Rheumatic mitral valve repair or replacement in the valve-in-valve era.

OBJECTIVE: For degenerative mitral disease, repair is superior to replacement; however, the best operative strategy for rheumatic mitral disease remains unclear. We evaluated the association between decision-making in choosing repair versus replacement and outcomes across 2 decades of rheumatic mitral surgery. METHODS: Patients undergoing isolated, first-time rheumatic mitral surgery were identified. Era 1 (1997-2008) and Era 2 (2009-2018) were distinguished by intraoperative assessment of anterior leaflet mobility/calcification (Era 2) in deciding between mitral repair versus replacement. Primary outcome was a composite of death, reoperation, and severe valve dysfunction. RESULTS: Among 180 patients, age was 59 ± 14 years, and ejection fraction was 58% ± 10%. A higher proportion in Era 1 (n = 56) compared with Era 2 (n = 124) had preoperative atrial fibrillation (68% vs 46%; P = .006); the groups were otherwise similar. Primary indication was mitral stenosis in 69% (124 out of 180; pure = 35, mixed = 89) and did not differ by era (P = .67). During Era 1, 70% (39 out of 56) underwent repair, compared with 33% (41 out of 124) during Era 2 (P < .001). Freedom from death, reoperation, or severe valve dysfunction at 5 years was higher in Era 2 (72% ± 9%) than Era 1 (54% ± 13%; P = .04). Five-year survival was higher in Era 2 than Era 1, but did not differ between repair versus replacement. Five-year cumulative incidence of reoperation with death as a competing risk did not differ by era, but was higher after repair than replacement. CONCLUSIONS: Careful assessment of anterior leaflet mobility/calcification to determine mitral repair or replacement was associated with improved outcomes. This decision-making strategy may alter the threshold for rheumatic mitral replacement in the current valve-in-valve era.

Mitral valve diseases: Pathophysiology and interventions.

Valvular heart disease is common and increasingly prevalent among the elderly. The end result of valvular pathologies is cardiac failure and can lead to sudden death; thus, diagnosis and interventions are very important in the early stages of these diseases. The usual treatment methods of mitral regurgitation include percutaneous mitral valve repair, mitral valve replacement and minimally invasive surgery, whereas the treatment methods of mitral stenosis include percutaneous transluminal mitral commissurotomy and mitral commissurotomy as well as open surgical repair. Nonetheless, ongoing clinical trials are a clear indicator that the management of valve diseases is ever evolving. The focus of this paper is on the various pathologies of the mitral valve, their etiology and clinical management, offering a comprehensive view of mitral valve diseases.

Energy loss associated with in-vitro modeling of mitral annular calcification.

INTRODUCTION: Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves-one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop transmitral gradients, without the commissural fusion typifying rheumatic mitral stenosis (MS), and may have symptoms similar to classical MS. A proposed mechanism relates to VED due to disturbed blood flow through the diseased valve into the ventricle. METHODS: A silicone model of a normal mitral valve (MV) was created using a transesophageal echocardiography dataset. 3D printed calcium phantoms were incorporated into a second valve model to replicate severe MAC. The synthetic MVs were tested in a left heart duplicator under rest and exercise conditions. Fine particles were suspended in a water/glycerol blood analogue for particle image velocimetry calculation of VED. RESULTS: Catheter mean transmitral gradients were slightly higher in the MAC valve compared to the normal MV, both at rest (3.2 vs. 1.3 mm Hg) and with exercise (5.9 vs. 5.0 mm Hg); Doppler gradients were 2.7 vs. 2.1 mm Hg at rest and 9.9 vs 8.2 mm Hg with exercise. VED was similar between the two valves at rest. During exercise, VED increased to a greater extent for the MAC valve (240%) versus the normal valve (127%). CONCLUSION: MAC MS is associated with slightly increased transmitral gradients but markedly increased VED during exercise. These energy losses may contribute to the exercise intolerance and exertional dyspnea present in MAC patients.

Lessons from reoperations for mitral stenosis after mitral valve repair.

