Epitranscriptomics of Ischemic Heart Disease-The IHD-EPITRAN Study Design and Objectives.

Epitranscriptomic modifications in RNA can dramatically alter the way our genetic code is deciphered. Cells utilize these modifications not only to maintain physiological processes, but also to respond to extracellular cues and various stressors. Most often, adenosine residues in RNA are targeted, and result in modifications including methylation and deamination. Such modified residues as N-6-methyl-adenosine (m6A) and inosine, respectively, have been associated with cardiovascular diseases, and contribute to disease pathologies. The Ischemic Heart Disease Epitranscriptomics and Biomarkers (IHD-EPITRAN) study aims to provide a more comprehensive understanding to their nature and role in cardiovascular pathology. The study hypothesis is that pathological features of IHD are mirrored in the blood epitranscriptome. The IHD-EPITRAN study focuses on m6A and A-to-I modifications of RNA. Patients are recruited from four cohorts: (I) patients with IHD and myocardial infarction undergoing urgent revascularization; (II) patients with stable IHD undergoing coronary artery bypass grafting; (III) controls without coronary obstructions undergoing valve replacement due to aortic stenosis and (IV) controls with healthy coronaries verified by computed tomography. The abundance and distribution of m6A and A-to-I modifications in blood RNA are charted by quantitative and qualitative methods. Selected other modified nucleosides as well as IHD candidate protein and metabolic biomarkers are measured for reference. The results of the IHD-EPITRAN study can be expected to enable identification of epitranscriptomic IHD biomarker candidates and potential drug targets.

Conduction Disturbance After Transcatheter Aortic Valve Implantation With Self- or Balloon-Expandable Valve According to the Implantation Depth.

Membranous septum (MS) length, in conjunction with implantation depth (ID), is known as a determinant of conduction disturbance (CD) after transcatheter aortic valve implantation (TAVI). However, its impact might be dissimilar among valve types because each valve has a different platform. This study sought to investigate the different impacts of ID and MS length on the new-onset CD between ACURATE neo and SAPIEN 3. This study included patients without a previous permanent pacemaker implantation who underwent TAVI with ACURATE neo and SAPIEN 3 and divided them into 2 groups based on the ID according to MS length (deep and shallow implantation group). Deep implantation was defined as transcatheter heart valve implantation deeper than MS length. The primary endpoint was new-onset CD (new permanent pacemaker implantation or new-onset complete left bundle branch block). A total of 688 patients (deep implantation: n = 373, shallow implantation: n = 315) were identified as a study cohort. New-onset CD developed more frequently in the deep implantation group (16.6% vs 7.0%; p = 0.0001). Deep implantation was revealed as a predictor of new-onset CD. Moreover, deep implantation was significantly associated with new-onset CD after SAPIEN 3 implantation but not after ACURATE neo. Among patients with MS shorter than 2 mm, ACURATE neo was superior in terms of avoiding new-onset CD. In conclusion, the deep implantation was associated with new-onset CD after TAVI with SAPIEN 3 but not with ACURATE neo. These results may impact device selection in patients with a preexisting high risk of CD.

Ultrasound-Guided Versus Conventional MANTA Vascular Closure Device Deployment After Transcatheter Aortic Valve Implantation.

Despite the development of device technology and operators' experience, access site vascular complications (VCs) remain one of the major concerns after transcatheter aortic valve implantation (TAVI). MANTA (Teleflex, Wayne, Pennsylvania) is a large-bore vascular closure device (VCD) with promising incidence of VC. Previously, we demonstrated that the ultrasound-guided MANTA (US-MANTA) technique further improved the outcomes compared with conventional MANTA (C-MANTA) without ultrasound guidance. The present study was established to prove the effectiveness of the technique in a larger population. In this study, we included 1,150 patients (335 patients with C-MANTA and 815 with US-MANTA) who received MANTA after TAVI from April 2017 to September 2021. The primary endpoint was MANTA-related VC. Overall VC, VCD failure, and bleeding complications were also assessed based on the Valve Academic Research Consortium 3 criteria. MANTA-related VC occurred in 12.5% in the C-MANTA group and 6.8% in the US-MANTA group (p = 0.001). VCD failure rate were 7.5% and 3.9%, respectively (p = 0.012). Valve Academic Research Consortium 3 major and minor VC were more frequent in C-MANTA group (major: 7.8% vs 4.4%, p = 0.023; minor: 8.1% vs 4.4%, p = 0.022). Multivariate analysis revealed US-MANTA as the negative predictor of MANTA-related VC (odds ratio 0.57, 95% confidence interval 0.36 to 0.89, p = 0.013). However, subgroup analysis showed the efficacy of the US-MANTA technique was limited to the patients without severely calcified puncture site (Pinteraction = 0.048). In conclusion, the US-MANTA technique was an effective strategy to reduce VC after transfemoral TAVI compared with C-MANTA.

