Semi-automatic quantification of aortic root progressive dilation by automatic co-registration of computed tomography angiograms: a preliminary comparison with manual assessment in Marfan patients

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Spanish Ministry of Science, Innovation and Universities Instituto de Salud Carlos III Background. Dilation of the aortic root is a key feature of Marfan syndrome and it is related to the occurrence of aortic events and death. On top of maximum diameter, rapid annual growth rate is suggested by guidelines for indication of aortic root replacement. Current gold-standard for aortic root diameter assessment is manual quantification on multiplanar reformatted 3D computed tomography (CT) or magnetic resonance angiogram. However, inter- and intra-observer reproducibility are limited and different measurement methods, i.e. cusp-to-cusp and cusp-to-commissure, may be used in different clinical centres, leading to difficulties in the clinical assessment of progressive dilation. Purpose. We aimed to test whether aortic root growth rate during follow-up can be reliably quantified by semi-automatic co-registration of two CT angiograms. Methods. Seven Marfan syndrome patients, free from previous aortic surgery, with a total of 11 pairs of CT were identified. Manual assessment of six aortic root diameters (right-non coronary -RN- , right-left -RL- and left-non coronary -LN- cusp-to-cusp and R, L and N cusp-to-commissure) was obtained from all CTs by an experienced researcher blind to semi-automatic results. The thoracic aorta and the outflow tract were semi-automatically segmented in the baseline CT and commissure and cusps were manually located. A 10 mm-thick region of interest containing the aortic wall was automatically generated from segmentation boundary. Co-registration was obtained with three, fully-automatic steps. Firstly, baseline and follow-up CT scans were aligned by means of a rigid registration. Then, scans were co-registered with multi-resolution affine followed by b-spline non-rigid registrations based on mutual information metric. The transformation pertaining to the location of baseline commissure and cusps points was used to locate the same points in the follow-up scan (Fig. 1 top). Results. Follow-up duration was 35 ± 22 (range 12-70.3) months. Automatic quantification of diameter growth during the follow-up was obtained in 62 out of 66 (94%) diameter comparisons. High Pearson correlation coefficients (R) and ICC were found between manual and semi-automatic assessment of growth rate, both for cusp-to-cusp and cusp-to-commissure diameters: R = 0.727 and ICC = 0.678 for RN; R = 0.822 and ICC = 0.602 for RL; R = 0.648 and ICC = 0.668 for LN; R = 0.726 and ICC = 0.711 for R; R = 0.911 and ICC = 0.895 for L and R = 0.553 and ICC = 0.482 for N. Scatter and Bland-Altman plots for all growth rates (Fig. 1) confirmed very good correlation (R = 0.810) but a slight tendency (R=-0.270) for underestimation at high growth rate. No correlation was found between follow-up duration and difference between techniques (R = 0.06). Conclusions. Semi-automatic quantification of aortic root growth rate by co-registration of pairs of CT angiograms is feasible for follow-up as short as one year. Larger studies are needed to confirm these preliminary data. Abstract Figure. CT measurements. Automatic vs manual.

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Influence of Aortic Stiffness on Aortic-Root Growth Rate and Outcome in Patients With the Marfan Syndrome

The American Journal of Cardiology ◽

10.1016/j.amjcard.2018.01.016 ◽

2018 ◽

Vol 121 (9) ◽

pp. 1094-1101 ◽

Cited By ~ 6

Author(s):

Elif Seda Selamet Tierney ◽

Jami C. Levine ◽

Lynn A. Sleeper ◽

Mary J. Roman ◽

Timothy J. Bradley ◽

...

Keyword(s):

Growth Rate ◽

Root Growth ◽

Marfan Syndrome ◽

Aortic Root ◽

Aortic Stiffness ◽

Root Growth Rate

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P1821Proximal aorta longitudinal but not circumferential strain predicts aortic events and aortic root dilation rate in marfan syndrome patients

European Heart Journal ◽

10.1093/eurheartj/ehz748.0573 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

A Guala ◽

G Teixido Tura ◽

J F Rodriguez-Palomares ◽

A Ruiz Munoz ◽

C Granato ◽

...