BACKGROUND: The durability of mitral valve repair (MVr) is usually defined by the absence of recurrent significant mitral regurgitation. Postrepair mitral stenosis (MS) is a less frequent and less studied mode of failure of MVr. We analyzed our experience in patients who underwent reoperation for postrepair MS to characterize mechanisms resulting in MS and to summarize reoperative surgical strategies and mid-term outcomes. METHODS: Using a prospective database, we retrospectively analyzed data on 35 consecutive patients who underwent reoperation for symptomatic moderate to severe MS between January 1, 2011, and February 1, 2020. RESULTS: The mean patient age was 61.4 ± 11.4 years, and 69% were female. The median annuloplasty ring size used at the initial repair was 28 mm (interquartile range, 26-30 mm). Additional repair techniques at the initial operation included leaflet resection in 12 patients (34%) and commissuroplasty or edge-to-edge repair in 6 patients (18%). At reoperation, the most common mechanism of MS was pannus ingrowth in 20 patients (57%), leaflet calcification in 12 (34%), commissural fusion in 5 (14%), and tunnel effect (functional MS) in 3 (9%). Twenty-two patients (63%) underwent valve replacement, and 13 (37%) underwent valve re-repair. In patients who underwent re-repair, annuloplasty revision was performed in all patients, with 6 patients (46%) converted from complete ring to band, 4 (11%) converted from ring to pericardial annuloplasty, 2 (6%) converted to no annuloplasty, and 1 (8%) with annuloplasty ring upsizing. There were no in-hospital or 1-year mortalities. Survival at the 5-year follow-up was 93.9%. CONCLUSIONS: MS causing late failure of MVr is frequently associated with smaller ring sizes and inflammatory or calcific changes in the valve. Highly selected patients may be good candidates for mitral valve re-repair.

TAVI in Patients with Mitral Annular Calcification and/or Mitral Stenosis.

BACKGROUND: We herein aimed for analysis of influence of mitral annular calcification (MAC) and mitral stenosis (MS) on outcomes in transcatheter aortic valve implantation (TAVI). METHODS: Between 11/2009 and 06/2017, 1,058 patients underwent TAVI in the presence of concomitant MAC or MS at our center. Subgroups were built and multivariate logistic regression, COX regression, Kaplan-Meier survival analyses, and receiver operating characteristics method were performed. RESULTS: Thirty-day mortality was 7.5% (79/1,058) with highest mortality in patients severe MS (MAC: 3.4% vs. mild MS: 5.9% vs. moderate MS: 15.0% vs. severe MS: 72.7%; p < 0.001). Moderate-to-severe MS (odds ratio [OR]: 7.75, confidence interval [CI]: 3.94-16.26, p < 0.001), impaired left ventricular ejection fraction (OR: 1.38, CI: 1.10-1.72, p < 0.01), and coronary artery disease (OR: 1.36, CI: 1.11-1.67, p < 0.01) were predictive of 30-day survival. Left ventricular systolic/end-diastolic pressure drop of <59.5 mm Hg / <19.5 mm Hg was associated with increased mortality. CONCLUSIONS: TAVI in the presence of MAC and mild MS is associated with acceptable acute outcomes but should be considered high-risk procedures in patients with moderate and especially those with severe MS. Our results suggest adverse hemodynamics after TAVI with concomitant MS, which may be caused by underfilling of the left ventricle leading to low-cardiac output.

Long-term Clinical Impacts of Functional Mitral Stenosis After Mitral Valve Repair.

BACKGROUND: The relationship between functional mitral stenosis (MS) after mitral valve (MV) repair and long-term clinical outcomes is not fully understood. Therefore, we reviewed an institutional series to identify the determinants of functional MS and its effect on long-term clinical outcomes after MV repair for degenerative mitral regurgitation. METHODS: Between January 1990 and December 2015, 792 patients who underwent MV repair for degenerative mitral regurgitation were retrospectively enrolled and divided into 2 groups: functional MS (n = 192) (≥5 mm Hg mean diastolic pressure gradient across the MV) and nonfunctional MS (n = 600) (<5 mm Hg mean diastolic pressure gradient). Mean follow-up was 11.6 ± 5.8 years. RESULTS: After propensity-score matching, patients' characteristics were comparable between groups (n = 192/group). At 20 years, the functional MS group had significantly lower rates of freedom from new-onset atrial fibrillation (73.0% ± 5.6% versus 93.2% ± 2.3%; P = .003), overall survival (72.1% ± 4.6% versus 85.6% ± 4.3%; P = .010), and freedom from MV reoperation (82.8% ± 4.1% versus 92.5% ± 4.2%; P = .019) than the nonfunctional group. The functional MS group also had a significantly greater postoperative left atrial volume index and tricuspid regurgitation grade. A small left ventricular end-diastolic dimension (hazard ratio = 0.975; 95% confidence interval, 0.955-0.996; P = .022) and annuloplasty ring (hazard ratio = 0.757; 95% confidence interval, 0.685-0.837; P < .001) were independent risk factors for functional MS. CONCLUSIONS: A small left ventricle and annuloplasty ring increased the risk for functional MS after MV repair and was associated with progressive left atrial enlargement and tricuspid regurgitation exacerbation. As a result, functional MS increased the risk for new-onset atrial fibrillation, MV reoperation, and decreased long-term survival.

