Retrospective study of the association between neutering status and changes secondary to degenerative mitral valve disease

Dissertação de Mestrado Integrado em Medicina VeterináriaMyxomatous mitral valve disease is the most common cardiovascular disease reported in dogs. Although many patients may remain asymptomatic, some of them progress to left-sided congestive heart failure and develop clinical signs. Little has yet been published regarding the possible influence of the neutering status on changes secondary to myxomatous mitral valve disease. This study aims to assess a possible correlation between neutering status and myxomatous mitral valve disease. A retrospective study was conducted and included all the cases diagnosed with myxomatous mitral valve disease, consulted at the Cardiology service of the University of Liverpool. To help assess the association between neutering status and cardiac remodelling, dogs were categorized into four groups: FE (female entire), FN (female neutered), ME (male entire) and MN (male neutered). Retrospective review of echocardiographic data, signalment, and underlying diseases were performed. Echocardiographic measurements were made through offline analysis. Echocardiographic measurements were then compared between groups. Five hundred and eighty-two dogs (n = 582) were included: female entire (n = 24), female neutered (n = 235), male entire (n = 115) and male neutered (n = 208). Left ventricular internal diameter at end diastole (LVIDd), left atrial dimension to the aortic root diameter (LA:Ao) and left atrium maximal dimension to the aortic root dimension (LAmax:Ao) were significantly different between ME and MN, with ME dogs presenting higher mean values for LVIDd and higher median LA:Ao and LAmax:Ao measurements. Left ventricular internal diameter at end systole (LVIDs) was not significantly different between ME and MN. There were no significant differences between FE and FN groups. This study shows that neutering status may influence the development of myxomatous mitral valve disease in male dogs and that entire male dogs could be at higher risk of developing cardiac remodelling secondary to myxomatous mitral valve disease. On the other hand, neutering status doesn’t seem to have an influence on disease progression in female dogs.RESUMO - Estudo retrospetivo da associação entre a esterilização e alterações secundárias à doença mixomatosa da válvula mitral - A doença mixomatosa da válvula mitral é a doença cardiovascular mais prevalente em cães. Apesar da maior parte dos pacientes permanecerem assintomáticos, alguns podem progredir para insuficiência cardíaca esquerda e desenvolver sinais clínicos. Até hoje, existem poucas publicações sobre o possível efeito que a esterilização possa ter no desenvolvimento da doença mixomatosa da válvula mitral. O objetivo deste estudo é avaliar se existe de facto uma relação entre a esterilização e a doença mixomatosa da válvula mitral. Foi realizado um estudo retrospetivo que incluiu todos os casos diagnosticados com doença mixomatosa da válvula mitral consultados no serviço de Cardiologia da Universidade de Liverpool. Para avaliar a relação entre a esterilização e a presença de remodelação cardíaca, os cães foram categorizados em quatro grupos: FE (fêmeas inteiras), FN (fêmeas esterilizadas), ME (machos inteiros) e MN (machos castrados). A história pregressa e os dados ecocardiográficos dos animais foram revistos retrospetivamente e as medidas ecocardiográficas foram obtidas por medição offline. Estas medições foram depois comparadas entre os diferentes grupos. Quinhentos e oitenta e dois cães (n = 582) foram incluídos: fêmeas inteiras (n = 24), fêmeas esterilizadas (n = 235), machos inteiros (n = 115) e machos castrados (n = 208). Nos resultados obtidos, o diâmetro interno do ventrículo esquerdo no final da diástole (LVIDd), o rácio átrio esquerdo-aorta (LA:Ao) e o rácio diâmetro máximo do átrio esquerdo-aorta (LAmax:Ao) foram estatisticamente significativos entre machos inteiros e machos castrados. Os machos inteiros apresentaram não só um LVIDd médio superior, como também uma mediana de LA:Ao e LAmax:Ao superior aos machos castrados. Ao mesmo tempo, o diâmetro interno do ventrículo esquerdo no final da sístole (LVIDs) não mostrou ser estatisticamente significativo entre machos inteiros e machos castrados e nenhum dos parâmetros ecocardiográficos anteriormente referidos revelou ser estatisticamente significativo entre fêmeas inteiras e fêmeas esterilizadas. Este estudo demonstra que a esterilização poderá influenciar o desenvolvimento da doença mixomatosa da válvula mitral e que os cães machos inteiros poderão apresentar um maior risco de desenvolver remodelação cardíaca secundária a esta doença. No entanto, a esterilização não aparenta influenciar a progressão desta doença em cadelas.N/

