Mitral Prolapse Research Articles

Metacognitive Beliefs and Mental Health in Patients with Symptomatic Mitral Valve Prolapse: A Letter to Editor

Metacognitive Beliefs and Mental Health in Patients with Symptomatic Mitral Valve Prolapse: A Letter to Editor

Clinical and prognostic significance of left ventricular dysfunction predictors in patients with ventricular ectopy and without structural heart disease

Aim. To determine the predictors of left ventricular dysfunction in patients with ventricular ectopic beats without structural heart disease.Material and Methods. We modeled ventricular ectopy in rats through early afterdepolarization (aconitine-induced arrhythmia) and delayed afterdepolarization (adrenaline arrhythmia). In addition, we modeled ventricular ectopy in rabbits and cats by delayed afterdepolarization (barium chloride-induced and strophanthin arrhythmias, respectively) and also modeled ventricular ectopy in dogs by re-entry hydrogen peroxide-induced arrhythmia. In addition to conventional electrocardiography parameters, we analyzed pre-ectopic interval, its variability, and the internal deviation index. Further, the study included 514 patients aged 16 to 34 years (mean 21.2 ± 0.2 years), and the number of premature ventricular contractions (PVCs) per day of observation ranged from 6,157 to 37,254 (mean 19,706 ± 656 PVCs). We registered the same parameters as in experimental arrhythmias but calculated them separately for mono- and polymorphic, left and right ventricular out-flow tract arrhythmias. The duration of follow-up of patients was up to 10 years. The endpoint was the detection or absence of cardiovascular and/or extracardiac pathology.Results. We recorded polymorphic PVCs and early monomorphic PVCs when modeling ventricular arrhythmias by the mechanism of delayed post-depolarization and early post-depolarization, respectively. Both early and late monomorphic PVCs were documented when inducing ventricular arrhythmias by re-entry. When modeling hydrogen peroxide-induced and strophanthin arrhythmias, we observed significantly higher values of PVC-QRS complex and ventricular arrhythmia internal deviation index in comparison with aconitine-induced arrhythmia. Favourable outcome was registered in 50.97% of patients, whilst coronary artery disease, arterial hypertension, and mitral valve prolapse were documented in 7.98%, 16.73% and 2.92% patients. The rest of the patients had gastrointestinal diseases. In patients with favourable outcome, the signs of monomorphic PVCs correlated with those revealed during the modeling of ventricular ectopy by early afterdepolarization (r = 0.92), whereas those signs of polymorphic PVCs correlated with those observed at barium chloride-induced delayed afterdepolarization (r = 0.94). In patients with CAD, signs of PVCs correlated with those registered during re-entry hydrogen peroxide-induced arrhythmia (r = 0.93), Finally, in patients with arterial hypertension and mitral valve prolapse signs of PVCs correlated with those documented at strophanthin-(r = 0.92) and adrenaline-induced delayed afterdepolarization (r = 0.89). In these patients, the values for both monomorphic and polymorphic PVCs, ventricular arrhythmia internal deviation index, duration of PVC-QRS complex and PVC-QRS/QRSaverage did not exceed 0.42 units, 149 ms and 1,44 units, respectively. The development of coronary artery disease and arterial hypertension well correlated with an increase in ventricular arrhythmia internal deviation index ≥ 0.56 units and QRS complex duration ≥ 157 ms. Mitral valve prolapse was associated with the duration of the QRS complex ≥ 159 ms of polymorphic PVCs.Conclusion. In patients with ventricular ectopy but without structural heart disease, an increase in the values of ventricular arrhythmia internal deviation index and the duration of PVC-QRS complex was ≥ 0.48 units and 149 ms, respectively, associated with the development of cardiovascular pathology. Development of coronary artery disease and hypertension correlated with ventricular arrhythmia internal deviation index ≥ 0.56 units, and QRS complex duration ≥ 157 ms in monomorphic and polymorphic PVCs, whereas development of mitral valve prolapse correlated QRS complex duration ≥ 159 ms in polymorphic PVCs.