Comparison of Clinical Characteristics, Natural History and Predictors of Disease Progression in Patients With Degenerative Mitral Stenosis Versus Rheumatic Mitral Stenosis.

Mitral annular calcification (MAC) is a common echocardiographic finding and an increasingly recognized cause of degenerative mitral stenosis (DMS). However, little is known about the clinical characteristics and disease progression in DMS, particularly in comparison with rheumatic mitral stenosis (RMS). We retrospectively reviewed 203 consecutive patients with mitral stenosis (113 with DMS and 90 with RMS) who underwent echocardiography at our institution between January 2014 and December 2017. We compared the clinical characteristics and disease progression between the 2 groups. In addition, we analyzed the predictors of disease progression (defined as annual progression rate of a mean gradient >0 mm Hg/year) among patients with DMS. Patients with DMS were significantly older and had higher prevalence of atherosclerotic comorbidities than those with RMS. During the median follow-up period of 2.2 years, the annual progression rates were comparable (0.8 ± 0.8 mm Hg/year in DMS vs 1.0 ± 1.2 mm Hg/year in RMS; p = 0.32) and were highly variable (0.0 to 3.5 mm Hg/year in DMS and 0.0 to 5.5 mm Hg/year in RMS) within both groups among disease progression. In DMS patients, atherosclerotic comorbidities and lower initial mean gradient were significantly associated with disease progression even after adjustment by age and sex. There was no significant difference in the disease progression according to the circumferential MAC severity determined by echocardiography among DMS. In conclusion, DMS disease progression was slow but highly variable, similar to that of RMS. In patients with DMS, the baseline MAC severity did not correlate with disease progression, suggesting the importance of follow-up echocardiography regardless of the MAC severity.

Inhaled versus intravenous milrinone in mitral stenosis with pulmonary hypertension.

OBJECTIVE: To evaluate and compare the hemodynamic effects of intraoperative intravenous milrinone versus inhalational milrinone at two timepoints in patients with severe pulmonary hypertension undergoing mitral valve surgery. METHODS: A prospective observational study was performed in 100 patients with severe rheumatic mitral stenosis (with/without regurgitation) and right ventricular systolic pressure > 50 mm Hg. They were divided into two groups based on the strategy used to reduce pulmonary hypertension. Fifty patients had inhalational milrinone after sternotomy until initiation of cardiopulmonary bypass and after release of the aortic crossclamp until weaning off cardiopulmonary bypass. The other 50 patients received an intravenous loading dose of milrinone 50 µg·kg-1 over 10 min on release of the aortic crossclamp. Both groups received intravenous milrinone 0.5 µg·kg-1 during weaning from cardiopulmonary bypass. Hemodynamic data were evaluated at the 3 timepoints. RESULTS: Pulmonary artery pressures, central venous pressure, and pulmonary capillary wedge pressure decreased significantly in the inhalational milrinone group compared to the intravenous milrinone group. Systemic vascular resistance index and cardiac index were significantly higher and pulmonary vascular resistance index was significantly lower in the inhalational milrinone group. The mean arterial pressure-to-mean pulmonary artery pressure ratio was significantly lower in the intravenous milrinone group. Tricuspid annular plane systolic excursion and right ventricular fractional area change were increased significantly in the inhalational milrinone group. CONCLUSION: Intraoperative inhalational milrinone before and after cardiopulmonary bypass is safe, easy to administer, and results in significant improvements in right ventricular hemodynamics, right ventricular function, and systemic hemodynamics.