Medico-legal autopsy in postoperative hemodynamic collapse following coronary artery bypass surgery.

Sudden unexpected postoperative hemodynamic collapse with a high mortality develops in 1-3% of patients undergoing coronary artery bypass surgery (CABG). The contribution of surgical graft complications to this serious condition is poorly known and their demonstration at autopsy is a challenging task. Isolated CABG was performed in 8,807 patients during 1988-1999. Of the patients, 76 (0.9%) developed sudden postoperative hemodynamic collapse resulting in subsequent emergency reopening of the median sternotomy and open cardiac massage. Further emergency reoperation could be performed in 62 (82%) whereas 14 patients died prior to reoperation and a further 21 did not survive the reoperation or died a few days later. All 35 (46%) patients who did not survive were subjected to medico-legal autopsy combined with postmortem cast angiography. By combining clinical data with autopsy and angiography data, various types of graft complications were observed in 27 (36%, 1.3 per patient) of the 76 patients with hemodynamic collapse. There were no significant differences in the frequency (33 vs. 40%) or number of complicated grafts per patient (1.2 vs. 1.4) between those who survived reoperation and who did not. Autopsy detected 25 major and minor findings not diagnosed clinically. Postmortem cast angiography visualized 2 graft twists not possible to detect by autopsy dissection only. Surgical graft complications were the most frequent single cause for sudden postoperative hemodynamic collapse in CABG patients leading to a fatal outcome in almost half of the cases. Postmortem angiography improved the accuracy of autopsy diagnostics of graft complications.

Ultrasound-Navigated Manta Deployment After Removal of Extracorporeal Membrane Oxygenation Cannula.

The case provided suggests that an ultrasound-navigated Manta device works well in closing percutaneously the peripheral arterial extracorporeal membrane oxygenation cannulation site. Ultrasonography use during extracorporeal membrane oxygenation decannulation can further diminish the possible device-related technical failures (toggle or collagen protrusion through the vessel wall, toggle stacking into calcifications, or delivery failure of the collagen pad) leading to bleeding and vascular complications. Further studies are needed on this topic.

Outcome of aortic valve replacement with bioprostheses in the elderly.

BACKGROUND AND AIM OF THE STUDY: Today, the elderly population continues to increase worldwide, and rates of aortic stenosis (AS) climb with age. Since aortic valve replacement (AVR) is the current treatment for elderly patients with symptomatic AS, the number of patients undergoing AVR is expected to grow. METHODS: Among patients operated on at Helsinki University Hospital between 1992 and 1997, a cohort (n = 145) was followed after AVR with a bioprosthesis. The patients were allocated to three groups, based on their age at the time of surgery: > or = 80 years (n = 30), < 80 to > or = 70 years (n = 94), and < or = 70 years (n = 21). All data relating to preoperative risk factors were collected. A control examination, which included echocardiography, was performed at least five years after surgery, and the follow up was continued until July 2006. The number of deaths and causes of death, as well as valve-related complications, were noted. RESULTS: The 30-day mortality rates were 3.3% in the oldest (> or = 80-year) group, 6.4% in the middle (< 80 to > or = 70-year) group, and zero in the youngest (< or = 70-year) group. The mean age at death was 88 and 81 years in the oldest and middle groups, respectively. In the oldest and youngest groups, there were no reoperations, but five valve-related reoperations were performed during follow up in the middle group. At the control visit, the left ventricular ejection fraction was > 60% in all groups. In the oldest and middle groups the aortic valve gradient was lower than the preoperative level, while the left ventricular diameters and wall dimensions were smaller (p < 0.05). Valve calcification was observed in one patient in the youngest group. CONCLUSION: Elderly patients who had undergone AVR with a bioprosthesis had a good outcome after more than 10 years of follow up, with an improved cardiac function being preserved for at least seven years after surgery. Despite a severely impaired preoperative aortic valve function, octogenarians especially had a good life expectancy, possibly due to their low comorbidity rates. Hence, AVR with a bioprosthesis proved to be an excellent treatment in this patient group.

