Identification of an H-Ras nanocluster disrupting peptide.

Hyperactive Ras signalling is found in most cancers. Ras proteins are only active in membrane nanoclusters, which are therefore potential drug targets. We previously showed that the nanocluster scaffold galectin-1 (Gal1) enhances H-Ras nanoclustering via direct interaction with the Ras binding domain (RBD) of Raf. Here, we establish that the B-Raf preference of Gal1 emerges from the divergence of the Raf RBDs at their proposed Gal1-binding interface. We then identify the L5UR peptide, which disrupts this interaction by binding with low micromolar affinity to the B- and C-Raf-RBDs. Its 23-mer core fragment is sufficient to interfere with H-Ras nanoclustering, modulate Ras-signalling and moderately reduce cell viability. These latter two phenotypic effects may also emerge from the ability of L5UR to broadly engage with several RBD- and RA-domain containing Ras interactors. The L5UR-peptide core fragment is a starting point for the development of more specific reagents against Ras-nanoclustering and -interactors.

An Improved PDE6D Inhibitor Combines with Sildenafil To Inhibit KRAS Mutant Cancer Cell Growth.

The trafficking chaperone PDE6D (or PDEδ) was proposed as a surrogate target for K-Ras, leading to the development of a series of inhibitors that block its prenyl binding pocket. These inhibitors suffered from low solubility and suspected off-target effects, preventing their clinical development. Here, we developed a highly soluble, low nanomolar PDE6D inhibitor (PDE6Di), Deltaflexin3, which has the lowest off-target activity as compared to three prominent reference compounds. Deltaflexin3 reduces Ras signaling and selectively decreases the growth of KRAS mutant and PDE6D-dependent cancer cells. We further show that PKG2-mediated phosphorylation of Ser181 lowers K-Ras binding to PDE6D. Thus, Deltaflexin3 combines with the approved PKG2 activator Sildenafil to more potently inhibit PDE6D/K-Ras binding, cancer cell proliferation, and microtumor growth. As observed previously, inhibition of Ras trafficking, signaling, and cancer cell proliferation remained overall modest. Our results suggest reevaluating PDE6D as a K-Ras surrogate target in cancer.

Valve Hemodynamics by Valve Size and 1-Year Survival Following Implantation of the Portico Valve in the Multicenter CONFIDENCE Registry.

Background: The CONtrolled delivery For ImproveD outcomEs with cliNiCal Evidence registry was initiated to characterize the clinical safety and device performance from experienced transcatheter aortic valve implantation (TAVI) centers in Europe and Australia that use the Portico valve to treat patients with severe aortic stenosis. We herein report for the first time the valve performance at 30-day across all implanted valve sizes and the 1-year survival from this registry. Methods: This was a prospective, multicenter, single-arm observational clinical investigation of patients clinically indicated for implantation of a Portico valve in experienced TAVI centers. Patients were treated with a commercially available valve (size 23, 25, 27, or 29 mm) using either the first-generation delivery system (DS) (n = 501) or the second-generation (FlexNav) DS (n = 500). Adverse events were adjudicated by an independent clinical events committee according to Valve Academic Research Consortium-2 criteria. Echocardiographic outcomes were assessed at 30 days by an independent core laboratory, and a survival check was performed at 1 year. Results: We enrolled 1001 patients (82.0 years, 62.5% female, 63.7% New York Heart Association functional class III/IV at baseline) from 27 clinical sites in 8 countries across Europe and one site in Australia. Implantation of a single valve was successful in 97.5% of subjects. Valve hemodynamics at 30 days were substantially improved relative to baseline, with large aortic valve areas and low mean gradients across all implanted valve sizes (aortic valve areas were 1.7 ± 0.4, 1.7 ± 0.5, 1.8 ± 0.5, and 2.0 ± 0.5 cm2, and mean gradients were 7.0 ± 2.7, 7.5 ± 4.7, 7.3 ± 3.3, and 6.4 ± 3.3 mmHg for 23, 25, 27, and 29 mm valve sizes, respectively). Across all implanted valve sizes, most patients (77.1%) had no patient-prosthesis mismatch. Death from any cause within 1 year occurred in 13.7% of the patients in the first-generation DS group as compared with 11.0% in the second-generation DS group (p = 0.2). Conclusions: The Portico valve demonstrated excellent hemodynamic performance across all valve sizes in a large cohort of subjects implanted in experienced TAVI centers. One-year survival rates were favorable when using both the first-generation and second-generation (FlexNav) DSs in this high-risk cohort. ClinicalTrialsgov Identifier: NCT03752866.

