Long-term Clinical and Echocardiographic Outcomes in Young and Middle-aged Adults Undergoing the Ross Procedure

Importance

There is no ideal valve substitute for young adults requiring aortic valve replacement. Multicenter data supporting use of the Ross procedure with respect to long-term postoperative valve-related mortality and reintervention, as well as function of the autograft and pulmonary homograft, are needed.

Objective

To determine the long-term clinical and echocardiographic outcomes in young and middle-aged patients undergoing the Ross procedure.

Design, Setting, and Participants

A retrospective multicenter international cohort study with a median follow-up period of 9.2 years was conducted in 5 experienced centers regularly performing the Ross procedure. Consecutive patients aged 18 to 65 years were included by each center between 1991 and 2018.

Main Outcomes and Measures

Survival and autograft-related and homograft-related reintervention. Serial echocardiographic measurements of valve function were analyzed using mixed-effects modeling.

Results

During the study period, 1431 patients (74.3% men; n = 1063) were operated on at a median age of 48.5 years (mean [SD], 47.7 [9.5]; range, 18.1-65; interquartile range, 42.7-54.0). Implantation techniques were root inclusion in 355 (24.9%), root replacement in 485 (34.0%), and subcoronary implantation in 587 (41.1%). Right ventricular outflow tract reconstruction was performed with homografts in 98.6% (n = 1189) and bioprostheses in 1.4% (n = 17). Ten patients (0.7%) died before discharge. Median follow-up was 9.2 years (13 015 total patient-years). Survival after 10 and 15 years was 95.1% (95% CI, 93.8%-96.5%) and 88.5% (95% CI, 85.9%-91.1%), respectively. Freedom from autograft and homograft reintervention after 15 years was 92.0% and 97.2%, respectively. Late events were autograft endocarditis in 14 patients (0.11% per patient-year), homograft endocarditis in 11 patients (0.08% per patient-year), and stroke in 37 patients (0.3% per patient-year).

Conclusions and Relevance

Given its excellent short-term and long-term outcome in young and middle-aged adults in this study, the Ross procedure should be considered in young and middle-aged adults who require aortic valve replacement. Patients should be referred to an experienced center with a program dedicated to the Ross procedure.

Collagen analysis of the ascending aortic dilatation associated with bicuspid aortic valve disease compared with tricuspid aortic valve

Dilatation of the ascending aorta is a common occurrence in patients with bicuspid aortic valve (BAV). The aim of the current study was to characterize collagen content in advanced glycation end products (AGEs) of dilated aortic tissue from two distinct areas, concave and convex aortic sites in patients with BAV and TAV. Collagen contents extracted from 100 mg tissue was isolated by enzymatic digestion using pepsin and the nondigested material was further digested using cyanogen bromide, insoluble collagen fraction (ICF) was extracted by hydrochloric acid hydrolysis. BAV tissue showed diminished fluorescence of the pepsin extracted fraction (PEF) compared with TAV tissue (12.4 ± 1.0% vs 32.9 ± 7.6%, p = 0.05). Patients with BAV had PEF of collagens significantly diminished in the dilated ascending aorta, especially in its convex portion, in course of aging and increment of dilated diameters. It is suggestible that BAV patients present more highly AGE-modified collagens in their ascending aorta.

Is the outcome in acute aortic dissection type A influenced by of femoral versus central cannulation?

BACKGROUND

The purpose of this study was to evaluate the single-center experience in initial femoral versus central cannulation of the extracorporeal circulation for acute aortic dissection type A (AADA).

METHODS

Between January 2003 and December 2015, 235 patients underwent repair of AADA. All patients were evaluated for the type of arterial cannulation (femoral vs. central) for initial bypass. Demographic data and outcome parameters were accessed.

RESULTS

One hundred and twenty seven (54.0%) were initially cannulated in the central aortic vessels (ascending aorta or subclavian/axillary artery) and 108 (46.0%) in the femoral artery. Patients were comparable between age (62.4±14.4 vs. 62.9±14.4 years, P=0.805), gender (male, 62.2 vs. 69.4%, P=0.152) and previous sternotomy (15.7 vs. 16.7%, P=0.861) between both cannulation groups; while EuroSCORE I (11.5±4.0 vs. 12.7±4.2, P=0.031) and ASA Score (3.5±0.81 vs. 3.8±0.57, P=0.011) were significantly higher in the femoral artery cannulation group. Bypass (249±102 vs. 240±81 min, P=0.474), X-clamp (166±85 vs. 157±67 min, P=0.418) and circulatory arrest time (51.6±28.7 vs. 48.3±21.7 min, P=0.365) were similar between the groups as were lowest temperature (18.1±2.0 vs. 18.1±2.2, P=0.775). Postoperative neurologic deficit and 30-day mortality were comparable between both cannulation groups (11.7 vs. 7.2%, P=0.449 and 20.2 vs. 16.9%, P=0.699, central vs. peripheral cannulation). Multivariate analysis revealed only EuroScore I above 13 as single preoperative predictor for mortality.

