Background-Mitral valve (MV) repair is preferred over replacement in clinical guidelines and is an important determinant of the indication for surgery in degenerative mitral regurgitation (MR). Yet, the level of evidence supporting current recommendations is low, and recent data cast doubts on its validity in the current era. Accordingly, the aim of the present study was to analyze very long-term outcome after MV repair and replacement for degenerative MR with a flail leaflet. Methods-MIDA is a multicenter registry enrolling patients with degenerative MR with a flail leaflet in 6 tertiary European and US centers. We analyzed the outcome after MV repair (n=1,709) and replacement (n= 213), overall, by propensity score matching and by inverse probability-of-treatment weighting. Results-At baseline, patients undergoing MV repair were younger, had more comorbidities and were more likely to present with a posterior leaflet prolapse than those undergoing MV replacement. After propensity score matching as well as after inverse probability-of-treatment weighting, the 2 treatments groups were balanced and absolute standardized differences were usually below 10%, indicating adequate match. Operative mortality (defined as a death occurring within 30 days from surgery or during the same hospitalization) was lower after MV repair than after replacement, both in the entire (1.3 vs 4.7%; p<0.001) and in propensity-matched population (0.2% vs 4.4%; p<0.001). During a mean follow-up of 9.2 years, 552 deaths were observed, of which 207 were of cardiovascular origin. Twenty-year survival was better after MV repair than after MV replacement, both in the entire (46% vs 23%, p<0.001) and in matched population (41% vs 24%, p<0.001). Similar superiority of MV repair were obtained in patients' subsets based on age, sex or any stratification criteria (all p<0.001). MV repair was also associated with reduced incidence of reoperations and valve-related complications.Conclusions-Among patients with degenerative MR with a flail leaflet, referred to mitral surgery, MV repair was associated with lower operative mortality, better long-term survival and fewer valve-related complications compared to MV replacement.

BackgroundGadolinium (Gd) Extracellular volume fraction (ECV) by Cardiovascular Magnetic Resonance (CMR) has been proposed as a non-invasive method for assessment of diffuse myocardial fibrosis. Yet only few studies used 3 T CMR to measure ECV, and the accuracy of ECV measurements at 3 T has not been established. Therefore the aims of the present study were to validate measurement of ECV by MOLLI T1 mapping by 3 T CMR against fibrosis measured by histopathology. We also evaluated the recently proposed hypothesis that native-T1 mapping without contrast injection would be sufficient to detect fibrosis.Methods31 patients (age = 58 ± 17 years, 77 % men) with either severe aortic stenosis (n = 12) severe aortic regurgitation (n = 9) or severe mitral regurgitation (n = 10), all free of coronary artery disease, underwent 3 T-CMR with late gadolinium enhancement (LGE) and pre- and post-contrast MOLLI T1 mapping and ECV computation, prior to valve surgery. LV biopsies were performed at the time of surgery, a median 13 [1–30] days later, and stained with picrosirius red. Pre-, and post-contrast T1 values, ECV, and amount of LGE were compared against magnitude of fibrosis by histopathology by Pearson correlation coefficients.ResultsThe average amount of interstitial fibrosis by picrosirius red staining in biopsy samples was 6.1 ± 4.3 %. ECV computed from pre-post contrast MOLLI T1 time changes was 28.9 ± 5.5 %, and correlated (r = 0.78, p < 0.001) strongly with the magnitude of histological fibrosis. By opposition, neither amount of LGE (r = 0.17, p = 0.36) nor native pre-contrast myocardial T1 time (r = −0.18, p = 0.32) correlated with fibrosis by histopathology.ConclusionsECV determined by 3 T CMR T1 MOLLI images closely correlates with histologically determined diffuse interstitial fibrosis, providing a non-invasive estimation for quantification of interstitial fibrosis in patients with valve diseases. By opposition, neither non-contrast T1 times nor the amount of LGE were indicative of the magnitude of diffuse interstitial fibrosis measured by histopathology.

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 time. (Circ Cardiovasc Imaging. 2014;7:714-722.)