Prognostic value of mitral valve prolapse and mild mitral regurgitation in competitive athletes

Mitral valve prolapse (MVP) and mild mitral regurgitation (MR) are ones of the most common structural changes of the heart and affect many young individuals, who aspire to partake in competitive sport or high intensity recreational exercise. These two conditions are associated with a different prognosis and possible omplications such as heart failure (HF), malignant arrhythmias and sudden cardiac death (SCD). Therefore it is essential to determine the risk factors predicting these complications and to define a follow-up algorithm. The objective is to present a literature review of consensus recommendations addressing criteria for eligibility and disqualification from organized competitive sports for the purpose of ensuring the health and safety of young athletes.

No impact of polymorphism in the phosphodiesterase 5A gene in Cavalier King Charles Spaniels on pimobendan-induced inhibition of platelet aggregation response.

A variant in the canine phosphodiesterase (PDE) 5A gene (PDE5A:E90K) is associated with decreased concentrations of circulating cyclic guanosine monophosphate (cGMP) and response to PDE5 inhibitor treatment. Pimobendan is a PDE inhibitor recommended for medical treatment of certain stages of myxomatous mitral valve disease (MMVD) in dogs. PDE5A:E90K polymorphism attenuates the inhibitory effect of pimobendan on in vitro platelet aggregation and increases basal platelet aggregation in Cavalier King Charles Spaniels (CKCS). Selected clinical variables (MMVD severity, sex, age, hematocrit, platelet count in platelet-rich plasma [PRP], and echocardiographic left ventricular fractional shortening [LV FS]) will not show an association with results. Fifty-two privately owned CKCS with no or preclinical MMVD. Using blood samples, we prospectively assessed PDE5A genotype using Sanger sequencing and adenosine diphosphate-induced platelet aggregation response (area under the curve [AUC], maximal aggregation [MaxA], and velocity [Vel]) with and without pimobendan using light transmission aggregometry. Dogs also underwent echocardiography. Pimobendan inhibited platelet function as measured by AUC, MaxA, and Vel at a concentration of 10 μM (P < .0001) and Vel at 0.03 μM (P < .001). PDE5A:E90K polymorphism did not influence the inhibitory effect of pimobendan or basal platelet aggregation response. The PDE5A:E90K polymorphism did not influence in vitro basal platelet aggregation response or the inhibitory effect of pimobendan on platelet aggregation in CKCS. Dogs with the PDE5A:E90K polymorphism did not appear to have altered platelet function or response to pimobendan treatment.

Development of an artificial intelligence-based method for the diagnosis of the severity of myxomatous mitral valve disease from canine chest radiographs.

An algorithm based on artificial intelligence (AI) was developed and tested to classify different stages of myxomatous mitral valve disease (MMVD) from canine thoracic radiographs. The radiographs were selected from the medical databases of two different institutions, considering dogs over 6 years of age that had undergone chest X-ray and echocardiographic examination. Only radiographs clearly showing the cardiac silhouette were considered. The convolutional neural network (CNN) was trained on both the right and left lateral and/or ventro-dorsal or dorso-ventral views. Each dog was classified according to the American College of Veterinary Internal Medicine (ACVIM) guidelines as stage B1, B2 or C + D. ResNet18 CNN was used as a classification network, and the results were evaluated using confusion matrices, receiver operating characteristic curves, and t-SNE and UMAP projections. The area under the curve (AUC) showed good heart-CNN performance in determining the MMVD stage from the lateral views with an AUC of 0.87, 0.77, and 0.88 for stages B1, B2, and C + D, respectively. The high accuracy of the algorithm in predicting the MMVD stage suggests that it could stand as a useful support tool in the interpretation of canine thoracic radiographs.

Mitral annular disjunction and Pickelhaube sign in children with mitral valve prolapse: A prospective cohort study

