Suri, Rakesh M.

Background Myxomatous mitral valve disease (MMVD) is a degenerative disorder marked by excess tissue fibrosis and matrix remodeling, leading to leaflet prolapse. While recent studies linked transforming growth factor beta (TGF-β) activation to MMVD development and progression, upstream regulators of this and other modulatory/causal pathways remain largely unexplored. Objectives In this study, we utilized high-throughput sequencing to conduct unbiased analyses of mRNA and microRNA (miRNA) levels in myxomatous and healthy mitral valve tissues, aiming to uncover novel molecular mechanisms involved in MMVD. Methods We defined differentially expressed mRNAs and miRNAs transcripts displaying a fold-change > 1.5 and P < .05. Pathway analysis was performed using Ingenuity Pathway Analysis and DAVID, with key findings validated via qRT-PCR. A total of 2378 transcripts were differentially expressed between myxomatous and normal valves. Established pathways, including TGF-β signaling, were confirmed as major contributors to MMVD. Additionally, Random Forests with Boruta Feature Selection identified transcripts with a 95% likelihood of importance, and subsequent pathway analysis on this subset of genes revealed unique signaling pathways. Results Most notably, circadian rhythm disruption emerged as a novel, highly ranked pathway in MMVD. Key miRNAs, such as miR-1, miR-133a, and miR-217 were highlighted as highly relevant, with miRNA–mRNA interactions displaying distinct molecular signatures predictive of MMVD. Conclusions Collectively, this study represents the first comprehensive analysis of both miRNA and mRNA expression in MMVD, revealing both established and novel disease-associated pathways. The discovery of circadian rhythm disturbances and new regulatory miRNAs suggests promising directions for further research and potential therapeutic targets for nonsurgical treatment strategies in patients with MMVD.

Introduction: Atrial fibrillation (AF) is a serious complication, which occurs in 30% to 40% of patients after surgical aortic valve replacement (SAVR) and contributes to adverse outcomes. Advanced technology has enabled transcatheter aortic valve replacement (TAVR) in patients with High-risk Severe Aortic Stenosis (HRSAS). In these patients, the compliance of the systemic vasculature is an independent predictor of diastolic dysfunction, a known predictor of postoperative AF (POAF). We hypothesize that patients with HRSAS undergoing TAVR represent a population at increased risk for POAF. METHODS: The medical records of 195 TAVR patients at the Mayo Clinic from November 2008 to January 2013 were analyzed. All patient demographic, clinical, pre- and post-procedural outcomes were collected from the patients’ medical records, and reviewed to ascertain all cases of POAF (AF ≤30 days of surgery). Patients with a prior history of AF (n= 75 (38.5%)) were excluded. Logistic regression analysis was used to identify clinical predictors of POAF after TAVR. Results: The mean age of the study population was 80.8±7.8 years and 60.8% (n=73) were men. The mean STS risk score was 8.9±5.1. Of the 120 patients without prior AF, 20.8% (n=25) developed new-onset POAF after TAVR. Patients who developed POAF were more likely to have undergone a transapical or transaortic TAVR approach (OR 3.20; 95% CI (1.3-8.0), had a higher incidence of renal complications (52.0% vs 21.5%; p= 0.003), greater hospital length of stay (7.4±2.58 vs 5.0±2.6 days; p= 0.0003, and a trend toward higher 30-day mortality (28.0% vs 13.7%; p= 0.09) and pulmonary complications (16.0% vs 5.4%; p= 0.08) compared with those who did not develop POAF, respectively. Neurologic complications were not different between the 2 group (4.0% vs 3.2%; p= 0.85). Conclusions: Patients with High-risk Severe Aortic Stenosis undergoing TAVR have increased risk of POAF, primarily associated with a transapical or aortic surgical approach. Patients who develop POAF had higher incidence of post-procedural complications and longer hospitalizations. Therefore, perioperative strategies aimed at prevention of POAF are as important in TAVR patients as in those undergoing SAVR.

