Mitral regurgitation (MR) has a significant haemodynamic impact on the left atrium. Assessment of left atrial reservoir strain (LARS) may have important prognostic implications, incremental to left atrial (LA) volume, and conventional parameters of left ventricular (LV) structure and function. This study investigated whether preoperative assessment of LARS by speckle tracking echocardiography is associated with long-term outcomes in patients undergoing mitral valve repair for severe primary MR. Echocardiography was performed prior to mitral valve surgery in 566 patients (age 64 ± 12years, 66% men) with severe primary MR. The study population was subdivided based on a LARS value of 22%, using a spline curve analysis. The primary endpoint was all-cause mortality. During a median follow-up of 7 (4–12) years, 129 (22.8%) patients died. Patients with LARS ≤22% showed significantly higher mortality rates at 1-, 3-, and 5-year follow-up (6%, 12%, and 15%, respectively) when compared with patients with LARS >22% (2%, 3% and 5%, respectively, P < 0.001). Age [hazard ratio (HR): 1.06; 95% confidence interval (CI): 1.03–1.09; P < 0.001], LV global longitudinal strain (HR: 0.92; 95% CI: 0.87–0.98; P = 0.014), and LARS (HR: 0.96; 95% CI: 0.93–0.99; P = 0.014) were independently associated with all-cause mortality. Preoperative LARS is independently associated with all-cause mortality in patients undergoing mitral valve repair for primary MR and provides incremental prognostic value over LA volume. LARS might be helpful to guide timing of mitral valve surgery in patients with severe primary MR. Assessment of left atrial reservoir strain and long-term survival in patients with severe primary mitral regurgitation undergoing mitral valve repair.

Mitral valve repair in native active infective endocarditis is technically challenging. The survival benefit over valve replacement is poorly established and possibly absent because of the high risk of repair failure and reoperation. In this study, we explore the results of our structured approach in these patients. Between January 2000 and January 2017, 149 patients underwent surgery for native mitral infective endocarditis. Among them, 97 (66%) patients underwent valve repair and 52 (34%) underwent valve replacement. Our structured approach consisted of early surgery, radical resection of infected tissue, liberal use of prosthetic materials and ‘patch’ repair techniques. A critical assessment of expected repair durability was made intraoperatively and repair was not performed if concerns of long-term durability existed. To study the effects of valve repair on overall survival, landmark analysis was performed. In-hospital mortality was 15.4% (14 repair vs 9 replacement patients; P = 0.642). There were no residual infective endocarditis cases or early reoperations. On Cox proportional hazards analysis, valve replacement was not inferior to repair within 1-year post-surgery [hazard ratio (HR) 1.134, 95% confidence interval (CI) 0.504–2.540; P = 0.76]. Beyond 1 year post-surgery, replacement was associated with decreased survival (HR 2.534, 95% CI 1.002–6.406; P = 0.049). There were no differences in freedom from recurrent infective endocarditis (P = 0.47) and mitral valve reintervention (P = 0.52). Active mitral valve endocarditis remains a complex disease with significant early and late morbidity and mortality. A structured approach allows valve repair in two-thirds of patients. Clinical results could be improved by focussing on early surgery, prior to extensive valve destruction, to enable durable repairs and improve late outcomes.

OBJECTIVES: Barlow’s disease (BD) is characterized by thick, redundant mitral valve (MV) leaflets, which can lead to prolapse and significant mitral regurgitation (MR). MV annular abnormalities are also commonly observed and increasingly recognized as possible primary pathology, with leaflet thickening being secondary to increased stress on the MV apparatus. To provide more insights into this hypothesis, the evolution of MV abnormalities over time in patients with BD was assessed. METHODS: A total of 64 patients (54 ± 12 years, 72% male) with BD who underwent MV surgery and had multiple transthoracic echocardiograms (TTE) before surgery were included. In total, 186 TTE were analysed (median time interval 4.2, interquartile range 2.2–6.5 years) including specific MV characteristics. RESULTS: At baseline, MV leaflet length, thickness, billowing height and annular diameter were larger in patients with BD compared to 59 healthy subjects. Systolic outward motion (curling) of the annulus was observed in 77% and severe mitral annular disjunction (≥5 mm) in 38% of patients with BD. Forty (63%) patients had MR grade I–II and 24 (37%) MR grade III–IV; at baseline, the 2 groups only differed in left atrial volume and in thickness and billowing height of the posterior leaflet, showing comparable MV annular abnormalities and dilatation despite different grades of MR. Over time, MV annulus diameter, leaflet length and billowing height increased significantly along with MR grade. CONCLUSIONS: In patients with BD, MV annulus abnormalities are present at an early stage and precede the development of significant MR, suggesting their substantial role in the pathophysiology of this disease and as an important target for surgical treatment.

