Wnt Signaling Inhibition Prevents Postnatal Inflammation and Disease Progression in Mouse Congenital Myxomatous Valve Disease.

BACKGROUND: Myxomatous valve disease (MVD) is the most common cause of mitral regurgitation, leading to impaired cardiac function and heart failure. MVD in a mouse model of Marfan syndrome includes valve leaflet thickening and progressive valve degeneration. However, the underlying mechanisms by which the disease progresses remain undefined. METHODS: Mice with Fibrillin 1 gene variant Fbn1C1039G/+ recapitulate histopathologic features of Marfan syndrome, and Wnt (Wingless-related integration site) signaling activity was detected in TCF/Lef-lacZ (T-cell factor/lymphoid enhancer factor-ß-galactosidase) reporter mice. Single-cell RNA sequencing was performed from mitral valves of wild-type and Fbn1C1039G/+ mice at 1 month of age. Inhibition of Wnt signaling was achieved by conditional induction of the secreted Wnt inhibitor Dkk1 (Dickkopf-1) expression in periostin-expressing valve interstitial cells of Periostin-Cre; tetO-Dkk1; R26rtTA; TCF/Lef-lacZ; Fbn1C1039G/+ mice. Dietary doxycycline was administered for 1 month beginning with MVD initiation (1-month-old) or MVD progression (2-month-old). Histological evaluation and immunofluorescence for ECM (extracellular matrix) and immune cells were performed. RESULTS: Wnt signaling is activated early in mitral valve disease progression, before immune cell infiltration in Fbn1C1039G/+ mice. Single-cell transcriptomics revealed similar mitral valve cell heterogeneity between wild-type and Fbn1C1039G/+ mice at 1 month of age. Wnt pathway genes were predominantly expressed in valve interstitial cells and valve endothelial cells of Fbn1C1039G/+ mice. Inhibition of Wnt signaling in Fbn1C1039G/+ mice at 1 month of age prevented the initiation of MVD as indicated by improved ECM remodeling and reduced valve leaflet thickness with decreased infiltrating macrophages. However, later, Wnt inhibition starting at 2 months did not prevent the progression of MVD. CONCLUSIONS: Wnt signaling is involved in the initiation of mitral valve abnormalities and inflammation but is not responsible for later-stage valve disease progression once it has been initiated. Thus, Wnt signaling contributes to MVD progression in a time-dependent manner and provides a promising therapeutic target for the early treatment of congenital MVD in Marfan syndrome.

Effect of Neprilysin Inhibition for Ischemic Mitral Regurgitation after Myocardial Injury.

Angiotensin receptor neprilysin inhibitor (ARNI) treatment reduces functional mitral regurgitation (MR) to a greater extent than angiotensin receptor blocker (ARB) treatment alone, but the mechanism is unclear. We evaluated the mechanisms of how ARNI has an effect on functional MR. After inducing functional MR by left circumflex coronary artery occlusion, male Sprague Dawley rats (n = 31) were randomly assigned to receive the ARNI LCZ696, the ARB valsartan, or corn oil only (MR control). Excised mitral leaflets and left ventricle (LV) were analyzed, and valvular endothelial cells were evaluated focusing on molecular changes. LCZ696 significantly attenuated LV dilatation after 6 weeks when compared with the control group (LV end-diastolic volume, 461.3 ± 13.8 µL versus 525.1 ± 23.6 µL; p < 0.05), while valsartan did not (471.2 ± 8.9 µL; p > 0.05 to control). Histopathological analysis of mitral leaflets showed that LCZ696 strongly reduced fibrotic thickness compared to the control group (28.2 ± 2.7 µm vs. 48.8 ± 7.5 µm; p < 0.05). Transforming growth factor-ß and downstream phosphorylated extracellular-signal regulated kinase were also significantly lower in the LCZ696 group. Consequently, excessive endothelial-to-mesenchymal transition (EndoMT) was mitigated in the LCZ696 group compared to the control group and leaflet area was higher (11%) in the LCZ696 group than in the valsartan group. Finally, the MR extent was significantly lower in the LCZ696 group and functional improvement was observed. In conclusion, neprilysin inhibitor has positive effects on LV reverse remodeling and also attenuates fibrosis in MV leaflets and restores adaptive growth by directly modulating EndoMT.