CONCLUSIONS

AADA can be operated with both femoral and central cannulation with similar results. Risk for early mortality was driven by the preoperative clinical and hemodynamic status before operation rather than the cannulation technique.

Abstract 204: Detection and Determination of Protein Network Associated With Atrial Fibrillation Subtypes

Atrial fibrillation (AF) is associated with increased risks of stroke, cardiac failure, and mortality. The underlying mechanisms and pathology of AF remain elusive. The aim of this study is to proteomically analyze the left atrial appendage tissue obtained from patients suffering from subtypes (paroxysmal, persistent, and long-standing persistent) AF.

MALDI Imaging mass spectrometry (MALDI-IMS) was applied to differentiate in classification of pathophysiological AF subtypes, through the direct (in situ) analysis of formalin-fixed paraffin embedded (FFPE) left atrial appendage (LAA) tissue. FFPE LAA tissue were collected from patients with predisposed paroxysmal (n = 9, mean age 69.0±3.1 years), persistent (n = 18, mean age 67.0±2.7 years), and long-standing persistent AF (n = 19, mean age 71.0±2.0 years). Sections were dewaxed and thereupon soused by trypsin solutions using an automated spraying device. Spectra were acquired at a mass range of m/z 800-3500Da and lateral resolution of 80 μm. Two hundred laser shots were acquired per pixel and random walk of 50/position. Data analyses were performed using SCiLS Lab software.

Component analysis of MALDI Imaging data through probabilistic latent semantic analysis results in a clear discrimination in the first 3 components of atrial fibrillation. Employing receiver operating characteristic analysis (AUC > 0.7), characteristic intensity distribution in given m/z values, which are discriminative for the considered cluster, was determined to distinguish between paroxysmal vs. persistent AF, and persistent vs. long-persistent AF, m/z values were determined between persistent vs long-persistent AF (1.59±0.12 vs 6.85±3.02, p = 0.02). Follow-up of neurological events in case-controlled assessment presented 13±12% in paroxysmal, 56±12% in persistent and 42±12% long-persistent AF.

The tissue-based proteomic approach provides clinically relevant beneficial information in improving risk stratification for AF patients. In the future, this obtained information might be considered new biomarker to support the diagnosis of the severity of AF status. They also suggest a new criterion to determine the most appropriate procedure for each AF subtype to improve postoperative outcomes.

Patient Age at the Ross Operation in Children Influences Aortic Root Dimensions and Aortic Regurgitation

Background:

The Ross operation provides the advantage of growth potential of the pulmonary autograft in the aortic position. However, development of autograft dilatation and regurgitation may occur. We sought to assess the progression of autograft diameters and aortic regurgitation (AR) with regard to patient age at the time of the Ross operation.

Methods:

Autograft echo dimensions from 48 children <16 years of age at the time of the Ross operation, who had follow-up echocardiograms at <20 years of age, were analyzed using hierarchical multilevel modeling. The z values of autograft dimensions were calculated according to the normal aortic dimensions. Mean follow-up was 5.1 ± 3.3 years. The mean age at the time of the Ross operation was 10.0 ± 4.3 years.

Results:

The mean z values of all patients showed a significant increase with follow-up time at the sinus (0.5 ± 0.1/year, P < .001) and the sinotubular junction (0.7 ± 0.2/year, P < .001) but not at the annulus (0.1 ± 0.1/year, P = .59). There was no significant difference in the z values of sinus and the sinotubular junction between younger and older children at implantation and with time. The initial annulus z value was significantly larger in younger children ( P < .0001), whereas the annual increase was significantly higher in older children ( P = .021). Age at operation has no impact on the initial AR grade ( P = .60). The AR tends to increase more quickly in older patients ( P = .040). Sinus and sinotubular junction dilate with time, regardless of patient age.

Conclusions:

Young children show larger initial annulus sizes than older children. However, annulus diameters tend to normalize in young children, whereas they increase in older children. Autograft regurgitation develops slowly, but significantly, and predominantly in older children. Stabilizing measures to prevent autograft root dilatation are warranted in adolescents, but they are not required in young children.

Elevation of matrix metalloproteinases in different areas of ascending aortic aneurysms in patients with bicuspid and tricuspid aortic valves

Our aim is to investigate the elevation of matrix proteins in tissues obtained from distal, above the sinotubular junction (proximal), concave, and convex sites of aneurysms in the ascending aorta using a simultaneous multiplex protein detection system. Tissues were collected from 41 patients with ascending aortic aneurysms. A total of 31 patients had a bicuspid aortic valve (BAV), whereas 10 had a tricuspid aortic valve (TAV). Concave and convex aortic site samples were collected from all patients, whereas proximal and distal convexity samples were obtained from 19 patients with BAV and 7 patients with TAV. Simultaneous detection of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) was performed at each of the four aortic sites. MMP-2 levels were higher in the concave aortic sites than in the convex aortic sites. In contrast, MMP-8 levels were higher in the convex sites than in the concave sites, as were MMP-9 levels. In both BAV and TAV patients, TIMP-3 levels were higher in the concave sites than in the convex sites. However, TIMP-2 and TIMP-4 levels were significantly elevated in the sinotubular proximal aorta of BAV patients. Simultaneous detection of MMPs and TIMPs revealed different levels at different aortic sites in the same patient.