Keyword(s):

Growth Rate ◽

Marfan Syndrome ◽

Aortic Root ◽

Longitudinal Strain ◽

Circumferential Strain ◽

Aortic Diameter ◽

Diameter Growth ◽

Z Score ◽

Aortic Dissections

Abstract Background The most common cardiovascular complications in Marfan syndrome (MFS) are aortic root dilation and type A aortic dissections. Elective aortic root surgery is indicated when maximum aortic diameter is larger than a defined threshold or in the case of fast-progressing dilation. However, maximum aortic diameter is limited for the prediction of aortic events. Indeed, a large international registry of acute aortic syndromes reported that as much as 40% of aortic dissections happen with maximum aortic diameter lower than 50 mm. Consequently, there is a need for new, non-invasive biomarkers to improve the prediction of aortic complications. Purpose The aim of the present study was to assess if proximal aorta circumferential and longitudinal strain and ascending aorta distensibility were associated with progressive aortic dilation and incidence of aortic events in Marfan syndrome patients. Methods Eighty seven Marfan syndrome patients free from previous cardiac/aortic surgery or dissection, were prospectively included in a multicenter follow-up. Patients were diagnosed by original Ghent criteria. Proximal aorta longitudinal and circumferential strain and distensibility were computed from baseline cine CMR images by means of feature-tracking. The predictive capacity of each stiffness biomarkers was separately tested with multivariable linear regression analysis (aortic growth) and with Cox logistic regression analysis (aortic events), both corrected for clinical and demographic variables, including baseline maximum aortic diameter. Results During a follow-up of 81.6±17 months, mean diameter growth-rate was 0.65±0.67 mm/year and z-score growth rate was 0.07±0.13 / year. Elective aortic root replacement was performed in 11 patients while two patients presented type A aortic dissection.Baseline proximal aorta longitudinal strain was independently related to diameter growth-rate (p=0.001), z-score growth-rate (p=0.018) and aortic events (p=0.018). Conversely, neither circumferential strain nor distensibility were independent predictors of diameter growth-rate (p=0.385 and p=0.381, respectively), z-score growth-rate (p=0.515 and p=0.484, respectively) and aortic events (p=0.064 and p=0.205, respectively). Conclusions Proximal aorta longitudinal strain predicts aortic root dilation and major aortic events in Marfan syndrome patients beyond aortic root diameter and clinical and demographic characteristics. Acknowledgement/Funding ISCIII PI14/0106, La Maratό de TV3 (20151330) and CIBERCV. Guala A. FP7/People n° 267128

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445Effects of losartan and beta-blockers on aortic root dilatation in patients with Marfan Syndrome - results of the extended COMPARE trial

European Heart Journal ◽

10.1093/eurheartj/ehz747.0111 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

M M Van Andel ◽

J Jalalzadeh ◽

R Indrakusuma ◽

R Balm ◽

J Timmermans ◽

...

Keyword(s):

Root Growth ◽

Marfan Syndrome ◽

Aortic Root ◽

Favourable Effect ◽

Study Cohort ◽

Aortic Root Dilatation ◽

Dilatation Rate ◽

Β Blocker ◽

Β Blockers

Abstract Introduction Despite several randomized trials, beneficial effects of Losartan and β-blockers in adults with Marfan syndrome (MFS) are not entirely clear. The COMPARE trial previously showed a small but significant beneficial effect of Losartan on top of β-blocker use on aortic root dilatation rate. Yet, this effect was not reproduced by other trials, although in general a favourable effect of Losartan could be demonstrated. All trials in adults with MFS showed lower than expected aortic root dilatation rates, suggesting mildly affected study populations. Therefore we extended the follow-up period of the COMPARE trial up to 10 years and aimed to assess the clinical outcomes of the study cohort, as well as the effect of medication regimes on aortic root dilatation rates in the subgroup of patients with a native aortic root at initial randomization. Methods Patients previously enrolled in the COMPARE trial were retrospectively analyzed. Cardiovascular events (aortic dissections, ruptures and operations) and all-cause mortality were assessed. Individual aortic root dilatation rates were estimated in patients with a native aortic root at time of randomization on the basis of linear regression analysis of multiple transthoracic echocardiogram (TTE) results. Correlations between aortic root dilatation rates and cumulative Losartan or β-blocker treatment days were assessed with Spearman's rho (ρ). Results During a median follow-up of 8.0 years, two dissections and three deaths occurred in the 151 patients with a native aortic root at time of randomization. The 122 patients that were eligible for aortic root dilatation analysis, underwent a median of 6 TTEs. The median aortic root dilatation rate in these patients was 0.28 (interquartile range 0.09 - 0.59) mm/y. These patients were further classified as either patients with a stable aortic root (n=102) or with aortic root growth (n=20), based on the threshold of 0.9 mm per year. Patients with aortic root growth had significantly more aortic root replacements during follow-up (17/20 vs 18/102, P=0.001). Furthermore, aortic root dilatation rate was negatively correlated with the number of Losartan treatment days (ρ=−0.272, P=0.003), β-blocker treatment days (ρ=−0.217, P=0.017) and with the duration of follow-up (ρ=−0.437, P<0.001). Conclusions Our results support previous findings that Losartan and β-blockers appear to be equally effective on aortic root dilatation rate in Marfan Syndrome patients. The low event rate in the long term follow-up of this subgroup of the COMPARE trial represent a relatively mildly affected study population and an aggressive prophylactic surgical regime.

