Pathogenic FBN1 Genetic Variation and Aortic Dissection in Patients With Marfan Syndrome.

BACKGROUND: Aortic risk has not been evaluated in patients with Marfan syndrome and documented pathogenic variants in the FBN1 gene. OBJECTIVES: This study sought to describe aortic risk in a population with Marfan syndrome with pathogenic variants in the FBN1 gene as a function of aortic root diameter. METHODS: Patients carrying an FBN1 pathogenic variant who visited our reference center at least twice were included, provided they had not undergone aortic surgery or had an aortic dissection before their first visit. Aortic events (aortic surgery or aortic dissection) and deaths were evaluated during the 2 years following each patient visit. The risk was calculated as the number of events divided by the number of years of follow-up. RESULTS: A total of 954 patients were included (54% women; mean age 23 years). During follow-up (9.1 years), 142 patients underwent prophylactic aortic root surgery, 5 experienced type A aortic dissection, and 12 died (noncardiovascular causes in 3, unknown etiology in 3, post-operative in 6). When aortic root diameter was <50 mm, risk for proven type A dissection (0.4 events/1,000 patient-years) and risk for possible aortic dissection (proven aortic dissection plus death of unknown cause, 0.7 events/1,000 patients-years) remained low in this population that was treated according to guidelines. Three type A aortic dissections occurred in this population during the 8,594 years of follow-up, including 1 in a patient with a tubular aortic diameter of 50 mm, but none in patients with a family history of aortic dissection. The risk for type B aortic dissection in the same population was 0.5 events/1,000 patient-years. CONCLUSIONS: In patients with FBN1 pathogenic variants who receive beta-blocker therapy and who limit strenuous exercise, aortic risk remains low when maximal aortic diameter is <50 mm. The risk of type B aortic dissection is close to the remaining risk of type A aortic dissection in this population, which underlines the global aortic risk.

Clinical Significance of Aortic Root Modification Associated With Bicuspid Aortic Valve in Marfan Syndrome.

BACKGROUND: Both bicuspid aortic valve (BAV) and Marfan syndrome have been associated with aortic dissection risk, but it is unknown whether the presence of BAV is associated with an increased aortic risk in patients with an FBN1 gene mutation. We evaluated aortic diameters, aortic valve function, and aortic shape in Marfan syndrome patients with and without BAV and reported aortic events during follow-up. METHODS: All patients with an FBN1 gene mutation evaluated in our clinic were included. Aortic root diameters were measured, and the aortic valve was studied using echocardiography at each visit. RESULTS: Of the 1437 patients with an FBN1 gene mutation, 26 patients (1.8%) had a BAV. Both aortic root maximal diameter and normalized Z score were larger at all ages, in patients with BAV when compared with patients with tricuspid aortic valve. Prophylactic aortic root surgery tended to be performed in younger patients when BAV was present, although aortic diameter threshold was similar in the 2 populations. No aortic dissection was observed in Marfan syndrome patients with BAV. CONCLUSIONS: In patients with a FBN1 mutation, BAV is associated with larger aortic root diameter, with no difference in evolution of Z score with age. We found a trend towards prophylactic aortic root surgery at younger ages but similar aortic diameter thresholds without occurrence of aortic dissection. We did not find any evidence for lowering aortic diameter thresholds used to propose preventive aortic root surgery in the presence of BAV in patients with FBN1 mutations.

Marfan Sartan: a randomized, double-blind, placebo-controlled trial.

