Negrotto, Sara

Introduction: Excised aortic valve weight (AVW) correlates with severity of AS. There is some debate about the true severity of AS in low gradient AS (LGAS) compared to high gradient AS (HGAS). We sought to compare patient characteristics and operatively excised AVW in patients with LGAS vs HGAS vs moderate AS. Methods: 916 patients with EF ≥50% undergoing surgical aortic valve replacement for AS between 2010-2012 were included. Clinical and echocardiographic characteristics of LGAS patients (AVA≤1cm 2 , MnG<40mmHg; N=68) were compared to HGAS patients (AVA≤1cm 2 , MnG≥40mmHg; N=745) and operatively excised AVW were compared to moderate AS (AVA>1cm 2 , MnG<40mmHg; N=102). Results: Compared to HGAS, LGAS patients were older (mean age 77 ± 10 vs 73 ± 10 years; p=0.001), often female (56% vs 38%; p=0.006), but without differences in diabetes (26% vs 29%; p=0.78), hyperlipidemia (85% vs 86%, p=0.86), coronary artery disease (49% vs 44%; p=0.53), or hypertension (81% vs 76%; p=0.38). LGAS patients predominantly had trileaflet aortic valves (91% vs 71%; p<0.001), smaller LVOT diameter (2.16 ± 0.15 vs 2.25 ± 0.20 cm; p=0.002), lower stroke volume index (42.1 ± 7.3 vs 49.0 ± 8.8 cc/m 2 ; p<0.001), lower systemic compliance (0.77 ± 0.30 vs 0.93 ± 0.33 ; p<0.001), but no difference in valvulo-arterial impedance (3.96 ± 0.76 vs. 3.84 ± 0.80, p=0.24) compared to HGAS. Excised AVW were lower in patients with LGAS vs HGAS (1.77 ± 0.76 vs 2.69 ± 1.26 g, p<0.001), but not different from moderate AS (1.77 ± 0.76 vs 2.04 ± 0.94 g; p=0.1). This relationship held true when AVW was indexed to body surface area. Three-year mortality post-valve replacement was significantly higher in LGAS compared to HGAS (22% vs 11%, p=0.02). Conclusions: LGAS occurs mostly in older female patients with trileaflet aortic valves. Excised AVW in LGAS is similar to moderate AS but lower than HGAS. However, systemic compliance is higher in LGAS vs HGAS contributing to increased afterload. Poorer outcomes after surgery in LGAS patients may be attributed to noncompliant vasculature which is not corrected with valve replacement and evaluation of patients with LGAS should include assessment of peripheral resistance.

Objective Spontaneous coronary artery dissection (SCAD) is an under-recognised but important cause of myocardial infarction and sudden cardiac death. We sought to determine the role of medical and molecular genetic screening for connective tissue disorders in patients with SCAD. Methods We performed a single-centre retrospective descriptive analysis of patients with spontaneous coronary artery disease who had undergone medical genetics evaluation 1984–2014 (n=116). The presence or absence of traits suggestive of heritable connective tissue disease was extracted. Genetic testing for connective tissue disorders and/or aortopathies, if performed, is also reported. Results Of the 116 patients (mean age 44.2 years, 94.8% women and 41.4% with non-coronary fibromuscular dysplasia (FMD)), 59 patients underwent genetic testing, of whom 3 (5.1%) received a diagnosis of connective tissue disorder: a 50-year-old man with Marfan syndrome; a 43-year-old woman with vascular Ehlers–Danlos syndrome and FMD; and a 45-year-old woman with vascular Ehlers–Danlos syndrome. An additional 12 patients (20.3%) had variants of unknown significance, none of which was thought to be a definite disease-causing mutation based on in silico analyses. Conclusions Only a minority of patients with SCAD who undergo genetic evaluation have a likely pathogenic mutation identified on gene panel testing. Even fewer exhibit clinical features of connective tissue disorder. These findings underscore the need for further studies to elucidate the molecular mechanisms of SCAD.