Transcutanous aortic valve replacement with Medtronic CoreValve in a publicprivate partnership hospital complex

Objective: The aim of this study was to assess the initial experience of transcutaneous aortic valve implantation (TAVI) in a high risk aortic stenosis population not suitable for conventional surgical valve replacement. Background: No data exist for TAVI with Medtronic CoreValve in South Africa and especially not in a public private partnership hospital complex. Methods: Retrospective data regarding severe aortic stenosis evaluation, risk stratifi cation and management were evaluated over a 24 month period. Results: A total of 106 patients were evaluated of whom17 were accepted for surgical valve replacement (SVR) while TAVI was attempted in 25. The CoreValve was successfully implanted in 96% (24/25) of the cases. No procedural or peri-procedural deaths occurred. Threepatients required permanent pacemaker insertion in the peri-procedural period and 2 patients had vascular access complications requiring blood transfusion only. Median hospital stay was 3.7days (range: 2 - 7). Aortic valve gradient showed a signifi cant reduction after valve implantation, which was sustained during follow-up (p<0.001). NYHA class symptomatology also improved from a median of 3.3 to 1.0 (p<0.001). During follow-up there were 4 late deaths, not related to the procedure, occurring after 78 to 193 days. Average cost for private and government patients were R268 000.00 and R163 000.00 respectively. Conclusions: The CoreValve can be implanted with a high success rate. Short term mortality and morbidity are acceptable. Signifi cant symptomatic improvement is gained at follow-up. The fi nancial implications are important

Quantification of Myocardial Creatine and Triglyceride Content in the Human Heart: Precision and Accuracy of in vivo Proton Magnetic Resonance Spectroscopy

Background: Proton magnetic resonance spectroscopy ( 1H-MRS) of the human heart is deemed to be a quantitative method to investigate myocardial metabolite content, but thorough validations of in vivo measurements against invasive techniques are lacking. Purpose: To determine measurement precision and accuracy for quantifications of myocardial total creatine and triglyceride content with localized 1H-MRS. Study type: Test–retest repeatability and measurement validation study. Subjects: Sixteen volunteers and 22 patients scheduled for open-heart aortic valve replacement or septal myectomy. Field Strength/Sequence: Prospectively ECG-triggered respiratory-gated free-breathing single-voxel point-resolved spectroscopy (PRESS) sequence at 3 T. Assessment: Myocardial total creatine and triglyceride content were quantified relative to the total water content by fitting the 1H-MR spectra. Precision was assessed with measurement repeatability. Accuracy was assessed by validating in vivo 1H-MRS measurements against biochemical assays in myocardial tissue from the same subjects. Statistical Tests: Intrasession and intersession repeatability was assessed using Bland–Altman analyses. Agreement between 1H-MRS measurements and biochemical assay was tested with regression analyses. Results: The intersession repeatability coefficient for myocardial total creatine content was 41.8% with a mean value of 0.083% ± 0.020% of the total water signal, and 36.7% for myocardial triglyceride content with a mean value of 0.35% ± 0.13% of the total water signal. Ex vivo myocardial total creatine concentrations in tissue samples correlated with the in vivo myocardial total creatine content measured with 1H-MRS: n = 22, r = 0.44; P < 0.05. Likewise, ex vivo myocardial triglyceride concentrations correlated with the in vivo myocardial triglyceride content: n = 20, r = 0.50; P < 0.05. Data Conclusion: We validated the use of localized 1H-MRS of the human heart at 3 T for quantitative assessments of in vivo myocardial tissue metabolite content by estimating the measurement precision and accuracy. Level of Evidence: 2. Technical Efficacy Stage: 2