The main pulmonary artery in adults: a controlled multicenter study with assessment of echocardiographic reference values, and the frequency of dilatation and aneurysm in Marfan syndrome

Abstract

BackgroundEchocardiographic upper normal limits of both main pulmonary artery (MPA) diameters (MPA-d) and ratio of MPA to aortic root diameter (MPA-r) are not defined in healthy adults. Accordingly, frequency of MPA dilatation based on echocardiography remains to be assessed in adults with Marfan syndrome (MFS).MethodsWe enrolled 123 normal adults (72 men, 52 women aged 42 ± 14 years) and 98 patients with MFS (42 men, 56 women aged 39 ± 14 years) in a retrospective cross-sectional observational controlled study in four tertiary care centers. We defined outcome measures including upper normal limits of MPA-d and MPA-r as 95 quantile of normal persons, MPA dilatation as diameters > upper normal limits, MPA aneurysm as diameters >4 cm, and indication for surgery as MPA diameters >6 cm.ResultsMPA diameters revealed normal distribution without correlation to age, sex, body weight, body height, body mass index and body surface area. The upper normal limit was 2.6 cm (95% confidence interval (CI) =2.44-2.76 cm) for MPA-d, and 1.05 (95% CI = .86–1.24) for MPA-r. MPA dilatation presented in 6 normal persons (4.9%) and in 68 MFS patients (69.4%; P < .001), MPA aneurysm presented only in MFS (15 patients; 15.3%; P < .001), and no patient required surgery. Mean MPA-r were increased in MFS (P < .001), but ratios >1.05 were equally frequent in 7 normal persons (5%) and in 8 MFS patients (10.5%; P = .161). MPA-r related to aortic root diameters (P = .042), reduced left ventricular ejection fraction (P = .006), and increased pulmonary artery systolic pressures (P = .040). No clinical manifestations of MFS and no FBN1 mutation characteristics related to MPA diameters.ConclusionsWe established 2.6 cm for MPA-d and 1.05 for MPA-r as upper normal limits. MFS exhibits a high prevalence of MPA dilatation and aneurysm. However, patients may require MPA surgery only in scarce circumstances, most likely because formation of marked MPA aneurysm may require LV dysfunction and increased PASP.

Reliability of non-contrast magnetic resonance angiography-derived aortic diameters in Marfan patients: comparison of inner vs. outer vessel wall measurements

“…Para-sagittal ECG-gated non-contrast MRA of the thoracic aorta with in a 28-year-old man with confirmed Marfan syndrome. Indicated measurement levels from proximal to distal: sinuses of Valsalva (1), sinotubular junction (2), ascending aorta (3), aortic arch (4) and descending aorta(5) …”

Potential Molecular Pathways Related to Pulmonary Artery Aneurysm Development: Lessons to Learn from the Aorta

“…Marfan syndrome: The dilatation of the pulmonary artery was a minor cardiovascular criteria for Marfan Syndrome diagnosis until the definition of the revised Ghent nosology, where it was not included [38,71]. However, up to a 74% of patients with Marfan Syndrome present a PA dilatation [72] and 15% a PAA [73], including PAA and PA dissection, which confirms that histological changes also affect the pulmonary vasculature [39,40].…”

Features of Marfan syndrome not listed in the Ghent nosology – the dark side of the disease

“…Dilatation of the main pulmonary artery, 'in the absence of valvular or peripheral pulmonic stenosis, before the age of 40 years' was a diagnostic criterion of Marfan syndrome in the first Ghent nosology, but it was removed from the list of diagnostic signs [44] in the revised nosology due to the lack of diagnostic specificity [16,29]. The prevalence of pulmonary artery dilatation ranges between 8% and 16% in children [20,45] and 37% and 74% in adults with Marfan syndrome [20,44,46]. In addition, the pulmonary valve was shown to exhibit echocardiographic signs of cusp prolapse in 6% children and in 4% adults with Marfan syndrome, as well as of mild pulmonary regurgitation in 11% children, and 6% adults with Marfan syndrome [47].…”

“…Therefore, surgeons tend to assume pulmonary root disease in Marfan syndrome that leads them to dissuade a Ross procedure in Marfan syndrome [48,49]. However, main pulmonary artery aneurysms >6 cm diameter as an isolated indication for elective surgery [44], or more than mild pulmonary regurgitation occurs only exceptionally in Marfan syndrome [20]. In conclusion, the pulmonary artery root may be affected by the same connective tissue defect as the aortic root in Marfan syndrome.…”