Surgical management in severe degenerative mitral regurgitation

From mitral valve replacement to robotic mitral valve repair(BIFA - Sciences biomédicales et pharmaceutiques) -- UCL, 201

Mid-term results of a randomized trial of tricuspid annuloplasty for less-than-severe functional tricuspid regurgitation at the time of mitral valve surgery†.

OBJECTIVES: The optimal management of functional tricuspid regurgitation (FTR) in the setting of mitral valve operations remains controversial. The current practice is both centre specific and surgeon specific with guidelines based on non-randomized data. A prospective randomized trial was performed to evaluate the worth of less-than-severe FTR repair during mitral valve procedures. METHODS: A single-centre randomized study was designed to allocate patients with less-than-severe FTR undergoing mitral valve surgery to be prophylactically treated with or without tricuspid valve annuloplasty (TVP- or TVP+). These patients were analysed using longitudinal cardiopulmonary exercise capacity, echocardiographic follow-up and cardiac magnetic resonance. The primary outcome was freedom from more than or equal to moderate tricuspid regurgitation with vena contracta ≥4 mm. Secondary outcomes were maximal oxygen uptake and right ventricular (RV) dimension and function. RESULTS: A total of 53 patients were allocated to receive concomitant TVP+, and 53 patients were treated conservatively (TVP-). At 5 years, tricuspid regurgitation was observed to be greater than mild in 10 patients in the TVP- group and no patients in the TVP+ group (P < 0.01). Maximal oxygen uptake, RV basal diameter, end-diastolic diameter and end-systolic diameter and fractional area changes were similar in both groups. Cardiac magnetic resonance confirmed no differences in RV end-diastolic volume, RV end-systolic volume and RV ejection fraction. CONCLUSIONS: This single-centre prospective randomized trial demonstrated that prophylactic tricuspid annuloplasty irrespective of annular dilatation at the time of mitral surgery reduced the recurrence of moderate or severe FTR at 5-year follow-up and reduced the pulmonary pressure. Nevertheless, the functional capacity, the RV function and the RV dimension remained similar

Very Long Term Survival After Mitral Repair Vs Replacement. A Propensity Score Analysis Of A Large, Prospective, Multicenter International Registry

Background: Despite the absence of randomized studies comparing mitral valve (MV) repair and replacement, international guidelines strongly recommend MV repair as the optimal surgical treatment for severe degenerative mitral regurgitation (dMR). Yet, the level of evidence supporting these recommendations is low, owing to the lack of available clinical trial data. In this context, analysis of large multicenter registries becomes critical. Objective: To compare very long-term survival among patients (pts) undergoing MV repair versus replacement for the treatment of severe dMR using the technique of propensity score (PS) matching to reduce bias in non-randomized cohorts. Methods: The Mitral Regurgitation International DAtabase (MIDA) is a prospective multicenter registry that includes 2,569 consecutive pts with dMR, who were recruited in 6 tertiary centers (France, Italy, Belgium, and the United States) between 1980 and 2005. Among these, we identified 1,922 pts who underwent mitral surgery, including 1,709 MV repairs and 213 MV replacements. We compared operative mortality and overall survival in both the entire study population and in 615 PS-matched (2:1) pts. Results: Operative mortality was lower after MV repair than after MV replacement, both in the entire population (2 vs 7%; p=0.001) and in the PS-matched pts (4 vs 8%; p=0.04). Similarly, 20-year survival was better after MV repair than after MV replacement, both in the entire population (46% [95% CI, 39%-52%] vs 23% [95% CI, 14%-32%], p<0.001) and in the PS-matched pts (41% [95% CI, 28%-54%] vs 24% [95% CI, 14%-33%], p<0.001). Similar results were obtained in pts aged < 65 years (p<0.005), 65-74 years (p<0.001) and ≥ 75 years (p<0.001). Conclusions: Among registry pts with dMR, performance of MV repair resulted in lower operative mortality and greater long-term survival compared to MV replacement, thus supporting current international recommendations

Assessment of Left Ventricular Reverse Remodeling by Cardiac MRI in Patients Undergoing Repair Surgery for Severe Aortic or Mitral Regurgitation.