AIMS: To evaluate the benefit of adding Losartan to baseline therapy in patients with Marfan syndrome (MFS). METHODS AND RESULTS: A double-blind, randomized, multi-centre, placebo-controlled, add on trial comparing Losartan (50 mg when <50 kg, 100 mg otherwise) vs. placebo in patients with MFS according to Ghent criteria, age >10 years old, and receiving standard therapy. 303 patients, mean age 29.9 years old, were randomized. The two groups were similar at baseline, 86% receiving ß-blocker therapy. The median follow-up was 3.5 years. The evolution of aortic diameter at the level of the sinuses of Valsalva was not modified by the adjunction of Losartan, with a mean increase in aortic diameter at the level of the sinuses of Valsalva of 0.44 mm/year (s.e. = 0.07) (-0.043 z/year, s.e. = 0.04) in patients receiving Losartan and 0.51 mm/year (s.e. = 0.06) (-0.01 z/year, s.e. = 0.03) in those receiving placebo (P = 0.36 for the comparison on slopes in millimeter per year and P = 0.69 for the comparison on slopes on z-scores). Patients receiving Losartan had a slight but significant decrease in systolic and diastolic blood pressure throughout the study (5 mmHg). During the study period, aortic surgery was performed in 28 patients (15 Losartan, 13 placebo), death occurred in 3 patients [0 Losartan, 3 placebo, sudden death (1) suicide (1) oesophagus cancer (1)]. CONCLUSION: Losartan was able to decrease blood pressure in patients with MFS but not to limit aortic dilatation during a 3-year period in patients >10 years old. ß-Blocker therapy alone should therefore remain the standard first line therapy in these patients.

Surgical management of patients with Marfan syndrome: evolution throughout the years.

AIM: To evaluate the evolution of surgical management in a large population of patients with Marfan syndrome. METHODS: This is a retrospective study of patients fulfilling the Ghent criteria for Marfan syndrome, who visited the Centre de référence national pour le syndrome de Marfan et apparentés and underwent a surgical event before or during follow-up in the centre. RESULTS: One thousand and ninety-seven patients with Marfan syndrome, according to international criteria, came to the clinic between 1996 and 2010. Aortic surgery was performed in 249 patients (22.7%; 20 children and 229 adults), including the Bentall procedure in 140 patients (56%) and valve-sparing surgery in 88 patients (35%); a supracoronary graft was performed in 19 patients (7.6%), usually for aortic dissection. During the past 20 years, the predominant reason for aortic surgery has switched from aortic dissection to aortic dilatation, while age at surgery has tended to increase (from 32.4 ± 11.9 years to 35.2 ± 12.4 years; P=0.075). Mitral valve surgery was performed in 61 patients (5.6%; six children and 55 adults), including 37 valvuloplasties (60.6%) and 18 mitral valve replacements (29.5%). No significant difference was observed when comparing mitral valve surgery before and after 2000. CONCLUSION: Surgery performed in patients with Marfan syndrome has switched from emergency surgery for aortic dissection to elective surgery for aortic dilatation; this is associated with surgery performed at an older age despite the indication for surgery having decreased from 60mm to 50mm. No significant evolution was observed for mitral valve surgery.

Aortic event rate in the Marfan population: a cohort study.

BACKGROUND: Optimal management, including timing of surgery, remains debated in Marfan syndrome because of a lack of data on aortic risk associated with this disease. METHODS AND RESULTS: We used our database to evaluate aortic risk associated with standardized care. Patients who fulfilled the international criteria, had not had previous aortic surgery or dissection, and came to our center at least twice were included. Aortic measurements were made with echocardiography (every 2 years); patients were given systematic ß-blockade and advice about sports activities. Prophylactic aortic surgery was proposed when the maximal aortic diameter reached 50 mm. Seven hundred thirty-two patients with Marfan syndrome were followed up for a mean of 6.6 years. Five deaths and 2 dissections of the ascending aorta occurred during follow-up. Event rate (death/aortic dissection) was 0.17%/y. Risk rose with increasing aortic diameter measured within 2 years of the event: from 0.09%/y per year (95% confidence interval, 0.00-0.20) when the aortic diameter was <40 mm to 0.3% (95% confidence interval, 0.00-0.71) with diameters of 45 to 49 mm and 1.33% (95% confidence interval, 0.00-3.93) with diameters of 50 to 54 mm. The risk increased 4 times at diameters ≥50 mm. The annual risk dropped below 0.05% when the aortic diameter was <50 mm after exclusion of a neonatal patient, a woman who became pregnant against our recommendation, and a 72-year-old woman with previous myocardial infarction. CONCLUSIONS: Risk of sudden death or aortic dissection remains low in patients with Marfan syndrome and aortic diameter between 45 and 49 mm. Aortic diameter of 50 mm appears to be a reasonable threshold for prophylactic surgery.

