Factors related to aortic regurgitation in the presence of a dilated aortic root

Specific circulating microRNA signature of bicuspid aortic valve disease

BACKGROUND

We aimed to determine the circulating miRNA expression profile associated with BAV and aortic dilation to provide diagnostic and prognostic biomarkers for BAV and/or aortic dilation.

METHODS AND RESULTS

We applied a miRNome-wide microarray approach using plasma samples (n = 24) from healthy tricuspid aortic valve individuals, BAV patients and BAV patients with aortic dilation to compare and identify the specific miRNAs associated with BAV and aortic dilation. In a second stage, the expression patterns of the miRNA candidates were validated by RT-qPCR in an independent cohort (n = 43). The miRNA microarray data and RT-qPCR analyses revealed that the expression levels of circulating miR-122, miR-130a and miR-486 are significantly influenced by the morphology of the aortic valve (bicuspid/tricuspid) and could be functionally involved in the regulation of TGF-β₁ signalling. Furthermore, the expression pattern of miR-718 in the plasma was strongly influenced by dilation of the ascending aorta. miR-718 expression was inversely correlated with the aortic diameter (R = -0.63, p = 3.1 × 10^-5) and was an independent predictor of aortic dilation (β = -0.41, p = 0.022). The genes targeted by miR-718 are involved in the regulation of vascular remodelling.

CONCLUSIONS

We propose that miR-122, miR-130a, miR-486 and miR-718 are new molecular features associated with BAV and aortic dilation principally by the activation of TGF-β₁ pathway and vascular remodelling mediated by VEGF signalling pathways.

Higher neutrophil to lymphocyte ratio is related to a lower ejectionfraction in bicuspid aortic valve patients

BACKGROUND/AIM

Inflammation plays an important role in the pathophysiology of vascular disease. In this study, we aimed to evaluate the associations of neutrophil to lymphocyte ratio (NLR; an indicator of inflammation) with left ventricular ejection fraction and ascending aorta diameter in patients with a bicuspid aortic valve (BAV).

MATERIALS AND METHODS

One hundred and thirty-nine consecutive patients with the diagnosis of BAV were enrolled in the study. Complete blood counts were analyzed for neutrophil and lymphocyte levels and NLR. The subjects were separated into two groups based on their ascending aorta diameter. The patients with ascending aorta diameter equal to or above 3.9 cm were included in group 1 whereas those with ascending aorta diameter below 3.9 cm were included in group 2.

RESULTS

When the results were compared, it was demonstrated that there was a positive correlation between NLR and ascending aorta diameter (r: 0.485, P = 0.026), whereas there was a negative correlation between NLR and left ventricular end-diastolic diameter (r: 0.475, P = 0.030), left ventricular end-systolic diameter (r: 0.482, P = 0.027), and left ventricular ejection fraction (r: -0.467, P = 0.033) in BAV patients with ascending aorta dilatation (group 1).

CONCLUSION

NLR is associated with ascending aorta diameter and left ventricular ejection fraction in BAV patients with ascending aorta dilatation.

Circulating endothelial microparticles are elevated in bicuspid aortic valve disease and related to aortic dilation

BACKGROUND/OBJECTIVES

The mechanisms underlying aortic dilation in bicuspid aortic valve (BAV) disease are unknown. Circulating endothelial microparticles (EMPs) have emerged as biomarkers of endothelial damage. We sought to evaluate the relationships among EMPs, BAV disease, and aortic dilation.

METHODS

Four evaluations were used. Circulating EMPs (PECAM(+), E-selectin(+)) were compared between BAV patients and tricuspid aortic valve (TAV) control subjects. The variables related to circulating EMPs were investigated in BAV patients. Circulating EMP levels were compared between BAV and TAV patients with a dilated aorta. Finally, circulating EMPs in BAV patients were evaluated over time with respect to aortic valve surgery (AVS) or aortic surgery.

RESULTS

We observed higher levels of circulating PECAM(+) EMPs in the BAV patients than in the control subjects (3.98±0.2 vs. 2.39±0.4 per log PECAM(+) EMPs/μl, p=0.001). Aortic dilation was the most significant variable that correlated with the PECAM(+) EMP levels in the BAV patients (β=0.321, p=0.008). The BAV patients with aortic dilation exhibited higher PECAM(+)EMP levels than the TAV patients with dilated aortas, and this correlation was independent of aortic valve function. We observed a drastic decrease in the circulating PECAM(+) EMPs following AVS and aortic root replacement (4.27±0.6 and 1.75±0.3 per log PECAM(+)EMPs/μl, p=0.002).

CONCLUSION

The observed pattern of higher circulating PECAM(+) EMP levels links BAV disease to endothelial damage and aortic dilation. Circulating PECAM(+) EMPs were identified as a biological variable related to aortic dilation in patients with BAV disease.