Altered Responsiveness to TGFß and BMP and Increased CD45+ Cell Presence in Mitral Valves Are Unique Features of Ischemic Mitral Regurgitation.

[Figure: see text].

Do the remodeling effects of sacubitril/valsartan treatment depend upon heart failure duration?

AIMS: The angiotensin receptor and neprilysin inhibitor (ARNI) sacubitril/valsartan (LCZ696) is recommended for the treatment of patients with heart failure in New York Heart Association (NYHA) class II-III and left ventricular ejection fraction (LVEF) 35% or less. We examined the effects of sacubitril/valsartan on cardiac remodeling and their correlation with heart failure duration in patients enrolled in our heart failure clinic from March 2017 to December 2019. METHODS: Echocardiographic and clinical/laboratory data were collected at baseline and at 6-month and 12-month follow-up visits in 69 patients (age 67 ±â€Š12 years, disease duration 8.4 ±â€Š5.8 years, 93% men). RESULTS: At both time points, mean NYHA class, NT-proBNP level, LVEF, LV end-systolic volume, and estimated systolic pulmonary pressure significantly (P < 0.05) improved versus baseline, as did the proportion of patients with diastolic dysfunction grade 3 or functional mitral regurgitation grade 3-4. In the subgroup with mean disease duration less than 8.5 years (n = 40), there was a significant improvement in all variables at both time points; in this group, a recovery of right ventricular function was also seen at the 12-month follow-up. On the contrary, patients with heart failure duration of at least 8.5 years (n = 29) showed only a slight improvement in LVEF and mitral regurgitation at 12 months. There were no significant changes in renal function and/or potassium levels in all patients. CONCLUSION: In patients with a relatively short disease duration, sacubitril/valsartan was associated with a strong favorable remodeling of the left ventricle and improvement in pulmonary circulation.

Precise Drug Sequential Therapy Can Improve the Cardioversion Rate of Atrial Fibrillation with Valvular Disease after Radiofrequency Ablation.

OBJECTIVE: Based on pathogenesis of atrial fibrillation (AF), investigate the effects of precision drugs continuous therapy on AF cardioversion rate after radiofrequency catheter ablation. METHODS: We included 1334 patients who underwent mitral valve replacement with bipolar radiofrequency ablation due to mitral valve disease with AF during June 2011 to July 2017. The data of clinical and related laboratory examinations at discharge and follow-up were recorded. All patients were treated with or without angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II-receptor blocker (ARB) drugs according to their conditions and doctor's willingness. The heart rhythm was evaluated after treatment and follow-up of 6 months. RESULTS: All 1162 cases were followed up, including 825 cases in mitral stenosis (MS) group, 337 cases in mitral regurgitation (MR) group. In MS group, left atrial diameter(LAD) and left ventricular diameter(LVD) of the patients taking ACEI and ARB were significantly lower (P < 0.05), and they can increase AF cardioversion rate from 79.1% of the control group to 83.7% and 82.8%, respectively (P = 0.03 and 0.04). In MR group, the patients with ACEI compared with control group, there were no significant differences in LAD, LVD, right atrial diameter (RAD), right ventricular diameter (RVD), left ventricular ejection fraction(LVEF), and left ventricular fractional shortening(LVFS) (P > 0.05); but ARB group, LAD, LVD decreased significantly (P < 0.05). And ACEI can increase AF cardioversion rate from 76.1% in the control group to 77.2% (P = 0.62), ARB to 81.6% (P = 0.02). CONCLUSION: It does improve AF cardioversion rate after radiofrequency catheter ablation that the precise anti-structural remodeling drugs continuous therapy was adopted based on the pathogenesis of AF.

A New Role for the Aldosterone/Mineralocorticoid Receptor Pathway in the Development of Mitral Valve Prolapse.

