Laura Gutiérrez

Efficacy of losartan vs. atenolol for the prevention of aortic dilation in Marfan syndrome: a randomized clinical trial

AIMS To determine the efficacy of losartan vs. atenolol in aortic dilation progression in Marfan syndrome (MFS) patients. METHODS AND RESULTS A phase IIIb, randomized, parallel, double-blind study was conducted in 140 MFS patients, age range: 5-60 years, with maximum aortic diameter <45 mm who received losartan (n = 70) or atenolol (n = 70). Doses were raised to a maximum of 1.4 mg/kg/day or 100 mg/day. The primary end-point was the change in aortic root and ascending aorta maximum diameter indexed by body surface area on magnetic resonance imaging after 36 months of treatment. No serious drug-related adverse effects were observed. Five patients presented aortic events during a follow-up (one in the losartan and four in the atenolol groups, P = 0.366). After 3 years of follow-up, aortic root diameter increased significantly in both groups: 1.1 mm (95% CI 0.6-1.6) in the losartan and 1.4 mm (95% CI 0.9-1.9) in the atenolol group, with aortic dilatation progression being similar in both groups: absolute difference between losartan and atenolol -0.3 mm (95% CI -1.1 to 0.4, P = 0.382) and indexed by BSA -0.5 mm/m2 (95% CI -1.2 to 0.1, P = 0.092). Similarly, no significant differences were found in indexed ascending aorta diameter changes between the losartan and atenolol groups: -0.3 mm/m2 (95% CI -0.8 to 0.3, P = 0.326). CONCLUSION Among patients with MFS, the use of losartan compared with atenolol did not result in significant differences in the progression of aortic root and ascending aorta diameters over 3 years of follow-up.

Aortic biomechanics by magnetic resonance: Early markers of aortic disease in Marfan syndrome regardless of aortic dilatation?

BACKGROUND Previous studies demonstrated the usefulness of MRI in the evaluation of aortic biomechanics in Marfan patients with aortic dilatation. However, these parameters have not been well studied in earlier stages of aortic disease. The present work aimed to study aortic biomechanics: aortic distensibility (AD) and pulse wave velocity (PWV), by MRI in Marfan patients without advanced aortic disease. METHODS Eighty consecutive Marfan patients were compared with 36 age- and sex-matched controls. MRI images at the level of ascending, descending and abdominal aorta were used to determine AD and PWV. RESULTS Marfan patients (27 men; age: 32.0 ± 10.5 years; mean aortic root diameter: 37.2 ± 4.6mm) had lower AD at all levels (ascending 2.6 ± 2.1 vs. 6.2 ± 3.7 mm Hg(-1)·10(-3), p<0.001; descending 3.1 ± 2.0 vs. 8.3 ± 4.2, p<0.001; and abdominal 4.5 ± 2.2 vs. 14.0 ± 5.2, p<0.001), higher aortic arch PWV (8.1 ± 6.5 vs. 4.3 ± 1.8m/s, p<0.01) and ascending-to-abdominal PWV (6.1 ± 3.0 vs. 4.7 ± 1.5m/s, p<0.01) compared with controls. Thirty-five Marfan patients had a non-dilated aortic root (mean aortic root diameter: 34.5 ± 3.8 mm). In multivariable analyses, after adjustment for age, pulse pressure and aortic dimensions, AD remained lower and PWV higher in Marfan patients; even Marfan patients with non-dilated aortic root showed impaired aortic biomechanics compared with controls. Z-score for ascending AD<-3.5 distinguished Marfan patients from controls with 82.5% sensitivity and 86.1% specificity. CONCLUSIONS Aortic biomechanics by MRI were abnormal in the entire aorta in Marfan patients. Moreover, Marfan patients without dilated aortic root showed clear impairment of aortic biomechanics, which suggests that they may be used as early markers of aortic involvement in these patients.

Valoración de la eficacia y la seguridad del losartán frente al atenolol en la prevención de la dilatación de la aorta en el síndrome de Marfan

INTRODUCTION AND OBJECTIVES Marfan syndrome is an inherited disease of the connective tissue. Recent trials have indicated the use of losartan (a transforming growth factor beta inhibitor) in these patients prevents aortic root enlargement. The aim of our clinical trial is to assess the efficacy and safety of losartan versus atenolol in the prevention of progressive dilation of the aorta in patients with Marfan syndrome. METHODS This is a phase III clinical trial conducted in two institutions. A total of 150 subjects diagnosed with Marfan syndrome, aged between 5 and 60 years, of both sexes, and who meet the Ghent diagnostic criteria will be included in the study, with 75 patients per treatment group. It will be a randomized, double blind trial with parallel assignment to atenolol versus losartan (50 mg per day in patients below 50 kg and 100 mg per day in patients over 50 kg). Both growth and distensibility of the aorta will be assessed with echocardiography and magnetic resonance. Follow-up will be 3 years. CONCLUSIONS Efficacy of losartan versus atenolol in the prevention of progressive dilation of the aorta, improved aortic distensibility, and prevention of adverse events (aortic dissection or rupture, cardiovascular surgery, or death) will be assessed in this study. It will also show the possible treatment benefits at different age ranges and with relation to the initial level of aortic root dilation.