K-Ras Binds Calmodulin-Related Centrin1 with Potential Implications for K-Ras Driven Cancer Cell Stemness.

Recent data suggest that K-Ras4B (hereafter K-Ras) can drive cancer cell stemness via calmodulin (CaM)-dependent, non-canonical Wnt-signalling. Here we examined whether another Ca2+-binding protein, the CaM-related centrin1, binds to K-Ras and could mediate some K-Ras functions that were previously ascribed to CaM. While CaM and centrin1 appear to distinguish between peptides that were derived from their classical targets, they both bind to K-Ras in cells. Cellular BRET- and immunoprecipitation data suggest that CaM engages more with K-Ras than centrin1 and that the interaction with the C-terminal membrane anchor of K-Ras is sufficient for this. Surprisingly, binding of neither K-Ras nor its membrane anchor alone to CaM or centrin1 is sensitive to inhibition of prenylation. In support of an involvement of the G-domain of K-Ras in cellular complexes with these Ca2+-binding proteins, we find that oncogenic K-RasG12V displays increased engagement with both CaM and centrin1. This is abrogated by addition of the D38A effector-site mutation, suggesting that K-RasG12V is held together with CaM or centrin1 in complexes with effectors. When treated with CaM inhibitors, the BRET-interaction of K-RasG12V with centrin1 was also disrupted in the low micromolar range, comparable to that with CaM. While CaM predominates in regulating functional membrane anchorage of K-Ras, it has a very similar co-distribution with centrin1 on mitotic organelles. Given these results, a significant overlap of the CaM- and centrin1-dependent functions of K-Ras is suggested.

Redo aortic valve replacement versus valve-in-valve trans-catheter aortic valve implantation: a UK propensity-matched analysis.

This study sought to compare the morbidity and mortality of redo aortic valve replacement (redo-AVR) versus valve-in-valve trans-catheter aortic valve implantation (valve-in-valve TAVI) for patients with a failing bioprosthetic valve. A multicenter UK retrospective study of redo-AVR or valve-in-valve TAVI for patients referred for redo aortic valve intervention due to a degenerated aortic bioprosthesis. Propensity score matching was performed for confounding factors. From July 2005 to April 2021, 911 patients underwent redo-AVR and 411 patients underwent valve-in-valve TAVI. There were 125 pairs for analysis after propensity score matching. The mean age was 75.2±8.5 years. In-hospital mortality was 7.2% (n=9) for redo-AVR versus 0 for valve-in-valve TAVI, p=0.002. Surgical patients suffered more post-operative complications, including intra-aortic balloon pump support (p=0.02), early re-operation (p<0.001), arrhythmias (p<0.001), respiratory and neurological complications (p=0.02 and p=0.03) and multi-organ failure (p=0.01). The valve-in-valve TAVI group had a shorter intensive care unit and hospital stay (p<0.001 for both). However, moderate aortic regurgitation at discharge and higher post-procedural gradients were more common after valve-in-valve TAVI (p<0.001 for both). Survival probabilities in patients who were successfully discharged from the hospital were similar after valve-in-valve TAVI and redo-AVR over the 6-year follow-up (log-rank p=0.26). In elderly patients with a degenerated aortic bioprosthesis, valve-in-valve TAVI provides better early outcomes as opposed to redo-AVR, although there was no difference in mid-term survival in patients successfully discharged from the hospital.

Detection of Ras nanoclustering-dependent homo-FRET using fluorescence anisotropy measurements.