BackgroundMitral annular disjunction (MAD) and the Pickelhaube sign are identified as risk factors for malignant ventricular arrhythmias (VAs) and sudden cardiac death in adults with mitral valve prolapse (MVP); their prevalence and consequences in children have never been studied. ObjectivesTo determine the proportion of MAD in children with MVP, and its potential link with VAs. MethodsA cohort of 49 consecutive children (mean age 12.8±3.0 years; 33 females) with MVP and comprehensive clinical arrhythmia (24-hour monitoring) and Doppler echocardiographic characterization, including pulsed-wave tissue Doppler (PWTD) of the lateral mitral annulus, was identified. The relationship between clinical and echocardiographic data and presence of VAs was studied. ResultsMAD was common (n=25; 51%). Only five patients had significant VAs (Lown grade>2) characterized by polymorphic premature ventricular contractions or couplets. MAD was not associated with VAs on 24-hour Holter monitoring, but an association was found between VAs and spiked high-velocity midsystolic signal>16cm/s on PWTD (Pickelhaube sign) (P=0.004), myxomatous mitral valve (P=0.004) and left ventricular dilatation (P=0.01). T-wave inversion in inferolateral leads on electrocardiogram was more frequent in patients with versus without the Pickelhaube sign (P=0.03). No difference was found between patients with or without MAD regarding sex, history of palpitation, severity of mitral regurgitation, aortic root diameter and incidence of connective tissue disorders. Myocardial fibrosis was detected in two of three patients who underwent a complementary cardiac magnetic resonance examination. ConclusionsMAD is common in children with MVP; its presence was not associated with significant VAs on 24-hour Holter monitoring, but the Pickelhaube sign and presence of myxomatous mitral valve may help to detect patients prone to significant VAs. Myocardial fibrosis can be detected by cardiac magnetic resonance in children with significant VAs.

Isometric myography is a feasible method to identify and quantify endothelial dysfunction in dogs with myxomatous mitral valve disease.

To assess the feasibility of isometric myography in pet dogs with myxomatous mitral valve disease (MMVD) to determine its use in quantifying endothelial dysfunction. 9 dogs euthanized for medical reasons. Femoral, renal, and mesenteric arteries were collected postmortem and stored in physiological saline solution at 4 °C for myography. Mitral valves were scored for myxomatous degeneration (grades 1 to 4). Sections of arteries were mounted in wells, immersed in physiological saline solution perfused with 95% O2 and 5% CO2 at 37 °C, and stretched to an internal circumference (IC) that generated the maximal difference between active and passive wall tension (IC1). Normalization factors were calculated by dividing the IC1 by the IC at which the passive wall tension was 100 mm Hg (IC100). Vasoconstriction to phenylephrine and vasodilation to acetylcholine (endothelial dependent) and sodium nitroprusside (endothelial independent) were assessed by cumulative dose-response curves. Median MMVD grade was 3. Mean values of normalization factors were 1.00 ± 0.14 (renal, n = 15), 1.00 ± 0.10 (femoral, 8), and 1.05 ± 0.12 (mesenteric, 6). Responses to phenylephrine were similar between dogs (P = .14). Reduced responses to acetylcholine compared with sodium nitroprusside were identified in 15 arteries, suggesting endothelial dysfunction. Isometric myography of arteries from pet dogs is feasible and can identify loss of endothelial-dependent relaxation in dogs with MMVD postmortem. Its use in further research can lead to a better understanding of the pathophysiology mechanisms of this disease.

Investigation of red blood cell and platelet indices in adult dogs suffered from myxomatous mitral valve disease with and without pulmonary hypertension.

Pulmonary hypertension (PH) is a common complication of cardiopulmonary disease. In dogs, PH commonly occurs secondary to myxomatous mitral valve disease (MMVD). Red blood cell and platelet indices including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), mean platelet volume (MPV) and platelet distribution width (PDW), have previously been found to be indicators for predicting and prognosing PH in humans. Therefore, this study aimed to investigate whether these indices are associated with MMVD and/or PH in dogs. Two hundred and forty-six dogs were retrospectively recruited for the study and classified into 4 groups: normal (n = 49), MMVD (n =102), PH (n =17), MMVD+PH (n =78). A sub-analysis was performed in dogs with MMVD without evidence of PH according to stage B1 (n =20), stage B2 (n =15), stage C (n =67). The data are expressed as median (interquartile range). No significant differences (p < 0.05) were found in MCV, RDW and MPV among all groups (normal, MMVD, PH and MMVD+PH). However, decreases in MCH and MCHC were found in MMVD [22.40 (20.90-23.50) pg and 35.25 (33.08-36.90) g/dL], MMVD+PH [22.25 (20.85-23.98) pg and 35.65 (33.30-37.33) g/dL] and PH groups [21.20 (20.60-22.20) pg and 33.80 (32.75-35.70) g/dL] compared to the normal dogs [24.29 (23.55-24.90) pg and 38.20 (37.50-39.05) g/dL] (p < 0.001). Decreases in PDW were found in dogs in the MMVD+PH [15.10 (14.98-15.30) %] groups compared to dogs in the normal group [15.30 (15.10-15.50) %] (p = 0.004). Sub-analysis of MMVD dogs without PH showed a decrease in MCH in dogs with stage B2 MMVD [21.00 (20.50-22.90) pg] and stage C MMVD [22.40 (20.90-23.20) pg] compared to normal dogs [24.29 (23.55-24.90) pg] (p < 0.001). MCHC of dogs with stage B1 [36.55 (33.53-37.78) g/dL] (p = 0.004), B2 [32.90 (32.00-35.00) g/dL] (p < 0.001) and C MMVD [35.30 (33.30-36.80) g/dL] (p < 0.001) were lower than those of normal dogs [38.20 (37.50-39.05) g/dL]. PDW in the stage C MMVD group [15.10 (15.00-15.30) %] was reduced compared to the normal group [15.30 (15.10-15.50) %] (p = 0.042) and the stage B1 MMVD group [15.35 (15.23-15.68) %] (p = 0.002). MCH, MCHC and PDW were negatively correlated with the left atrial and left ventricular size. Decreases in MCH and MCHC are related to MMVD, precapillary PH and postcapillary PH while PDW are associated with MMVD severity but not with the presence of PH.

