Proximal aorta longitudinal strain predicts aortic root dilation rate and aortic events in Marfan syndrome.

AIMS: Life expectancy in Marfan syndrome patients has improved thanks to the early detection of aortic dilation and prophylactic aortic root surgery. Current international clinical guidelines support the use of aortic root diameter as a predictor of complications. However, other imaging markers are needed to improve risk stratification. This study aim to ascertain whether proximal aorta longitudinal and circumferential strain and distensibility assessed by cardiac magnetic resonance (CMR) predict the aortic root dilation rate and aortic events in Marfan syndrome. METHODS AND RESULTS: One hundred and seventeen Marfan patients with no previous aortic dissection, cardiac/aortic surgery, or moderate/severe aortic regurgitation were prospectively included in a multicentre protocol of clinical and imaging follow-up. At baseline, CMR was performed and proximal aorta longitudinal strain and ascending aorta circumferential strain and distensibility were obtained. During follow-up (85.7 [75.0-93.2] months), the annual growth rate of aortic root diameter was 0.62 ± 0.65 mm/year. Fifteen patients underwent elective surgical aortic root replacement and four presented aortic dissection. Once corrected for baseline clinical and demographic characteristics and aortic root diameter, proximal aorta longitudinal strain, but not circumferential strain and distensibility, was an independent predictor of the aortic root diameter growth rate (P = 0.001, P = 0.823, and P = 0.997, respectively), z-score growth rate (P = 0.013, P = 0.672, and P = 0.680, respectively), and aortic events (P = 0.023, P = 0.096, and P = 0.237, respectively). CONCLUSION: Proximal aorta longitudinal strain is independently related to the aortic root dilation rate and aortic events in addition to aortic root diameter, clinical risk factors, and demographic characteristics in Marfan syndrome patients.

Increased rotational flow in the proximal aortic arch is associated with its dilation in bicuspid aortic valve disease.

AIMS: Aortic dilation in bicuspid aortic valve (BAV) might extend to the proximal arch. Arch flow dynamics and their relationship with this segment dilation are still unexplored. Using 4D-flow cardiovascular magnetic resonance, we analysed flow dynamics in the arch for each BAV morphotype and their association with this segment dilation. METHODS AND RESULTS: One hundred and eleven BAV patients (aortic diameters ≤55 mm, non-severe valvular disease), 21 age-matched tricuspid aortic valve (TAV) patients with dilated arch and 24 healthy volunteers (HV) underwent 4D-flow. BAV were classified per fusion morphotype: 75% right-left (RL-BAV), and per arch dilation: 57% dilated, mainly affecting the right-noncoronary (RN) BAV (86% dilated vs. 47% in RL-BAV). Peak velocity, jet angle, normalized displacement, in-plane rotational flow (IRF), wall shear stress, and systolic flow reversal ratio (SFRR) were calculated along the thoracic aorta. ANCOVA and multivariate linear regression analyses were used to identify correlates of arch dilation. BAV had higher rotational flow and eccentricity than TAV in the proximal arch. Dilated compared with non-dilated BAV had higher IRF being more pronounced in the RN-morphotype. RN-BAV, IRF, and SFRR were independently associated with arch dilation. Aortic stenosis and male sex were independently associated with arch dilation in RL-BAV. Flow parameters associated with dilation converged to the values found in HV in the distal arch. CONCLUSION: Increased rotational flow could explain dilation of the proximal arch in RN-BAV and in RL-BAV patients of male sex and with valvular stenosis. These patients may benefit from a closer follow-up with cardiac magnetic resonance or computed tomography.

The current role of echocardiography in acute aortic syndrome.

Acute aortic syndrome (AAS) comprises a range of interrelated conditions caused by disruption of the medial layer of the aortic wall, including aortic dissection, intramural haematoma and penetrating aortic ulcer. Since mortality from AAS is high, a prompt and accurate diagnosis using imaging techniques is paramount. Both transthoracic (TTE) and transoesophageal echocardiography (TEE) are useful in the diagnosis of AAS. TTE should be the first imaging technique to evaluate patients with thoracic pain in the emergency room. Should AAS be suspected, contrast administration is recommended when images are not definitive. TEE allows high-quality images in thoracic aorta. The main drawback of this technique is that it is semi-invasive and the presence of a blind area that limits visualisation of the distal ascending aorta near. TEE identifies the location and size of the entry tear, secondary communications, true lumen compression and the dynamic flow pattern of false lumen. Although computed tomography (CT) is the most used imaging technique in the diagnosis of AAS, echocardiography offers complementary information relevant for its management. The best imaging strategy for appropriately diagnosing and assessing AAS is to combine CT, mainly ECG-gated contrast-enhanced CT, and TTE. Currently, TEE tends to be carried out in the operating theatre immediately before surgical or endovascular therapy and in monitoring their results. The aims of this review are to establish the current role of echocardiography in the diagnosis and management of AAS based on its advantages and limitations.