The small GTPase Ras is frequently mutated in cancer and a driver of tumorigenesis. The recent years have shown great progress in drug-targeting Ras and understanding how it operates on the plasma membrane. We now know that Ras is non-randomly organized into proteo-lipid complexes on the membrane, called nanoclusters. Nanoclusters contain only a few Ras proteins and are necessary for the recruitment of downstream effectors, such as Raf. If tagged with fluorescent proteins, the dense packing of Ras in nanoclusters can be analyzed by Förster/ fluorescence resonance energy transfer (FRET). Loss of FRET can therefore report on decreased nanoclustering and any process upstream of it, such as Ras lipid modifications and correct trafficking. Thus, cellular FRET screens employing Ras-derived fluorescence biosensors are potentially powerful tools to discover chemical or genetic modulators of functional Ras membrane organization. Here we implement fluorescence anisotropy-based homo-FRET measurements of Ras-derived constructs labelled with only one fluorescent protein on a confocal microscope and a fluorescence plate reader. We show that homo-FRET of both H-Ras- and K-Ras-derived constructs can sensitively report on Ras-lipidation and -trafficking inhibitors, as well as on genetic perturbations of proteins regulating membrane anchorage. By exploiting the switch I/II-binding Ras-dimerizing compound BI-2852, this assay is also suitable to report on the engagement of the K-Ras switch II pocket by small molecules such as AMG 510. Given that homo-FRET only requires one fluorescent protein tagged Ras construct, this approach has significant advantages to create Ras-nanoclustering FRET-biosensor reporter cell lines, as compared to the more common hetero-FRET approaches.

30-Day Clinical Outcomes of a Self-Expanding Transcatheter Aortic Valve: The International PORTICO NG Study.

BACKGROUND: The self-expanding, intra-annular Navitor (Abbott Structural Heart) valve includes an outer cuff to reduce paravalvular leak (PVL) and large stent cells for future coronary access. OBJECTIVES: The purpose of the PORTICO NG (Evaluation of the Portico NG [Next Generation] Transcatheter Aortic Valve in High and Extreme Risk Patients With Symptomatic Severe Aortic Stenosis) study is to evaluate the safety and effectiveness of the Navitor valve in patients with symptomatic, severe aortic stenosis who are at high or extreme surgical risk. METHODS: PORTICO NG is a prospective, multicenter, global study with follow-up at 30 days, 1 year, and annually through 5 years. The primary endpoints are all-cause mortality and moderate or greater PVL at 30 days. Valve Academic Research Consortium-2 events and valve performance are assessed by an independent clinical events committee and echocardiographic core laboratory. RESULTS: A total of 260 subjects were treated at 26 clinical sites across Europe, Australia, and the United States between September 2019 and August 2022. The mean age was 83.4 ± 5.4 years, 57.3% were female, and the average Society of Thoracic Surgeons score was 3.9% ± 2.1%. At 30 days, the rate of all-cause mortality was 1.9%, and no subjects had moderate or greater PVL. The rate of disabling stroke was 1.9%, life-threatening bleeding was 3.8%, stage 3 acute kidney injury was 0.8%, major vascular complications were 4.2%, and new permanent pacemaker implantation was 19.0%. Hemodynamic performance included a mean gradient of 7.4 ± 3.5 mm Hg and an effective orifice area of 2.00 ± 0.47 cm2. CONCLUSIONS: The Navitor valve is safe and effective for the treatment of subjects with severe aortic stenosis who are at high or greater risk for surgery, which is supported by low rates of adverse events and PVL. (Evaluation of the Portico NG [Next Generation] Transcatheter Aortic Valve in High and Extreme Risk Patients With Symptomatic Severe Aortic Stenosis [PORTICO NG]; NCT04011722).

Thirty-day and one-year outcomes of the Navitor transcatheter heart valve in patients with aortic stenosis: the prospective, multicentre, global PORTICO NG Study.