Local C-reactive protein expression in obliterative lesions and the bronchial wall in posttransplant obliterative bronchiolitis.

The local immunoreactivity of C-reactive protein (CRP) was studied in a heterotopic porcine model of posttranplant obliterative bronchiolitis (OB). Bronchial allografts and control autografts were examined serially 2-28 days after subcutaneous transplantation. The autografts stayed patent. In the allografts, proliferation of inflammatory cells (P < .0001) and fibroblasts (P = .02) resulted in occlusion of the bronchial lumens (P < .01). Influx of CD4+ (P < .001) and CD8+ (P < .0001) cells demonstrated allograft immune response. CRP positivity simultaneously increased in the bronchial walls (P < .01), in macrophages, myofibroblasts, and endothelial cells. Local CRP was predictive of features characteristic of OB (R = 0.456-0.879, P < .05-P < .0001). Early obliterative lesions also showed CRP positivity, but not mature, collagen-rich obliterative plugs (P < .05). During OB development, CRP is localized in inflammatory cells, myofibroblasts and endothelial cells probably as a part of the local inflammatory response.

Clinical value of intra-operative transit-time flow measurement for coronary artery bypass grafting: a prospective angiography-controlled study.

OBJECTIVE: Transit-time flow measurement (TTFM) is the most widely used method for intra-operative graft quality control in coronary artery bypass surgery. Although it may provide the opportunity for the surgeon to promptly revise the graft before the patient is discharged from the operating room, controlled clinical data on the ultimate usefulness of the TTFM are scarce. Clear cut-off values for when to revise grafts have not been set. METHODS: A total of 204 consecutive grafts (left internal mammary artery (n=46), vein graft (n=155), and radial artery (n=3)) underwent TTFM in 75 elective coronary artery bypass grafting (CABG) patients. The following parameters were recorded: mean graft flow (MGF), pulsatility index (PI), and insufficiency ratio (IR). After a mean follow-up of 199 ± 42 days, coronary angiography was performed for assessment of graft patency. RESULTS: A total of 166 grafts were found to be patent (85%), and 29 (15%) were completely occluded. The median and interquartile range (IQR) of MGF for the occluded grafts at the time of surgery was 38 ml min(-1) (IQR, 2549 ml min(-1)) and for the patent grafts 45 ml min(-1) (IQR, 31-71 ml min(-1); p=ns]. The corresponding PI values were 3.3 (IQR, 2.8-5.0) and 2.2 (IQR, 1.7-3.2; p=0.003), and the IR values were 1.6 (IQR, 0.6-6.1) and 0.2 (IQR, 0-2.2; p=0.03). By receiver operating characteristic (ROC) analysis, the highest sensitivity (72%) and specificity (70%) were associated with a PI value>3.0. However, 49 out of 70 such grafts (70%) were found to be patent. Furthermore, 10 out of 16 (63%) grafts, that had a combination of low flow (MGF<15 ml min(-1)) and high PI (>3.0), were patent at control angiography. CONCLUSIONS: TTFM predicts graft failure within the 6 months after CABG. However, specific cut-off recommendations for when to revise a graft cannot be set on the basis of TTFM. The cut-off values suggested in the literature lead to unnecessary graft revisions in the majority of cases, and, on the other hand, many technical defects probably remain unnoticed. Better methods to assess the quality of coronary artery bypass grafts are needed.

Medtentia double helix mitral annuloplasty system evaluated in a porcine experimental model.

OBJECTIVE: : To further develop and improve minimally invasive surgical procedures, dedicated appropriate surgical devices are mandatory. In this study, the safety and feasibility of implanting the novel Medtentia double helix mitral annuloplasty ring, which uses the key-ring principle to potentially allow faster and sutureless implantation, was assessed using both minimally invasive and conventional surgical techniques. Because of ethical concerns, a human compatible porcine experimental model of mitral valve surgery was used. METHODS: : Twelve 50-kg pigs were allocated to implantation of the Medtentia double helix annuloplasty ring using conventional midline sternotomy including cardioplegic arrest or a minimally invasive approach using peripheral cannulation and left ventricular fibrillation. Ten weeks after surgery, echocardiography was performed to assess mitral valve function. Animals were then killed, and gross mitral valve anatomy was examined ex vivo. RESULTS: : All animals survived 10 weeks without developing mitral regurgitation, structural leaflet damage, ring dehiscence, or endocarditis. In the minimally invasive compared with the midline sternotomy group (mean ± SD), significantly reduced recovery time (80 ± 16 vs. 327 ± 23 minutes, P < 0.01) and a tendency toward increased operating time (199 ± 33 vs. 168 ± 15 minutes, P > 0.05) and cardiopulmonary bypass time (98 ± 12 vs. 91 ± 11 minutes, P > 0.05) were observed. CONCLUSIONS: : By using a both minimally invasive and conventional midline sternotomy implantation techniques, the Medtentia double helix annuloplasty ring showed no mitral valve dysfunction or tissue damage 10 weeks postoperatively.

