Endogenous reference genes for gene expression studies on bicuspid aortic valve associated aortopathy in humans

Bicuspid aortic valve (BAV) disease is the most common congenital cardiac abnormality and predisposes patients to life-threatening aortic complications including aortic aneurysm. Quantitative real-time reverse transcription PCR (qRT-PCR) is one of the most commonly used methods to investigate underlying molecular mechanisms involved in aortopathy. The accuracy of the gene expression data is dependent on normalization by appropriate housekeeping (HK) genes, whose expression should remain constant regardless of aortic valve morphology, aortic diameter and other factors associated with aortopathy. Here, we identified an appropriate set of HK genes to be used as endogenous reference for quantifying gene expression in ascending aortic tissue using a spin column-based RNA extraction method. Ascending aortic biopsies were collected intra-operatively from patients undergoing aortic valve and/or ascending aortic surgery. These patients had BAV or tricuspid aortic valve (TAV), and the aortas were either dilated (?4.5cm) or undilated. The cohort had an even distribution of gender, valve disease and hypertension. The expression stability of 12 reference genes were investigated (ATP5B, ACTB, B2M, CYC1, EIF4A2, GAPDH, SDHA, RPL13A, TOP1, UBC, YWHAZ, and 18S) using geNorm software. The most stable HK genes were found to be GAPDH, UBC and ACTB. Both GAPDH and UBC demonstrated relative stability regardless of valve morphology, aortic diameter, gender and age. The expression of B2M and SDHA were found to be the least stable HK genes. We propose the use of GAPDH, UBC and ACTB as reference genes for gene expression studies of BAV aortopathy using ascending aortic tissue

Candidate plasma biomarkers for predicting ascending aortic aneurysm in bicuspid aortic valve disease.

BACKGROUND: Bicuspid aortic valve (BAV) disease is the most common congenital cardiac abnormality affecting 1-2% of the population and is associated with a significantly increased risk of ascending aortic aneurysm. However, predicting which patients will develop aneurysms remains a challenge. This pilot study aimed to identify candidate plasma biomarkers for monitoring ascending aortic diameter and predicting risk of future aneurysm in BAV patients. METHODS: Plasma samples were collected pre-operatively from BAV patients undergoing aortic valve surgery. Maximum ascending aortic diameter was measured on pre-operative transoesophageal echocardiography. Maximum diameter ≥ 45 mm was classified as aneurysmal. Sequential Window Acquisition of all THeoretical Mass Spectra (SWATH-MS), an advanced mass spectrometry technique, was used to identify and quantify all proteins within the samples. Protein abundance and aortic diameter were correlated using logistic regression. Levene's test was used to identify proteins demonstrating low abundance variability in the aneurysmal patients (consistent expression in disease), and high variability in the non-aneurysmal patients (differential expression between 'at risk' and not 'at risk' patients). RESULTS: Fifteen plasma samples were collected (seven non-aneurysmal and 8 aneurysmal BAV patients). The mean age of the patients was 55.5 years and the majority were female (10/15, 67%). Four proteins (haemoglobin subunits alpha, beta and delta and mannan-binding lectin serine protease) correlated significantly with maximal ascending aortic diameter (p < 0.05, r = 0.5-0.6). Five plasma proteins demonstrated significantly lower variability in the aneurysmal group and may indicate increased risk of aneurysm in non-aneurysmal patients (DNA-dependent protein kinase catalytic subunit, lumican, tetranectin, gelsolin and cartilage acidic protein 1). A further 7 proteins were identified only in the aneurysmal group (matrin-3, glucose-6-phosphate isomerase, coactosin-like protein, peptidyl-prolyl cis-trans isomerase A, golgin subfamily B member 1, myeloperoxidase and 2'-deoxynucleoside 5'-phosphate N-hydrolase 1). CONCLUSIONS: This study is the first to identify candidate plasma biomarkers for predicting aortic diameter and risk of future aneurysm in BAV patients. It provides valuable pilot data and proof of principle that could be used to design a large-scale prospective investigation. Ultimately, a more affordable 'off-the-shelf' follow-on blood assay could then be developed in place of SWATH-MS, for use in the healthcare setting

Mini-Stern Trial: A randomised trial comparing mini-sternotomy to full median sternotomy for aortic valve replacement

Objective Aortic valve replacement (AVR) can be performed either through full median sternotomy (FS) or upper mini-sternotomy (MS). The Mini-Stern trial aimed to establish whether MS leads to quicker postoperative recovery and shorter hospital stay after first-time isolated AVR. Methods This pragmatic, open-label, parallel RCT compared MS with FS for first-time isolated AVR in two UK NHS hospitals. Primary endpoints were duration of postoperative hospital stay and the time to fitness for discharge from hospital after AVR, analysed in the intent-to-treat population. Results In this RCT, 222 patients were recruited and randomised (118 MS, 104 FS). Compared to FS patients, MS patients had longer hospital stay (mean 9.5 vs. 8.6 days) and took longer to achieve fitness for discharge home (mean 8.5 vs. 7.5 days). Adjusting for valve type, sex and surgeon, hazard ratios (HR) from Cox models did not show a statistically significant effect of MS (relative to FS) on either hospital stay (HR 0.874, 95% CI 0.668-1.143, p-value 0.3246) or time to fitness for discharge (HR 0.907, 95% CI 0.688-1.197, p-value 0.4914). During mean follow up of 760 days (MS:745 and FS:777 days), 12 (10%) MS and 7 (7%) FS patients died (HR 1.871, 95% CI 0.723-4.844, p-value 0.1966). Average extra cost for MS was £1,714, during the first 12 months after AVR. Conclusions Compared to FS for AVR, MS did not result in shorter hospital stay, faster recovery or improved survival and was not cost-effective. MS approach is not superior to FS for performing AVR