Long-term outcomes of rheumatic mitral valve repair: Is it worthwhile to do it?

AIM: This retrospective study was undertaken to evaluate the long-term outcomes of mitral valve repair in rheumatic patients. METHODS: From 2003 to 2019, 151 patients (mean age 26.5 ± 14.9 years; 68.9% female) underwent mitral valve repair. Fifty-three (35.1%) had atrial fibrillation, and 79 (52.3%) were in New York Heart Association class III/IV. Pure mitral regurgitation was present in 109 (72.2%) patients, pure stenosis in 9 (6%), and mixed regurgitation and stenosis in 33. RESULTS: Three (2%) patients died postoperatively and 4 (2.6%) were lost during follow-up. Mean follow-up was 90.5 ± 55.6 months. There were 22 (14.8%) late deaths. Actuarial survival at 5, 10, and 15 years was 90.7% ± 2.5%, 83.5% ± 3.6%, and 76.5 ± 6.1%, respectively. Twelve (8.5%) patients underwent reoperation. Freedom from reoperation at 5, 10, and 15 years was 96.1% ± 1.7%, 89.8% ± 3.2%, and 82.3% ± 6.1%, respectively. Forty-two (29.2%) patients developed recurrent mitral regurgitation. Freedom from recurrence of mitral regurgitation at 5, 10, and 15 years was 70.9% ± 4.3%, 56% ± 5.9%, and 53.3% ± 6.4%, respectively. Eighty-one (56.6%) patients were and free from all events during follow-up. Freedom from all events at 5, 10, and 15 years was 64.8% ± 4.1%, 48.6% ± 5.3%, and 43.7% ± 5.8%, respectively. CONCLUSIONS: Although rheumatic mitral valve repair is associated with late recurrence of mitral regurgitation, it has benefits in selected patients, especially children and young patients who want to avoid the lifelong risks of anticoagulation. Long-term follow-up is essential in these patients.

Left atrial structural and functional remodeling following balloon mitral valvuloplasty.

Mitral stenosis (MS) is associated with left atrial (LA) functional and morphological changes as a result of chronic increase in LA pressure. Relieving the mitral obstruction via balloon mitral valvuloplasty (BMV) might be associated with LA structural and functional remodeling. To study alterations of LA volume and functions 1 year following successful BMV in patients with isolated rheumatic severe mitral stenosis. Thirty patients (median age 33 years, 22 women) with severe rheumatic MS were included in the study. Using biplane method, trans-thoracic 2D echocardiography was used to estimate LA volume indexed to body surface area (BSA). Maximal, minimal and pre-A left atrial volumes were measured and indexed to BSA. LA volumetric functions were then assessed and the measurements were repeated 6 months and 1 year after successful valvuloplasty. At baseline, median mitral valve area (MVA) was 0.9 (0.6-1.3) cm2 measured by planimetry with a mean pressure gradient of 12.5 (8-24) mmHg. Following BMV, a significant regression of left atrial volume index was noticed at 6 months compared to baseline (51 vs. 60 ml/m2, p = 0.001) with a further decrease at 1 year (48 vs. 51 ml/m2, p = 0.03). At 6 months, volumetric assessment of left atrial functions showed a significant improvement in LA total emptying fraction (42% vs 30%, p = 0.001) as well as in LA passive emptying fraction (26% vs 14%, p = 0.033) and LA active emptying fraction (20% vs. 18%, p = 0.016). All these indices showed further improvement at 1 year [47% (P = 0.02), 29% (p = 0.03) and 31% (p = 0.001) respectively]. In patients with isolated rheumatic MS, mitral valvuloplasty was associated with a significant decline of LA volume accompanied by a significant improvement of its volumetric functions.

Presence of mitral stenosis is a risk factor of new development of acute decompensated heart failure early after transcatheter aortic valve implantation.

