Mitral regurgitation in patients with severe aortic stenosis: Diagnosis and management

Severe aortic stenosis (AS) and mitral regurgitation (MR) frequently coexist. Although some observational studies have reported that moderate or severe MR is associated with higher mortality, the optimal management of such patients is still unclear. Simultaneous replacement of both aortic and mitral valves is linked to significantly higher morbidity and mortality. Recent advances in minimally invasive surgical or transcatheter therapies for MR allow for staged procedures in which surgical or transcatheter aortic valve replacement (SAVR/TAVR) is done first and MR severity re-evaluated afterwards. Current evidence suggests MR severity improves in some patients after SAVR or TAVR, depending on several factors (MR aetiology, type of valve used for TAVR, presence/absence of atrial fibrillation, residual aortic regurgitation, etc). However, as of today, the absence of randomised clinical trials does not allow for evidence-based recommendations about whether or not MR should be addressed at the time of SAVR or TAVR. A careful patient evaluation and clinical judgement are recommended to distinguish patients who might benefit from a double valve intervention from those in which MR should be left alone. The aim of this review is to report and critique the available data on this subject in order to help guide the clinical decision making in this challenging subset of patients

Comparison of Efficacy and Safety of Transcatheter Aortic Valve Implantation in Patients With Bicuspid Versus Tricuspid Aortic Valves

Bicuspid aortic valve (BAV) stenosis has been considered a contraindication to transcatheter aortic valve implantation (TAVI). The aim of this study is to compare the efficacy and safety of TAVI in patients with BAV with those with tricuspid aortic valve (TAV) using balloon-expandable and self-expanding transcatheter heart valves. This retrospective study included 823 consecutive patients with severe, symptomatic aortic valve stenosis undergoing TAVI in 2 institutions, Baylor Heart and Vascular Hospital (Dallas, TX) and The Heart Hospital Baylor Plano (Plano, TX), from January 2012 to February 2016. Efficacy was evaluated by postprocedural valve function as mean gradient, peak velocity, effective orifice area, and ≥moderate paravalvular leak. Safety end points included all-cause 30-day and 1-year mortality, immediate postprocedural mortality and 30-day cardiovascular mortality, procedural success, pacemaker implantation, and procedural complications. Of the 823 included patients, 735 had TAV and 77 had BAV. Baseline characteristics were similar between the 2 groups. Procedural success was high in both BAV and TAV (98.7% vs 99.1%, p = ns). There were no significant differences between groups in valve hemodynamics after TAVI, pacemaker implantation rate, or procedural complications. There were no differences regarding immediate postprocedural mortality (BAV vs TAV, 1.1% vs 0.8%, p = ns), nor 30-day cardiovascular mortality (3.4% vs 2.3%, p = ns). All-cause mortality at 30 days (3.4% vs 3.1%, p = ns) and 1-year (8.5% vs 10.5%) were similar. Patients with BAV showed similar procedural and clinical outcomes to patients with TAV. Therefore, TAVI appears to be a safe and effective procedure for patients with BAVs as well as those with TAVs

2-year outcomes for transcatheter repair in patients with functional mitral regurgitation from the CLASP study