To evaluate left ventricular (LV) reverse remodeling after repair surgery for mitral regurgitation (MR) or aortic regurgitation (AR), aiming at determining optimal preoperative thresholds for normalization of LV volumes and function after surgery. Observational prospective cohort study. Single-center, academic, tertiary care cardiovascular center. Patients and volunteers. Cardiac magnetic resonance with measurement of indexed LV end-diastolic volume (LVEDVi) and end-systolic volume (LVESVi), mass (LVmassi), and ejection fraction (LVEF) was performed preoperatively and postoperatively. The authors included 29 patients with AR and 59 patients with MR (46 ± 12 and 56 ± 12 years, follow-up 222 ± 57 days). Both AR and MR repair resulted in a significant reduction of LV volumes and mass (respectively, delta change in LVEDVi -55 mL/m² and -43 mL/m²; in LVESVi -26 mL/m² and -10 mL/m²; and in LVmassi -24 g/m² and -12 g/m²; p 106 mL/m²) relative to controls and 16 (27%) patients with MR developed systolic LV dysfunction (LVEF 155 mL/m² for AR and >129 mL/m² for MR. Although both AR and MR repair allow significant reverse postoperative LV remodeling, persistent LV dilatation after AR correction and systolic LV dysfunction after MR repair are common and best predicted by increased preoperative LV volumes. This highlights the importance of considering LV volumes in the decision-making process

Valve Weight and Severity of Valve Calcification are less in Paradoxical Low Gradient than in High Gradient Severe Aortic Stenosis

Background: Paradoxical low gradient (PLG) severe aortic stenosis (SAS) is a recently described subset of SAS, whose exact clinical significance is a matter of intense debate. Some authors indeed consider this new entity as a more advanced form of SAS, whereas others believe it represents a relatively benign form of AS. To get further insight into the pathophysiology of PLG SAS, we compared the weight of the valves explanted at the time of surgery (AVR) and the degree of valve calcification, two surrogates markers of the true stenosis severity, among consecutive patients with PLG SAS and high-gradient (HG) SAS. Methods: We prospectively recruited 38 consecutive patients (20 men; mean age: 73 yrs) with isolated non-rheumatic SAS (indexed aortic valve area (AVAi) 0.90) and in-vivo (r2=0.71) Agatston scores. Interestingly, valves explanted from patients with PLG SAS were lighter (1.58±0.65 vs 2.65±1.24 g, p=0.001) and showed lower ex-vivo Agatston scores (363±282 vs 1211±840, p<0.001) than HG SAS valves. These differences remained significant after adjustment for gender (1.58±0.65 vs 2.36±0.88 g, p=0.011 for valves weight and 363±282 vs 1023±597, p=0.002 for ex-vivo Agatston score). Conclusion: The valves weight and degree of valve calcification reported in our study indicate that PLG SAS valves are less severely affected than HG SAS valves. These data thus reinforce the hypothesis that PLG SAS is a lesser advanced form of aortic stenosis than HG SAS

Is paradoxical Low Gradient severe Aortic Stenosis a More Advanced form of Aortic Stenosis? New Insights gained from measurements of Valvular Calcium Content by use of 256-slice MDCT.

Background: Paradoxical low gradient severe aortic stenosis (PLG SAS) is a recently described subset of aortic stenosis (AS) the clinical and prognostic implications of which are a matter of intense debate. Some authors indeed consider this new entity as a more advanced form of AS, with increased interstitial fibrosis, reduced LV longitudinal function and poor prognosis, whereas others believe it represents a relatively benign form of AS, with an outcome similar to that of moderate AS. Because the severity of degenerative AS is intimately correlated with its calcium content, the aim of the present work was to directly compare the degree of valve calcification among PLG SAS and high-gradient (HG) SAS. Methods: Forty three consecutive patients (16 men; mean age: 74±9 years) with isolated non-rheumatic SAS, preserved LVEF and regular sinusal rhythm underwent 256-slice MDCT to measure aortic valve calcium within 15 days of their echocardiographic examination. Patients were categorised according to mean transaortic gradient (MG) into PLG SAS (n=14, MG≤40 mmHg) or HG SAS (n=29, MG>40mmHg). Aortic valve calcification was assessed by use of the Agatston score. Analyses were conducted in the entire population as well as in subsets of patients matched for indexed aortic valve area (AVAi) and gender. Results: With the exception of MG which by definition, was lower in PLG SAS than in HG SAS (30±5 vs 57±14 mmHg), PLG and HG SAS had similar baseline clinical and echocardiographic characteristics. In particular AS severity, as evaluated by the AVAi was similar in both groups (0.41±0.10 vs 0.36±0.08 cm2/m2, p=ns). By contrast, the Agatston score was significantly lower in PLG SAS than HG SAS (1684±859 vs 3209±1530, p≤0.001). This difference remained significant after matching the patients for AVAi and gender (1657±850 vs 2592±774, p=0.017). Conclusion: Patients with PLG SAS display less calcified aortic valves by MDCT than patients with HG SAS. This suggests that the aortic valve disease process is less advanced in PLG SAS than in HG SAS

