PubMed Posts

Objectives: The goal of therapy of proximal aortic aneurysms is to prevent an aortic catastrophe, e.g. acute dissection or rupture. The decision to intervene is currently based on maximum aortic diameter complemented by known risk factors like bicuspid aortic valve, positive family history or rapid growth rate. When applying Laplace’s law, wall tension is determined by pressure × radius divided by aortic wall thickness. Because current imaging modalities lack precision, wall thickness is currently neglected. The purpose of our study was therefore to correlate maximum aortic diameter with aortic wall thickness and known indices for adverse aortic events.

Methods: Aortic samples from 292 patients were collected during cardiac surgery, of whom 158 presented with a bicuspid aortic valve and 134, with a tricuspid aortic valve. Aortic specimens were obtained during the operation and stored in 4% formaldehyde. Histological staining and analysis were performed to determine the thickness of the aortic wall.

Results: Patients were 62 ± 13 years old at the time of the operation; 77% were men. The mean aortic dimensions were 44 mm, 41 mm and 51 mm at the aortic root, sinotubular junction and ascending aorta, respectively. Aortic valve stenosis was the most frequent (49%) valvular dysfunction, followed by aortic valve regurgitation (33%) and combined dysfunction (10%). The maximum aortic diameter at the ascending level did not correlate with the thickness of the media (R = 0.07) or the intima (R = 0.28) at the convex sample site. There was also no correlation of the ascending aortic diameter with age (R = -0.18) or body surface area (R = 0.07). The thickness of the intima (r = 0.31) and the media (R = 0.035) did not correlate with the Svensson index of aortic risk. Similarly, there was a low (R = 0.29) or absent (R = -0.04) correlation between the aortic size index and the intima or media thickness, respectively. There was a similar relationship of median thickness of the intima in the 4 aortic height index risk categories (P < 0.001).

Conclusions: Aortic diameter and conventional indices of aortic risk do not correlate with aortic wall thickness. Other indices may be required in order to identify patients at high risk for aortic complications.

Background: Patients with tricuspid valve (TV) disease and indication for TV surgery frequently have permanent pacemaker (PM) or defibrillator (AICD) leads, placed in the right ventricle (RV). The aim of this study was to analyze postoperative results and mid-term outcomes after isolated TV surgery (with no further concomitant cardiac procedures) in the presence of permanent RV leads.

Methods: From January 2005 to January 2019 a total of 80 patients (mean age: 67.7±10.3 yrs; 56.3% male) with isolated TV disease and presence of at least one permanent RV lead in place were referred to our institution for isolated TV repair/replacement; patients with concomitant procedures were excluded for this analysis. All data were retrospectively analyzed. The follow-up was 98% complete.

Results: Mean follow-up time was 4.3±3.9 years. Mean preoperative clinical NYHA status was 3.0±0.8, left ventricular ejection fraction 50.7±12.9%, mean pulmonary artery pressure 23.8±9.3mmHg, creatinine 125.7±57.5μmol/L, mean MELD-XI Score (Model of End-stage-Liver Disease excluding INR) was 14.6±5.0 μmol/L. Thirty-day mortality was 6.3% with a 5-years survival of 58.2±6.0%. Cox regression analysis revealed the MELD-XI-Score as the only highly significant predictor for postoperative mortality (P=0.002).

Conclusions: Hepatorenal dysfunction – possibly indicating long lasting TV failure – could be a factor for limited postoperative survival in our patient cohort. This finding could underline our hypothesis, that early TV surgery may achieve better postoperative survival, even in patients with TV disease caused by RV leads. Therefore, further investigations are needed.

Background: It is current practice to perform concomitant coronary artery bypass grafting (CABG) in patients with infective endocarditis (IE) who have relevant coronary artery disease (CAD). However, CABG may add complexity to the operation. We aimed to investigate the impact of concomitant CABG on perioperative outcomes in patients undergoing surgery for IE.

Methods: We retrospectively used data of surgically treated IE patients between 1994 and 2018 in six German cardiac surgery centers. We performed inverse probability weighting (IPW), multivariable adjustment, chi-square analysis, and Kaplan-Meier survival estimates.

Results: CAD was reported in 1242/4917 (25%) patients. Among them, 527 received concomitant CABG. After adjustment for basal characteristics between CABG and no-CABG patients using IPW, concomitant CABG was associated with higher postoperative stroke (26% vs. 21%, p = 0.003) and a trend towards higher postoperative hemodialysis (29% vs. 25%, p = 0.052). Thirty-day mortality was similar in both groups (24% vs. 23%, p = 0.370). Multivariate Cox regression analysis after IPW showed that CABG was not associated with better long-term survival (HR: 1.00, 95% CI: 0.82-1.23, p = 0.998).

