Ross procedure with personalized external aortic root support.

The Ross-Personalized External Aortic Root Support procedure is a surgical aortic valve replacement technique in which the autologous pulmonary valve is transposed in the aortic position to replace the malfunctioning aortic valve and a homograft is implanted in the pulmonary position. To prevent autograft dilatation, a Personalized External Aortic Root Support prosthesis is included in the proximal autograft anastomosis and wrapped around the ascending aorta. The aorta is transected transversely, the aortic valve is resected, and the coronary arteries are mobilized and cut out of the sinuses, leaving a rim. The pulmonary autograft is harvested by transecting the pulmonary artery and part of the right ventricular outflow tract. The autograft is approximated to the aortic root and inverted inside the ventricle. The proximal anastomosis is performed including the prosthesis between the aortic root and the autograft. The coronary buttons are threaded through appropriately positioned and sized holes in the prosthesis and reimplanted into the autograft. The ascending aorta is appropriately adapted and anastomosed with the distal autograft. When the patient is off cardiopulmonary bypass, the prosthesis can be closed longitudinally and is anchored to the distal aortic adventitia.

Dynamic electrophysiological mechanism in patients with long-standing persistent atrial fibrillation.

Background: Improved understanding of the mechanisms that sustain persistent and long-standing persistent atrial fibrillation (LSpAF) is essential for providing better ablation solutions. The findings of traditional catheter-based electrophysiological studies can be impacted by the sedation required for these procedures. This is not required in non-invasive body-surface mapping (ECGI). ECGI allows for multiple mappings in the same patient at different times. This would expose potential electrophysiological changes over time, such as the location and stability of extra-pulmonary vein drivers and activation patterns in sustained AF. Materials and methods: In this electrophysiological study, 10 open-heart surgery candidates with LSpAF, without previous ablation procedures (6 male, median age 73 years), were mapped on two occasions with a median interval of 11 days (IQR: 8-19) between mappings. Bi-atrial epicardial activation sequences were acquired using ECGI (CardioInsight™, Minneapolis, MN, United States). Results: Bi-atrial electrophysiological abnormalities were documented in all 20 mappings. Interestingly, the anatomic location of focal and rotor activities changed between the mappings in all patients [100% showed changes, 95%CI (69.2-100%), p < 0.001]. Neither AF driver type nor their number varied significantly between the mappings in any patient (median total number of focal activities 8 (IQR: 1-16) versus 6 (IQR: 2-12), p = 0.68; median total number of rotor activities 48 (IQR: 44-67) versus 55 (IQR: 44-61), p = 0.30). However, individual zones showed a high number of quantitative changes (increase/decrease) of driver activity. Most changes of focal activity were found in the left atrial appendage, the region of the left lower pulmonary vein and the right atrial appendage. Most changes in rotor activity were found also at the left lower pulmonary vein region, the upper half of the right atrium and the right atrial appendage. Conclusion: This clinical study documented that driver location and activation patterns in patients with LSpAF changes constantly. Furthermore, bi-atrial pathophysiology was demonstrated, which underscores the importance of treating both atria in LSpAF and the significant role that arrhythmogenic drivers outside the pulmonary veins seem to have in maintaining this complex arrhythmia.

Nose-shaped mass in the ascending aorta.

A 79-year-old man was referred for urgent coronary artery bypass grafting. Contrast-enhanced computed tomography revealed an atypically nose-shaped contrast defect, which intraoperatively turned out to be an atheromatous plaque. Its preoperative detection allowed us to prevent an adverse cerebral event. This case highlights that a thorough preoperative work-up should ideally include a CT angiography, in patients where atherosclerotic changes are to be expected.

The adapted Heart Donor Score.