Relationship between fibrillin-1 genotype and severity of cardiovascular involvement in Marfan syndrome

Background The effect of FBN1 mutation type on the severity of cardiovascular manifestations in patients with Marfan syndrome (MFS) has been reported with disparity results. Objectives This study aims to determine the impact of the FBN1 mutation type on aortic diameters, aortic dilation rates and on cardiovascular events (ie, aortic dissection and cardiovascular mortality). Methods MFS patients with a pathogenic FBN1 mutation followed at two specialised units were included. FBN1 mutations were classified as being dominant negative (DN; incorporation of non-mutated and mutated fibrillin-1 in the extracellular matrix) or having haploinsufficiency (HI; only incorporation of non-mutated fibrillin-1, thus a decreased amount of fibrillin-1 protein). Aortic diameters and the aortic dilation rate at the level of the aortic root, ascending aorta, arch, descending thoracic aorta and abdominal aorta by echocardiography and clinical endpoints comprising dissection and death were compared between HI and DN patients. Results Two hundred and ninety patients with MFS were included: 113 (39%) with an HI-FBN1 mutation and 177 (61%) with a DN-FBN1. At baseline, patients with HI-FBN1 had a larger aortic root diameter than patients with DN-FBN1 (HI: 39.3±7.2 mm vs DN: 37.3±6.8 mm, p=0.022), with no differences in age or body surface area. After a mean follow-up of 4.9±2.0 years, aortic root and ascending dilation rates were increased in patients with HI-FBN1 (HI: 0.57±0.8 vs DN: 0.28±0.5 mm/year, p=0.004 and HI: 0.59±0.9 vs DN: 0.30±0.7 mm/year, p=0.032, respectively). Furthermore, patients with HI-FBN1 tended to be at increased risk for the combined endpoint of dissection and death compared with patients with DN-FBN1 (HR: 3.3, 95% CI 1.0 to 11.4, p=0.060). Conclusions Patients with an HI mutation had a more severely affected aortic phenotype, with larger aortic root diameters and a more rapid dilation rate, and tended to have an increased risk of death and dissections compared with patients with a DN mutation.

Non-obstructive prosthetic heart valve thrombosis (NOPVT): Really a benign entity?

AIMS To assess the effectiveness of different treatment strategies in patients with non-obstructive prosthetic valve thrombosis (NOPVT) during hospitalization and long-term follow-up. METHODS NOPVT was diagnosed by transesophageal echocardiography. Resolution was defined as the disappearance or reduction of the thrombus under anticoagulation. All cases were first managed with optimization of anticoagulation. At discharge, patients received oral anticoagulation (OAC) alone or OAC and antiplatelet therapy (double treatment). Adverse events were defined as cardiovascular death, recurrence, thromboembolic events or major bleeding. RESULTS From 1997 to 2012, 47 patients (mean age: 65years; women: 60%) were diagnosed with NOPVT (mitral valve: 97%). Previous poor anticoagulation control was documented in 66% of patients. Twenty-one patients (45%) were treated with unfractionated heparin (UFH), especially those with thrombus size >10mm (19/21). Optimization of OAC was performed in the remaining patients. Treatment failed in 13 (27.6%) patients, mostly in those who received UFH (10/13), requiring surgery (53.8%) or fibrinolysis (30.7%). Forty-two patients survived and, at discharge, 44% of patients received OAC alone and 56% the double treatment. At follow-up (median 23months; range 0.03-116months), 59.5% of patients presented cardiovascular events, however no differences in outcome were observed with double treatment or OAC alone (p=0.385). CONCLUSIONS NOPVT is a high-risk complication, not only during hospitalization but also during follow-up. Optimization of anticoagulation is efficient in most patients except in thrombi ≥10mm treated with UFH. The double treatment does not prevent adverse events or complications during follow-up.

