Impact of Venoarterial Extracorporeal Membrane Oxygenation on Alkaline Phosphatase Metabolism after Cardiac Surgery.

(1) Alkaline phosphatase (AP) is consumed during cardiopulmonary bypass (CPB). A high AP depletion leads to an impaired outcome after cardiac surgery. However, data is scarce on the postoperative course of AP under venoarterial ECMO (VA-ECMO) support. (2) A total of 239 patients with VA-ECMO support between 2000 and 2019 at the Department of Cardiac Surgery (Vienna General Hospital, Austria) were included in this retrospective analysis. Blood samples were collected at several timepoints (baseline, postoperative day (POD) 1-7, POD 14 and 30). Patients were categorized according to the relative AP drop (<60% vs. ≥60%) and ECMO duration (<5 days vs. ≥5 days). (3) Overall, 44.4% reached the baseline AP values within 5 days-this was only the case for 28.6% with a higher AP drop (compared to 62.7% with a lower drop; p = 0.000). A greater AP drop was associated with a significantly higher need for renal replacement therapy (40.9% vs. 61.9%; p = 0.002) and an impaired 1-year survival (51.4% vs. 66.0%; p = 0.031). (4) CPB exceeds the negative impact of VA-ECMO; still, ECMO seems to delay alkaline phosphatase recovery. A greater initial AP drop bears the risk of higher morbidity and mortality.

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.

Transcatheter Caval Valve Implantation of the Tricento Valve for Tricuspid Regurgitation Using Advanced Intraprocedural Imaging.

A 75-year-old patient with previous mitral and tricuspid reconstruction experienced severe tricuspid regurgitation. On the basis of a prohibitive surgical risk, an interventional heterotopic tricuspid valve implantation was planned. Implantation was performed using fusion-imaging, which facilitated intraprocedural navigation. At 6-month follow-up, the patient presented in improved condition with reduced symptoms. (Level of Difficulty: Advanced.).

Intravenous Heme Arginate Induces HO-1 (Heme Oxygenase-1) in the Human Heart.

Objective- HO-1 (heme oxygenase-1) induction may prevent or reduce ischemia-reperfusion injury. We previously evaluated its in vivo induction after a single systemic administration of heme arginate in peripheral blood mononuclear cells. The current trial was designed to assess the pharmacological tissue induction of HO-1 in the human heart with heme arginate in vivo. Approach and Results- Patients planned for conventional aortic valve replacement received placebo (n=8), 1 mg/kg (n=7) or 3 mg/kg (n=9) heme arginate infused intravenously 24 hours before surgery. A biopsy of the right ventricle was performed directly before aortic cross-clamping and after cross-clamp release. In addition, the right atrial appendage was partially removed for analysis. HO-1 protein and mRNA concentrations were measured in tissue samples and in peripheral blood mononuclear cells before to and up to 72 hours after surgery. No study medication-related adverse events occurred. A strong, dose-dependent effect on myocardial HO-1 mRNA levels was observed (right ventricle: 7.9±5.0 versus 88.6±49.1 versus 203.6±148.7; P=0.002 and right atrium: 10.8±8.8 versus 229.8±173.1 versus 392.7±195.7; P=0.001). This was paralleled by a profound increase of HO-1 protein concentration in atrial tissue (8401±3889 versus 28 585±10 692 versus 29 022±8583; P<0.001). Surgery and heme arginate infusion significantly increased HO-1 mRNA concentration in peripheral blood mononuclear cells ( P<0.001). HO-1 induction led to a significant increase of postoperative carboxyhemoglobin (1.7% versus 1.4%; P=0.041). No effect on plasma HO-1 protein levels could be detected. Conclusions- Myocardial HO-1 mRNA and protein can be dose-dependently induced by heme arginate. Protective effects of this therapeutic strategy should be evaluated in upcoming clinical trials. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT02314780.

The Ross procedure offers excellent survival compared with mechanical aortic valve replacement in a real-world setting.

OBJECTIVES: The ideal prosthesis for young patients requiring aortic valve replacement has not been defined to date. Although the Ross procedure provides excellent survival, its application is still limited. We compared the long-term survival after the Ross procedure with mechanical aortic valve replacement. METHODS: All consecutive Ross procedures and mechanical aortic valve replacements performed between 1991 and 2008 at a single centre were analysed. Only adult patients between 18 and 50 years of age were included in the study. Survival and valve-related complications were evaluated. Furthermore, survival was compared with the age- and sex-matched Austrian population. RESULTS: A total of 159 Ross patients and 173 mechanical valve patients were included. The cumulative survival for the Ross procedure was significantly better, with survival rates of 96, 94 and 93% at 5, 10 and 15 years, respectively, in comparison to 90, 84 and 75% (P < 0.01) for patients with mechanical valves. A Cox regression analysis including patients' age, gender and valve type revealed age and the type of aortic valve replacement as independent significant factors influencing survival (for age, hazard ratio = 1.1, 95% confidence interval = 1.0-1.1, P = 0.03; and for valve type, hazard ratio = 2.6, 95% confidence interval = 1.2-5.8, P = 0.02). The observed survival was comparable to the expected standard survival for the Ross group but was significantly reduced in the mechanical valve group. CONCLUSIONS: In a real-world setting, the Ross procedure is associated with a long-term survival benefit in young adults in comparison to mechanical aortic valve replacement.