Use of serum osmolality to identify heart disease stage in dogs and relationship to mathematical chloride correction.

Heart failure-associated hypochloremia can be depletional from diuretics or dilutional from water retention. Serum osmolality reflects water balance but has not been evaluated in dogs with heart disease. To determine if serum osmolality is related to heart disease stage and amount of mathematical correction of serum chloride (Cl- ) concentrations in healthy dogs and dogs with myxomatous mitral valve degeneration (MMVD). Seventy-seven dogs (20 healthy, 25 Stage B MMVD, 32 Stage C/D MMVD). Serum Cl- concentrations were mathematically corrected. Osmolality was calculated (calOsm) and directly measured by freezing point depression (dmOsm) and compared by Bland-Altman analysis. Biochemical variables and osmolality were compared among healthy, Stage B, and Stage C/D dogs. Correlations were explored between osmolality and biochemical variables. Median and range are presented. P < .05 was considered significant. The calOsm was different among groups (P = .003), with Stage B (310 mOsm/kg; 306, 316) and C/D dogs (312 mOsm/kg; 308, 319) having higher calOsm than healthy dogs (305 mOsm/kg; 302, 308). Osmolality methods were moderately correlated (P < .0001, rs = .46) but with proportional bias and poor agreement. The amount of Cl- correction was negatively correlated with calOsm (P < .0001, rs = -.78) and dmOsm (P = .004, rs = -.33). Serum bicarbonate concentration was negatively correlated with Cl- (P < .0001, rs = -.67). Dogs with Stage B and Stage C/D heart disease had higher calOsm than healthy dogs. Osmolality was inversely related to the amount of Cl- correction, which supports its use in assessing relative body water content. Poor agreement between calOsm and dmOsm prevents methodological interchange.

Mitral Valve Prolapse in Obstructive Hypertrophic Cardiomyopathy

Obstructive hypertrophic cardiomyopathy (oHCM) and mitral valve (MV) prolapse (MVP) are the 2 conditions which could cause symptomatic heart failure and sudden cardiac death. The clinical characteristics and surgical outcomes of patients with oHCM and MVP have not been well reported. From April 2012 to February 2018, 84 patients with oHCM (28 patients with MVP and 56 gender- and age-matched patients without MVP) who underwent septal myectomy at our institution were enrolled in this study. Information on clinical characteristics and outcomes was obtained from electronic medical records and follow-up surveys. Compared with those without MVP, patients with MVP were more symptomatic (New York Heart Association class III to IV; 96% vs 77%), more often moderate-to-severe mitral regurgitation (86% vs 48%), atrial fibrillation (39% vs 11%) and higher incidence of nonsustained ventricular tachycardia (44% vs 15%). Twenty (71%) had MV repair and 8 (29%) had MV replacement. Compared with patients without MVP, those with MVP had a longer postoperative hospital stay (10.9 ± 6.4 vs 7.8 ± 2.8days). None of the 84 study patients died during hospital or follow-up. At the most recent echocardiographic evaluation, left ventricular outflow tract gradient significantly decreased from 69.7 ± 35.4millimeters of mercury to 7.3 ± 5.1millimeters of mercury and the degree of mitral valve regurgitation improved from grade 2.43 ± 0.69 to grade 0.5 ± 0.69. In conclusion, MVP occurs rarely in oHCM, and was related to atrial fibrillation, ventricular arrhythmia and mitral regurgitation. Mitral valve surgery in combination with myectomy is effective and safe for patients with oHCM and MVP, relieving substantially left ventricular outflow tract gradients and mitral regurgitation.