Background: Patients with severe aortic stenosis being considered for transcatheter aortic valve replacement (TAVR) undergo aortoiliac computed tomographic angiography (CTA) of the chest/abdomen/pelvis. Despite the increasing number of TAVR procedures worldwide, little is known regarding the clinical significance of non-cardiovascular incidental findings (IFs) on TAVR-CTA scans. Objective: To determine the frequency, clinical significance and impact on survival of non-cardiovascular IFs detected on TAVR-CTA scans. Methods: CTA studies for 424 consecutive patients being evaluated for TAVR were reviewed for non-cardiovascular IFs (62% male, median age 82±8.3 years). The electronic medical record was reviewed to assess for subsequent clinical management and survival. Results: An IF was present in nearly all patients (99%). The mean number of IFs per patient was 5.3 (±2.8; range 0-14). After excluding obviously benign IFs, 67% had at least one potentially pathologic IF (mean 1.1±1.0). Factors associated with higher numbers of IFs were age (p<0.0001) and use of IV contrast (p=0.03). IFs prompted clinical work-up in 39 patients (9.2%) and delayed or cancelled procedures in 7 patients (1.7%). The number needed to image to diagnose a new malignancy or medical condition was 19. The number of IFs was predictive of poor overall survival before (HR 1.09; 95% CI (1.02 to 1.70), p=0.02) and after adjustment for baseline clinical variables (HR 1.07; (1.0 to 1.15); p=0.04). Conclusions: This investigation demonstrates that IFs are present in nearly all TAVR-CTA scans, commonly require further clinical evaluation, and are associated with poorer survival. TAVR institutions should have mechanisms in place to ensure communication and follow-up of IFs.

Importance In patients with severe aortic valve stenosis at intermediate surgical risk, transcatheter aortic valve replacement (TAVR) with a self-expanding supra-annular valve was noninferior to surgery for all-cause mortality or disabling stroke at 2 years. Comparisons of longer-term clinical and hemodynamic outcomes in these patients are limited. Objective To report prespecified secondary 5-year outcomes from the Symptomatic Aortic Stenosis in Intermediate Risk Subjects Who Need Aortic Valve Replacement (SURTAVI) randomized clinical trial. Design, Setting, and Participants SURTAVI is a prospective randomized, unblinded clinical trial. Randomization was stratified by investigational site and need for revascularization determined by the local heart teams. Patients with severe aortic valve stenosis deemed to be at intermediate risk of 30-day surgical mortality were enrolled at 87 centers from June 19, 2012, to June 30, 2016, in Europe and North America. Analysis took place between August and October 2021. Intervention Patients were randomized to TAVR with a self-expanding, supra-annular transcatheter or a surgical bioprosthesis. Main Outcomes and Measures The prespecified secondary end points of death or disabling stroke and other adverse events and hemodynamic findings at 5 years. An independent clinical event committee adjudicated all serious adverse events and an independent echocardiographic core laboratory evaluated all echocardiograms at 5 years. Results A total of 1660 individuals underwent an attempted TAVR (n = 864) or surgical (n = 796) procedure. The mean (SD) age was 79.8 (6.2) years, 724 (43.6%) were female, and the mean (SD) Society of Thoracic Surgery Predicted Risk of Mortality score was 4.5% (1.6%). At 5 years, the rates of death or disabling stroke were similar (TAVR, 31.3% vs surgery, 30.8%; hazard ratio, 1.02 [95% CI, 0.85-1.22]; P = .85). Transprosthetic gradients remained lower (mean [SD], 8.6 [5.5] mm Hg vs 11.2 [6.0] mm Hg; P &amp;lt; .001) and aortic valve areas were higher (mean [SD], 2.2 [0.7] cm 2 vs 1.8 [0.6] cm 2 ; P &amp;lt; .001) with TAVR vs surgery. More patients had moderate/severe paravalvular leak with TAVR than surgery (11 [3.0%] vs 2 [0.7%]; risk difference, 2.37% [95% CI, 0.17%- 4.85%]; P = .05). New pacemaker implantation rates were higher for TAVR than surgery at 5 years (289 [39.1%] vs 94 [15.1%]; hazard ratio, 3.30 [95% CI, 2.61-4.17]; log-rank P &amp;lt; .001), as were valve reintervention rates (27 [3.5%] vs 11 [1.9%]; hazard ratio, 2.21 [95% CI, 1.10-4.45]; log-rank P = .02), although between 2 and 5 years only 6 patients who underwent TAVR and 7 who underwent surgery required a reintervention. Conclusions and Relevance Among intermediate-risk patients with symptomatic severe aortic stenosis, major clinical outcomes at 5 years were similar for TAVR and surgery. TAVR was associated with superior hemodynamic valve performance but also with more paravalvular leak and valve reinterventions.