AIMS: Acute decompensated heart failure (ADHF) can occur early after transcatheter aortic valve implantation (TAVI), but the risk factors or mechanisms associated with it have not been fully determined. This hypothesis-generating study aimed to investigate the clinical indices associated with the development of ADHF within 72 hours after TAVI and to improve procedural approaches for TAVI. METHOD AND RESULTS: In this single-centre hypothesis generating prospective observational study, we enrolled 156 consecutive patients with severe aortic stenosis who underwent TAVI between January 2016 and February 2018 at our institution. We set the primary endpoint as the new development of ADHF within 72 hours after TAVI, and clinical indices associated with it were evaluated using a multivariable logistic model. The median age of the patients was 83 (quartile range 80-86) years, 48 (30.8%) were men and the median Society of Thoracic Surgery-Predicted Risk of Mortality was 7.1 (range 5.2-10.4). Mitral stenosis (MS), defined as mean transmitral valve pressure gradient ≥5 mm Hg, was present in 15 (9.6%) patients. After TAVI, the invasive mean transaortic valve pressure gradient (mAVPG) decreased from 48 (36-66) to 7 (5-11) mm Hg, and 12 (7.7%) patients developed ADHF within 72 hours after TAVI. Multivariable logistic regression analysis showed that MS (adjusted OR, 14.227; 95% CI 2.654 to 86.698; p=0.002) and greater decreases in mAVPG (1.038; 1.003 to 1.080; p=0.044) were associated with ADHF. CONCLUSIONS: MS and drastic improvement of mAVPG were associated with new development of ADHF within 72 hours after TAVI.

Severe Cardiopulmonary Disease in a Parturient With Noonan Syndrome.

Noonan syndrome is a relatively common genetic disorder and the second most common cause of congenital heart disease after trisomy 21. The spectrum of cardiac anomalies in Noonan syndrome typically involves pulmonary valve stenosis occasionally in conjunction with hypertrophic cardiomyopathy. Mitral valve involvement is a rare finding in Noonan syndrome and is most commonly associated with either mitral valve prolapse or abnormal valvular insertion causing left ventricular outflow tract obstruction. Patients with Noonan syndrome typically have preserved fertility and, given the success of cardiac surgery and medical management of heart failure in this population, are beginning to present more commonly as parturients in adulthood. Maternal physiologic changes during pregnancy introduce an added complexity to hemodynamic management and anesthetic considerations during labor and delivery. In this article, we present a case of a patient with Noonan syndrome with severe mitral stenosis, pulmonary valve insufficiency, and severe restrictive and obstructive pulmonary disease who presented preterm for delivery due to increased dyspnea at rest. Here we review the pathophysiology behind Noonan syndrome and peripartum management strategies in a patient with severe combined cardiac and pulmonary disease.

Contemporary trends in mitral valve surgery in East China: a 10-year experience.

BACKGROUND: Contemporary nationwide data from mainland China on trends in mitral valve surgery are scarce. The purpose of the present study was to review a single-center experience with mitral valve surgery over a 10-year period in East China. METHODS: Between July 2009 and June 2019, 3238 consecutive patients who underwent mitral valve surgery in our center were retrospectively reviewed. The patients were evenly divided into three periods: July 2009 to October 2012 (period I), November 2012 to February 2016 (period II), March 2016 to June 2019 (period III). RESULTS: The 3238 patients included 536 (16.6%) who had mitral valve repair and 2702 (83.4%) who had mitral valve replacement. Early mortalities for mitral valve repair and mitral valve replacement were 0.2% and 0.9%, respectively. There were trends towards a higher proportion of degenerative valve lesions (24.6%, 35.8%, 54.7% in periods I, II, and III, respectively) and a lower proportion of rheumatic valve lesions (71.0%, 62.6%, 38.0%) in more recent years. The proportions of minimally invasive surgery (0.7%, 2.1%, 30.2%), mitral valve repair (8.3%, 15.4%, 27.5%), use of a bioprosthesis (10.1%, 17.0%, 23.1%), and concomitant tricuspid valve procedures (13.2%, 28.5%, 46.0%) increased dramatically, while early mortality remained constant during the 10-year period (1.0%, 0.3%, 0.9%). CONCLUSIONS: In the past 10 years, the spectrum of mitral valve disease experienced a trend towards more degenerative valve lesions and less rheumatic valve lesions in East China. Mitral valve repair, bioprostheses, tricuspid valve repair, and minimally invasive surgery have been more often applied in recent years.