Conclusion: In endocarditis patients with CAD, adding CABG to valve surgery may be associated with a higher likelihood of postoperative stroke without adding long-term survival benefits. Therefore, in the absence of critical CAD, concomitant CABG may be omitted without impacting outcome. The results are limited due to a lack of data on the severity of CAD, and therefore there is a need for a randomized trial.

Background: Severe pulmonary hypertension is a relative contraindication for isolated tricuspid valve (TV) surgery. However, some patients may still benefit from TV surgery. We hypothesized that pulmonary pressure alone is an inadequate predictor of outcomes post-TV surgery, and that aorto-pulmonary pressure quotient (AoP/PAP) is a better predictor.

Methods: From 2005 to 2019, a total of 122 patients (mean age: 68.5±10.5 years; 43.3% male) with isolated TV regurgitation and preoperative right heart catheterization referred to our institution for isolated TV surgery were included. Patients with concomitant procedures were excluded from this analysis. All data were retrospectively analyzed. Follow-up was 97% complete.

Results: The mean follow-up time was 4.3±3.6 years. The mean preoperative New York Heart Association (NYHA) class was 2.9±0.7, left ventricular ejection fraction was 52.3±11.3%, creatinine level was 124.8±102.6μmol/l, mean pulmonary artery pressure was 25.5±9.4mmHg, mean MELD-XI score 13.5±4.2, and mean AoP/PAP was 4.1±1.9 mmHg. Thirty-day mortality was 10.9%, and 5-years survival was 56.6±4.9%. Cox regression analysis revealed age (p=0.001; HR: 1.058; CI 95%: 1.023-1.094), the mean arterial pressure (p=0.002; HR: 0.969; CI 95%: 0.950-0.988) and systolic pulmonary artery pressure (p=0.035; HR: 1.054; CI 95%: 1.004-1.107), as well as mean AoP/PAP > 4 (p=0.001; HR: 6.678; CI 95%: 2.197-20.294) as predictors for long-term mortality.

Conclusions: Regardless of the degree of pulmonary hypertension, a mean AoP/PaP quotient >4 impacts the postoperative survival of patients undergoing isolated TV surgery. However, further research is still required to verify this finding.

Carcinomas showing thymic-like differentiation (CASTLE tumors) are very rare entities requiring an individualized therapeutic plan. This report describes a case of reconstruction of the innominate artery after radical resection of the tumor in a patient in whom a custom-made cerebral shunt was used for continuous cerebral perfusion.

Background: To compare clinical and hemodynamic in-hospital outcomes of patients undergoing sutureless versus rapid deployment aortic valve replacement (SURD-AVR) in the large population of the Sutureless and Rapid Deployment International Registry (SURD-IR).

Methods: We examined 4695 patients who underwent isolated or combined SURD-AVR. The “sutureless” Perceval valve was used in 3133 patients and the “rapid deployment” Intuity in 1562. Potential confounding factors were addressed by the use of propensity score matching. After matching, 2 well-balanced cohorts of 823 pairs (isolated SURD-AVR) and 467 pairs (combined SURD-AVR) were created.

Results: Patients who received Perceval and Intuity valves showed similar in-hospital mortality and rate of major postoperative complications. Perceval was associated shorter cross clamp and cardiopulmonary bypass time. In the isolated SURD-AVR group, patients receiving Perceval were more likely to undergo anterior right thoracotomy incision. Postoperative transvalvular gradients were significantly lower for the Intuity valve compared to those of the Perceval valve, either in isolated and combined SURD-AVR. The Intuity valve was associated with a lower rate of postoperative mild aortic regurgitation.

Conclusions: Our results confirm the safety and efficacy of SURD-AVR regardless of the valve type. The Perceval valve was associated with reduced operative times and increased anterior right thoracotomy incision. The Intuity valve showed superior hemodynamic outcomes and a lower incidence of postoperative mild aortic regurgitation.

Introduction: Atrial fibrillation is common in patients with hypertrophic cardiomyopathy, and significantly impacts mortality and morbidity. In patients with atrial fibrillation undergoing septal myectomy, concomitant surgery for atrial fibrillation may improve outcomes.

Methods: A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies reporting the outcomes of combined septal myectomy and atrial fibrillation surgery were included.