Aims: In mitral valve prolapse (MVP), leaflet thickening has recently been suggested to be due, in addition to a myxomatous degeneration, to the presence of a superimposed tissue (SIT), defined as an additional fibrous layer on top of the original leaflet. The mechanisms of SIT formation are currently unknown. We hypothesized that SIT formation would result from excessive leaflet stress and we used a unique ex vivo model to assess the correlation between leaflet remodelling and the type and location of mechanical stress and to elucidate the mechanisms underlying SIT formation. Methods and results: Human diseased mitral valves (MVs; n = 21) were histologically analysed for SIT formation and original leaflet thickening. The SIT comprised of various compositions of extracellular matrix and could reach more than 50% of total leaflet thickness. Original leaflet and SIT thickness did not show significant correlation (r = −0.27, P = 0.23), suggesting different regulatory mechanisms. To study the role of the mechanical environment on MV remodelling, mouse MV were cultured in their natural position in the heart and subjected to various haemodynamic conditions representing specific phases of the cardiac cycle and the MVP configuration. SIT formation was induced in the ex vivo model, mostly present on the atrial side, and clearly dependent on the duration, type, and extent of mechanical stress. Specific stainings and lineage tracing experiments showed that SIT comprises of macrophages and myofibroblasts and is associated with the activation of the transforming growth factor-beta and bone morphogenetic protein signalling pathways. Migration of valvular interstitial cells and macrophages through breakages of the endothelial cell lining contributed to SIT formation. Conclusions: Mechanical stresses induce specific cellular and molecular changes in the MV that result in SIT formation. These observations provide the first insights in the mechanism of SIT formation and represent an initial step to identify potential novel and early treatment for MVP.

OBJECTIVES: Robotic-assisted mitral valve repair surgery has a steep learning curve, and it is not clear whether previous experience in minimally invasive mitral valve surgery (MIMVS) facilitates this process. We aimed to investigate the initial experience of 2 cardiac centres starting their robotic programmes, evaluating the impact of previous MIMVS experience. METHODS: Retrospective analysis was performed for the 1st consecutive cases operated due to severe degenerative mitral valve regurgitation using the robotic surgical platform in 2 European centres, 1 transitioning from conventional surgery (centre 1) and the other from mini thoracotomy MIMVS (centre 2). Cumulative sum analysis was used to evaluate the learning process using both surgical times and a combined primary outcome including relevant intra- and postoperative results. RESULTS: First 62 patients in each centre were included. All median surgical times were shorter in centre 2: cardiopulmonary bypass: 238 vs 115 min, P < 0.001; cross-clamp: 143 vs 82 min, P < 0.001; and total intervention: 313 vs 228 min, P < 0.001. The combined primary outcome showed no significant differences (9.7% vs 8%; P = 1). However, the turning point making the end of the learning phase was detected at the 60th case in centre 1 and at the 50th in centre 2. Regarding surgical time, the learning curve was steeper in centre 1 with both cardiopulmonary bypass and cross-clamp overcoming the learning phase after 32 cases, as compared to 16 cases in centre 2. CONCLUSIONS: A successful robotic-assisted mitral repair programme can be safely started coming from either conventional open approach or mini thoracotomy MIMVS. However, previous mini thoracotomy MIMVS experience had positive impact on the initial learning curve.

The adoption of robotics in cardiac surgery is increasing rapidly [ 1]. The unparalleled range of motion and precision combined with 3-dimensional (3D) vision in a minimally invasive surgical setting facilitates complex cardiosurgical procedures without compromising on the surgical techniques utilized. This unique combination of innovative characteristics holds the promise to improve outcome in various groups of patients. Until the recent surge in robotic cases, the penetrance of robotics in cardiac surgery has been low for decades, likely related to the high initial costs in combination with a lack of structured training and mentoring programs. Furthermore, the new European Medical Device Regulation may hamper further adoption of this technique because it seems to lead to the paradoxical withdrawal of robotic tools from the market rather than the anticipated improvement in quality.