BACKGROUND: The Navitor transcatheter heart valve (THV) is a self-expanding valve, with an intra-annular leaflet position and an outer cuff intended to reduce paravalvular leak (PVL). AIMS: The aim of the PORTICO NG Study is to assess the safety and performance of the Navitor THV in patients with symptomatic, severe aortic stenosis who are at high or extreme surgical risk. METHODS: PORTICO NG is a prospective, multicentre, global, single-arm, investigational study with follow-up at 30 days, 1 year, and annually up to 5 years. The primary endpoints are all-cause mortality and moderate or greater PVL at 30 days. Valve Academic Research Consortium-2 events and valve performance are assessed by an independent clinical events committee and echocardiographic core laboratory. RESULTS: A total of 120 high- or extreme-risk subjects (age 83.5±5.4 years; 58.3% female; Society of Thoracic Surgeons score 4.0±2.0%) were enrolled in the European conformity (CE) mark cohort. Procedural success was high at 97.5%. At 30 days, the rate of all-cause mortality was 0%, and no subjects had moderate or greater PVL. The rate of disabling stroke was 0.8%, life-threatening bleeding was 2.5%, stage 3 acute kidney injury 0%, major vascular complications 0.8%, and new pacemaker implantation 15.0%. At 1 year, the rates of all-cause mortality and disabling stroke were 4.2% and 0.8%, respectively. The rate of moderate PVL was 1.0% at 1 year. Haemodynamic performance with a mean gradient of 7.5±3.2 mmHg and effective orifice area of 1.9±0.4 cm2 was sustained up to 1 year. CONCLUSIONS: The PORTICO NG Study demonstrates low rates of adverse events and PVL up to 1 year in patients at high or extreme surgical risk, confirming the safety and efficacy of the Navitor THV system.

First-in-Human Dedicated Leaflet Splitting Device for Prevention of Coronary Obstruction in Transcatheter Aortic Valve Replacement.

BACKGROUND: Coronary artery obstruction is a life-threatening complication of transcatheter aortic valve replacement (TAVR) procedures. Current preventive strategies are suboptimal. OBJECTIVES: The aim of this study was to describe bench testing and clinical experience with a novel device that splits valve leaflets that are at risk for causing coronary obstruction after TAVR, allowing normal coronary flow. METHODS: The ShortCut device was initially tested in vitro and preclinically in a porcine model for functionality and safety. The device was subsequently offered to patients at elevated risk for coronary obstruction. Risk for coronary obstruction was based on computed tomography-based anatomical characteristics. Procedure success was determined as patient survival at 30 days with a functioning new valve, without stroke or coronary obstruction. RESULTS: Following a successful completion of bench testing and preclinical trial, the device was used in 8 patients with failed bioprosthetic valves (median age 81 years; IQR: 72-85 years; 37.5% man) at 2 medical centers. A total of 11 leaflets were split: 5 patients (63.5%) were considered at risk for left main obstruction alone, and 3 patients (37.5%) were at risk for double coronary obstruction. All patients underwent successful TAVR without evidence of coronary obstruction. All patients were discharged from the hospital in good clinical condition, and no adverse neurologic events were noted. Procedure success was 100%. CONCLUSIONS: Evaluation of the first dedicated transcatheter leaflet-splitting device shows that the device can successfully split degenerated bioprosthetic valve leaflets. The procedure was safe and successfully prevented coronary obstruction in patients at risk for this complication following TAVR.

Procedural Safety and Device Performance of the Portico™ Valve from Experienced TAVI Centers: 30-Day Outcomes in the Multicenter CONFIDENCE Registry.

A total of 1001 subjects (82.0 years, 62.5% female, 63.7% NYHA III/IV at baseline) with severe aortic stenosis at high surgical risk were enrolled in the prospective CONFIDENCE registry and treated with a Portico™ transcatheter heart valve (THV) using either a first-generation delivery system (DS) or the FlexNav™ DS. The objective of this registry is to characterize the procedural safety and device performance of the Portico™ THV at 30 days. The study collected 'standard-of-care' clinical and device performance data, with adverse events adjudicated by an independent clinical event committee according to the Valve Academic Research Consortium-2 criteria. The implantation of a single Portico™ THV was successful in 97.5% of subjects. The 30-day all-cause mortality, cardiovascular mortality, and disabling stroke rates were 2.6%, 2.1%, and 1.8%, respectively. A new pacemaker was implanted in 19.0% of subjects at 30 days. At 30 days, the effective orifice area and mean gradient values were 1.82 cm2 and 7.1 mmHg, respectively. The 30-day rate of moderate paravalvular leak (PVL) was 2.1%, with no occurrence of severe PVL. The Portico™ THV demonstrated improved hemodynamic performance and low rates of safety events at 30 days in a large cohort of subjects implanted with the Portico™ THV with either the first-generation DS or FlexNav™ DS.

Potential of phenothiazines to synergistically block calmodulin and reactivate PP2A in cancer cells.