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Accurate and reproducible aortic growth rate mapping via registration of serial contrast-enhanced computed tomography angiograms

European Heart Journal ◽

10.1093/eurheartj/ehab724.0171 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

L Dux-Santoy ◽

J F Rodriguez Palomares ◽

G Teixido-Tura ◽

A Ruiz-Munoz ◽

G Casas ◽

...

Keyword(s):

Computed Tomography ◽

Growth Rate ◽

Image Registration ◽

Thoracic Aorta ◽

Growth Rates ◽

Aortic Root ◽

Clinical Management ◽

Current Standard ◽

Contrast Enhanced

Abstract Introduction Accurate assessment of aortic diameters and growth rates is key for clinical management of patients with aortic aneurysms [1]. Manual assessment on multiplanar reformatted views of computed tomography angiograms (CTA) is recommended [1], although its reproducibility in the assessment of growth rates has not been reported [2]. Image registration has been proposed to provide 3D maps of aortic diameters and growth [3], but its accuracy and reproducibility have not been established. Purpose To quantify accuracy and inter-observer reproducibility of aortic root and thoracic aorta diameters and growth rate by registration of serial CTAs compared to current standard. Methods Forty non-operated patients with ≥2 contrast-enhanced ECG-gated CTA acquired at least 6 months apart were included. Aortic diameters and growth rates were measured in the aortic root and thoracic aorta by two independent observers, both with the current standard and with the registration-based technique. To perform registration-based assessment, each observer semi-automatically segmented the aorta at baseline and located typical anatomical landmarks (Fig. 1A). Then, deformable image registration was used to map baseline and follow-up CT scans and deformation was applied to the baseline aortic surface points to obtain their location at follow-up (Fig. 1B). Finally, aortic root diameters and growth rate and 3D maps of thoracic aortic diameters and growth rate were automatically obtained (Fig. 1C). Agreement between techniques and their inter-observer reproducibility were calculated. Results Follow-up duration was 3.3±1.5 years (range 0.52–6.2). Compared with manual assessment, registration-based aortic diameters presented low bias and excellent agreement in the aortic root (0.42 mm, ICC=0.99) and the thoracic aorta (0.55 mm, ICC=0.99), and similar inter-observer reproducibility (ICC=0.99 for both). Compared with manual assessment, registration-based growth rates presented low bias and good agreement in the aortic root (0.12 mm/y, ICC=0.84) and the thoracic aorta (0.03 mm/y, ICC=0.77) (Fig. 2A), and much higher inter-observer reproducibility (ICC=0.96 vs 0.68 in the aortic root, ICC=0.96 vs 0.80 in the thoracic aorta) (Fig. 2B and C). Registration-based aortic growth rates reproducibility at 6 months follow-up was comparable to that obtained by manual assessment at 2.7 years (LoA = [−0.01, 0.33] and LoA = [−0.13, 0.21], respectively). Aortic diameters and growth rate 3D maps were highly reproducible (ICC>0.9) in the whole thoracic aorta. Conclusions Progressive aortic dilation assessment via registration of CTAs is accurate and more reproducible than the current standard even over follow-ups as short as 6 months, and further provides robust 3D mapping of aortic diameters and growth rates. Its application may provide new insights in aneurysms pathophysiology and improve the clinical management of these patients. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study has received funding from the Instituto de Salud Carlos III (PI17/00381). Guala A. has received funding from Spanish Ministry of Science, Innovation and Universities (IJC2018-037349-I). Figure 1. Methodology. Figure 2. Growth rate comparison.