The Heart Donor Score (HDS) predicts donor organ discard for medical reasons and survival after heart transplantation (HTX) in the Eurotransplant allocation system. Our aim was to adapt the HDS for application in the United Network for Organ Sharing (UNOS) registry. To adjust for differences between the Eurotransplant and UNOS registries, the "adapted HDS" was created (aHDS) by exclusion of the covariates "valve function," "left-ventricular hypertrophy," and exclusion of "drug abuse" from the variable "compromised history." Two datasets were analyzed to evaluate associations of the aHDS with donor organ discard (n = 70 948) and survival (n = 19 279). The aHDS was significantly associated with donor organ discard [odds ratio 2.72, 95% confidence interval (CI) 2.68-2.76, P < 0.001; c-statistic: 0.937). The score performed comparably in donors <60 and ≥60 years of age. The aHDS was a significant predictor of survival as evaluated by univariate Cox proportional hazards analysis (hazard ratio 1.04, 95% CI 1.01-1.07, P = 0.023), although the association lost significance in a multivariable model. The aHDS predicts donor organ discard. Negative effects of most aHDS components on survival are likely eliminated by highly accurate donor selection processes.

Molecular-level HLA mismatch is associated with rejection and worsened graft survival in heart transplant recipients - a retrospective study.

The aim was to evaluate the association of molecular-level human leukocyte antigen (HLA) mismatching with post-transplant graft survival, rejection, and cardiac allograft vasculopathy (CAV). We retrospectively analyzed all primary cardiac transplant recipients between 01/1984-06/2016. 1167 patients fulfilled inclusion criteria and had HLA typing information available. In 312 donor-recipient pairs, typing at serological split antigen level was available. We used the Epitope MisMatch Algorithm to calculate the number of amino acid differences in antibody-verified HLA eplets (amino acid mismatch load (AAMM)) between donor and recipient. Patients with a higher HLA-DR AAMM load had inferior 1-year graft survival (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.01-1.28). The HLA-AB AAMM load showed no impact on graft survival. In the subgroup with available split-level information, we observed an inferior graft survival for a higher HLA-DR AAMM load 3 months after transplantation (HR, 1.22; 95% CI, 1.04-1.44) and a higher risk for rejection for an increasing HLA-AB (HR, 1.70; 95% CI, 1.29-2.24) and HLA-DR (HR, 1.32; 95% CI, 1.09-1.61) AAMM load. No impact on the development of CAV was found. Molecular-level HLA mismatch analysis could serve as a tool for risk stratification after heart transplantation and might take us one step further into precision medicine.

Atrial Fibrillation After Cardiac Surgery: Electrophysiological Mechanism and Outcome.

BACKGROUND: Postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with an inferior outcome. The high cure rate compared with non-POAF raises questions regarding the electrophysiologic mechanism. Despite being common, until now the electrophysiologic mechanism of POAF was never assessed. METHODS: Ten patients (5 men; mean age, 75 ± 5 years) with POAF underwent noninvasive 3-dimensional beat-by-beat mapping and were compared with 10 patients (6 men; mean age, 70 ± 10 years) with preoperative persistent AF (PEAF) undergoing open heart procedures. Three-dimensional mappings were compared by the nature and location of focal and rotor activity using the validated Bordeaux classification. RESULTS: Rotor activity was present in both atria of all patients; 299 rotors (mean, 30 ± 12) were mapped in the POAF group and 289 (mean, 29 ± 22) in the PEAF group. The most common region for macro reentry in both groups was the pulmonary vein area. Left atrium and left atrial appendage activity accounted for 59% (177/299 POAF group) and 62% (180/289 PEAF group) of all drivers. Rotor activity in the right atrium was documented in all patients. Focal activity was captured in only 2 patients in the POAF group and in 6 patients in the PEAF group. CONCLUSIONS: The mechanism of POAF is comparable with that of PEAF. Rotor activity was similar in both groups, but focal activity was numerically less common in the POAF group, which may be related to differences in atrial tissue remodeling. In POAF, transient substrate changes seem to facilitate the development of AF. A better understanding of atrial tissue changes by mapping and tissue analysis should lead to better preventive approaches.

Diminished impact of cytomegalovirus infection on graft vasculopathy development in the antiviral prophylaxis era - a retrospective study.

