) at moderate-volume eLER hospitals, and 112,728 (77.3%) at high-volume eLER hospitals. On multivariable analysis, there was no difference with regard to in-hospital mortality among moderate-volume hospitals (adjusted odds ratio [OR]: 0.78; 95% CI: 0.60-1.01) and high-volume hospitals (adjusted OR: 0.84; 95% CI: 0.64-1.05) compared with low-volume hospitals. There was lower risk of in-hospital major amputation (adjusted OR: 0.82; 95% CI: 0.70-0.96) and minor amputation at high- versus low-volume hospitals. The length of hospital stay was shorter and discharges to nursing facilities were fewer among moderate- and high-volume hospitals compared with low-volume hospitals. Compared with low-volume hospitals, eLER for CLI at high-volume hospitals had a lower risk for 30-day readmission with major adverse limb events (adjusted OR: 0.83; 95% CI: 0.70-0.99), while there was no difference among moderate-volume hospitals (adjusted OR: 0.92; 95% CI: 0.77-1.10). Conclusions: This nationwide observational analysis suggests that annual eLER volume does not influence in-hospital mortality after eLER for CLI. However, high eLER volume (\u3e550 eLER procedures) was associated with better rates of limb preservation after eLER for CLI

Racial, ethnic and socioeconomic disparities in patients undergoing transcatheter mitral edge-to-edge repair.

BACKGROUND: Transcatheter mitral edge-to-edge repair (TEER) is an increasingly common procedure performed on patients with severe mitral regurgitation. This study assessed the impact of race/ethnicity and socioeconomic status on in-hospital complications after TEER. METHODS: Cohort-based observational study using the National Inpatient Sample between October 2013 and December 2018. The population was stratified into 4 groups based on race/ethnicity and quartiles of neighborhood income levels. The primary outcome was in-hospital complications, defined as the composite of death, bleeding, cardiac and vascular complications, acute kidney injury, and ischemic stroke. RESULTS: 3795 hospitalizations for TEER were identified. Patients of Black and Hispanic race/ethnicity comprised 7.4% and 6.4%, respectively. We estimated that White patients received TEER with a frequency of 38.0/100,000, compared to 29.7/100,000 for Blacks and 30.5/100,000 for Hispanics. In-hospital complications occurred in 20.2% of patients and no differences were found between racial/ethnic groups (P = 0.06). After multilevel modelling, Black and Hispanic patients had similar rate of overall in-hospital complications (OR: 0.84, CI:0.67-1.05 and OR: 0.84, CI:0.66-1.07, respectively) as compared to White patients, however, higher rates of death were observed in Black patients. Individuals living in income quartile-1 had worse in-hospital outcomes as compared to quartile-4 (OR: 1.19, CI:0.99-1.42). CONCLUSION: In this study assessing racial/ethnic disparities in TEER outcomes, aged-adjusted race/ethnicity minorities were less underrepresented as compared to other structural heart interventions. Black patients experienced a higher rate of in-hospital death, but similar overall rate of post-procedural adverse events as compared to White patients. Lower income levels appear to negatively impact on in-hospital outcomes. BRIEF SUMMARY: This study appraises race/ethnic and socioeconomical disparities in access and outcomes following transcatheter mitral edge-to-edge repair. Racial minority groups were less underrepresented as compared to other structural heart interventions. While Black patients experienced a higher rate of in-hospital death, they experienced similar overall rate of post-procedural complications compared to White patients. Lower income levels also appeared to negatively impact on outcomes