RATIONALE: Mitral valve prolapse (MVP) is one of the most common valvular disorders. However, the molecular and cellular mechanisms involved in fibromyxomatous changes in the mitral leaflet tissue have not been elucidated. Aldosterone (Aldo) promotes fibrosis in myocardium, and MR (mineralocorticoid receptor) antagonists (MRAs) improve cardiac function by decreasing cardiac fibrosis. OBJECTIVE: We investigated the role of the Aldo/MR in the fibromyxomatous modifications associated with MVP. METHODS AND RESULTS: Aldo enhanced valvular interstitial cell activation markers and induced endothelial-mesenchymal transition in valvular endothelial cells, resulting in increased proteoglycan secretion. MRA blocked all the above effects. Cytokine arrays showed CT-1 (cardiotrophin-1) to be a mediator of Aldo-induced valvular interstitial cell activation and proteoglycan secretion and CD (cluster of differentiation) 14 to be a mediator of Aldo-induced endothelial-mesenchymal transition and proteoglycan secretion in valvular endothelial cells. In an experimental mouse model of MVP generated by nordexfenfluramine administration, MRA treatment reduced mitral valve thickness and proteoglycan content. Endothelial-specific MR deletion prevented fibromyxomatous changes induced by nordexfenfluramine administration. Moreover, proteoglycan expression was slightly lower in the mitral valves of MVP patients treated with MRA. CONCLUSIONS: These findings demonstrate, for the first time, that the Aldo/MR pathway regulates the phenotypic, molecular, and histological changes of valvular interstitial cells and valvular endothelial cells associated with MVP development. MRA treatment appears to be a promising option to reduce fibromyxomatous alterations in MVP.

Interventions for Secondary Mitral Regurgitation in Patients With Heart Failure: A Network Meta-Analysis of Randomized Controlled Comparisons of Surgery, Medical Therapy and Transcatheter Intervention.

BACKGROUND: Mitral regurgitation (MR) in heart failure (HF) notoriously carries a poor prognosis. While there are multiple interventional options for treatment, the optimal intervention remains controversial. Therefore, we aimed to evaluate the efficacy and safety of surgery, medical therapy, and transcatheter intervention in secondary MR. METHODS: A systematic database search was performed to identify all randomized controlled trials (RCTs) that evaluate various interventions for secondary MR. We performed a Bayesian network meta-analysis to calculate odd ratios (ORs) and 95% credible intervals (CIs). The primary endpoint was all-cause mortality. Secondary endpoints were moderate-severe MR, HF-hospitalizations, and freedom from severe HF symptoms. RESULTS: We identified 12 RCTs (2316 total patients; age 67.6 ±â€¯11; 63% males, and 74% with ischemic cardiomyopathy). There was a significant reduction of mortality at 24-months with transcatheter leaflet repair compared with medical therapy (OR = 0.57; 95% CI = 0.34-0.96). However, there were no significant differences among the competing treatments in all-cause mortality at the earlier time points of 30-days or 12-months (P > 0.05). Recurrent moderate-severe MR was significantly less with valvular interventions compared with medical therapy (P < 0.05), but there were no differences in the rates of HF-hospitalizations or persistent severe HF symptoms between the competing interventions (P > 0.05). CONCLUSIONS: Among patients with HF and secondary MR, transcatheter leaflet repair was associated with significantly reduced 24-month mortality compared with medical therapy. Valvular interventions were associated with lower rates of recurrent moderate-severe MR, but non-significant improvements in clinical outcomes. Further long-term studies are needed to identify the best route of intervention for secondary MR.

Bretschneider (Custodiol®) and St. Thomas 2 Cardioplegia Solution in Mitral Valve Repair via Anterolateral Right Thoracotomy: A Propensity-Modelled Comparison.