Phenothiazines (PTZ) were developed as inhibitors of monoamine neurotransmitter receptors, notably dopamine receptors. Because of this activity they have been used for decades as antipsychotic drugs. In addition, they possess significant anti-cancer properties and several attempts for their repurposing were made. However, their incompletely understood polypharmacology is challenging. Here we examined the potential of the PTZ fluphenazine (Flu) and its mustard derivative (Flu-M) to synergistically act on two cancer associated targets, calmodulin (CaM) and the tumor suppressor protein phosphatase 2A (PP2A). Both proteins are known to modulate the Ras- and MAPK-pathway, cell viability and features of cancer cell stemness. Consistently, we show that the combination of a CaM inhibitor and the PP2A activator DT-061 synergistically inhibited the 3D-spheroid formation of MDA-MB-231 (K-Ras-G13D), NCI-H358 (K-Ras-G12C) and A375 (B-raf-V600E) cancer cells, and increased apoptosis in MDA-MB-231. We reasoned that these activities remain combined in PTZ, which were the starting point for PP2A activator development, while several PTZ are known CaM inhibitors. We show that both Flu and Flu-M retained CaM inhibitory activity in vitro and in cells, with a higher potency of the mustard derivative in cells. In line with the CaM dependence of Ras plasma membrane organization, the mustard derivative potently reduced the functional membrane organization of oncogenic Ras, while DT-061 had a negligible effect. Like DT-061, both PTZ potently decreased c-MYC levels, a hallmark of PP2A activation. Benchmarking against the KRAS-G12C specific inhibitor AMG-510 in MIA PaCa-2 cells revealed a higher potency of Flu-M than combinations of DT-061 and a CaM inhibitor on MAPK-output and a strong effect on cell proliferation. While our study is limited, our results suggest that improved PTZ derivatives that retain both, their CaM inhibitory and PP2A activating properties, but have lost their neurological side-effects, may be interesting to pursue further as anti-cancer agents.

Reframing Optimal Implantation of the Sapien 3 Transcatheter Heart Valve.

OBJECTIVES: To define the optimal implantation of the Sapien 3 (Edwards Lifesciences) transcatheter heart valve (THV), this study systematically analyzed the predeployment fluoroscopic THV position and correlated this to clinical outcomes. METHODS: This was an observational study of 279 patients treated with the Sapien 3 THV. Fluoroscopic imaging was used to categorize patients into low (n = 147), intermediate (n = 86), and high (n = 46) implantation zones. These zones were based on the relationship of the balloon marker and radiolucent line of the valve frame (line of lucency) to the annular plane at deployment. The primary outcome was the rate of permanent pacemaker implantation (PPI) at 30 days. The secondary outcomes were the rates of new left bundle-branch block (LBBB) in-hospital and all-cause mortality at 1 year. RESULTS: In the high, intermediate, and low groups, 30-day PPI rates were 4.3%, 8.1%, and 8.8% (P=.62); in-hospital LBBB rates were 10.9%, 26.7%, and 32.0% (P=.02); and all-cause mortality rates at 1 year were 3.1%, 7.3%, and 12.5% (P=.14), respectively. No differences were observed with respect to procedural success/complications or THV performance between the groups. CONCLUSION: This study demonstrates fewer conduction abnormalities for Sapien 3 valves positioned within a higher zone defined fluoroscopically by the line of lucency and balloon marker.

Final 3-year clinical outcomes following transcatheter aortic valve implantation with a supra-annular self-expanding repositionable valve in a real-world setting: Results from the multicenter FORWARD study.

OBJECTIVES: The Evolut R FORWARD study confirmed safety and effectivenesss of the Evolut R THV in routine clinical practice out to 1 year. Herein, we report the final 3-year clinical follow up of the FORWARD study. BACKGROUND: Transcatheter aortic valve replacement (TAVR) is a proven alternative to surgery in elderly patients with symptomatic severe aortic stenosis. Long-term clinical outcome data with the Evolut R platform are scarce. METHODS: FORWARD is a prospective multicenter observational study that evaluated the Evolut R system in routine clinical practice at 53 centres. Eligible patients had symptomatic native aortic valve stenosis or failed surgical aortic bioprosthesis and elevated operative risk per Heart-Team assessment. TAVR was attempted in 1039 patients. RESULTS: Mean age was 81.8 ± 6.2 years, 64.9% were women, STS score was 5.5 ± 4.5% and 34.2% were frail. Rates of all-cause mortality and disabling stroke were 24.8% and 4.8% at 3 years. Early need for a new pacemaker implantation after TAVR (all-cause mortality: with new PPI; 21.0% vs. without; 22.8%, p = 0.55) and the presence of > trace paravalvular regurgitation (all-cause mortality: no or trace; 22.0% vs. ≥ mild; 25.5%, p = 0.29) did not affect survival. Between 1 and 3 years incidence rates of valve related intervention, endocarditis and clinically relevant valve thrombosis were low. CONCLUSIONS: The Evolut R valve maintained a favorable safety profile through 3 years in routine clinical practice. Rates of transcatheter heart valve-related adverse events were low.