Risk factors for paravalvular leak after transcatheter aortic valve replacement

Objective. To assess risk factors for paravalvular leak (PVL) after transcatheter aortic valve implantation (TAVI) in a large single-center cohort, including measurement of aortic valve calcification using a reproducible method. Methods. We retrospectively analyzed preoperative contrast-enhanced multidetector computed tomography (MDCT) scans of patients who underwent TAVI in our center between 2009 and 2016. Calcium volume was calculated for each aortic cusp in the aortic valve (AV), left ventricular outflow tract (LVOT) and device-landing zone (DLZ). Results. Overall, 539 patients were included in the study (Edwards SapienXT, n=192; Edwards Sapien3, n=206; Medtronic CoreValve EvolutR, n=44; Symetis Acurate, n=97). Median calcium volume in the DLZ was 757 mm3, with no significant differences among the four prosthesis groups. None of the patients had severe PVL. The overall incidence of mild-to-moderate PVL was 15.8% (95% CI: 12.8-19.1%). On multivariate logistic regression, DLZ calcification (p=0.00006; OR for an increase of 100 mm3 1.08; 95% CI: 1.04-1.13) and use of the CoreValve (p=0.0028; OR 4.1; 95% CI: 1.6-10 with SapienXT as reference) prosthesis were found to be associated with ≥mild PVL. In contrast, degree of oversizing (p=0.002; OR 0.97; 95% CI: 0.95-0.99), and use of Sapien3 (p=0.00005; OR 0.23; 95% CI: 0.11-0.47 with SapienXT as reference) were associated with a lower incidence of ≥mild PVL. Conclusions. Aortic calcification volume in the DLZ is associated with residual PVL after TAVI. When taking calcification into account, the balloon-expandable prosthesis Sapien3 seems to be associated with a lower incidence of PVL

Remote Ischemic Preconditioning Neither Improves Survival nor Reduces Myocardial or Kidney Injury in Patients Undergoing Transcatheter Aortic Valve Implantation (TAVI)

BACKGROUND: Peri-interventional myocardial injury occurs frequently during transcatheter aortic valve implantation (TAVI). We assessed the effect of remote ischemic preconditioning (RIPC) on myocardial injury, acute kidney injury (AKIN) and 6-month mortality in patients undergoing TAVI. METHODS: We performed a prospective single-center controlled trial. Sixty-six patients treated with RIPC prior to TAVI were enrolled in the study and were matched to a control group by propensity-score. RIPC was applied to the upper extremity using a conventional tourniquet. Myocardial injury was assessed using high-sensitive troponin-T (hsTnT), and kidney injury was assessed using serum creatinine levels. Data were compared with the Wilcoxon-Rank and McNemar tests. Mortality was analysed with the log-rank test. RESULTS: TAVI led to a significant rise of hsTnT across all patients (p < 0.001). No significant inter-group difference in maximum troponin release or areas-under-the-curve was detected. Medtronic CoreValve and Edwards Sapien valves showed similar peri-interventional troponin kinetics and patients receiving neither valve did benefit from RIPC. AKIN occurred in one RIPC patient and four non-RIPC patients (p = 0.250). No significant difference in 6-month mortality was observed. No adverse events related to RIPC were recorded. CONCLUSION: Our data do not show a beneficial role of RIPC in TAVI patients for cardio- or renoprotection, or improved survival

Characterizing cardiac involvement in chronic kidney disease using CMR—a systematic review

Purpose of Review: The aim of the review was to identify and describe recent advances (over the last 3 years) in cardiac magnetic resonance (CMR) imaging in patients with chronic kidney disease (CKD). We conducted a literature review in line with current guidelines. Recent Findings: The authors identified 22 studies. Patients with CKD had left ventricular global and regional dysfunction and adverse remodeling. Stress testing with CMR revealed a reduced stress-response in CKD patients. Native T1 relaxation times (as a surrogate markers of fibrosis) are elevated in CKD patients, proportional to disease duration. Patients with CKD have reduced strain magnitudes and reduced aortic distensibility. Summary: CMR has diagnostic utility to identify and characterize cardiac involvement in this patient group. A number of papers have described novel findings over the last 3 years, suggesting that CMR has potential to become more widely used in studies in this patient group