BACKGROUND: Single-dose cardioplegia is preferred in minimal invasive mitral valve surgery to maintain the adjustment of the operative site without change of preset visualization. The aim of our study was to compare two widely used crystalloid cardioplegias Bretschneider (Custodiol®) versus St. Thomas 2 in patients who underwent mitral valve repair via small anterolateral right thoracotomy. MATERIAL AND METHODS: From May 2012 until February 2019, 184 isolated mitral valve procedures for mitral valve repair via anterolateral right thoracotomy were performed using Bretschneider (Custodiol®) cardioplegia (n = 123) or St. Thomas (n = 61). Primary efficacy endpoint was peak postoperative high-sensitivity cardiac troponin (hs-cTnT) during hospitalization. Secondary endpoints were peak creatine kinase-muscle brain type (CK-MB) and creatine kinase (CK) as well as safety outcomes. We used inverse probability of treatment weighting (IPTW) in order to adjust for confounding by indication. RESULTS: Peak hs-cTnT was higher after use of Bretschneider (Custodiol®) (geometric mean 716 mg/L, 95% confidence interval (CI) 605-847 mg/L) vs. St. Thomas 2 (561 mg/L, CI 467-674 mg/L, p = 0.047). Peak CK-MB (geometric mean after Bretschneider (Custodiol®): 40 µg/L, CI 35-46, St. Thomas 2: 33 µg/L, CI 27-41, p = 0.295) and CK (geometric mean after Bretschneider (Custodiol®): 1370 U/L, CI 1222-1536, St. Thomas 2: 1152 U/L, CI 972-1366, p = 0.037) showed the same pattern. We did not see any difference with respect to postoperative complications between treatment groups after IPTW. CONCLUSION: Use of St. Thomas 2 cardioplegia was associated with lower postoperative peak levels of all cardiac markers that reflect cardiac ischemia such as hs-cTnT, CK, and CK-MB as compared to Bretschneider (Custodiol®) in propensity-weighted treatment groups.

Left ventricular blood flow patterns at rest and under dobutamine stress in healthy pigs.

Intracardiac blood flow patterns are affected by the morphology of cardiac structures and are set up to support the heart's pump function. Exercise affects contractility and chamber size as well as pre- and afterload. The aim of this study was to test the feasibility of four-dimensional phase contrast cardiovascular MRI under pharmacological stress and to study left ventricular blood flow under stress. 4D flow data were successfully acquired and analysed in 12 animals. During dobutamine infusion, heart rate and ejection fraction increased (82 ± 5 bpm versus 124 ± 3 bpm/46 ± 9% versus 65 ± 7%; both p < 0.05). A decrease in left ventricular end-diastolic volume (72 ± 14 mL versus 55 ± 8 mL; p < 0.05) and end-systolic volume (40 ± 15 mL versus 19 ± 6 mL; p < 0.05) but no change in stroke volume were observed. Trans-mitral diastolic inflow velocity increased under dobutamine and the trajectory of inflowing blood was directed towards the anterior septum with increased inflow angle (26 ± 5°) when compared with controls (15 ± 2°). In 5/6 animals undergoing stress diastolic vortices developed later, and in 3/6 animals vortices collapsed earlier with significantly smaller cross-sectional area during diastole. The vorticity index was not affected. Under the stress condition direct flow (% ejection within the next heart beat) increased from 43 ± 6% to 53 ± 8%. 4D MRI blood flow acquisition and analysis are feasible in pig hearts under dobutamine-induced stress. Flow patterns characterized by high blood velocity and antero-septally oriented diastolic inflow as well as decreased ventricular volumes are unfavourable conditions for diastolic vortex development under pharmacological stress, and cardiac output is increased by a rise in heart rate and directly ejected left ventricular blood volume.

Elevated IL-17 levels and echocardiographic signs of preserved myocardial function in benznidazole-treated individuals with chronic Chagas' disease.

BACKGROUND: The immunological and clinical impact of trypanocidal treatment in chronic Chagas' disease (CCD) is unclear. METHODOLOGY AND FINDINGS: Several cytokines were measured in plasma of 66 patients with CCD. Thirty-three patients had been previously treated with benznidazole and 33 had never been treated. The treated group exhibited higher levels of IL-17 (median 142.45×1.22pg/ml, P=0.025), which was the only one significantly associated with Bz treatment, especially after adjusting for time of disease and NYHA class (P=0.024; OR 1.006, 95% CI 1.001-1.010). Compared to untreated patients, the treated group exhibited higher median values of mitral annular E' lateral (13.0×10.0cm/s, P=0.038), S' infero-lateral (8.9×7.6cm/s, P=0.013), S' septal (8.5×7.4cm/s, P=0.034), mean S' (9.0×7.9cm/s, P=0.013) and tricuspid annular S' (13.3×11.1cm/s, P=0.001) and lower values of E/E' septal (7.2×9.5cm/s, P=0.049). After adjustment for time of disease and NYHA class, S' infero-lateral (P=0.031), mean S' (P=0.049) and S' tricuspid (P=0.024) persisted as significantly associated with treatment. CONCLUSION: The present findings suggest that the group of CCD patients treated with Bz displayed increased plasma levels of IL-17 and preserved myocardial function, reinforcing the idea that Bz treatment may be beneficial.