Radiographic lung congestion scores in dogs with acute congestive heart failure caused by myxomatous mitral valve disease.

In humans, lung congestion scores are predictive of recurrence of acute congestive heart failure (CHF) and are superior to cardiac biomarkers in predicting survival. The primary aim of this retrospective study was to determine if a modified lung congestion score (LCS) in dogs diagnosed with acute CHF because of myxomatous mitral valve disease was associated with time until recurrence or death. Complete medical records were available for a total of 94 dogs between 2010 and 2019, but only 35 dogs fulfilled the criteria for inclusion. This retrospective study used descriptive statistics to describe the cumulative and corrected LCS. Correlations were used to examine the association of the corrected LCS and time until recurrence or death, selected echocardiographic variables, and timing of furosemide administration. The mean LCS was 8.4 (SD 3.3) and corrected LCS was 0.48 (SD 0.19). The pattern was predominantly symmetric (40% of dogs) and focal (caudal) but more commonly right-sided when asymmetric (40% vs 20%). The median number of days after initial diagnosis of acute CHF to readmission and death was 150 days (range 4-572), and 266 days (range 5-965), respectively. No significant association between the dog's corrected LCS and number of days until readmission (r = .173, P = .42) nor survival (r = .109, P = .56) was found. There was a negative significant correlation (r = -.71, P < .001) between the time interval of furosemide administration and corrected LCS.

Arrhythmic Mitral Valve Prolapse: A Comprehensive Review.

Mitral valve prolapse (MVP) is a prevalent cardiac disorder that impacts approximately 2% to 3% of the overall population. While most patients experience a benign clinical course, there is evidence suggesting that a subgroup of MVP patients face an increased risk of sudden cardiac death (SCD). Although a conclusive causal link between MVP and SCD remains to be firmly established, various factors have been associated with arrhythmic mitral valve prolapse (AMVP). This study aims to provide a comprehensive review encompassing the historical background, epidemiology, pathology, clinical manifestations, electrocardiogram (ECG) findings, and treatment of AMVP patients. A key focus is on utilizing multimodal imaging techniques to accurately diagnose AMVP and to highlight the role of mitral annular disjunction (MAD) in AMVP.

Evaluation of antioxidant status and lipid peroxidation in dogs with myxomatous mitral valve degeneration stage B1.

Myxomatous mitral valve degeneration (MMVD) is the most common naturally occurring heart disease in dogs. There is a lack of data on antioxidant status and oxidative damage in dogs with MMVD stage B1 according to the American College of Veterinary Internal Medicine (ACVIM B1). The aim of this study was to investigate antioxidant status (plasma vitamin E, lipid-standardized vitamin E (LS-VitE), antioxidant capacity of lipid-(ACL) and water-soluble antioxidants, whole blood glutathione peroxidase and erythrocyte superoxide dismutase), and lipid peroxidation [malondialdehyde (MDA)] in dogs with MMVD ACVIM B1. Serum cholesterol and triglyceride concentrations were measured to calculate LS-VitE. Fourteen dogs with MMVD ACVIM B1 and 12 control dogs were included in the study. Dogs with MMVD had significantly higher vitamin E, ACL, MDA, and cholesterol concentrations and significantly higher LS-VitE values than control dogs. No significant correlations between MDA and antioxidant parameters were determined in either group. In conclusion, oxidative damage to lipids is already present and the antioxidant status is altered but not depleted in dogs with MMVD ACVIM B1. The antioxidant response to increased oxidative damage consists mainly of the activation of fat-soluble antioxidants. Further research is needed to evaluate the efficacy and targets of early antioxidant supplementation to prevent or ameliorate oxidative stress and mitigate disease progression in dogs with early-stage MMVD.

Prognostic Efficacy of Complete Blood Count Indices for Assessing the Presence and the Progression of Myxomatous Mitral Valve Disease in Dogs.

