Cardiovascular manifestations of Marfan's syndrome: improved evaluation by transoesophageal echocardiography

Volume Measurements in Aortic Root Assessment Using Two-Dimensional Echocardiography

BACKGROUND

Aortic dilatation is associated with the presence of aortic diseases. Current guidelines for assessing the aortic root (AoR) depend on linear measurements acquired by two-dimensional (2D) echocardiography. We considered that real-time three-dimensional echocardiography, which correlates better with AoR volume obtained by computed tomography, is widely unavailable, and therefore, there is a need to determine the AoR volume using 2D echocardiography.

METHODS

Fifty-one consecutive apparently healthy volunteers were recruited and subsequently divided into three age groups. Specified planes of acquisition and previously defined landmarks were identified, and phases of the cardiac cycle that allowed for measurement standardization were used. Volume was determined by the modified Simpson’s method.

RESULTS

Although the average diastolic and systolic volume measurements of the AoR dimensions were not significantly different across the three age groups in the study population, a highly significant difference was observed in the volume measurements between male and female normotensive persons, P < 0.01 in each case. AoR volume measurements were five times in the diseased compared with the normotensive individuals; however, linear measurements were only 1.5 times in size of the normal individuals. Both point and interval estimates of the volume measurements of AoR in adult normotensives in three age groups were presented as baseline information.

CONCLUSIONS

We hereby present a novel way to determine the AoR volume using 2D echocardiography and the normal reference range with respect to age and gender. We also established the relevance of our measurement by comparing the normal population with two isolated diseased aortas.

Aneurysms of the ascending aorta: diagnostic features and prognosis in patients with Marfan's syndrome versus hypertension

BACKGROUND

In Marfan's syndrome progressive dilation of the sinuses of Valsava, the supra-aortic ridge and the ascending aorta are well characterized abnormalities likely to set the stage for severe aortic sequelae accounting for 70% of lethal complications. However, the specific anatomical, clinical, and prognostic profiles of aortic pathology are less well characterized in the setting of patients with Marfan's syndrome symptomatic from aortic complications.

HYPOTHESIS

The study was designed to characterize the spectrum of anatomical, clinical, and prognostic profiles of thoracic aortic disease in symptomatic patients with Marfan's syndrome compared with patients with arterial hypertension. Noninvasive imaging techniques were used for comprehensive mapping of aortic pathology associated with Marfan's syndrome.

METHODS

Thirty-five consecutive patients with Marfan's syndrome (16 women, 19 men; mean age 35 +/- 12 years) were imaged by transthoracic (TTE; n = 26) and transesophageal echocardiography (TEE; n = 11), contrast enhanced computed tomography (XCT; n = 16), or magnetic resonance techniques (MRI; n = 14). Diagnostic results were compared with both intraoperative or angiographic findings and also with a group of 85 consecutive patients with aortic pathology associated with arterial hypertension.

RESULTS

Aortic pathology was more frequently confined to the ascending aorta (p < 0.05) and aortic regurgitation was more prevalent in Marfan's syndrome than in arterial hypertension (p < 0.05). In 23 cases (66%) of dissection and 12 cases (34%) of nondissecting aneurysms, no Marfan-specific aortic macropathology was identified when compared with arterial hypertension. Diagnostic results of TEE, XCT, and MRI were all excellent; however, in contrast to the transesophageal ultrasound approach, transthoracic ultrasound was not useful in the detection of aortic dissection and intramural hemorrhage. Both 30-day (100 vs. 70%; p < 0.05) and 5-year survival rates (91 vs. 57%; NS) were higher in patients with Marfan's syndrome than in those with arterial hypertension. Repeat surgery, however, was more frequently required in patients with Marfan's syndrome (25% vs. none in aortic aneurysm; p < 0.05).

CONCLUSIONS

There are no macropathologic findings of the aorta specific for Marfan's syndrome. In patients with Marfan's syndrome with an inherently high rate of aortic complications, serial noninvasive imaging should be encouraged, preferably utilizing TEE or MRI.