We recently reported activation of TGF-β superfamily pathways and activation of Wnt/β-catenin signaling in the pathogenesis of myxomatous mitral valve disease (MMVD), which may converge upon increased Runx2 expression. We also demonstrated that chronic in vivo administration of angiotensin II (AngII) recaptures various molecular aberrations characteristic of human disease -including increased TGF-β signaling and activation of Runx2- in mouse mitral valves. Here, we sought to determine whether Runx2 haploinsufficiency can attenuate molecular and/or phenotypic effects of AngII infusion in mouse mitral valves. We implanted littermate matched Runx2+/+ and Runx2+/- mice with osmotic minipumps delivering AngII (1000ng/kg/min) or saline for 2 weeks. We measured changes in mRNA (qRT-PCR) and protein (immunohistochemistry) levels in mitral valves, and assessed mitral valve function by echocardiography. In Runx2+/+ mice, AngII elicited increased mRNA levels of TGF-β3 and the TGF-β target COL3A1, and increased staining for canonical (p-SMAD2/3) and non-canonical (p-AKT) TGF-β signaling proteins. Runx2 haploinsufficiency attenuated AngII-induced changes in COL3A1 expression and p-AKT staining, without impacting AngII-mediated alterations in TGF-β3 and p-SMAD2/3. Evaluating collagen thickness by picrosirius red staining and visualization under circularly polarized light, AngII infusion in Runx2+/+ mice was associated with increased collagen density at the base of posterior mitral valve leaflets, a change that was abrogated by Runx2 haploinsufficiency. Similarly, Runx2-haploinsufficiency was again protective when examining mRNA and protein levels of the proliferation marker KI67 in response to AngII. Echocardiography identified a trend towards increased mitral valve regurgitation following AngII infusion that was unaltered by Runx2 haploinsuffiency. Collectively, these data suggest that increases in Runx2 expression in the mitral valve may serve to orchestrate tissue fibrosis and cellular proliferation that are hallmarks of MMVD, and that future pharmacological strategies aimed at reducing activity of Runx2 in the mitral valve may yield viable non-surgical alternatives for the management of this condition.

Introduction: The risk of stroke or transient ischemic attack (TIA) remains increased after transcatheter aortic valve replacement (TAVR), especially in the first 30 days. Limited data is available regarding the impact of procedural characteristics on risk of stroke/TIA. Hypothesis: Post deployment balloon dilatation (PD) and total number of balloon dilatations (pre, valve and post insertion) may be associated with increased risk of stroke/TIA in patients undergoing TAVR. Methods: We included consecutive patients who underwent balloon-expandable TAVR until June 2014 at Mayo Clinic, Rochester. Patients who died in the operating room, converted to open surgery, or had valve-in-valve, or underwent self-expanding TAVR were excluded. Primary end-point was stroke or TIA at 30 days. Results: Mean age was 80.9±8 y, mean STS score was 8.3±5 and 50% underwent transfemoral access. The overall incidence of PD was 14% (n=53). Total number of dilations ranged from 2-7, with 5% (n=19) getting ≥ 4 total dilatations. Out of the 370 patients, 13 patients (3.5%) suffered stroke/TIA (9.4% in PD group vs. 2.2% in non-PD group) in the first 30 days after TAVR. Cox-proportional hazards regression analysis indicated that PD during TAVR was associated with a significantly increased risk of 30-day stroke/TIA (HR, 3.8; 95% CI, 1.2-11.6; p=0.02). There was a trend towards increased stroke/TIA with total number of dilations (HR, 1.5; 95% CI, 0.87-2.6; p=0.14), longer procedural time (HR per 30 minutes, 1.3; 95% CI, 0.96-1.7; p=0.09) and severity of atherosclerosis (moderate-severe - HR, 1.9; 95% CI 0.95- 3.8; p=0.07). PD was not significantly associated with the risk of 30 day death (HR, 1.1; 95% CI, 0.24-4.85; p=0.93). Conclusions: In patients undergoing PD after balloon-expandable TAVR, 9.4% suffered a stroke or TIA in the first 30 days. PD was associated with a four-fold increase in 30 day risk of stroke or TIA.

