Natural History of Mitral Annular Calcification and Calcific Mitral Valve Disease.

BACKGROUND: The natural history of mitral annular calcification (MAC) and risk for developing calcific mitral valve disease (CMVD) have been poorly defined. The aim of this study was to evaluate the progression rate of MAC and of the development of CMVD. METHODS: Patients with MAC and paired echocardiograms ≥1 year apart between 2005 and 2019 were included. Progression rates from mild or moderate to severe MAC and to CMVD (defined as severe MAC and significant mitral stenosis and/or regurgitation) were assessed, along with potential association with sex. RESULTS: A total of 11,605 patients (mean age, 73 ± 10 years; 51% men) with MAC (78% mild, 17% moderate, 5% severe) were included and underwent follow-up echocardiography at 4.2 ± 2.7 years. Among patients with mild or moderate MAC, 33% presented with severe MAC at 10 years. The rate of severe MAC was higher in women than in men (41% vs 24% [P < .001]; hazard ratio, 1.3; P < .001) and in patients with moderate versus mild MAC (71% vs 22% [P < .001]; hazard ratio, 6.1; P < .001). At 10 years, 10% presented with CMVD (4%, 23%, and 60% in patients with mild, moderate, and severe MAC, respectively), which was predicted by female sex (15% vs 5%; P < .0001), even after adjustment for MAC severity (hazard ratio, 1.9; P < .001). CONCLUSION: In this large cohort of patients with MAC, progression to severe MAC was common and frequently resulted in CMVD. Female sex was associated with higher progression rates. MAC and CMVD are expected to dramatically increase as the population ages, highlighting the importance of a better understanding of the pathophysiology of MAC to develop effective preventive medical therapies.

Clinical implications of left atrial size adjustment: Impact of obesity.

BACKGROUND: American and European societies recommend using left atrial (LA) volume adjusted to body surface area (BSA) as the means of indexing LA volume to the patient's body size irrespective of morphometric characteristics. AIM: To evaluate the impact of obesity on LA volume indexation to BSA on the presence and degree of LA enlargement. METHODS: From our echocardiography database, we extracted all consecutive adults referred for a transthoracic echocardiography in 2019 (n=28,725; 64±17 years; 55% male; 31% obese [body mass index≥30kg/m2]). LA volume indexed to BSA was calculated using measured weight (LAMeas) and ideal weight (LAIdeal) calculated using the Devine Formula. RESULTS: LAMeas and LAIdeal were 35±17mL/m2 and 40±19mL/m2, respectively (P<0.0001); 13% were classified as having a normal LAMeas but LAIdeal enlargement overall, 25% in obese patients and 7% in non-obese patients (P<0.0001). The percentages of patients with no, mild, moderate and severe LA dilatation were 57%, 19%, 9% and 16%, respectively, using LAMeas, and 45%, 20%, 11% and 24%, respectively, using LAIdeal (kappa=0.57). Degree of LA enlargement differed in 8194 patients (29%); 96% of the disagreement was related to underestimation of the degree of LA enlargement using LAMeas. Agreement for the degree of LA enlargement was poor in obese and good in non-obese patients (kappa=0.28 and 0.71, respectively). As illustrative clinical implications, diastolic function grade was modified in 8.3% of patients with preserved ejection fraction and 10.8% of patients with reduced left ventricular ejection fraction/myocardial disease, and timing for intervention was potentially different in 12.9% of patients with primary mitral regurgitation. CONCLUSIONS: Indexing LA volume to measured BSA versus ideal BSA markedly underestimates the presence and severity of LA enlargement, especially in obese patients, with potential important clinical implications.

Alterations of pre- and postsynaptic noradrenergic signaling in a rat model of adriamycin-induced cardiotoxicity.

BACKGROUND: Altered sympathetic nervous system signaling is known to play a role in the cardiotoxicity of the anthracycline chemotherapeutic agents, but the interaction of pre- and postsynaptic function is not well understood. METHODS AND RESULTS: Our aim was to study the noradrenergic signaling in an established rat model of adriamycin cardiotoxicity (15 mg/kg administered i.p. over 2 weeks) using radiotracers having potential applicability for imaging with positron emission tomography (PET). Ex vivo biodistribution was performed 1 and 3 weeks post-adriamycin treatment with the noradrenaline analogue [(11)C]meta-hydroxyephedrine ([(11)C]HED), beta-adrenergic receptor antagonist [(3)H]CGP12177, and phosphodiesterase-4 inhibitor (R)-[(11)C]rolipram. Cardiac function (echocardiographic parameters) and heart/body weight ratio were not affected. Myocardial retention of [(11)C]HED, [(3)H]CGP12177, and (R)-[(11)C]rolipram were unchanged 1 week post-adriamycin. Compared to controls, 3 weeks post-treatment [(3)H]CGP12177 uptake decreased (left ventricle free wall and septum; P < 0.05), while [(11)C]HED and (R)-[(11)C]rolipram uptake were unaffected. Following acute increase in myocardial noradrenaline levels with desipramine treatment, (R)-[(11)C]rolipram retention increased in the left atrium, right ventricle, left ventricle free wall and septum (P < 0.05) in vehicle-, but not adriamycin-treated animals. CONCLUSION: Our results suggest that adriamycin-induced toxicity exhibits no change in presynaptic noradrenaline uptake, but decreased beta-adrenergic receptors in cardiac tissues, supporting a role for PET imaging of noradrenaline signaling in the study of anthracycline cardiotoxicity.