Association of B-Type Natriuretic Peptide With Survival in Patients With Degenerative Mitral Regurgitation.

BACKGROUND: Studies suggesting that B-type natriuretic peptide (BNP) may predict outcomes of mitral regurgitation (MR) are plagued by small size, inconsistent etiologies, and lack of accounting for shifting normal BNP ranges with age and sex. OBJECTIVES: This study assessed the effect of BNP activation on mortality in a large, multicenter cohort of patients with degenerative MR. METHODS: In 1,331 patients with degenerative MR, BNP was prospectively measured at diagnosis and expressed as BNPratio (ratio to upper limit of normal for age, sex, and assay). Initial surgical management was performed within 3 months of diagnosis in 561 patents. RESULTS: The cohort had a mean age of 64 ± 15 years, was 66% male, and had a mean ejection fraction 64 ± 9%, mean regurgitant volume 67 ± 31 ml, and low mean Charlson comorbidity index of 1.09 ± 1.76. Median BNPratio was 1.01 (25th and 75th percentiles: 0.42 to 2.36). Overall, BNPratio was a powerful, independent predictor of mortality (hazard ratio: 1.33 [95% confidence interval: 1.15 to 1.54]; p < 0.0001), whereas absolute BNP was not (p = 0.43). In patients who were initially treated medically (n = 770; 58%), BNPratio was a powerful, independent, and incremental predictor of mortality after diagnosis (hazard ratio: 1.61 [95% confidence interval: 1.34 to 1.93]; p < 0.0001). Higher BNP activation was associated with higher mortality (p < 0.0001). All subgroups, particularly severe MR, incurred similar excess mortality with BNP activation. After initial surgical treatment (n = 561, 42%) BNP activation did not impose excess long-term mortality (p = 0.23). CONCLUSIONS: In patients with degenerative MR, BNPratio is a powerful, independent, and incremental predictor of long-term mortality under medical management. BNPratio should be incorporated into the routine clinical assessment of patients with degenerative MR

Natural history of paradoxical low-gradient severe aortic stenosis

BACKGROUND: Up to 30% of patients with severe aortic stenosis (SAS; indexed aortic valve area <0.6 cm(2)/m(2)) present with low transvalvular gradient despite a normal left ventricular ejection fraction. Presently, there is intense controversy as to the prognostic implications of such findings. Accordingly, the aim of the present work was to compare the natural history of patients with paradoxical low-gradient (PLG) or high-gradient (HG) SAS. METHODS AND RESULTS: We prospectively studied 349 patients with SAS and preserved left ventricular ejection fraction. Patients were categorized into HG-SAS (n=144) and PLG-SAS (n=205) according to mean transvalvular gradient (mean gradient >40 or ≤40 mm Hg). Primary end points were all-cause mortality and echocardiographic disease progression. To evaluate natural history, patients undergoing aortic valve replacement were censored at the time of surgery (n=92). During a median follow-up of 28 months, 148 patients died. Kaplan-Meier survival curves showed better survival in PLG-SAS than in HG-SAS, both in the overall population (48% versus 31%; P<0.01) and in the asymptomatic subgroup (59% versus 35%; P<0.02). In asymptomatic patients, Cox analysis identified age, diabetes mellitus, left atrial volume, and mean gradient as independent predictors of death. Finally, at last echocardiographic follow-up, PLG-SAS demonstrated significant increases in mean gradient (from 29±6 to 38±11 mm Hg; P<0.001). CONCLUSIONS: Our study indicates that PLG-SAS is a less malignant form of AS compared with HG-SAS, because their spontaneous outcome is better. We further demonstrated that patients with PLG-SAS are en route toward the more severe HG-SAS form, because the majority of them evolve into HG-SAS over tim