Introduction: Pulmonary hypertension (PH) is associated with increased mortality after surgical or transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS). Hypothesis: We hypothesized that clinical or hemodynamic factors might influence the relationship between significant PH and increased mortality. Methods: Among patients with symptomatic AS at high or prohibitive surgical risk receiving TAVR in the PARTNER I randomized trial or registry, 2180 patients with an invasive measurement of mean pulmonary artery pressure (mPAP) recorded were included. PH was defined as: none (mPAP<25 mmHg), mild (25 to <35), and mod/sev (≥35). Results: One year all-cause mortality was worse with increasing severity of PH: none (n=785, 18.6%), mild (n=838, 22.7%), and mod/sev (n=557, 25.0%) (p=0.01). The association between mod/sev PH (vs. no PH) and 1y mortality varied by sex and renal function (interaction p=0.03 and p=0.06, respectively). In females, mod/sev PH was associated with increased mortality (24.6% vs. 14.1%, HR 1.89, 95% CI 1.32-2.73); in males it was not (24.9% vs. 22.2%, HR 1.12, 95% CI 0.82-1.52). Additionally, mod/sev PH was associated with mortality in those with glomerular filtration rate (GFR) <40 (HR 1.76, 95% CI 1.28-2.42), but not in those with GFR ≥40. In a multivariable Cox PH model of patients with mod/sev PH, oxygen dependent lung disease, cerebrovascular disease, lower GFR, and lower baseline transvalvular mean gradient were each independently associated with increased 1y mortality (p<0.05 for all), whereas pulmonary artery compliance was the only hemodynamic variable associated with mortality (p=0.043) (Table). Conclusions: The relationship between mod/sev PH and increased mortality after TAVR is altered by sex and renal function. While lower pulmonary artery compliance is associated with increased mortality in patients with significant PH, clinical factors appear to be more influential in stratifying risk than hemodynamic indices.

Introduction: Accurate stroke volume (SV) calculation is critical for calculating aortic valve area by echocardiography. 2D-Doppler estimation of SV (SV 2D ) assumes uniform blood flow velocities through the left ventricular outflow tract (LVOT). Non-uniform flow through the LVOT, appreciated as spectral broadening of the LVOT Doppler signal, could result in inaccurate SV calculation. Hypothesis: Increased spectral broadening in the LVOT will result in overestimation of SV by the SV 2D method compared to 3D volumetric assessment of SV (SV 3D ). Methods: Fifty-one consecutive patients with aortic stenosis underwent comprehensive 2D-TTE and assessment of SV 3D . Patients with ≥ moderate mitral or aortic regurgitation were excluded. An LVOT pulse-wave Doppler signal with > 0.4 m/s difference between outer and inner edge of velocity spectral display (at time of peak velocity) was considered non-uniform flow (i.e., spectral broadening). Results: Spectral broadening was present in 33% of the cohort. These patients were commonly female with smaller ventricles and higher ejection fraction. Spectral broadening was associated with a significant overestimation of SV on Doppler-based measurements (101±20 ml vs 78±15 mL, SV 2D vs SV 3D , respectively; r=0.83, p<0.0001); such differences were not seen in patients with uniform flow velocities (82±15 vs 79±14 mL, r=0.83, p=0.03). Patient characteristics by spectral broadening are shown in table 1. Conclusion: In aortic stenosis patients with non-uniform flow, Doppler-based methods overestimated SV by 29.5% on average (maximum 64%) when compared to 3D methods. This results in a proportional increase in calculated valve area despite a similar mean gradient between groups. Substituting SV 3D resulted in similar SV, valve area, and mean gradient between uniform and non-uniform groups. When spectral broadening >0.40 cm/s is present, 3D volumetric assessment of SV should be considered for accurate estimation of aortic valve area.