Recommendations for the management of patients after heart valve surgery

Approximately 50,000 valve replacement operations take place in Europe annually and almost as many valve repair procedures. Previous European guidelines on management of patients after valve surgery were last published in 1995 and were limited to recommendations about antithrombotic prophylaxis. American guidelines covering the broader topic of the investigation and treatment of patients with valve disease were published in 1998 but devoted relatively little space to post-surgical management. This document represents the consensus view of a committee drawn from three European Society of Cardiology (ESC) Working Groups (WG): the WG on Valvular Heart Disease, the WG on Thrombosis, and the WG on Rehabilitation and Exercise Physiology. In almost all areas of patient management after valve surgery, randomized trials and meta-analyses do not exist. Such randomized trials as do exist are very few in number, are narrowly focused with small numbers, have limited general applicability, and do not lend themselves to meta-analysis because of widely divergent methodologies and different patient characteristics. Recommendations are therefore almost entirely based on non-randomized studies and relevant basic science.

Aortic root asymmetry in marfan patients; evaluation by magnetic resonance imaging and comparison with standard echocardiography

BACKGROUND

Patients with Marfan syndrome may develop aortic root dissection despite only mild aortic root dilation as shown by standard echocardiography, which may be due to aortic root asymmetry. Purpose of the present study was to investigate aortic root asymmetry by magnetic resonance (MR) imaging in patients with Marfan syndrome and to compare these measurements with standardly performed echocardiography.

METHODS

Eighty-seven Marfan patients (mean age 31 +/- 8 years) underwent MR imaging. From this population, 15 patients (mean age 29 +/- 3 years) were selected in whom both echocardiography and MR imaging had been performed within 3 months. With echocardiography, the aortic root was measured according to the recommendations of the American Society of Echocardiography. With MR imaging, a short axis view of the aortic root was obtained to measure distances between the noncoronary, right coronary and left coronary cusps and the aortic root area. Correlations between aortic root area and diameters were assessed, and 95% confidence intervals (95% CIs) calculated.

RESULTS

No difference in the standardly measured noncoronary to right coronary cusp diameter between MR imaging and echocardiography was shown (42 +/- 6 mm). Largest aortic root diameter on the MR images was the right to left coronary cusp diameter (46 +/- 7 mm, p < 0.02). For a given noncoronary to right coronary cusp diameter, 95% confidence intervals revealed a variation of -20 to +20% in the aortic root area.

CONCLUSIONS

The majority of Marfan patients show asymmetric dilation of the aortic root by MR imaging. This phenomenon may go unnoticed when standard echocardiography is performed. The asymmetry of the aortic root might be of clinical importance in unexpected aortic root dissection.

Aortic root complications in Marfan's syndrome: identification of a lower risk group

OBJECTIVES

The purpose of this study was to examine clinical and echocardiographic predictors of outcome in a cohort of patients with Marfan's syndrome.

BACKGROUND

Serial echocardiographic measurements of aortic root dimensions are an important clinical method for monitoring patients with Marfan's syndrome. However, there are few data on the prognostic importance of echocardiographic variables for risk stratification and timing of aortic root replacement.

METHODS

In 89 consecutive patients with Marfan's syndrome (age range 1-54 years) clinical and serial echocardiographic data (n = 62) were evaluated as potential predictors of outcome (mean (range) follow up 4 (< 1-16) years). Aortic sinus diameter and an aortic ratio normalised for age and body surface area were examined using Kaplan-Meier life table and Cox regression analysis, with the end point defined as death or surgery for ascending aortic dissection and events defined as an end point or surgery for ascending aortic aneurysm.

RESULTS

Overall actuarial survival at two and five years was 96% and 92% and event free survival was 85% and 76%, respectively. There were five deaths due to aortic dissection, four patients survived surgery for ascending dissection, and nine underwent root replacement with a composite graft for ascending aneurysm. Those with aortic events were older (35 (12) v 25 (13) years, P = 0.007) and had greater initial aortic root dimensions (47 (14) v 33 (8) mm, P < 0.0001) and ratios (1.6 (0.5) v 1.3 (0.2), P < 0.0001). In the 62 patients with serial echocardiographic follow up, the rate of aortic root dilatation was more rapid in those with events (15 (17) v 0 (3)%/year, P < 0.0001). Utilising a Cox proportional hazards model, the groups with an initial aortic ratio > or = 1.3 or an annual change in aortic ratio > or = 5% had a relative risk of an aortic complication of 2.7 and 4.1, respectively (95% confidence limits 1.5 to 4.8 and 1.8 to 9.3). Only one of 31 patients with an initial aortic ratio of < 1.3 and a rate of change of < 5% had an event (five year event free survival 97%).