Epithelial tenascin predicts obliterative airway disease.

BACKGROUND: Epithelial cell injury, inflammation, fibrosis and airway obliteration result in remodeling of terminal bronchi in post-transplant obliterative bronchiolitis. Tenascin as an extracellular matrix glycoprotein is expressed in several remodeling processes. METHODS: Heterotopic bronchial allografts of pigs were studied to assess tenascin expression during development of post-transplant obliterative bronchiolitis. A total of 157 allografts or autograft controls were serially obtained 2 to 28 days after transplantation and processed for histology and immunocytochemistry for tenascin, CD4, CD8 and macrophages. Epithelial tenascin index was calculated by multiplying the percentage of positive cells by the grade of tenascin intensity (1 to 3). RESULTS: Epithelial tenascin expression occurred during the initial ischemic damage to the respiratory epithelium. After partial recovery and before total epithelial loss and subsequent airway obliteration, tenascin expression peaked in allografts (p < 0.001). Epithelial tenascin index on Day 7 was predictive of subsequent epithelial damage, bronchial wall inflammation and the number of (CD4(+) and CD8(+)) cells, fibroproliferation, and obliteration of the bronchial lumen (R > or = 0.47, p < or = 0.01). Tenascin expression in the bronchial wall was more intense in allografts (p < 0.001), paralleling proliferation of fibroblasts and influx of inflammatory cells, and was predictive of inflammatory alterations also in the early obliterative lesions (R > or = 0.45, p < 0.05). Expression decreased during maturation of fibrosis (p < 0.05). CONCLUSIONS: Epithelial tenascin was predictive of features observed in post-transplant obliterative bronchiolitis, demonstrating a role for tenascin in the development of obliterative bronchiolitis. Tenascin may have relevant properties in serving as a clinical marker for early obliterative bronchiolitis.

Platelet-derived growth factor, transforming growth factor-beta, and connective tissue growth factor in a porcine bronchial model of obliterative bronchiolitis.

The expression of platelet-derived growth factor (PDGF), transforming growth factor (TGF)-beta, and connective tissue growth factor (CTGF) and the effect of imatinib, an agent inhibiting PDGF receptors, were assessed in a porcine bronchial transplantation model of obliterative bronchiolitis (OB). Up-regulation of PDGF-A, PDGF receptors alpha and beta, and TGF-beta expression occurred in allografts, whereas PDGF-B and CTGF expression was similar in allo- and autografts. Imatinib modified the inflammatory responses and expression patterns of PDGF-A and PDGF receptors. This study further confirms PDGF and TGF-beta as mediators of OB and supports the concept of the importance of the pathways signaled through PDGF receptors in post-transplant OB.

Immune cells in a heterotopic lamb-to-pig bronchial xenograft model.

We developed our porcine model to elucidate the cellular rejection mechanisms of xenografts. Bronchial segments from a donor lamb were implanted into domestic pigs. The immunosuppressive regimens consisted of no immusuppression, or of daily oral cyclosporine A (CsA) 15 mg/kg, or of everolimus, 1.5 mg/kg, or of both. Implants were serially harvested during 17 days. Epithelial damage and obliteration were graded histologically, followed by a count of CD4+, CD8+, MHC class II-expressing cells, and macrophages. Furthermore, we studied the pharmocokinetics of everolismus. Epithelial damage preceded luminal obliteration, which was eventually total, except when both drugs had been given. In xenografts, an influx of cells with CD8+ cells dominating peaked on day 9, thereafter declining, except in the combination drug group. There, the immunological reaction was delayed and blunted, with CD4+ cells dominating. More macrophages appeared in xenografts than in allografts except with the combination CsA and everolimus. A dose of 1.5 mg/kg everolimus yields adequate blood concentrations for porcine studies. In this xenograft model, chronic rejection appears to be caused by an immune response to the graft, but it is more short-lived than the response in allografts. The combination of CsA and everolimus was able to blunt the response and delay the subsequent obliteration.