Activation of cardiomyocyte apoptotic pathways in the transition to heart failure

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Aortic root remodeling in atheromatous aneurysms: The role of selected sinus repair

Abstract Objective: Atheromatous ascending aortic aneurysms (AAA) frequently present with aortic regurgitation (AR) from dilatation of the sinotubular junction (STJ) and extension of the pathological process into the root. Experience suggests that root dilatation begins in the noncoronary, then right coronary sinus. Rather than employ aortic root replacement or the David procedure, we have elected to replace the ascending aorta and remodel the STJ and involved sinuses. We studied the outcome after selective sinus replacement in 29 consecutive AAA patients between 1995 and 2001. Methods: There were nine male and 20 females. Age ranged from 47 to 79 years (mean 67.5). Seven had arch aneurysms and four coronary artery disease. Nineteen were NYHA III or IV. Grade of AR was IV in 20, III in five and II in four. The STJ was dilated .50% of annulus diameter in each case (5.3-10.0 cm, mean 6.4 cm). All valves had three cusps. All patients underwent ascending aortic replacement. Seven had arch replacement and four coronary artery bypass. Seven had replacement of both right and noncoronary sinuses with re-implantation of the right coronary ostium. Twelve had replacement of the non-coronary sinus alone whilst nine had right coronary sinus replacement. One with dextrocardia had left coronary sinus replacement with ostial re-implantation. The graft size was within 2 mm of annulus size except for two patients (24 mm 12, 26 mm 11, and 28 mm six). Post operative echocardiographic studies were performed. None of the patients received anticoagulation. Results: There were no hospital or late deaths and no thromboembolic or infective complications. Two patients had mild to moderate aortic regurgitation. These had a size 28 graft, which in retrospect was too large. Others had no significant regurgitation. Conclusions: The native aortic valve can be preserved in the majority of patients with AAA. Remodelling of the STJ and selective sinus replacement restores valve competence. Anticoagulation and prosthesis related complications are thereby avoided.

Candidate plasma biomarkers for predicting ascending aortic aneurysm in bicuspid aortic valve disease.

BACKGROUND: Bicuspid aortic valve (BAV) disease is the most common congenital cardiac abnormality affecting 1-2% of the population and is associated with a significantly increased risk of ascending aortic aneurysm. However, predicting which patients will develop aneurysms remains a challenge. This pilot study aimed to identify candidate plasma biomarkers for monitoring ascending aortic diameter and predicting risk of future aneurysm in BAV patients. METHODS: Plasma samples were collected pre-operatively from BAV patients undergoing aortic valve surgery. Maximum ascending aortic diameter was measured on pre-operative transoesophageal echocardiography. Maximum diameter ≥ 45 mm was classified as aneurysmal. Sequential Window Acquisition of all THeoretical Mass Spectra (SWATH-MS), an advanced mass spectrometry technique, was used to identify and quantify all proteins within the samples. Protein abundance and aortic diameter were correlated using logistic regression. Levene's test was used to identify proteins demonstrating low abundance variability in the aneurysmal patients (consistent expression in disease), and high variability in the non-aneurysmal patients (differential expression between 'at risk' and not 'at risk' patients). RESULTS: Fifteen plasma samples were collected (seven non-aneurysmal and 8 aneurysmal BAV patients). The mean age of the patients was 55.5 years and the majority were female (10/15, 67%). Four proteins (haemoglobin subunits alpha, beta and delta and mannan-binding lectin serine protease) correlated significantly with maximal ascending aortic diameter (p < 0.05, r = 0.5-0.6). Five plasma proteins demonstrated significantly lower variability in the aneurysmal group and may indicate increased risk of aneurysm in non-aneurysmal patients (DNA-dependent protein kinase catalytic subunit, lumican, tetranectin, gelsolin and cartilage acidic protein 1). A further 7 proteins were identified only in the aneurysmal group (matrin-3, glucose-6-phosphate isomerase, coactosin-like protein, peptidyl-prolyl cis-trans isomerase A, golgin subfamily B member 1, myeloperoxidase and 2'-deoxynucleoside 5'-phosphate N-hydrolase 1). CONCLUSIONS: This study is the first to identify candidate plasma biomarkers for predicting aortic diameter and risk of future aneurysm in BAV patients. It provides valuable pilot data and proof of principle that could be used to design a large-scale prospective investigation. Ultimately, a more affordable 'off-the-shelf' follow-on blood assay could then be developed in place of SWATH-MS, for use in the healthcare setting

Patient demographics.

<p>Patient demographics.</p