Angiotensin Receptor Neprilysin Inhibitor for Functional Mitral Regurgitation.

BACKGROUND: The morbidity and mortality of patients with functional mitral regurgitation (MR) remain high, but no pharmacological therapy has been proven effective. The hypothesis of this study was that sacubitril/valsartan would be superior to valsartan alone in improving functional MR via dual inhibition of the renin-angiotensin system and neprilysin. METHODS: In this double-blind trial, we randomly assigned 118 patients with heart failure with chronic functional MR secondary to left ventricular (LV) dysfunction to receive either sacubitril/valsartan or valsartan, in addition to standard medical therapy for heart failure. The primary end point was the change in effective regurgitant orifice area of functional MR from baseline to the 12-month follow-up. Secondary end points included changes in regurgitant volume, LV end-systolic volume, LV end-diastolic volume, and incomplete mitral leaflet closure area. RESULTS: The decrease in effective regurgitant orifice area was significantly greater in the sacubitril/valsartan group than in the valsartan group (-0.058±0.095 versus -0.018±0.105 cm2; P=0.032) in an intention-to-treat analysis including 117 (99%) patients. Regurgitant volume was also significantly decreased in the sacubitril/valsartan group in comparison with the valsartan group (mean difference, -7.3 mL; 95% CI, -12.6 to -1.9; P=0.009). There were no significant between-group differences regarding the changes in incomplete mitral leaflet closure area and LV volumes, with the exception of LV end-diastolic volume index ( P=0.044). We noted no significant difference in the change of blood pressure between the treatment groups, and 7 patients (12%) in the sacubitril/valsartan group and 9 (16%) in the valsartan group had ≥1 serious adverse events ( P=0.54). CONCLUSIONS: Among patients with secondary functional MR, sacubitril/valsartan reduced MR to a greater extent than did valsartan. Our findings suggest that an angiotensin receptor-neprilysin inhibitor might be considered for optimal medical therapy of patients with heart failure and functional MR. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02687932.

Safe Use of Glutaraldehyde to Repair the Destroyed Valve in Active Infective Mitral Valve Endocarditis.

BACKGROUND: The aim of this study was to review our experience of mitral valve (MV) repair for acute and active infective endocarditis (AAIE) and to identify the feasibility of a new approach together with the mid-term results. Methods and Results: A retrospective analysis was performed on 35 consecutive AAIE patients surgically treated in the isolated mitral position. Mean follow-up after the surgery was 4.3±3.7 years. 30 of the 35 patients were successfully treated by MV plasty (MVP); however, MV replacement (MVR) was necessary in the remaining 5 patients. Our novel approach included resection of the infective lesion, approximation with direct suture and/or patch repair with bovine or autopericardium after 2-min treatment of it and the defective leaflet edge(s) with 0.625% glutaraldehyde solution, reconstruction with artificial chordae and ring annuloplasty. The success rate of MVP was 85.7%. The longest postoperative follow-up echocardiography showed no mitral regurgitation (MR) in 4, trivial MR in 4, mild MR in 16 and moderate MR in 5 patients in the MVP group. The 5-year survival rate in the MVP group was 89±6%. MVR was required in 1 patient 2 months after MVP because of increasing MR. Recurrence of endocarditis has not been observed in any case. CONCLUSIONS: Glutaraldehyde was safely used in a surgical intervention for AAIE in the mitral position with acceptable early and mid-term results.

miR-27a protects human mitral valve interstitial cell from TNF-α-induced inflammatory injury via up-regulation of NELL-1.