Results: A total of 10 observational studies were identified, including 644 patients. Most patients had paroxysmal atrial fibrillation. The proportion with prior unsuccessful ablation ranged from 0 to 19%, and preoperative left atrial diameter ranged from 44 ± 17 to 52 ± 8 mm. Cox-Maze IV (n = 311) was the most common technique used, followed by pulmonary vein isolation (n = 222) and Cox-Maze III (n = 98). Patients with persistent or longstanding atrial fibrillation more frequently received Cox-Maze III/IV. Ranges of early postoperative outcomes included: mortality 0 to 7%, recurrence of atrial tachyarrhythmias 4.4 to 48%, cerebrovascular events 0 to 1.5%, and pacemaker insertion 3 to 21%. Long-term data was limited. Freedom from atrial tachyarrhythmias at 1 year ranged from 74% to 96%, and at 5 years from 52% to 100%. Preoperative predictors of late atrial tachyarrhythmia recurrence included left atrial diameter >45 mm, persistent or longstanding preoperative atrial fibrillation and longer atrial fibrillation duration.

Conclusion: In patients with atrial fibrillation undergoing septal myectomy, the addition of ablation surgery adds low overall risk to the procedure, and likely reduces the risk of recurrent atrial fibrillation in the long term. Future randomised studies comparing septal myectomy with or without concomitant AF ablation are needed.

Co-investigators: Dr Nicholas McNamara, Dr John Brookes, Dr Benjamin Robinson, Prof Michael Solomon, Prof Paul Bannon

Purpose/Introduction:
Gastrointestinal (GI) complications following cardiac surgery have been associated with significant morbidity and mortality. The pathogenesis of GI complications in this cohort is thought to revolve around splanchnic hypoperfusion, whereby the circulatory shifts during cardiac surgery greatly affect blood supply to splanchnic organs. These complications are difficult to diagnose for a number of reasons, including the use of sedation, vasopressors and analgesia, which mask symptoms and signs. This study sought to investigate the prevalence and risk factors for the development of GI complications post cardiac surgery.

Methodology:
A retrospective study was performed examining the prevalence and characteristics of patients who had GI complications following cardiac surgery at our institution over a 14-year period.

Results:
7986 patients were included in the analysis. 190 patients (2.4%) developed GI complications following cardiac surgery, and 32 (16.8%) of these patients died within 30 days of operation. Patients with these complications were 6.8 times more likely to die than those without. (95%CI 4.52-10.11, p<0.0001). The most common GI complication was GI bleeding (59), while intestinal ischaemia was most commonly associated with mortality (24). Eighty patients required surgical or radiological intervention, including laparotomy (36) or endoscopy (37). The risk factors for development of GI complications included age, smoking status, perioperative use of inotropes, cardiopulmonary bypass time, and reoperation.

Conclusion/s:
GI complications following cardiac surgery are uncommon; however, they are associated with high mortality and morbidity. The identification of patients at risk of these complications may provide a useful tool to reduce morbidity and mortality in this patient cohort.

There is an urgent need for models that faithfully replicate heart failure with preserved ejection fraction (HFpEF), now recognized as the most common form of heart failure in the world. In vitro approaches have several shortcomings, most notably the immature nature of stem cell-derived human cardiomyocytes [induced pluripotent stem cells (iPSC)] and the relatively short lifespan of primary cardiomyocytes. Three-dimensional ‘organoids’ incorporating mature iPSCs with other cell types such as endothelial cells and fibroblasts are a significant advance, but lack the complexity of true myocardium. Animal models can replicate many features of human HFpEF, and rodent models are the most common, and recent attempts to incorporate haemodynamic, metabolic, and ageing contributions are encouraging. Differences relating to species, physiology, heart rate, and heart size are major limitations for rodent models. Porcine models mitigate many of these shortcomings and approximate human physiology more closely, but cost and time considerations limit their potential for widespread use. Ex vivo analysis of failing hearts from animal models offer intriguing possibilities regarding cardiac substrate utilisation, but are ultimately subject to the same constrains as the animal models from which the hearts are obtained. Ex vivo approaches using human myocardial biopsies can uncover new insights into pathobiology leveraging myocardial energetics, substrate turnover, molecular changes, and systolic/diastolic function. In collaboration with a skilled cardiothoracic surgeon, left ventricular endomyocardial biopsies can be obtained at the time of valvular surgery in HFpEF patients. Critically, these tissues maintain their disease phenotype, preserving inter-relationship of myocardial cells and extracellular matrix. This review highlights a novel approach, where ultra-thin myocardial tissue slices from human HFpEF hearts can be used to assess changes in myocardial structure and function. We discuss current approaches to modelling HFpEF, describe in detail the novel tissue slice model, expand on exciting opportunities this model provides, and outline ways to improve this model further.

Data from animal models is now available to initiate assessment of human safety and feasibility of wide-angle three-dimensional intracardiac echocardiography (3D ICE) to guide point-of-care implantation of percutaneous left ventricular assist devices in critical care settings. Assessment of these combined new technologies could be best achieved within a surgical institution with pre-existing expertise in separate utilization of ICE and Impella.