Suri, Rakesh M.

Introduction: Excised aortic valve weight (AVW) correlates with severity of AS. There is some debate about the true severity of AS in low gradient AS (LGAS) compared to high gradient AS (HGAS). We sought to compare patient characteristics and operatively excised AVW in patients with LGAS vs HGAS vs moderate AS. Methods: 916 patients with EF ≥50% undergoing surgical aortic valve replacement for AS between 2010-2012 were included. Clinical and echocardiographic characteristics of LGAS patients (AVA≤1cm 2 , MnG<40mmHg; N=68) were compared to HGAS patients (AVA≤1cm 2 , MnG≥40mmHg; N=745) and operatively excised AVW were compared to moderate AS (AVA>1cm 2 , MnG<40mmHg; N=102). Results: Compared to HGAS, LGAS patients were older (mean age 77 ± 10 vs 73 ± 10 years; p=0.001), often female (56% vs 38%; p=0.006), but without differences in diabetes (26% vs 29%; p=0.78), hyperlipidemia (85% vs 86%, p=0.86), coronary artery disease (49% vs 44%; p=0.53), or hypertension (81% vs 76%; p=0.38). LGAS patients predominantly had trileaflet aortic valves (91% vs 71%; p<0.001), smaller LVOT diameter (2.16 ± 0.15 vs 2.25 ± 0.20 cm; p=0.002), lower stroke volume index (42.1 ± 7.3 vs 49.0 ± 8.8 cc/m 2 ; p<0.001), lower systemic compliance (0.77 ± 0.30 vs 0.93 ± 0.33 ; p<0.001), but no difference in valvulo-arterial impedance (3.96 ± 0.76 vs. 3.84 ± 0.80, p=0.24) compared to HGAS. Excised AVW were lower in patients with LGAS vs HGAS (1.77 ± 0.76 vs 2.69 ± 1.26 g, p<0.001), but not different from moderate AS (1.77 ± 0.76 vs 2.04 ± 0.94 g; p=0.1). This relationship held true when AVW was indexed to body surface area. Three-year mortality post-valve replacement was significantly higher in LGAS compared to HGAS (22% vs 11%, p=0.02). Conclusions: LGAS occurs mostly in older female patients with trileaflet aortic valves. Excised AVW in LGAS is similar to moderate AS but lower than HGAS. However, systemic compliance is higher in LGAS vs HGAS contributing to increased afterload. Poorer outcomes after surgery in LGAS patients may be attributed to noncompliant vasculature which is not corrected with valve replacement and evaluation of patients with LGAS should include assessment of peripheral resistance.

Background: Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement in patients at high surgical risk. We investigated the impact of TAVR on left (LV) and right ventricular (RV) function using conventional echocardiography parameters. Methods and results: A total of 202 consecutive patients (age 80.6±8.0 years, aortic valve area 0.80±0.16cm 2 ) who underwent TAVR at Mayo Clinic between 2008 and 2013 were included in the study. LV ejection fraction (EF) and RV systolic function including tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC) and, systolic excursion velocity (S’) were compared before (median 33.5 days) and after TAVR procedure (median 30 days). Patients who underwent pacemaker implantation after TAVR were excluded. LV EF significantly improved following TAVR (55.3±12.6% pre vs 58.5±11.1% post; p<0.05). In contrast, RV systolic function significantly decreased after TAVR (pre vs post; TAPSE: 18.8±6.3 mm vs 17.4±6.3 mm, FAC: 42.6±9.8% vs 37.3±8.2%; S’: 10.7±2.6 cm/s vs 10.2±2.6 cm/s; p<0.05 for all). Stratifying RV functional change by TAVR approach site, patients undergoing trans-femoral TAVR (n=100) showed RV deterioration only by FAC (see Table). In contrast, RV systolic dysfunction was more prominent in trans-apical approach group (n=87) with significant decline in all parameters of RV systolic function (see Table). Conclusion: TAVR is associated with early enhancement in LV systolic function. However, there is evidence of worsening RV function in a significant number of patients. Further studies are necessary to determine whether this deterioration in RV function is related to anatomic access site or to other factors, and to evaluate its prognostic significance.