MicroRNAs (miRNAs) have been reported to be associated with heart valve disease, which can be caused by inflammation. This study aimed to investigate the functional impacts of miR-27a on TNF-α-induced inflammatory injury in human mitral valve interstitial cells (hMVICs). hMVICs were subjected to 40 ng/mL TNF-α for 48 h, before which the expressions of miR-27a and NELL-1 in hMVICs were altered by stable transfection. Trypan blue staining, BrdU incorporation assay, flow cytometry detection, ELISA, and western blot assay were performed to detect cell proliferation, apoptosis, and the release of proinflammatory cytokines. We found that miR-27a was lowly expressed in response to TNF-α exposure in hMVICs. Overexpression of miR-27a rescued hMVICs from TNF-α-induced inflammatory injury, as cell viability and BrdU incorporation were increased, apoptotic cell rate was decreased, Bcl-2 was up-regulated, Bax and cleaved caspase-3/9 were down-regulated, and the release of IL-1ß, IL-6, and MMP-9 were reduced. NELL-1 was positively regulated by miR-27a, and NELL-1 up-regulation exhibited protective functions during TNF-α-induced cell damage. Furthermore, miR-27a blocked JNK and Wnt/ß-catenin signaling pathways, and the blockage was abolished when NELL-1 was silenced. This study demonstrated that miR-27a overexpression protected hMVICs from TNF-α-induced cell damage, which might be via up-regulation of NELL-1 and thus modulation of JNK and Wnt/ß-catenin signaling pathways.

Bicuspid Aortic Valve Stenosis and the Effect of Vitamin K2 on Calcification Using 18F-Sodium Fluoride Positron Emission Tomography/Magnetic Resonance: The BASIK2 Rationale and Trial Design.

BASIK2 is a prospective, double-blind, randomized placebo-controlled trial investigating the effect of vitamin K2 (menaquinone-7;MK7) on imaging measurements of calcification in the bicuspid aortic valve (BAV) and calcific aortic valve stenosis (CAVS). BAV is associated with early development of CAVS. Pathophysiologic mechanisms are incompletely defined, and the only treatment available is valve replacement upon progression to severe symptomatic stenosis. Matrix Gla protein (MGP) inactivity is suggested to be involved in progression. Being a vitamin K dependent protein, supplementation with MK7 is a pharmacological option for activating MGP and intervening in the progression of CAVS. Forty-four subjects with BAV and mild-moderate CAVS will be included in the study, and baseline 18F-sodiumfluoride (18F-NaF) positron emission tomography (PET)/ magnetic resonance (MR) and computed tomography (CT) assessments will be performed. Thereafter, subjects will be randomized (1:1) to MK7 (360 mcg/day) or placebo. During an 18-month follow-up period, subjects will visit the hospital every 6 months, undergoing a second 18F-NaF PET/MR after 6 months and CT after 6 and 18 months. The primary endpoint is the change in PET/MR 18F-NaF uptake (6 months minus baseline) compared to this delta change in the placebo arm. The main secondary endpoints are changes in calcium score (CT), progression of the left ventricularremodeling response and CAVS severity (echocardiography). We will also examine the association between early calcification activity (PET) and later changes in calcium score (CT).

Long-term mortality in patients with severe secondary mitral regurgitation and normal left ventricular ejection fraction: interventional perspective.

AIMS: Patients with severe secondary mitral regurgitation (MR) and normal ejection fraction are being excluded from clinical trials evaluating transcatheter mitral devices. We sought to evaluate the long-term mortality with medical management alone in this patient population. METHODS AND RESULTS: We retrospectively evaluated patients diagnosed with ≥3+ MR at our institution over 15 years. Only patients with an ejection fraction ≥60% were included in the study. Those with degenerative mitral valve disease, papillary muscle dysfunction, or hypertrophic cardiomyopathy, and those who underwent mitral valve intervention were excluded. The study included 400 patients (age 71.1±14.8, 25.1% male, ejection fraction 62.5±3.6%). Mechanism of secondary MR was restricted valve motion, annular dilation and apical tethering in 91.5, 4.5 and 4%, respectively. One-year and three-year mortality were 19.1 and 26.3%, respectively. On multivariable Cox proportional regression analysis, older age, New York Heart Association functional Class III or IV, >3+ MR and larger left atrium were independent predictors of mortality. CONCLUSIONS: Severe secondary MR with normal left ventricular systolic function has significant mortality with medical management alone. This initial observation needs to be confirmed in larger prospective studies. These patients should be included in future transcatheter clinical trials.