Background: Transcatheter mitral valve repair has emerged as a favourable option in patient care for treating functional mitral regurgitation (FMR) with a need for longer term data. We herein report two-year outcomes from the FMR group of the multicentre, prospective, single arm CLASP study with the PASCAL transcatheter valve repair system. Methods: Patients with symptomatic, clinically significant FMR ≥3+ as evaluated by the core laboratory and deemed candidates for transcatheter repair by the local heart team were eligible for the study. Follow-up was conducted at 30 days, one year, and two years with echocardiographic outcomes evaluated by the core laboratory at all timepoints and major adverse events (MAEs) evaluated by an independent clinical events committee to one year (site-reported thereafter). Results: Eighty-five FMR patients were treated with mean age 72 years, 55% male, 65% in NYHA Class III-IVa, 37% LVEF, and 100% MR grade ≥3+. Successful implantation was achieved in 96% of patients. MAEs included one cardiovascular mortality (1.2%) and one conversion tomitral valve replacement surgery (1.2%) at 30 days, and two reinterventions between 30 days and two years. Kaplan-Meier (KM) estimates for survival were 88% at one year and 72% at two years. Freedom from heart failure (HF) rehospitalization KM estimates were 81% at one year and 78% for two years. The reduction in annualized HF hospitalization rate was 81% at two years (p\u3c0.001). MR ≤1+ was achieved in 73% of patients at 30 days, 75% at one year, and 84% at two years; MR ≤2+ was achieved in 96% of patients at 30 days, 100% at one year, and 95% two years (all p\u3c0.001). Mean LVEDV of 199 mL at baseline decreased by 9 mL at 30 days (p=0.039), 29 mL at one year (p\u3c0.001), and 31 mL at two years (p\u3c0.001). NYHA class I/II was achieved in 87% of patients at 30 days, 86% at one year, and 88% at two years (all p\u3c0.001). Six-minute walk distance (6MWD) improved by 22 m at 30 days (p=0.004) and 40 m at one year (p=0.003). Kansas City Cardiomyopathy Questionnaire (KCCQ) score improved by 16 points at 30 days and one year (all p\u3c0.001). Conclusions: In the CLASP study, the PASCAL transcatheter valve repair system demonstrated sustained favourable outcomes at two years in patients with FMR. Results showed a high survival rate of 72% and freedom from HF rehospitalization of 78% at two years. An 81% reduction in annualized HF hospitalization rate was observed. At two years, sustained MR reduction of MR ≤2+ was achieved in 95% andMR ≤1+ in 84% of patients, with evidence of left ventricular reverse remodelling. Improvements in functional status were significant and sustained at two years. The CLASP IIF randomized pivotal trial is ongoing

Frequency of and Prognostic Significance of Atrial Fibrillation in Patients Undergoing Transcatheter Aortic Valve Implantation

The prognostic implications of preexisting atrial fibrillation (AF) and new-onset AF (NOAF) in transcatheter aortic valve implantation (TAVI) remain uncertain. This study assesses the epidemiology of AF in patients treated with TAVI and evaluates their outcomes according to the presence of preexisting AF or NOAF. A retrospective analysis of 708 patients undergoing TAVI from 2 heart hospitals was performed. Patients were divided into 3 study groups: sinus rhythm (n = 423), preexisting AF (n = 219), and NOAF (n = 66). Primary outcomes of interest were all-cause death and stroke both at 30-day and at 1-year follow-up. Preexisting AF was present in 30.9% of our study population, whereas NOAF was observed in 9.3% of patients after TAVI. AF and NOAF patients showed a higher rate of 1-year all-cause mortality compared with patients in sinus rhythm (14.6% vs 6.5% for preexisting AF and 16.3% vs 6.5% for NOAF, p = 0.007). No differences in 30-day mortality were observed between groups. In patients with AF (either preexisting and new-onset), those discharged with single antiplatelet therapy displayed higher mortality rates at 1 year (42.9% vs 11.7%, p = 0.006). Preexisting AF remained an independent predictor of mortality at 1-year follow-up (hazard ratio [HR] 2.34, 95% CI 1.22 to 4.48, p = 0.010). Independent predictors of NOAF were transapical and transaortic approach as well as balloon postdilatation (HR 3.48, 95% CI 1.66 to 7.29, p = 0.001; HR 5.08, 95% CI 2.08 to 12.39, p <0.001; HR 2.76, 95% CI 1.25 to 6.08, p = 0.012, respectively). In conclusion, preexisting AF is common in patients undergoing TAVI and is associated with a twofold increased risk of 1-year mortality. This negative effect is most pronounced in patients discharged with single antiplatelet therapy compared with other antithrombotic regimens

Baseline mitral regurgitation predicts outcome in patients referred for dobutamine stress echocardiography