Pharmacophore Model for SARS-CoV-2 3CLpro Small-Molecule Inhibitors and in Vitro Experimental Validation of Computationally Screened Inhibitors.

Among the biomedical efforts in response to the current coronavirus (COVID-19) pandemic, pharmacological strategies to reduce viral load in patients with severe forms of the disease are being studied intensively. One of the main drug target proteins proposed so far is the SARS-CoV-2 viral protease 3CLpro (also called Mpro), an essential component for viral replication. Ongoing ligand- and receptor-based computational screening efforts would be facilitated by an improved understanding of the electrostatic, hydrophobic, and steric features that characterize small-molecule inhibitors binding stably to 3CLpro and by an extended collection of known binders. Here, we present combined virtual screening, molecular dynamics (MD) simulation, machine learning, and in vitro experimental validation analyses, which have led to the identification of small-molecule inhibitors of 3CLpro with micromolar activity and to a pharmacophore model that describes functional chemical groups associated with the molecular recognition of ligands by the 3CLpro binding pocket. Experimentally validated inhibitors using a ligand activity assay include natural compounds with the available prior knowledge on safety and bioavailability properties, such as the natural compound rottlerin (IC50 = 37 µM) and synthetic compounds previously not characterized (e.g., compound CID 46897844, IC50 = 31 µM). In combination with the developed pharmacophore model, these and other confirmed 3CLpro inhibitors may provide a basis for further similarity-based screening in independent compound databases and structural design optimization efforts to identify 3CLpro ligands with improved potency and selectivity. Overall, this study suggests that the integration of virtual screening, MD simulations, and machine learning can facilitate 3CLpro-targeted small-molecule screening investigations. Different receptor-, ligand-, and machine learning-based screening strategies provided complementary information, helping to increase the number and diversity of the identified active compounds. Finally, the resulting pharmacophore model and experimentally validated small-molecule inhibitors for 3CLpro provide resources to support follow-up computational screening efforts for this drug target.

A Covalent Calmodulin Inhibitor as a Tool to Study Cellular Mechanisms of K-Ras-Driven Stemness.

Recently, the highly mutated oncoprotein K-Ras4B (hereafter K-Ras) was shown to drive cancer cell stemness in conjunction with calmodulin (CaM). We previously showed that the covalent CaM inhibitor ophiobolin A (OphA) can potently inhibit K-Ras stemness activity. However, OphA, a fungus-derived natural product, exhibits an unspecific, broad toxicity across all phyla. Here we identified a less toxic, functional analog of OphA that can efficiently inactivate CaM by covalent inhibition. We analyzed a small series of benzazulenones, which bear some structural similarity to OphA and can be synthesized in only six steps. We identified the formyl aminobenzazulenone 1, here named Calmirasone1, as a novel and potent covalent CaM inhibitor. Calmirasone1 has a 4-fold increased affinity for CaM as compared to OphA and was active against K-Ras in cells within minutes, as compared to hours required by OphA. Calmirasone1 displayed a 2.5-4.5-fold higher selectivity for KRAS over BRAF mutant 3D spheroid growth than OphA, suggesting improved relative on-target activity. Importantly, Calmirasone1 has a 40-260-fold lower unspecific toxic effect on HRAS mutant cells, while it reaches almost 50% of the activity of novel K-RasG12C specific inhibitors in 3D spheroid assays. Our results suggest that Calmirasone1 can serve as a new tool compound to further investigate the cancer cell biology of the K-Ras and CaM associated stemness activities.