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 218, April 1981

This bibliography lists 161 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1981

Improvement in Hemodynamic Responses to Metaboreflex Activation after One Year of Training in Spinal Cord Injured Humans

Spinal cord injured (SCI) individuals show an altered hemodynamic response to metaboreflex activation due to a reduced capacity to vasoconstrict the venous and arterial vessels below the level of the lesion. Exercise training was found to enhance circulating catecholamines and to improve cardiac preload and venous tone in response to exercise in SCI subjects. Therefore, training would result in enhanced diastolic function and capacity to vasoconstrict circulation. The aim of this study was to test the hypothesis that one year of training improves hemodynamic response to metaboreflex activation in these subjects. Nine SCI individuals were enrolled and underwent a metaboreflex activation test at the beginning of the study (T0) and after one year of training (T1). Hemodynamics were assessed by impedance cardiography and echocardiography at both T0 and T1. Results show that there was an increment in cardiac output response due to metaboreflex activity at T1 as compared to T0 (545.4 ± 683.9 mL · min(-1) versus 220.5 ± 745.4 mL · min(-1), P < 0.05). Moreover, ventricular filling rate response was higher at T1 than at T0. Similarly, end-diastolic volume response was increased after training. We concluded that a period of training can successfully improve hemodynamic response to muscle metaboreflex activation in SCI subjects

Thyroid hormone levels within reference range are associated with heart rate, cardiac structure, and function in middle-aged men and women

Background: Triiodothyronine (T3) has many effects on the heart, and marked changes in cardiac function and structure occur in patients with (subclinical) thyroid disease. We investigated whether between-subject variation in thyroid hormone levels within the euthyroid range is also associated with heart rate and echocardiographic heart function and structure. Methods: Subjects were selected from the Asklepios study (n=2524), a population-representative random sample of patients aged between 35 and 55 years, free from overt cardiovascular disease at baseline. Analyses were restricted to 2078 subjects (1013 women and 1065 men), not using antihypertensive or thyroid medication nor having antithyroperoxidase antibody levels above clinical cut-off or thyrotropin (TSH) levels outside the reference range. All subjects were phenotyped in-depth and underwent comprehensive echocardiography, including diastolic evaluation. Thyroid function parameters were determined by automated electrochemiluminescence. Results: Heart rate was robustly positively associated with (quartiles of) free T3 (FT3) and T3, both in subjects with TSH levels within reference (0.27-4.2 μU/L) and in narrow TSH range (0.5-2.5 μU/L; p<0.0001). FT3 and T3 were negatively associated with left ventricular (LV) end-diastolic volume but positively associated with relative wall thickness. Total T3 (TT3) was associated with enhanced ventricular contraction (as assessed by tissue Doppler imaging). Free thyroxine, FT3, and TT3 were positively associated with late ventricular filling, and TT3 was associated with early ventricular filling. Conclusion: We have demonstrated a strong positive association between thyroid hormone levels within the euthyroid range and heart rate, and more subtle effects on cardiac function and structure. More specifically, we suggest a smaller LV cavity size (with increased relative wall thickness), an enhanced atrial and ventricular contraction, and LV relaxation with higher circulating thyroid hormones. These results illustrate that variation in thyroid hormone levels, even within the reference range, exerts effects on the heart

Deep Learning in Cardiology

The medical field is creating large amount of data that physicians are unable to decipher and use efficiently. Moreover, rule-based expert systems are inefficient in solving complicated medical tasks or for creating insights using big data. Deep learning has emerged as a more accurate and effective technology in a wide range of medical problems such as diagnosis, prediction and intervention. Deep learning is a representation learning method that consists of layers that transform the data non-linearly, thus, revealing hierarchical relationships and structures. In this review we survey deep learning application papers that use structured data, signal and imaging modalities from cardiology. We discuss the advantages and limitations of applying deep learning in cardiology that also apply in medicine in general, while proposing certain directions as the most viable for clinical use.Comment: 27 pages, 2 figures, 10 table