Implications of Asymmetry and Valvular Morphotype on Echocardiographic Measurements of the Aortic Root in Bicuspid Aortic Valve

Background: Transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI) have yielded excellent results in aortic root diameter measurement in patients with tricuspid aortic valve. However, accuracy in bicuspid aortic valve (BAV), often associated with aortic root asymmetry, is not fully defined. The aim of this study was to determine the agreement between TTE and MRI in proximal ascending aortic diameters in patients with BAVs. Methods: Seventy‐six consecutive patients with BAVs (mean age, 53 ± 15 years; 65% men) who underwent both TTE and MRI for ascending aortic assessment in a follow‐up protocol were included in the study. Maximum aortic root and ascending aortic diameters were compared. Results: For the whole population, TTE slightly underestimated aortic root diameter (difference, −0.8 ± 2.9 mm; P = .02). However, agreement was significantly better in BAV with fusion of the left and right coronary cusps than with fusion of the right coronary and noncoronary cusps, both with (type 1) and without (type 0) raphe (mean difference, 0.1 ± 2.5 vs −2.8 ± 2.8 mm, P < .001, respectively). In raphe BAV, mean absolute differences of maximum diameters between both techniques were significantly greater in asymmetric versus symmetric aortic roots (3.3 ± 2.2 vs 1.6 ± 1.9 mm, P = .002). BAV type and root asymmetry were independent related to measurement disagreement between both modalities. Conclusions: Although TTE is the technique of choice in the follow‐up of patients with BAVs, aortic root diameter measurements may be inaccurate in the presence of root asymmetry and in BAV with fusion of the right coronary and noncoronary cusps. In these cases, cross‐sectional imaging, with MRI or computed tomography, to confirm aortic diameters may be advisable. HIGHLIGHTSIn patients with BAVs, TTE slightly underestimated aortic root diameter.In BAV, aortic diameter differences by TTE and MRI are ≥3 mm in 39% of cases.Root asymmetry increases aortic root diameter differences between TTE and MRI in BAV.In BAV‐RN, underestimation of aortic root diameter may be significant.TTE‐PSAX helps in root asymmetry diagnosis but has low diameter reproducibility.

Left atrial strain: a new predictor of thrombotic risk and successful electrical cardioversion

Background Left atrial deformation (LAD) parameters are new markers of atrial structural remodelling that seem to be affected in atrial fibrillation (AF) and atrial flutter (AFL). This study aimed to determine whether LAD can identify patients with a higher risk of thrombosis and unsuccessful electrical cardioversion (ECV). Methods Retrospective study including 56 patients with AF or AFL undergoing ECV, with previous transthoracic (TTE) and transoesophageal echocardiography (TEE) studies. Echocardiographic parameters analysed were as follows: left ventricle function, left atrium (LA) dimensions, LAD parameters (positive and negative strain peaks), left atrial appendage (LAA) filling and emptying velocities and the presence of thrombi. Strain values were analysed according to thrombotic risk and success of ECV. Results Lower mean values of peak-positive strain (PPS) in patients with prothrombotic velocities (<25 cm/s) and a higher incidence of thrombi in LAA were observed compared with those with normal velocities. Multivariate analysis revealed PPS normalised by LA maximum volume indexed by body surface area (BSA) to be associated with prothrombotic risk (odds ratio 0.000 (95% CI: 0.000–0.243), P 0.017), regardless of CHADs2VASC score. Peak-negative strain normalised by LA volumes indexed by BSA were associated with unsuccessful ECV. Conclusions Atrial deformation parameters identify AF and AFL patients with a high risk of thrombosis and unsuccessful ECV. Therefore, these new parameters should be included in anticoagulation management and rhythm vs rate control strategies.

Papel de las técnicas de imagen en el TAVI. ¿La técnica utilizada influye en los resultados?

Resumen Las tecnicas de imagen tienen un papel fundamental para conseguir excelentes resultados en el implante de las protesis aorticas transcateter. La ecocardiografia transtoracica diagnostica la gravedad de la estenosis aortica y la presencia de valvulopatias asociadas, valora la morfologia y la funcion del ventriculo izquierdo y determina el diametro del anillo aortico. La tomografia computarizada permite definir mejor el tamano del anillo aortico, especialmente cuando es de morfologia ovoide, la calcificacion valvular, la distancia entre las coronarias y el anillo aortico y la idoneidad de la via para implantar la protesis. Tanto la ecocardiografia transesofagica como la fluoroscopia y la angiografia facilitan una correcta monitorizacion del procedimiento. La ecocardiografia transesofagica, especialmente si es 3D, no solo confirma el tamano del anillo aortico, sino que es fundamental para verificar la adecuada posicion de la protesis y el grado de regurgitacion residual y descartar posibles complicaciones durante el procedimiento.