Introduction: Myxomatous mitral valve disease (MMVD) is a degenerative condition characterized by tissue fibrosis and matrix remodeling which ultimately progresses to leaflet prolapse. While recent work has shown that transforming growth factor beta (TGF-β) signaling contributes to the pathogenesis of MMVD, upstream regulators of this and other pathways remain poorly understood. Hypothesis: We sought to use high-throughput RNA sequencing coupled with microRNA (miRNA) sequencing to identify novel molecular targets as well as upstream regulators contributing to MMVD. Methods: We conducted mRNA and miRNA sequencing on normal (n = 10) and myxomatous human mitral valve samples (n = 10). Differential expression was identified using linear modeling and parallel random forest analyses. Canonical pathways were identified by Ingenuity Pathway Analyses (IPA). Predicted miRNA targets were identified using TargetScanHuman 6.2. Results: We found 2784 mRNAs that were differentially expressed between normal and myxomatous mitral valves, which IPA largely categorized in to pro-fibrotic, matrix remodeling and cellular proliferation signaling. In miRNA sequenced from the same samples, 67 miRNAs were differentially-expressed between normal and myxomatous mitral valves. Increased expression of TGF-β ligands, collagen isoforms, and matrix metalloproteinases were associated with reductions in miRNAs predicted to target them. Conversely, mRNA levels of the “protective” genes TGFβ-induced factor homeobox 1, salt-inducible kinase 1, TIMP metallopeptidase inhibitor 4, and cyclin-dependent kinase inhibitor 1C mRNA levels were decreased in myxomatous tissue, and miRNAs predicted to target these genes (e.g., miR-656, miR-379-3p, miR-664a-3p, and miR-34c-5p) were significantly increased. Conclusions: Collectively, these data not only identify novel genes that are differentially regulated in MMVD, but also suggest miRNAs may play an active role in suppressing key protective molecules in MMVD. Thus, anti-mIRs therapy may be a viable therapeutic target to restore anti-fibrotic and anti-proliferative molecules in the valve and slow progression of MMVD. Future mechanistic studies will lay a critical foundation for translational work in these areas.

Introduction: Left ventricular longitudinal strain (LV-LS) 1) predicts mortality in patients with aortic stenosis (AS) and 2) is highly correlated to type-B natriuretic peptide (BNP) values. The BNP ratio (measured BNP/maximal expected BNP value specific for age and sex) is a powerful independent predictor of death in patients with AS. Hypothesis: we hypothesize that BNP activation (i.e. BNP ratio >1) affects the association between LV-LS and mortality in patients with asymptomatic AS and preserved LV ejection fraction (EF ≥50%). Methods: 315 patients (age 74±12 years, 56% men and mean aortic valve area = 1.02±0.15cm2) underwent simultaneous Doppler echocardiographic and BNP measurements. LV-LS was calculated as the average of 12 LV segments from apical 2- and 4-chamber views using Velocity Vector Imaging. Results: Mean LV-LS was -16.8±3.2%, LV EF 66±7%, median BNP level 121 (interquartile 48-320) pg/ml. 58% of patients had BNP activation. Better LV-LS was associated with lower log BNPratio (regression coefficient 0.10, p<0.001). After a median follow-up of 6.5 yrs (interquartile: 3.6-8.2), 119 deaths occurred. After adjustment for age, sex, Charlson score index, hemoglobin level, aortic valve replacement (as a time dependent variable), LV-LS and log BNPratio were separately associated with increased risk for death (all p<0.01). Further adjustment for predictors of mortality, LV-LS and log-BNP ratio remained associated with increased risk for death (hazard ratio HR [95%CI]: 1.09 [1.03-1.15]; p=0.003 and 1.82 [1.52-2.19]; p<0.0001 respectively). In patients without BNP activation (i.e. normal BNP), LV-LS was associated with mortality (HR: 1.22 [1.04-1.43]; p=0.01) while it was not in patients with BNP activation (p=0.22). Conclusions: In patients with asymptomatic AS, without clinically obvious myocardial impairment (i.e. normal LVEF), a notable proportion of patients present with myocardial alterations detected by an elevated BNPratio or reduced LV-LS. These signs of myocardial alterations were predictive of mortality after diagnosis. Thus both BNP and LV-LS should be assessed in the clinical setting to provide complementary information on prognosis in patients with asymptomatic AS and preserved LV EF.