LDL cholesterol and apolipoprotein B are associated with ascending aorta dilatation in bicuspid aortic valve patients

BACKGROUND

The factors related to ascending aorta dilation (AAD) in patients with bicuspid aortic valve (BAV) are not completely understood. In addition, the role of cholesterol metabolism in AAD has not been studied.

METHODS

We analyzed the relationship between different lipid parameters and the ascending aorta diameter/presence of aortic dilatation in 91 consecutive patients with BAV.

RESULTS

We observed a positive linear correlation between the total cholesterol, low-density lipoprotein (LDL) cholesterol and apolipoprotein B (ApoB) levels and the ascending aorta diameter. The patients with AAD had higher LDL cholesterol and ApoB levels. Whereas LDL cholesterol and ApoB were identified as independent factors predictors of the aortic root diameter, only ApoB predicted the diameter of the ascending aorta. On the other hand, the levels of ApoB were an independent factor related to the dilatation of the aortic root.

CONCLUSIONS

We have observed that cholesterol is associated with ascending aorta diameter and dilation in BAV patients. Further experimental and clinical studies are needed to explain the pathobiology of this association.

Giant Proximal Aorta Aneurysm: A Successfully Managed Time Bomb

Management of aortic aneurismatic disease is often care of specialists, from vascular to cardiac surgeons. However, initial diagnosis and management are not unfrequently responsibility of an emergency staff as the disease presentation may be dramatically acute. Thoracic aortic aneurysms (TAA) in particular have a silent clinical history until they become evident with dissection or rupture with a high global mortality rate. The importance of a rapid diagnosis and of correct management in such a subsetting is clear, but recent guidelines where published with the declared rationale of emphasizing the importance of an early detection of the disease. The goal is to reduce morbidity and mortality and improvement of quality of life of such patients. We present a case of successfully managed asymptomatic giant proximal aortic aneurysm in a healthy young man. On a routine transthoracic echocardiogram, severe dilatation of the proximal aorta was detected, with severe aortic regurgitation in a normal tricuspid valve determining left ventricle (LV) dilatation and impaired contractility. Computed tomography scan was scheduled, confirming the findings and open heart surgery performed within 1 week. Clinical and echocardiographical follow-up was started; after 2 months imaging studies showed good surgical results with well-functioning, non-regurgitant prosthetic aortic valve and initial recovery of left ventricular dilatation; at the last control, 14 months later, LV mass and dimensions where markedly improved, with no more signs of hypertrophy nor dilatation. TAA needs a rapid diagnosis and appropriate management. Clinicians should be aware of proper diagnostic tools and of applicable therapeutic strategies in order to grant the better assistance to the patient. In this setting, the role of echocardiography remains pivotal.

Factors related to the need for surgery after the diagnosis of bicuspid aortic valve: one center´s experience under a conservative approach

BACKGROUND AND AIM

Bicuspid aortic valve (BAV) increases the risk of aortic valve dysfunction and ascending aorta aneurysm and, consequently, the need for aortic valve replacement and/or aortic repair. However, there is no universal consensus about the surgical criteria and the predictors for surgery. The aim of this study was to investigate related factors to the need for surgery in the setting of a strict long-term follow-up with relatively conservative surgical criteria.

METHODS

We prospectively followed 120 patients after the diagnosis of BAV. Predisposing factors for a future need for aortic valve replacement and ascending aorta repair were assessed. Aortic surgery was indicated when the ascending aorta diameter was ≥ 55 mm and was recommended based on patient characteristics and in the presence of a severe aortic valve dysfunction with an aortic diameter ≥ 50 mm.

RESULTS

During follow-up (mean, 86 months), 34 patients (28%) (mean age, 56 ± 12 years) were surgically treated. Aortic valve dysfunction (n=22; 64%) and ascending aorta dilatation (n=12; 36%) were the indications for surgery. Aortic regurgitation was the most frequent valve dysfunction at the time of diagnosis for BAV, but aortic stenosis was the most frequent indication for surgery. The presence at surgery of either aortic regurgitation or stenosis was clearly related to age, with regurgitation predominating in patients under 55 years, and aortic stenosis in older patients.Multivariate Cox analysis showed that aortic stenosis (hazard ratio 4.1, p=0.001), indexed ascending aorta dilatation (hazard ratio 3.0, p=0.03) and left ventricular end-diastolic diameter ≥ 60 mm (hazard ratio=4.0, p=0.01) at diagnosis were factors associated with future surgery. Aortic dissection was not observed in patients that did not undergo surgery.

CONCLUSIONS

A relatively conservative approach for the indication of ascending aortic surgery in BAV is safe. In this setting, the presence of aortic or left ventricle dilatation and aortic stenosis at diagnosis of BAV were predictive of the need for surgery in the follow-up.