Survival relative to pacemaker status after transcatheter aortic valve implantation.

OBJECTIVES: To determine whether a permanent pacemaker (PPM) in situ can enhance survival after transcatheter aortic valve implantation (TAVI), in a predominantly inoperable or high risk cohort. BACKGROUND: New conduction disturbances are the most frequent complication of TAVI, often necessitating PPM implantation before hospital discharge. METHODS: We performed an observational cohort analysis of the UK TAVI registry (2007-2015). Primary and secondary endpoints were 30-day post-discharge all-cause mortality and long-term survival, respectively. RESULTS: Of 8,651 procedures, 6,815 complete datasets were analyzed. A PPM at hospital discharge, irrespective of when implantation occurred (PPM 1.68% [22/1309] vs. no PPM 1.47% [81/5506], odds ratio [OR] 1.14, 95% confidence interval [CI] 0.71-1.84; p = .58), or a PPM implanted peri- or post-TAVI only (PPM 1.44% [11/763] vs. no PPM 1.47% [81/5506], OR 0.98 [0.51-1.85]; p = .95) did not significantly reduce the primary endpoint. Patients with a PPM at discharge were older, male, had right bundle branch block at baseline, were more likely to have received a first-generation self-expandable prosthesis and had experienced more peri- and post-procedural complications including bailout valve-in-valve rescue, bleeding and acute kidney injury. A Cox proportional hazards model demonstrated significantly reduced long-term survival in all those with a PPM, irrespective of implantation timing (hazard ratio [HR] 1.14 [1.02-1.26]; p = .019) and those receiving a PPM only at the time of TAVI (HR 1.15 [1.02-1.31]; p = .032). The reasons underlying this observation warrant further investigation. CONCLUSIONS: A PPM did not confer a survival advantage in the first 30 days after hospital discharge following TAVI.

Open transcatheter valve implantation for mitral annular calcification: One-year outcomes.

BACKGROUND: Transcatheter mitral valve implantation (TMVI) for native mitral valve pathology with severe mitral annular calcification has emerged as an alternative treatment option to conventional mitral valve surgery. The objective of this study was to evaluate patients who were referred for TMVI with severe mitral annular calcification and their procedural outcomes. METHODS: Retrospective analysis of patients from 2017 to 2020 referred for TMVI was carried out. Demographic characteristic details; surgical strategy; perioperative complications; and hospital stay, including 30-day and 1-year mortality, were analyzed. RESULTS: Eleven patients were referred for consideration of TMVI. The 8 patients who underwent TMVI had a median age of 74 years (range, 57-80 years), the median Society of Thoracic Surgeons score was 4.6 (range, 2.4-10.9), and European System for Cardiac Operative Risk Evaluation II score was 5.2% (2%-10.1%). The median cardiopulmonary bypass time and crossclamp times were 170 minutes (range, 150-248 minutes) and 152 minutes (range, 118-214 minutes), respectively. The median hospital stay was 29 days (range, 2-40 days). Thirty-day in hospital mortality was 12%, whereas 1-year mortality was 25%. There was symptomatic improvement with downgrade of New York Heart Association functional class from III or IV to I or II. The 3 patients who were turned down had a median age of 73 years, median Society of Thoracic Surgeons score was 13.4, and median European System for Cardiac Operative Risk Evaluation II score was 5.72%. They were alive at 12 months follow-up from the date of surgical assessment; however, all with New York Heart Association functional class III or IV symptoms. CONCLUSIONS: We describe a series demonstrating the technical consideration and capability of transatrial TMVI to treat mitral annular calcification and native mitral valve disease. Our results are favorable when compared with TMVI global registry data for transseptal or transapical approach.

Safety Profile of an Intra-Annular Self-Expanding Transcatheter Aortic Valve and Next-Generation Low-Profile Delivery System.