Antegrade Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction: A Simplified Technique From Bench to Bedside.

BACKGROUND: Intentional laceration of the anterior mitral leaflet (LAMPOON) is an effective adjunct to transcatheter mitral valve replacement that prevents left ventricular outflow tract (LVOT) obstruction. To date, LAMPOON has been performed in over 150 patients using a retrograde approach that can be technically challenging. A modified antegrade transseptal technique may simplify the procedure. METHODS: Antegrade LAMPOON was developed and tested in nonsurvival pig experiments. Thereafter, antegrade LAMPOON was performed in patients at prohibitive risk of LVOT obstruction. Clinical, procedural, and angiographic details were abstracted from medical records of their index procedure, and were compared with findings in comparable patients at risk of fixed-LVOT obstruction in the LAMPOON investigational device exemption trial. RESULTS: Eight patients at risk of fixed LVOT obstruction underwent antegrade LAMPOON. Leaflet traversal and laceration were technically successful in all. There were no cases of clinically significant LVOT obstruction (mean LVOT gradient at discharge: 5.4±1.4 mm Hg). One patient suffered a ventricular wire perforation, unrelated to the antegrade LAMPOON technique, and did not survive to discharge. At the time of discharge, no patients had an increase of >10 mm Hg in LVOT gradient compared with baseline. Procedure times (from traversal to transcatheter mitral valve replacement) were shorter, compared with the retrograde technique in the LAMPOON investigational device exemption trial (39±09 versus 65±35 minutes). All patients survived (8/8, 100%) the procedure, and 7/8 (88%) survived to 30 days, similar to subjects in the LAMPOON investigational device exemption trial. CONCLUSIONS: Antegrade LAMPOON is an effective, reproducible, and simplified strategy to lacerate the anterior leaflet before transcatheter mitral valve replacement. The authors recommend the technique as the new standard for LAMPOON.

Severe Mitral Annular Calcification and Mitral Valve Surgery: An Algorithmic Approach to Management.

The management of mitral valve dysfunction in the setting of substantial mitral annular calcification (MAC) remains controversial and is one of the most challenging problems in mitral valve surgery. The physiopathology of severe MAC is related to a combination of progressive, degenerative and active calcium deposition in the annulus that is often multifactorial, but largely attributable to aging and chronic disease conditions. Given the fact that overall life expectancy in the elderly population are increasing, it is imperative to understand contemporary and future therapeutic options since this MAC is likely going to be a frequent problem faced by the next generation of cardiac surgeons. This review provides a relevant synthesis of existing literature and aims to assess the efficacy of existing therapeutic choices for patients with mitral valve dysfunction and 'big' MAC with a goal of minimizing postoperative complications (e.g. left ventricular outflow tract obstruction, prosthetic paravalvular leak, valve embolization, and stroke) that can be achieved via a multidisciplinary heart team approach.

Acute fulminant hemolysis after transcatheter mitral valve replacement for mitral annular calcification.

Transcatheter mitral valve replacement (TMVR) is emerging as an alternative treatment strategy to surgery for patients with severe mitral annular calcification (MAC) who are not candidates for traditional mitral valve surgery. Paravalvular leak (PVL) is common following TMVR for severe MAC and can lead to heart failure symptoms and/or intravascular hemolysis, the latter of which usually is clinically stable. We report the case of a 67-year-old woman with symptomatic severe aortic stenosis and mitral stenosis with MAC in the setting of prior chest irradiation who was treated initially with transcatheter aortic valve replacement followed by TMVR at a later date (Sapien S3 system; Edwards Lifesciences). Immediately following TMVR, she developed acute profound hemolysis which manifested with hemoglobinuria, transfusion-dependent anemia, and acute renal failure requiring renal replacement therapy. She was treated with post-dilation balloon valvuloplasty after failed transcatheter PVL closure 10 days following TMVR with resulting improvement in the PVL. The hemolytic anemia resolved and renal function recovered without the need for continued hemodialysis 2 months later and stabilization of glomerular filtration rate at 6 months. This case highlights a potential severe complication of TMVR in MAC and suggests that improvement in hemolysis and late recovery of renal function may occur following treatment of PVL.