Introduction: In asymptomatic patients with severe aortic stenosis (SAS), left ventricular (LV) ejection fraction (EF) <50% is generally considered to be the threshold for referral for aortic valve replacement (AVR). Hypothesis: We investigated the importance of LVEF on long-term outcome after AVR in symptomatic and asymptomatic SAS patients and studied whether LVEF < 50% is the optimal threshold for referral for AVR. Methods and Results: We retrospectively identified 2017 patients with SAS (aortic valve area (AVA)<1cm2, mean aortic valve gradient ≥40 mm Hg, or indexed AVA <0.6 cm2/m2) who underwent surgical AVR from January 1995 to June 2009 at our institution. Patients were divided into 4 groups depending on preoperative LVEF (<50% in 300 (15%) patients, 50-59% in 331 (17%), 60-69% in 908 (45%), and ≥70% in 478 (24%)). The primary end-point was all-cause mortality. During follow-up of 5.3±4.4 years, 1056 (52%) died. Five-year mortality rate increased with decreasing LVEF (41% (n=106), LVEF<50%); 35% (n=98), LVEF 50-59%; 26% (n=192), LVEF 60-69%; 22% (n=90), LVEF≥70%, p<0.0001). Compared to patients with LVEF≥60%, patients with LVEF 50-59% had increased mortality (HR 1.58, p<0.001), with a similar risk increase in both symptomatic (HR=1.56, p<0.001) and asymptomatic patients (HR 1.58, p=0.006, Figure). In a Cox regression analysis corrected for standard risk factors, LV mass index, AVA, and stroke volume index, LVEF was predictive of all-cause mortality (HR=0.89 per 10%, p<0.001). When this multivariable analysis was repeated in the subset of 1333 patients with no history of coronary artery disease, LVEF was still associated with all-cause mortality (HR=0.90 per 10%, p=0.009). Conclusion: In patients with SAS undergoing AVR, patients with LVEF 50-59% have also increased mortality compared to patients with LVEF>60%, suggesting that a different LVEF threshold should be used when referring for AVR.

Introduction: Levels of type-B natriuretic peptide (BNP) adjusted for age and sex are a powerful predictor of mortality after the diagnosis of aortic stenosis (AS). Objective: To assess whether BNP activation (compared to normal values) affects mortality after aortic valve replacement (AVR). Methods: In 494 patients with AS, plasma level of BNP was measured pre-operatively at the time of Doppler-Echocardiography. BNP was normalized as BNPratio (BNP measured/BNP maximum normal value for age and sex) to evaluate the impact of BNP activation on post-operative outcomes. Results: Mean age was73±11 years and 300 (61%) patients were male. Mean aortic valve area was 0.82±0.20cm2, mean gradient 51±16mmHg, and mean Left Ventricular Ejection Fraction 59±15%. Incidence of hypertension was 65%, diabetes 27% and chronic kidney disease 22%. Median of BNP was 211 (interquartile: 87-508) and BNPratio 2.2 (1.0-5.2). After adjustment age, gender, body surface area, Charlson score index, presence of symptoms, creatinine, hemoglobin, systolic blood pressure, indexed aortic valve area and left ventricular ejection fraction, the BNPratio (log transformed) was a predictor of long-term mortality (p<0.0001) with an hazard ratio 1.34 (1.14-1.60). Moreover, stratification by BNPratio showed increasing long-term post-operative mortality with BNPratios>2 (Figure). Conclusions: BNP activation defined using BNPratios (normalized for age and sex) is a powerful independent predictor of long-term mortality after aortic valve replacement for AS. Furthermore, patients with a BNPratio>2 before aortic valve replacement incur excess mortality during follow-up in relation to the increasing BNPratio. These data support the use of the BNPratio to guide the timing of AVR.

Background Structural and functional mitral valve abnormalities are commonly encountered in the general population. In order to determine which functional protein classes may be important to normal valve function we performed the first reported comprehensive proteomic profiling of structurally normal human mitral valves. Methods We harvested mitral valve leaflets from 5 patients who underwent orthotopic cardiac transplantation for cardiomyopathy. The morphologic appearance of mitral valves was normal with only mild functional mitral regurgitation on echocardiogram. High resolution 2D gel electrophoresis was performed to separate proteins. Gel spots were excised from 2 representative samples and protein identification was carried out using liquid chromatography tandem mass spectrometry. Results We identified 190 unique proteins with >99% probability and at least 2 unique peptides. The proteins were from various cellular locations, including cell surface, cytoskeleton, endoplasmic reticulum, extracellular matrix, mitochondrion, nucleus, cytoplasm, and plasma membrane. Functional clustering revealed that the identified proteins were involved in major molecular pathways including, energy along with fatty acid metabolism, calcium signaling acute phase response & oxidative stress, and anti‐apoptosis pathways. Conclusion Proteomic profiling of the normal human mitral valve demonstrates a pattern of expression suggesting multiple biological functions. Further quantification of protein levels and comparison with diseased mitral valves will provide new insights into the etiology and therapy of mitral valve disease in humans.

Myxomatous mitral valve disease (MMVD) is associated with increases in valvular fibrosis, matrix remodeling, and transforming growth factor beta (TGF β) signaling. While interleukin 10 (IL‐10) can suppress tissue fibrosis and matrix metalloproteinase (MMP) expression, its role in MMVD is unknown. We tested the hypotheses that reduced IL‐10 expression contributes to increased tissue fibrosis in MMVD, and that IL‐10 tonically suppresses TGF‐β signaling in normal mitral valves. We used qRT‐PCR to measure expression of IL10, TGF‐β1, MMP 2 and 9, and connective tissue growth factor (CTGF) in normal and myxomatous human mitral valves and in mitral and tricuspid valves from wild‐type and IL‐10 knockout mice. IL‐10 expression was significantly reduced in human myxomatous valves compared to normal valves (53± 12%), and was associated with increases in TGFβ, CTGF, and MMP2. Mitral valve gene expression patterns in IL‐10 −/− mice favored fibrosis and matrix remodeling compared to wild‐type littermates, with increases in TGF β (132±7%), CTGF (154±3%), and MMP9 (259±7%) (p< 0.05 for all), but not MMP2. Interestingly, expression of these genes was not altered in tricuspid valves from IL‐10 −/− mice. Collectively, these data are the first to show that IL‐10 tonically suppresses TGF β signaling in normal mitral valves and that deficiency of IL‐10 is likely to contribute to fibrosis and matrix remodeling in MMVD. NHLBI