OBJECTIVES: The aim of this study was to characterize the safety profile of an intra-annular self-expanding valve with a next-generation low-profile delivery system (DS). BACKGROUND: Key design modifications to the FlexNav DS include the addition of a hydrophilic-coated, integrated sheath and stability layer to facilitate gradual, controlled deployment in vessels with diameter ≥5 mm. METHODS: Patients were pooled from 2 concurrent prospective, multicenter, single-arm studies (FlexNav DS arm of PORTICO IDE [Portico Re-Sheathable Transcatheter Aortic Valve System U.S. IDE Trial] [n = 134] and the FlexNav EU CE Mark Study [n = 46]) for the analysis. The primary endpoint was Valve Academic Research Consortium-2-defined major vascular complications at 30 days. Clinical outcomes and valve performance were assessed through 30 days by an independent clinical events committee and an echocardiography core laboratory, respectively. RESULTS: One hundred forty high-risk and 40 extreme-risk subjects enrolled between October 15, 2018, and December 10, 2019, from 28 sites in the United States, Australia, and Europe who underwent attempted transfemoral Portico valve implantation were included. The mean age was 85.1 ± 5.6 years, 60% were women, the mean Society of Thoracic Surgeons score was 5.3%, and 96.1% presented with ≥1 frailty factor. Technical device success was 96.7%. At 30 days, the rate of major vascular complications was 5.0%, with 4.4% of complications adjudicated as access site-related (3.3% transcatheter aortic valve replacement DS access site-related). Death (0.6%) and disabling stroke (1.1%) were rare. The rate of new permanent pacemaker implantation was 15.4%. Echocardiography revealed a mean gradient of 7.1 ± 3.2 mm Hg, mean valve area of 1.77 ± 0.41 cm2, and a 4.1% rate of moderate paravalvular leak at 30 days. CONCLUSIONS: Portico valve implantation with the FlexNav DS was associated with an excellent safety profile at 30 days.

Thirty-day clinical outcomes of the Evolut PRO self-expanding transcatheter aortic valve: the international FORWARD PRO study.

AIMS: The Evolut PRO is a new transcatheter heart valve with an outer pericardial wrap intended to reduce paravalvular leak and facilitate tissue ingrowth. We aimed to evaluate the clinical performance and safety of the Evolut PRO valve in standard practice. METHODS AND RESULTS: FORWARD PRO is a prospective, multinational, multicentre observational study. Transcatheter aortic valve implantation with the Evolut PRO valve (23, 26, or 29 mm) was attempted in 629 non-consecutive patients from 39 centres from February 2018 to January 2019. The primary endpoint was the rate of all-cause mortality at 30 days compared to a pre-specified performance goal. An independent clinical events committee adjudicated safety endpoints based on VARC-2 definitions. All echocardiograms were centrally assessed by an independent core laboratory (Mayo Clinic, Rochester, MN, USA). Baseline characteristics included mean age 81.7±6.1 years, 61.8% female, STS score 4.7±3.3%, and 33.6% were frail. All-cause mortality at 30 days was 3.2%, which was lower than the pre-specified performance goal of 5.5% (p=0.004). Greater than mild AR was present in 1.8% of patients at discharge. CONCLUSIONS: The FORWARD PRO study confirmed the safety and efficacy of the Evolut PRO transcatheter aortic valve system with an external pericardial wrap. ClinicalTrials.gov Identifier: NCT03417011

PDE6D Inhibitors with a New Design Principle Selectively Block K-Ras Activity.

The trafficking chaperone PDE6D (also referred to as PDEδ) has been nominated as a surrogate target for K-Ras4B (hereafter K-Ras). Arl2-assisted unloading of K-Ras from PDE6D in the perinuclear area is significant for correct K-Ras localization and therefore activity. However, the unloading mechanism also leads to the undesired ejection of PDE6D inhibitors. To counteract ejection, others have recently optimized inhibitors for picomolar affinities; however, cell penetration generally seems to remain an issue. To increase resilience against ejection, we engineered a "chemical spring" into prenyl-binding pocket inhibitors of PDE6D. Furthermore, cell penetration was improved by attaching a cell-penetration group, allowing us to arrive at micromolar in cellulo potencies in the first generation. Our model compounds, Deltaflexin-1 and -2, selectively disrupt K-Ras, but not H-Ras membrane organization. This selectivity profile is reflected in the antiproliferative activity on colorectal and breast cancer cells, as well as the ability to block stemness traits of lung and breast cancer cells. While our current model compounds still have a low in vitro potency, we expect that our modular and simple inhibitor redesign could significantly advance the development of pharmacologically more potent compounds against PDE6D and related targets, such as UNC119 in the future.