Bédard, Élisabeth

Abstract Aims This study aims to describe the prevalence of discordant mild/moderate aortic stenosis (AS) in a population-based study and to identify the mechanisms that lead to reduced stroke volume (SV) and discordant moderate AS. Methods and results Discordant high-gradient (HG)-mild AS, defined as AVA > 1.5 cm2 and mean pressure gradient (MG) of 20–40 mmHg, and discordant low-gradient (LG) moderate AS, defined as AVA 1.0–1.5 cm2 and MG < 20 mmHg, were assessed in 883 individuals from the DANCAVAS screening study with aortic valve calcification and 257 individuals form the PROGRESSA study excluding those with left ventricular (LV) ejection fraction < 50%. In the DANCAVAS cohort, 150 men had mild/moderate AS of which 34% had discordance between MG and AVA, representing 66% with moderate AS. Among 262 patients in the combined cohort, 39% had discordant LG-moderate AS and 6% discordant HG-mild AS. Compared with concordant mild and moderate AS, individuals with discordant LG-moderate AS were more likely to present with LV concentric remodelling geometry (26 vs. 33 vs. 45%, P < 0.001), increased valvulo-arterial impedance (3.3 ± 0.7 vs. 3.6 ± 0.5 vs. 4.1 ± 0.7 mmHg/mL/m2, P < 0.001), and reduced systemic arterial compliance (SAC) (0.74 ± 0.22 vs. 0.81 ± 0.22 vs. 0.64 ± 0.18 mL/m2/mmHg, P < 0.001). Factors associated with SV index were relative wall thickness, LV end-diastolic diameter index, SAC, and LV remodelling pattern. Conclusion Discordant moderate AS is common, accounting for two-thirds of patients with moderate AS in the general male population. Patients with discordant LG-moderate AS have predominantly a concentric remodelling pattern with reduced SV. Reduced SV index was associated with signs of reduced vascular compliance, suggesting that altered vascular properties drive differences in remodelling patterns and discordant moderate AS.

AbstractBicuspid aortic valve is the most prevalent cardiac valvular malformation. It is associated with a high rate of long‐term morbidity including development of calcific aortic valve disease, aortic regurgitation and concomitant thoracic aortic aneurysm and dissection. Recently, basic and translational studies have identified some key processes involved in the development of bicuspid aortic valve and its morbidity. The development of aortic valve disease and thoracic aortic aneurysm and dissection is the result of complex interactions between genotypes, environmental risk factors and specific haemodynamic conditions created by bicuspid aortic valve anatomy. Herein, we review the pathobiology of bicuspid aortic valve with a special emphasis on translational aspects of these basic findings. Important but unresolved problems in the pathology of bicuspid aortic valve and thoracic aortic aneurysm and dissection are discussed, along with the molecular processes involved.