Ross procedure

INTRODUCTION

In 1967 Donald Ross introduced the subcoronary Ross procedure consisting of transplantation of the autologous pulmonary valve into aortic position. We describe our 15-year experience in Ross procedures.

METHODS

576 subcoronary operations have been performed (436 male and 140 female patients); the mean age was 45±11.9 years. (range, 13 to 70 years). The mean follow-up was 7±4.2 years (range, 0 to 16 years). There were 4597 patient years at follow-up with a clinical completeness of 95% and echo completeness of 91%.

RESULTS

There were two operative deaths (0.3%) and 31 patients with reoperation. The survival is similar to that of the normal population and the freedom from allo- and autograft reoperation is 87% at 15 years. Autograft regurgitation at last examination was grade 0 in 40%, trace in 54%, grade I in 19%, grade II in 4% and grade III in 0.4%; the pressure gradient was smaller than 5 mmHg in 57% and between 5 and 10 mmHg in 24%. Only 6% had a transvalvular pressure gradient of more than 10 mmHg.

DISCUSSION

After 15 years of experience it can be concluded that the subcoronary technique provides near normal survival in adult patients, with excellent hemodynamics and acceptable rate of reoperations.

Upregulation of the high mobility group AT-hook 2 gene in acute aortic dissection is potentially associated with endothelial-mesenchymal transition

The high mobility group AT-hook 2 (HMGA2) gene is proposed to regulate the genes involved in the epithelial-mesenchymal transition (EMT). One form of EMT is endothelial-mesenchymal transition (EndMT). We analyzed the expression profile of the HMGA2 gene in different human aortic diseases. Aortic specimens were collected from 51 patients, including 19 with acute aortic dissection, 26 with aortic aneurysm, two with Marfan syndrome and four aortic valves. Quantitative real-time polymerase chain reaction was carried out for HMGA2 and immunohistochemical analyses were performed for HMGA2, SNAI1, Vimentin, CD34, MKI-67 and TGFB1. The expression of let-7d microRNA, which is assumed to play a role in the regulation of HMGA2, was also quantified. The level of HMGA2 gene expression was significantly higher in acute aortic dissection compared with all the other samples (193.1 vs. 8.1 fold normalized to calibrator, P<0.001). The immunohistochemical investigation showed that HMGA2, SNAI1, and Vimentin proteins were mainly detected in the endothelial cells of the vasa vasorum. The HMGA2 gene is upregulated in acute aortic dissection. This is the first report describing a link between HMGA2 and acute aortic dissection. The HMGA2, SNAI1 and Vimentin proteins were mainly detected in the endothelium of the vasa vasorum. It seems that HMGA2 overexpression in acute aortic dissection occurs in a let-7d-independent manner and is associated with EndMT of the vasa vasorum.

Altered microRNAs in bicuspid aortic valve: a comparison between stenotic and insufficient valves

BACKGROUND AND AIM OF THE STUDY

Bicuspid aortic valve (BAV), the most common form of congenital heart disease, is a leading cause of aortic stenosis (AS) and aortic insufficiency (AI). AS is typically caused by calcific valve disease. Recently, microRNAs (miRNAs) have been shown to modulate gene expression. The study aim was to examine the miRNAs that were altered in the aortic valve leaflets of patients with AS compared to those in patients with AI. In-vitro experiments were also carried out to determine if these miRNAs could modulate calcification-related genes.

METHODS

Aortic valve samples (fused and unfused leaflets) were collected from nine male patients (mean age 44.9 +/- 13.8 years) undergoing aortic valve replacement (AVR). PIQOR miRXplore Microarrays containing 1,421 miRNAs were used and hybridized to fused leaflet samples labeled with Cy5; unfused samples were used as controls and labeled with Cy3. A quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to validate the miRNA array results. Cultured human aortic valve interstitial cells (AVICs) were treated with miRNA mimics, and qRT-PCR was carried out to determine any changes in mRNAs.

RESULTS

By microarray analysis, seven miRNAs were shown to be statistically different between the AS and AI patients. In the stenotic samples, the MiR-26a and miR-195 levels were shown (by qRT-PCR) to be reduced by 65% and 59%, respectively (p < 0.05), and MiR-30b to be reduced by 62% (p < 0.06). Human AVICs treated with miR-26a or miR-30b mimics showed decreased mRNA levels of calcification-related genes. MiR-26a repressed BMP2 by 36%, alkaline phosphatase (ALPL) by 38%, and SMAD1 by 26%, while MiR-30b reduced the expression of SMAD1 by 18% and of SMAD3 by 12%. In contrast, miR-195-treated AVICs had increased mRNA levels of calcification-related genes, such as BMP2 by 68% and RUNX2 by 11%.

CONCLUSION

MiR-26a, miR-30b, and miR-195 were each decreased in the aortic valves of patients requiring AVR due to AS, compared to those requiring replacement due to AI. These miRNAs appear to modulate calcification-related genes in vitro.