Feasibility, Accuracy, and Reproducibility of Aortic Valve Sizing for Transcatheter Aortic Valve Implantation Using Virtual Reality.

BACKGROUND: Detailed visualization and precise measurements of aortic valve dimensions are critical for the success of transcatheter aortic valve implantation and for the prevention of complications. Currently, multislice computed tomography is the gold standard for assessment of the aortic annulus and surrounding structures to determine the prosthesis size. New technologies such as virtual reality (VR) not only enable 3-dimensional (3D) visualization with the potential to improve understanding of anatomy and pathology but also allow measurements in 3D. This study aims to investigate the feasibility, accuracy, and reproducibility of VR for the visualization of the aortic valve, the surrounding structures, and its role in preprocedural sizing for transcatheter aortic valve implantation. METHODS AND RESULTS: Based on the preprocedural multislice computed tomography data, 3mensio measurements and 3D visualizations and measurements using VR software were performed retrospectively on 60 consecutive patients who underwent transcatheter aortic valve implantation at our heart center. There were no significant differences but strong correlations between the VR measurements compared with those performed with the 3mensio software. Furthermore, excellent or good intra- and interobserver reliability could be demonstrated for all values. In a structured questionnaire, users reported that VR simplified anatomical understanding, improved 3D comprehension of adjacent structures, and was associated with very good self-perceived depth perception. CONCLUSIONS: The use of VR for preprocedural transcatheter aortic valve implantation sizing is feasible and has precise and reproducible measurements. In addition, 3D visualization improves anatomical understanding and orientation. To evaluate the potential benefits of 3D visualization for planning further cardiovascular interventions, research in this field is needed.

Six-years survival and predictors of mortality after CABG using cold vs. warm blood cardioplegia in elective and emergent settings.

BACKGROUND: The aim of this study was to determine whether intermittent warm blood cardioplegia (IWC) is associated with comparable myocardial protection compared to cold blood cardioplegia (ICC) in patients undergoing elective vs. emergent CABG procedures. METHODS: Out of 2292 consecutive patients who underwent isolated on-pump CABG surgery using cardioplegic arrest either with ICC or IWC between January 2008 and December 2010, 247 consecutive emergent patients were identified and consecutively matched 1:2 with elective patients based on gender, age (<50 years, 50-70 years, >70 years) and ejection fraction (<40 %, 40-50 %, >50 %). Perioperative outcomes and long-term mortality were compared between ICC and IWC strategies and predictors for 30-day mortality and perioperative myocardial injury were identified in both elective and emergent subgroups of patients. RESULTS: Preoperative demographics and baseline characteristics, logistic Euroscore, CPB-time, number of distal anastomoses and LIMA-use were comparable. Aortic cross clamp time was significantly longer in the IWC-group regardless of the urgency of the procedure (p = 0.05 and p = 0.015 for emergent and elective settings). There were no significant differences regarding ICU-stay, ventilation time, total blood loss and need for dialysis. The overall 30-day, 1-, 3- and 6-year survival of the entire patient cohort was 93.7, 91.8, 90.4 and 89.1 %, respectively, with significantly better outcomes when operated electively (p < 0.001) but no differences between ICC and IWC both in elective (p = 0.857) and emergent (p = 0.741) subgroups. Multivariate analysis did not identify the type of cardioplegia as a predictor for 30-day mortality and for perioperative myocardial injury. However, independent factors predictive of 30-day mortality were: EF < 40 % (OR 3.66; 95 % CI: 1.79-7.52; p < 0.001), atrial fibrillation (OR 3.33; 95 % CI: 1.49-7.47; p < 0.003), peripheral artery disease (OR 2.51; 95 % CI: 1.13-5.55; p < 0.023) and COPD (OR 0.26; 95 % CI: 1.05-6.21; p < 0.038); predictors for perioperative myocardial infarction were EF < 40 % (OR 2.04; 95 % CI: 1.32-3.15; p < 0.001), preoperative IABP support (OR 3.68; 95 % CI: 1.34-10.13; p < 0.012), and hemofiltration (OR 3.61; 95 % CI: 2.22-5.87; p < 0.001). CONCLUSION: Although the aortic cross clamp time was prolonged in the IWC group our results confirm effective myocardial protection under IWC, regardless of the urgency of the procedure. We suggest that intermittent warm cardioplegia in emergent CABG setting is a low-cost alternative and safe. It is associated with similar long-term outcomes both in elective and emergent settings compared to intermittent cold cardioplegia.