Evidence concerning an association between cytomegalovirus (CMV) infection and accelerated cardiac allograft vasculopathy (CAV) is inconclusive. Data were analyzed retrospectively from 297 consecutive heart transplants between 1.1.2002 and 31.12.2012. Patients ≤18 years of age, survival, and follow-up ≤1-year post-transplant and patients with early CAV were excluded. CMV-infection was diagnosed and monitored closely in the first year. CAV was diagnosed by coronary angiography via left heart catheterization, and results were categorized according to the International Society of Heart and Lung Transplantation (ISHLT) scoring system. Risk factors for CAV were tested in a multivariable model. Median follow-up was 7.5 years (IQR: 5.6-10.3). CMV infection in the first year after transplantation occurred in 26% of patients (n = 78), CMV disease in 5% (n = 15). CAV ≥1 ISHLT was detected in 36% (n = 108). Incidence of CAV >1 ISHLT and severity of CAV increased over time. No statistically significant association between CMV infection and disease within the first year and risk of CAV after 1-year post-HTx was detected in the univariate (P = 0.16) and multivariable [hazard ratio (HR), 1.36; confidence interval (CI), 0.89-2.07; P = 0.16] Cox regression. In the multivariable Cox regression, donor age (HR, 1.04; 95% CI, 1.02-1.06; P < 0.01) and acute cellular rejection (ACR) ≥2R in the first year after HTx (HR, 1.77; 95% CI, 1.06-2.95; P = 0.03) were independent risk factors for CAV development. In our cohort, CMV infection and disease in the first year after transplantation did not significantly influence the risk of CAV in the long-term follow-up.

High-dose catecholamine donor support and outcomes after heart transplantation.

BACKGROUND: Higher dose norepinephrine donor support is a frequent reason for donor heart decline, but its associations with outcomes after heart transplantation are unclear. METHODS: We retrospectively analyzed 965 patients transplanted between 1992 and 2015 in the Heart Transplant Program Vienna. Stratification was performed according to donor norepinephrine dose administered before organ procurement (Group 0: 0 µg/kg/min; Group 1: 0.01 to 0.1 µg/kg/min; Group 2: >0.1 µg/kg/min). Sub-stratification of Group 2 was performed for comparison of high-dose subgroups (Group HD 1: 0.11 to 0.4 µg/kg/min; Group HD 2: >0.4 µg/kg/min). Associations between groups and outcome variables were investigated using a multivariable Cox proportional hazards model and logistic regression analyses. RESULTS: Donor norepinephrine dose groups were not associated with overall mortality (Group 1 vs 0: hazard ratio [HR] 1.12, 95% confidence interval [CI] 0.87 to 1.43; Group 2 vs 0: HR 1.07, 95% CI 0.82 to 1.39; p = 0.669). No significant group differences were found for rates of 30-day mortality (p = 0.35), 1-year mortality (p = 0.897), primary graft dysfunction (p = 0.898), prolonged ventilation (p = 0.133) and renal replacement therapy (p = 0.324). Groups 1 and 2 showed higher rates of prolonged intensive care unit stay (18.9% vs 28.5% vs 27.5%, p = 0.005). High-dose subgroups did not differ significantly in 1-year mortality (Group HD 1: 14.3%; Group HD 2: 17.8%; p = 0.549). CONCLUSIONS: Acceptance of selected donor hearts supported by higher doses of norepinephrine may be a safe option to increase the donor organ pool.

mTOR Inhibition and Clinical Transplantation: Heart.

This brief overview discusses recent data on the use of mammalian target of rapamycin (mTOR) inhibitors in heart transplantation. Trials on de novo use have shown good efficacy of mTOR inhibitors; however, adverse events are often seen. Conversion protocols in long-term patients are mainly used in patients with renal insufficiency. Calcineurin inhibitor minimization and conversion to calcineurin inhibitor-free protocols have proven to stabilize renal function in recent trials. Lastly, beneficial effects of mTORs against the development of graft vasculopathy, cytomeglovirus infection and malignancy have been shown. Nevertheless, lower tolerability of the drug has affected the long-term use in patients. Future consideration of using mTORs will be individualized protocols in special subpopulation after heart transplantation.