Kaptzan, Tatiana

Abstract Background The MITRAL Trial (Mitral Implantation of TRAnscatheter vaLves) evaluates the safety and feasibility of balloon-expandable aortic transcatheter heart valves in patients with severe mitral valve disease with mitral annular calcification (MAC), failed surgical rings or failed bioprostheses. Purpose We sought to evaluate 4-year outcomes of patients enrolled in the MITRAL trial. Methods This is a prospective study that enrolled 91 high surgical risk patients at 13 sites in the U.S. 30 patients underwent Mitral Valve-in-Valve (MViV), 30 Valve-in-Ring (MViR) and 31 Valve-in-MAC (ViMAC). 4-year outcomes of these patients were evaluated in this analysis. Primary endpoints and key serious adverse events including deaths were adjudicated by an independent Clinical Events Committee. Cardiac computed tomography (CT) and echocardiographic images were evaluated by independent CT and Echocardiographic Core Laboratories. Results Mean age was 74.3±8.9 years. Most patients undergoing MViV and ViMAC were female (MVIV=63.3%, MViR=36.7% and ViMAC=71%). Mean STS score was 9.2±6.6% (MViV 10.2±6.5%, MViR 8.7±4.7%, ViMAC=8.6±8.2%). All-cause mortality at 4 years was higher for ViMAC and MViR: MViV=6.9% (cardiovascular 3.4%), MViR=48.1% (cardiovascular 18.5%), ViMAC=51.9% (cardiovascular 29.6%), p=0.002 (Figure 1). At 4 years, all survivors had ≤1+ mitral regurgitation and most had none or trace mitral regurgitation (MViV=87.5, MViR=33.3% and ViMAC=100%). Mean mitral valve gradients remained stable (MViV=5.9±2.2 mmHg, MViR= 6.6±5.1 mmHg, ViMAC=5.1±1.0 mmHg), Figure 2. Most survivors experienced significant improvement of symptoms and were in NYHA class I-II at 4-year follow-up (MViV=78.9%, MViR=66.7% and ViMAC=66.7%). Conclusions MViV is associated with excellent outcomes at 4 years. MViR and ViMAC were associated with higher mortality at 4 years. However, most survivors in all groups experienced sustained improvement of symptoms and stable THV performance at 4 years. Whether survival bias had an impact on THV performance and improved symptoms at follow-up is not known and deserves further evaluation. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Unrestricted Research Grant from Edwards Lifesciences.

Abstract Background H3K27M-mutant diffuse midline glioma (DMG) is a lethal brain tumor that usually occurs in children. Despite advances in our understanding of its underlying biology, efficacious therapies are severely lacking. Methods We screened a library of drugs either FDA-approved or in clinical trial using a library of patient-derived H3K27M-mutant DMG cell lines with cell viability as the outcome. Results were validated for clinical relevance and mechanistic importance using patient specimens from biopsy and autopsy, patient-derived cell lines, inhibition by gene knockdown and small molecule inhibitors, and patient-derived xenografts. Results Kinase inhibitors were highly toxic to H3K27M-mutant DMG cells. Within this class, STAT3 inhibitors demonstrated robust cytotoxic activity in vitro. Mechanistic analyses revealed one form of activated STAT3, phospho-tyrosine- 705 STAT3 (pSTAT3), was selectively upregulated in H3K27M-mutant cell lines and clinical specimens. STAT3 inhibition by CRISPR/Cas9 knockout, shRNA or small molecule inhibition reduced cell viability in vitro, and partially restored expression of the polycomb repressive mark H3K27me3, which is classically lost in H3K27M-mutant DMG. Putative STAT3-regulated genes were enriched in an H3K27M-knockout DMG cell line, indicating relative gain of STAT3 signaling in K27M-mutant cells. Treatment of patient-derived intracranial xenografts with WP1066, a STAT3 pathway inhibitor currently in clinical use for pediatric brain tumors, resulted in stasis of tumor growth, and increased overall survival. Finally, pSTAT3(Y705) was detected in circulating plasma extracellular vesicles of patients with H3K27M-mutant DMG. Conclusions STAT3 is a biologically relevant therapeutic target in H3K27M-mutant DMG. STAT3 inhibition should be considered in future clinical trials.

AbstractObjectivesTo assess the impact of pulmonary hypertension (PH) on outcomes of patients with severe mitral annular calcification (MAC) undergoing transcatheter mitral valve replacement (TMVR).BackgroundPH is associated with poor outcomes after mitral valve surgery. Whether the presence of PH in patients with MAC undergoing (TMVR) is associated with poor outcomes, is unknown.MethodsRetrospective evaluation of 116 patients from 51 centers in 11 countries who underwent TMVR with valve in mitral annular calcification (ViMAC) using balloon‐expandable aortic transcatheter valves (THVs) from September 2012 to March 2017. Pulmonary artery systolic blood pressure (PASP) by echocardiogram was available in 90 patients. The subjects were stratified based on PASP: No PH = PASP ≤35 mmHg (n = 11); mild to moderate PH = PASP 36–49 mmHg (n = 21) and severe PH = PASP ≥50 mmHg (n = 58). Clinical, procedural, and echocardiographic outcomes were assessed.ResultsMean age was 72.7 (±12.8) years, 59 (65.6%) were female, Society of Thoracic Surgeons score was 15.8 + 11.8% and 90.0% where in New York Heart Association (NYHA) class III–IV. There was no significant difference in all‐cause mortality at 30 days (no PH = 27.3%, mild–moderate PH = 19.0%, severe PH = 31.6%; p = 0.55) or at 1 year (no PH = 54.5%, mild–moderate PH = 38.1%, severe PH = 56.1%; p = 0.36). No difference in adverse events, NYHA class or amount of residual mitral regurgitation at 1 year were observed between the groups.ConclusionThis study suggests that the presence of PH in patients with predominantly mitral stenosis with MAC undergoing TMVR does not impact mortality or adverse events. Further studies are needed to fully understand the effect of PH in this group of patients.