This study investigated the complete blood count (CBC) indices, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) in dogs with myxomatous mitral valve disease (MMVD) and analyzed their correlation with conventional biomarkers, as well as the effect of CBC indices on survival time in dogs with MMVD. Medical records of 75 healthy controls and 249 dogs with MMVD from March 2015 to October 2022 were analyzed. The NLR, MLR, and PLR were calculated by dividing the absolute counts of the CBC parameters. Dogs with MMVD had significantly higher NLR, MLR, and PLR than healthy dogs (all p < 0.0001), especially those in the symptomatic MMVD group with pulmonary edema (p < 0.0001, p = 0.0002, and p = 0.0387, respectively). The NLR and MLR were significantly correlated with N-terminal pro-B type natriuretic peptide levels (both p < 0.0001). The CBC indices showed potential as biomarkers for detecting the presence of MMVD (all p < 0.0001) and severity of MMVD (p < 0.0001, p < 0.0001, and p = 0.006, respectively) using receiver operating characteristic curve analysis. The negative effects of increased NLR, MLR, and PLR on survival were confirmed using Kaplan-Meier curve analysis. In conclusion, NLR, MLR, and PLR could be cost-effective and readily available potential diagnostic and prognostic biomarkers for MMVD in dogs.

Are children with mitral valve prolapse more anxious?

Mitral valve prolapse (MVP) is a common valvular disease in children. Symptoms in children with MVP are not explained by the severity of mitral regurgitation alone. Hence, we sought to correlate symptom status with the incidence of anxiety disorder in this population. Groups were as follows: (a) MVP; n = 115; mean age: 13.5 ± 3.06 years and (b) control; n = 53; mean age: 15.1 ± 13.2. The Screen for Child Anxiety-Related Emotional Disorders (SCAREDs) scale was filled by all participants. The SCARED scores of 25 and above determined a warning for anxiety disorders. The mean SCARED scale values of MVP and control groups were 29.2 ± 13.08 and 24.9 ± 14.17, respectively (P = 0.065). Although the SCARED scale score was higher among the MVP patients, no significant difference was found between the groups in terms of the mean SCARED score, or the number of participants with a score of 25 or more. While girls with MVP had higher anxiety scores compared to boys with the disorder, there was no difference with respect to SCARED scores in children with MVP and the general population when analyzed separately by gender. Moreover, the SCARED scale score was significantly higher in symptomatic MVP patients than in asymptomatic cases. Children with MVP did not have higher anxiety scores compared to those without the syndrome. However, MVP patients with higher anxiety scores may benefit from a psychiatric assessment since higher scores correlate with symptoms.

Genetic mechanisms underlying arrhythmogenic mitral valve prolapse: Current and future perspectives.

Mitral valve prolapse (MVP) is a heart valve disease that is often familial, affecting 2%-3% of the general population. MVP with or without mitral regurgitation can be associated with an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). Research on familial MVP has specifically focused on genetic factors, which may explain the heritable component of the disease estimated to be present in 20%-35%. Furthermore, the structural and electrophysiological substrates underlying SCD/ventricular arrhythmia risk in MVP have been studied postmortem and in the electrophysiology laboratory, respectively. Understanding how familial MVP and rhythm disorders are related may help patients with MVP by individualizing risk and working to develop effective management strategies. This contemporary, state-of-the-art, expert review focuses on genetic factors and familial components that underlie MVP and arrhythmia and encapsulates clinical, genetic, and electrophysiological issues that should be the objectives of future research.

Prevalence and consequences of mitral annular disjunction and Pickelhaude sign in children with mitral valve prolapse

Prevalence and consequences of mitral annular disjunction and Pickelhaude sign in children with mitral valve prolapse

Machine learning-based risk prediction model for canine myxomatous mitral valve disease using electronic health record data.