CONCLUSIONS

A low risk subgroup of patients with Marfan's syndrome can be identified as those with an aortic ratio < 1.3 and an annual change in aortic ratio of < 5%. These findings are helpful in optimising echocardiographic monitoring and risk stratification of patients with Marfan's syndrome.

Detection of abnormal aortic elastic properties in asymptomatic patients with Marfan syndrome by combined transoesophageal echocardiography and acoustic quantification

OBJECTIVE

To evaluate the potential value of transoesophageal echocardiography combined with automated border detection and acoustic quantification for the assessment of elastic properties of the thoracic aorta in patients with Marfan syndrome.

SUBJECTS

16 patients with Marfan syndrome and 12 age matched normal controls.

METHODS

Transoesophageal echocardiography was performed in all subjects. Minimum and maximum diameters of the descending thoracic aorta were obtained from M mode images and acoustic quantification was used for the on-line evaluation of cross sectional aortic area and peak positive area changes over time. Compliance, distensibility, and stiffness index were calculated using M mode data and non-invasively measured blood pressure and were compared with the indices derived from acoustic quantification.

RESULTS

Aortic dimensions normalised for body surface area were not statistically different between patients and normal controls, but there were significant differences for all elasticity indices except compliance. Marfan patients had a lower distensibility [4.2 (SD 1.8) v 5.8 (2.1) cm2/dyn, P < 0.05] and a higher stiffness index [9.7 (3.0) v 7.1 (1.8), P < 0.05]. The dynamic indices derived from the acoustic quantification were significantly smaller in Marfan patients [peak positive area change: 5.1 (1.0) v 7.7 (1.7) cm2/s; P < 0.001; and normalised peak positive area change: 2.5 (1.2) v 4.0 (0.8) cm2/s respectively, P < 0.001] and were suitable to discriminate between normal and abnormal elastic properties.

CONCLUSIONS

In Marfan syndrome elastic properties of the descending aorta are significantly different from normal controls, even in the absence of vessel dilatation. In addition to established static indices, indices derived from acoustic quantification reflect dynamic changes of the cross sectional area for the evaluation of regional vessel mechanics. The on-line assessment of peak positive area change allows differentiation from normal individuals and may be more accurate than standard M mode measurements.

Acute aortic dissection in a patient with Marfan's syndrome complicated by gestational hypertension

OBJECTIVE

To present a case of aortic dissection in a pregnant woman with Marfan's syndrome.

CLINICAL FEATURES

A 34-year-old woman with Marfan's syndrome developed gestational hypertension and Type III aortic dissection during the third trimester. The diagnosis was confirmed by computed tomography and aortography.

OUTCOME

Although the dissection progressed, the woman was treated successfully. Elective caesarean section was performed. At follow-up the dissection had healed.

CONCLUSION

Marfan's syndrome introduces a high risk of aortic dissection during pregnancy and the treatment chosen is crucial. As dilatation of the aorta is progressive, patients with Marfan's syndrome should be followed up closely and offered prophylactic surgery if necessary.

Elective replacement of the aortic root in Marfan's syndrome

We offer elective aortic replacement ot those we regard as being at high risk. The aortic root dimension and its rate of increase are the best predictors we have. We regard 5.5 cm as the probable upper limit and we are inclined to advocate surgery at an earlier stage in high risk families and in women planning pregnancy. These operations are planned for a calculated gain in life expectancy and it would be reasonable for there to be a degree of centralisation of referral and development of surgical expertise. We use beta-blockade for life, both before and after surgery, in all patients with Marfan's syndrome with aortic root enlargement. The data on which these recommendations are based are incomplete and we can only hope that with an increasing number of carefully documented cases we will refine them and improve upon them in the future. The concept of a "forme fruste" or a "Marfanoid aorta" in the absence of the syndrome is highly questionable so the comments made apply only to patients with Marfan's syndrome--not to other forms of annuloaortic ectasia or other less well characterised forms of aortic root disease.