Dissection in Marfan syndrome: the importance of the descending aorta.

AIMS: To better characterize patients with Marfan syndrome who have survived an acute aortic dissection and to estimate the risks of events in the descending aorta. Up until now, this portion of the aorta has not been well studied but is gaining importance due to improved patient survival. METHODS AND RESULTS: We report a retrospective cohort of 100 Marfan patients who survived an aortic dissection. Dissection occurred in either the ascending aorta (AscAo) (n = 37), the descending aorta (DescAo) (n = 20), or both (As + DescAo, n = 43). During a mean follow-up of 9.8 ± 6.0 years (complete for 88% of the patients), 17 patients died and 52 had a clinical event (new aortic dissection, surgery, ischaemia, haemorrhage), 60% of which involved the descending aorta. Event-free survival was similar whatever the location of the aortic dissection. However, a better event-free survival was observed when no dissected portion of the aorta remained after surgery, which was the case in 62% (23/37) of the AscAo patients (30% incurred an event vs. 86%; P = 0.008 by log-rank test). Interestingly, the diameter of the ascending aorta was below the surgical threshold in 60% of the patients who incurred a dissection of the descending aorta, and within the normal range in 25%. CONCLUSION: The descending aorta may dissect whatever the diameter of the ascending aorta. The descending aorta is the location of most late clinical events after any dissection of the aorta. The rate of clinical events is much lower when all the dissected aorta has been removed in patients with AscAo dissection.

Nomograms for aortic root diameters in children using two-dimensional echocardiography.

The evaluation of aortic root dilation is of major importance for the diagnosis and follow-up of patients with diverse diseases, including the Marfan syndrome. However, we noted that the available nomograms suggested a lower aortic root dilation rate in adults (75%) than in children (90%), when the opposite would have been expected. To establish new nomograms, we selected a population of 353 normal children. We took transthoracic echocardiographic measurements of the aortic root diameters at the level of the aortic annulus, sinuses of Valsalva, sinotubular junction, and ascending aorta according to the American Society of Echocardiography recommendations. All diameters correlated well with the height, weight, body surface area, and age (r = 0.75 to 0.84, p <0.0001). Covariance analysis adjusting for body surface area showed slightly larger diameters at the level of the sinuses of Valsalva in male children than in female children (+1 mm, p = 0.0002). Equations and derived nomograms were developed, giving the upper limit of normal (allowing simple recognition of aortic dilation) and the Z score (allowing fine quantification of dilation and differentiation of normal growth from pathologic dilation) for all 4 aortic root diameters (ie, aortic annulus, sinuses of Valsalva, sinotubular junction, and proximal ascending aorta) according to body surface area and gender. We applied the nomograms to 282 children with confirmed Marfan syndrome, of whom 65.2% presented with dilation of the sinuses of Valsalva. In conclusion, we propose equations to calculate the upper limit of normal and Z-score for aortic root diameters measured by 2-dimensional echocardiography, which should be useful tools for the diagnosis and follow-up of aortic root aneurysms in children.

[Marfan syndrome]. / Syndrome de Marfan.

Marfan syndrome is a genetic illness, generally linked to an anomaly in fibrillin type 1, which is transmitted in an autosomally dominant fashion. Its diagnosis is sometimes difficult and should always be evoked in the face of a non-atheromatous aneurysm of the ascending aorta, lead to family screening in the search for aneurysms in any relatives, and an ophthalmological and rheumatological examination in the search for extracardiac signs. The diagnosis made, the dilatation of the aorta can be limited by proscribing violent sports and prescribing beta-blockers. The diameter of the ascending aorta should be measured with an annual ultrasound in order to propose a surgical replacement of the ascending aorta, before a complication (above all aortic dissection) arises.