Myxomatous mitral valve disease (MMVD) is the most common cause of heart failure in dogs, and assessing the risk of heart failure in dogs with MMVD is often challenging. Machine learning applied to electronic health records (EHRs) is an effective tool for predicting prognosis in the medical field. This study aimed to develop machine learning-based heart failure risk prediction models for dogs with MMVD using a dataset of EHRs. A total of 143 dogs with MMVD between May 2018 and May 2022. Complete medical records were reviewed for all patients. Demographic data, radiographic measurements, echocardiographic values, and laboratory results were obtained from the clinical database. Four machine-learning algorithms (random forest, K-nearest neighbors, naïve Bayes, support vector machine) were used to develop risk prediction models. Model performance was represented by plotting the receiver operating characteristic (ROC) curve and calculating the area under the curve (AUC). The best-performing model was chosen for the feature-ranking process. The random forest model showed superior performance to the other models (AUC = 0.88), while the performance of the K-nearest neighbors model showed the lowest performance (AUC = 0.69). The top three models showed excellent performance (AUC ≥ 0.8). According to the random forest algorithm's feature ranking, echocardiographic and radiographic variables had the highest predictive values for heart failure, followed by packed cell volume (PCV) and respiratory rates. Among the electrolyte variables, chloride had the highest predictive value for heart failure. These machine-learning models will enable clinicians to support decision-making in estimating the prognosis of patients with MMVD.

224 Surgical Repair of Mitral Valve Prolapse: Hypertension and Other Determinants of Failure

Abstract Aim It has been postulated that hypertension is associated with an increased likelihood of repair failure in patients with mitral valve prolapse. This study aims to assess whether there is a significant association between hypertension and disease recurrence and need for reoperation. Method A retrospective observational cohort study was conducted at a single centre in the United Kingdom. Patients who underwent surgical repair for mitral valve prolapse were identified between January 2011 and December 2020, with follow-up data collected to December 2021. Patients were classified as hypertensive if they had a pre- operative clinic blood pressure of 140/90 mm Hg or above. Treatment failure was confirmed by the presence of moderate or worse regurgitation on post-operative echocardiography and/or need for reoperation. Multivariate logistic regression and Cox regression were used for statistical analysis. Results A total of 278 patients were identified who had pre-operative blood pressure data available, of those 144 were hypertensive. By the conclusion of the study period, treatment failure occurred in 11.5% of the study sample. No significant association was identified between the presence of hypertension and treatment failure, or time to treatment failure. Concomitant atrial ablation was, however, found to be protective against treatment failure (odds ratio, 6.1; 95% confidence interval, 1.2 to 32.8) and associated with longer time to treatment failure (hazard ratio, 6.3; 95% confidence interval, 1.6 to 25.1). Conclusions There is insufficient evidence to demonstrate that hypertension is associated with treatment failure or time to treatment failure for patients undergoing surgical repair for mitral valve prolapse.

Mitral valve aneurysms: echocardiographic characteristics, formation mechanisms, and patient outcomes.

The accurate etiology of mitral valve aneurysm (MVA) formation is not completely understood, and the most effective management approach for this condition remains controversial. We retrospectively analyzed 20 MVA patients who underwent either surgical interventions or conservative follow-ups at the Zhongnan Hospital of Wuhan University between 2017 and 2021. We examined their clinical, echocardiographic, and surgical records and tracked their long-term outcomes. Of the 20 patients, 12 were diagnosed with MVA using transthoracic echocardiography, seven required additional transesophageal echocardiography for a more definitive diagnosis, and one child was diagnosed during surgery. In all these patients, the MVAs were detected in the anterior mitral leaflet. We found that 15 patients (75%) were associated with infective endocarditis (IE), whereas the remaining patients were associated with bicuspid aortic valve and moderate aortic regurgitation (AR) and mild aortic stenosis (5%), congenital heart disease (5%), elderly calcified valvular disease (5%), mitral valve prolapse (5%), and unknown reasons (5%). Of the 17 patients who underwent hospital surgical interventions, two died due to severe cardiac events. The remaining 15 patients had successful surgeries and were followed up for an average of 13.0 ± 1.8 months. We observed an improvement in their New York Heart Association functional class and mitral regurgitation and AR degrees (P-value < 0.001). During follow-up, only one infant had an increased left ventricular end-diastolic diameter and left ventricular end-systolic diameter, whereas the remaining 14 patients had decreased values (P < 0.001). In addition, none of the three conservatively managed patients experienced disease progression during the 7-24 months of follow-up. We recommend using echocardiography as a highly sensitive method for MVA diagnosis. Although most cases are associated with IE or AR, certain cases still require further study to determine their causes. A prompt diagnosis of MVA in patients using echocardiography can aid in its timely management.