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Determinants of aortic growth rate in patients with bicuspid aortic valve by cardiovascular magnetic resonance

Open Heart ◽

10.1136/openhrt-2019-001095 ◽

2019 ◽

Vol 6 (2) ◽

pp. e001095

Author(s):

Froso Sophocleous ◽

Bostjan Berlot ◽

Maria Victoria Ordonez ◽

Mai Baquedano ◽

Elena Giulia Milano ◽

...

Keyword(s):

Growth Rate ◽

Cardiovascular Magnetic Resonance ◽

Magnetic Resonance ◽

Aortic Valve ◽

Root Growth ◽

Bicuspid Aortic Valve ◽

Aortic Root ◽

Magnetic Resonance Data ◽

Valve Function ◽

Root Growth Rate

ObjectivesThis study aimed to identify determinants of aortic growth rate in bicuspid aortic valve (BAV) patients. We hypothesised that (1) BAV patients with repaired coarctation (CoA) exhibit decreased aortic growth rate, (2) moderate/severe re-coarctation (reCoA) results in increased growth rate, (3) patients with right non-coronary (RN) valve cusps fusion pattern exhibit increased aortic growth rate compared with right-left cusps fusion and type 0 valves.MethodsStarting from n=521 BAV patients with cardiovascular magnetic resonance data, we identified n=145 patients with at least two scans for aortic growth analysis. Indexed areas of the sinuses of Valsalva and ascending aorta (AAo) were calculated from cine images in end-systole and end-diastole. Patients were classified based on dilation phenotype, presence of CoA, aortic valve function and BAV morphotype. Comparisons between groups were performed. Linear regression was carried out to identify associations between risk factors and aortic growth rate.ResultsPatients (39±16 years of age, 68% male) had scans 3.7±1.8 years apart; 32 presented with AAo dilation, 18 with aortic root dilation and 32 were overall dilated. Patients with repaired CoA (n=61) showed decreased aortic root growth rate compared with patients without CoA (p≤0.03) regardless of sex or age. ReCoA, aortic stenosis, regurgitation and history of hypertension were not associated with growth rate. RN fusion pattern showed the highest aortic root growth rate and type 0 the smallest (0.30 vs 0.08 cm2/m*year, end-systole, p=0.03).ConclusionsPresence of CoA and cusp fusion morphotype were associated with changes in rate of root dilation in our BAV population.

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

European Heart Journal ◽

10.1093/eurheartj/ehz191 ◽

2019 ◽

Vol 40 (25) ◽

pp. 2047-2055 ◽

Cited By ~ 17

Author(s):

Andrea Guala ◽

Gisela Teixidó-Tura ◽

Jose Rodríguez-Palomares ◽

Aroa Ruiz-Muñoz ◽

Lydia Dux-Santoy ◽

...

Keyword(s):

Growth Rate ◽

Aortic Dissection ◽

Marfan Syndrome ◽

Aortic Root ◽

Longitudinal Strain ◽

Circumferential Strain ◽

Root Diameter ◽

Demographic Characteristics ◽

Dilation Rate

Abstract 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.

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Effect of statins on aortic root growth rate in patients with bicuspid aortic valve anatomy

The International Journal of Cardiovascular Imaging ◽

10.1007/s10554-015-0749-0 ◽

2015 ◽

Vol 31 (8) ◽

pp. 1583-1590 ◽

Cited By ~ 7

Author(s):

Madelien V. Regeer ◽

Philippe J. van Rosendael ◽

Vasileios Kamperidis ◽

Martin J. Schalij ◽

Jeroen J. Bax ◽

...

Keyword(s):

Growth Rate ◽

Aortic Valve ◽

Root Growth ◽

Bicuspid Aortic Valve ◽

Aortic Root ◽

Root Growth Rate

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Response of Bromus valdivianus (Pasture Brome) Growth and Physiology to Defoliation Frequency Based on Leaf Stage Development

Agronomy ◽

10.3390/agronomy11102058 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2058

Author(s):

Iván P. Ordóñez ◽

Ignacio F. López ◽

Peter D. Kemp ◽

Daniel J. Donaghy ◽

Yongmei Zhang ◽

...