Myxomatous mitral valve disease is characterized by fibrosis and matrix degradation and increases in transforming growth factor beta‐1 (TGFbeta‐1). Little is known, however, about changes in molecules that regulate TGFbeta‐1 signaling in myxomatous valves. Thus, we tested the hypothesis that TGFbeta‐1 promotes valvular fibrosis and matrix remodeling in myxomatous valves through canonical Smad2 signaling and permissive reductions in Smad inhibitors. Expression of TGFbeta‐1, TGFbeta‐1 target genes (connective tissue growth factor, matrix metalloproteinases 2/9), E3 ubiquitin‐protein ligases (Smurf 1/2, which degrade Smad2), and NAD(P)H oxidase catalytic subunits (Nox 2, 4, and 5) was measured using quantitative real‐time RT‐PCR. Phospho‐Smad2 levels were measured using western blotting. TGFbeta‐1 expression was higher in myxomatous valves (138.3 ± 12.5% of control, n = 24 per group; p < 0.05), while CTGF and MMP2 were increased by 5‐ and 2‐fold, respectively. Surprisingly, phospho‐Smad2 levels were unchanged between myxomatous and control tissue due to selective increases in Smurf2 expression in myxomatous valve tissue (165.2 ± 17.7% of control, p < 0.05), as Smurf1 expression was unchanged. Expression of Nox2 and Nox4—which can drive pro‐fibrotic and matrix remodeling gene expression in other tissues—were significantly elevated in myxomatous valves (211 ± 44% and 224 ± 35 % of control, respectively; p < 0.05). In conclusion, our data suggest that canonical TGFbeta‐1/Smad2 signaling is not required for progression of myxomatous valve disease, and that reducing Nox2‐and Nox4‐derived reactive oxygen species may be a novel intervention to slow progression of fibrosis and matrix remodeling in myxomatous valves.

Myxomatous mitral valve disease (MMVD), if untreated, progresses to valve prolapse, mitral regurgitation, and heart failure. Molecular mechanisms contributing to MMVD are poorly understood, and surgery remains the primary treatment for this disease. In the current study, we used whole‐genome expression microarrays in normal (n = 12) and myxomatous (n = 11) mitral valves as a nonbiased approach to identify novel pathways contributing to MMVD. In addition to identifying known contributors to fibrosis in MMVD (e.g. TGFβ signaling), we found robust evidence of immune cell infiltration and activation in myxomatous valves. Specifically, toll‐like receptors (TLRs) 3 and 7, which play a key role in antigen recognition, alongside cell surface receptors CD14 and CD83, characteristic of antigen presenting cells of monocytic lineage, were overexpressed in myxomatous tissue. Interleukin‐7 and the chemokine receptor CX3CR1, implicated in monocyte activation and recruitment, were also upregulated. Interestingly, immune localization appeared independent of “classic” inflammatory cytokines such as IL‐6. Differential expression of a subset of genes was confirmed with qRT‐PCR and immunohistochemistry. In conclusion, these data are the first to demonstrate infiltration of immune cells in MMVD, which may represent a critical process in the initiation and/or progression of this disease. NHLBI

Produced by senescent cells, the senescence-associated secretory phenotype (SASP) is a potential driver of age-related dysfunction. We tested whether circulating concentrations of SASP proteins reflect age and medical risk in humans. We first screened senescent endothelial cells, fibroblasts, preadipocytes, epithelial cells, and myoblasts to identify candidates for human profiling. We then tested associations between circulating SASP proteins and clinical data from individuals throughout the life span and older adults undergoing surgery for prevalent but distinct age-related diseases. A community-based sample of people aged 20–90 years (retrospective cross-sectional) was studied to test associations between circulating SASP factors and chronological age. A subset of this cohort aged 60–90 years and separate cohorts of older adults undergoing surgery for severe aortic stenosis (prospective longitudinal) or ovarian cancer (prospective case-control) were studied to assess relationships between circulating concentrations of SASP proteins and biological age (determined by the accumulation of age-related health deficits) and/or postsurgical outcomes. We showed that SASP proteins were positively associated with age, frailty, and adverse postsurgery outcomes. A panel of 7 SASP factors composed of growth differentiation factor 15 (GDF15), TNF receptor superfamily member 6 (FAS), osteopontin (OPN), TNF receptor 1 (TNFR1), ACTIVIN A, chemokine (C-C motif) ligand 3 (CCL3), and IL-15 predicted adverse events markedly better than a single SASP protein or age. Our findings suggest that the circulating SASP may serve as a clinically useful candidate biomarker of age-related health and a powerful tool for interventional human studies.