Management of Chronic Congestive Heart Failure Caused by Myxomatous Mitral Valve Disease in Dogs: A Narrative Review from 1970 to 2020

The treatment of chronic congestive heart failure (CHF), secondary to myxomatous mitral valve disease (MMVD) in dogs, has considerably changed in the last fifty years. An analysis of the literature concerning the therapy of chronic CHF in dogs affected by MMVD is not available, and it is needed. Narrative reviews (NRs) are aimed at identifying and summarizing what has been previously published, avoiding duplications, and seeking new study areas that have not yet been addressed. The most accessible open-access databases, PubMed, Embase, and Google Scholar, were chosen, and the searching time frame was set in five decades, from 1970 to 2020. The 384 selected studies were classified into categories depending on the aim of the study, the population target, the pathogenesis of MMVD (natural/induced), and the resulting CHF. Over the years, the types of studies have increased considerably in veterinary medicine. In particular, there have been 43 (24.29%) clinical trials, 41 (23.16%) randomized controlled trials, 10 (5.65%) cross-over trials, 40 (22.60%) reviews, 5 (2.82%) comparative studies, 17 (9.60%) case-control studies, 2 (1.13%) cohort studies, 2 (1.13%) experimental studies, 2 (1.13%) questionnaires, 6 (3.40%) case-reports, 7 (3.95%) retrospective studies, and 2 (1.13%) guidelines. The experimental studies on dogs with an induced form of the disease were less numerous (49–27.68%) than the studies on dogs affected by spontaneous MMVD (128–72.32%). The therapy of chronic CHF in dogs has considerably changed in the last fifty years: in the last century, some of the currently prescribed drugs did not exist yet, while others had different indications.

Aortic valve repair for the treatment of rheumatic aortic valve disease: a systematic review and meta-analysis

Valvuloplasty for rheumatic aortic valve disease remains controversial. We conducted this study to explore whether aortic valvuloplasty is appropriate for the rheumatic population. A comprehensive search was conducted, and 7 eligible retrospective studies were identified from PubMed, Embase, Medline and Cochrane (up to April 7, 2020) according to the inclusion and exclusion criteria. The data for hospital mortality, 5-year survival, 5-year reoperation, aortic insufficiency grade (AIG) and aortic valve gradient (AVG) were extracted by 2 independent reviewers and were analysed to evaluate the safety and availability of aortic valvuloplasty for rheumatic patients. The heterogeneity of the results was estimated using the Q test and I2 statistics. The fixed pooling model was used when I2 ≤ 50%; otherwise, the random pooling model was selected. 7 articles with 418 patients were included. The pooled hospital mortality, 5-year survival and 5-year reoperation rates were 3.2%, 94.5% and 9.9%, respectively. The heterogeneities of the weighted mean differences (WMD) values of the AIG and AVG between preoperation and postoperation were extremely high (I2 = 81.5%, p < 0.001 in AIG, I2 = 97.6%, p = 0.003 in AVG). Subgroup analysis suggested that the AIG and AVG were improved by 3.03 grades (I2 = 0%, p < 0.001) and 3.16 mmHg (I2 = 0%, p < 0.001) in the European group, respectively. In the Asian group, the AIG and AVG were improved by 2.57 grades (I2 = 0%, p < 0.001) and 34.39 mmHg (I2 = 0%, p < 0.001), respectively. Compared with the values at discharge, the AIG was increased by 0.15 grades (I2 = 0%, p = 0.031) and the AVG was still decreased by 2.07 mmHg (I2 = 0%, p = 0.031) at the time of follow up. Valvuloplasty is safe and effective to treat rheumatic aortic insufficiency and stenosis, and the duration of maintenance required to improve stenosis was longer than that of insufficiency.

Pathogenesis and Molecular Immune Mechanism of Calcified Aortic Valve Disease

Calcified aortic valve disease (CAVD) was previously regarded as a passive process associated with valve degeneration and calcium deposition. However, recent studies have shown that the occurrence of CAVD is an active process involving complex changes such as endothelial injury, chronic inflammation, matrix remodeling, and neovascularization. CAVD is the ectopic accumulation of calcium nodules on the surface of the aortic valve, which leads to aortic valve thickening, functional stenosis, and ultimately hemodynamic disorders. CAVD has become an important cause of death from cardiovascular disease. The discovery of therapeutic targets to delay or block the progression of CAVD and the clinical application of transcatheter aortic valve implantation (TAVI) provide new ideas for the prevention and treatment of CAVD. This article summarizes the pathogenesis of CAVD and provides insight into the future directions of CAVD diagnosis and treatment.

Myxomatous mitral valve disease in Miniature Schnauzers and Yorkshire Terriers: 134 cases (2007–2016)

OBJECTIVE To characterize features of myxomatous mitral valve disease (MMVD) in Miniature Schnauzers and Yorkshire Terriers. ANIMALS 69 Miniature Schnauzers and 65 Yorkshire Terriers, each with MMVD. PROCEDURES Medical record data for each dog were collected; the study period was January 2007 through December 2016. If available, radiographic data were evaluated, and a vertebral heart scale score was assigned for each dog. Statistical analysis was performed with Student t and Fisher exact tests. RESULTS Compared with Yorkshire Terriers, the prevalence of MMVD was significantly higher in Miniature Schnauzers and affected dogs were significantly younger at the time of diagnosis. Miniature Schnauzers were significantly more likely to have mitral valve prolapse and syncope, compared with Yorkshire Terriers. Yorkshire Terriers were significantly more likely to have coughing and have had previous or current treatment with cardiac medications, compared with Miniature Schnauzers. There was no statistical difference between breeds with regard to abnormally high vertebral heart scale scores or radiographic evidence of congestive heart failure. CONCLUSIONS AND CLINICAL RELEVANCE With regard to MMVD, features of the disease among Miniature Schnauzers and Yorkshire Terriers were similar, but there were also a few discernable differences between these 2 breeds and from historical findings for dogs with MMVD of other breeds. Clinical signs at the time of diagnosis differed between the 2 breeds, which may have reflected concurrent breed-specific conditions (sick sinus syndrome or airway disease [eg, tracheal collapse]). Future work should include prospective studies to provide additional information regarding the natural progression of MMVD in these dog breeds.