Keyword(s):

Growth Rate ◽

Stomatal Conductance ◽

Root Growth ◽

Water Soluble ◽

Soluble Carbohydrates ◽

Leaf Stage ◽

Water Soluble Carbohydrates ◽

Stage Development ◽

Defoliation Frequency ◽

Root Growth Rate

The increase in drought events due to climate change have enhanced the relevance of species with greater tolerance or avoidance traits to water restriction periods, such as Bromus valdivianus Phil. (B. valdivianus). In southern Chile, B. valdivianus and Lolium perenne L. (L. perenne) coexist; however, the pasture defoliation criterion is based on the physiological growth and development of L. perenne. It is hypothesised that B. valdivianus needs a lower defoliation frequency than L. perenne to enhance its regrowth and energy reserves. Defoliation frequencies tested were based on B. valdivianus leaf stage 2 (LS-2), leaf stage 3 (LS-3), leaf stage 4 (LS-4) and leaf stage 5 (LS-5). The leaf stage development of Lolium perenne was monitored and contrasted with that of B. valdivianus. The study was conducted in a glasshouse and used a randomised complete block design. For Bromus valdivianus, the lamina length, photosynthetic rate, stomatal conductance, tiller number per plant, leaf area, leaf weights, root growth rate, water-soluble carbohydrates (WSCs) and starch were evaluated. Bromus valdivianus maintained six live leaves with three leaves growing simultaneously. When an individual tiller started developing its seventh leaf, senescence began for the second leaf (the first relevant leaf for photosynthesis). Plant herbage mass, the root growth rate and tiller growth were maximised at LS-4 onwards. The highest leaf elongation rate, evaluated through the slope of the lamina elongation curve of a fully expanded leaf, was verified at LS-4. The water-soluble carbohydrates (WSCs) increased at LS-5; however, no statistical differences were found in LS-4. The LS-3 and LS-2 treatments showed a detrimental effect on WSCs and regrowth. The leaf photosynthetic rate and stomatal conductance diminished while the leaf age increased. In conclusion, B. valdivianus is a ‘six-leaf’ species with leaf senescence beginning at LS-4.25. Defoliation at LS-4 and LS-5 was optimum for plant regrowth, maximising the aboveground plant parameters and total WSC accumulation. The LS-4 for B. valdivianus was equivalent to LS-3.5 for L. perenne. No differences related to tiller population in B. valdivianus were found in the different defoliation frequencies.

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Root Morphology of Eight Hybrid Oil Palms Under Iron (Fe) Toxicity

Ilmu Pertanian (Agricultural Science) ◽

10.22146/ipas.11254 ◽

2016 ◽

Vol 1 (1) ◽

pp. 013

Author(s):

Aprilia Ike Nurmalasari ◽

Eka Tarwaca Susila Putra ◽

Prapto Yudono

Keyword(s):

Growth Rate ◽

Root Growth ◽

Surface Area ◽

Root Morphology ◽

Block Design ◽

Dry Weight ◽

Root Volume ◽

Oil Palms ◽

Fe Toxicity ◽

Root Growth Rate

The research aims to study the change of morphology root characters of eight hybrid oil palms under iron toxicity (Fe). Field experiment done in arranged in a Randomized Complete Block Design (RCBD) two factors and three blocks as replications. The first factor was Fe concentration. It consists of two levels which are concentration 0µ.g-1 and concentration 600 µg.g-1 Fe. The second factor is the hybrid of oil palms which consists of eight hybrid oil palms as Yangambi, Avros, Langkat, PPKS 239, Simalungun, PPKS 718, PPKS 540 and Dumpy. Fe was applied by pouring FeSO4 solvent for 600 µg.g-1 500 ml.-1plant.-1day-1 on two months of plants after transplanting in the main nursery. Data were collected on root morphology and plant dry weight The data were analysis of variance (ANOVA) at 5% significanly, followed by Duncan's multiple range test (DMRT). The relationships by among variables were determined by correlation analysis. The results showed that Fe concentration 600 µg.g-1 inhibits relatively root growth rate, narrows surface area, reduces the diameter, and shrinks root volume of all hybrid oil palms tested. The slowing relatively root growth rate, narrowing of root surface area and root diameter also root volume shrinkage due to Fe stress. It was also shown that the dry weight of plants was inhibit by existing of Fe toxicity.

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