Purpose: A number of parameters recorded during dobutamine stress echocardiography (DSE) are associated with worse outcome. However, the relative importance of baseline mitral regurgitation (MR) is unknown. The aim of this study was to assess the prevalence and associated implications of functional MR with long-term mortality in a large cohort of patients referred for DSE. Methods: 6745 patients (mean age 64.9±12.2 years) were studied. Demographic, baseline and peak DSE data were collected. All-cause mortality was retrospectively analyzed. DSE was successfully completed in all patients with no adverse outcomes. Results: MR was present in 1019 (15.1%) patients. During a mean follow up of 5.1±1.8 years, 1642 (24.3%) patients died and MR was significantly associated with increased all-cause mortality (p<0.001). With Kaplan-Meier analysis, survival was significantly worse for patients with moderate and severe MR (p<0.001). With multivariate Cox regression analysis, moderate and severe MR (HR 2.78; 95% CI 2.17 - 3.57; and HR 3.62; 95% CI 2.89 - 4.53, respectively) were independently associated with all-cause mortality. The addition of MR to C statistic models significantly improved discrimination. Conclusions: MR is associated with all-cause mortality and adds incremental prognostic information among patients referred for DSE. The presence of MR should be taken into account when evaluating the prognostic significance of DSE results

Shrimp Farming Practices in the Puttallam District of Sri Lanka: Implications for Disease Control, Industry Sustainability, and Rural Development

Shrimp farming has great potential to diversify and secure income in rural Sri Lanka, but production has significantly declined in recent years due to civil conflicts, some unsustainable practices and devastating outbreaks of disease. We examined management practices affecting disease prevention and control in the Puttalam district to identify extension services outputs that could support sustainable development of Sri Lankan shrimp farming. A survey on 621 shrimp farms (603 operational and 18 nonoperational) was conducted within the Puttalam district over 42 weeks comprising a series of three-day field visits from August 2008 to October 2009, covering two consecutive shrimp crops. Fundamental deficits in disease control, management, and biosecurity practices were found. Farmers had knowledge of biosecurity but the lack of financial resources was a major impediment to improved disease control. Smallholder farmers were disproportionately constrained in their ability to enact basic biosecurity practices due to their economic status. Basic breaches in biosecurity will keep disease as the rate limiting step in this industry. Plans to support this industry must recognize the socioeconomic reality of rural Sri Lankan aquaculture

Simple sequence repeats in Neurospora crassa: distribution, polymorphism and evolutionary inference

<p>Abstract</p> <p>Background</p> <p>Simple sequence repeats (SSRs) have been successfully used for various genetic and evolutionary studies in eukaryotic systems. The eukaryotic model organism <it>Neurospora crassa </it>is an excellent system to study evolution and biological function of SSRs.</p> <p>Results</p> <p>We identified and characterized 2749 SSRs of 963 SSR types in the genome of <it>N. crassa</it>. The distribution of tri-nucleotide (nt) SSRs, the most common SSRs in <it>N. crassa</it>, was significantly biased in exons. We further characterized the distribution of 19 abundant SSR types (AST), which account for 71% of total SSRs in the <it>N. crassa </it>genome, using a Poisson log-linear model. We also characterized the size variation of SSRs among natural accessions using Polymorphic Index Content (PIC) and ANOVA analyses and found that there are genome-wide, chromosome-dependent and local-specific variations. Using polymorphic SSRs, we have built linkage maps from three line-cross populations.</p> <p>Conclusion</p> <p>Taking our computational, statistical and experimental data together, we conclude that 1) the distributions of the SSRs in the sequenced N. crassa genome differ systematically between chromosomes as well as between SSR types, 2) the size variation of tri-nt SSRs in exons might be an important mechanism in generating functional variation of proteins in <it>N. crassa</it>, 3) there are different levels of evolutionary forces in variation of amino acid repeats, and 4) SSRs are stable molecular markers for genetic studies in <it>N. crassa</it>.</p