Aortic valve calcification and myocardial fibrosis determine outcome following transcatheter aortic valve replacement.

AIMS: There is evidence to suggest that the subtype of aortic stenosis (AS), the degree of myocardial fibrosis (MF), and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Because little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as their association with adverse cardiac events following transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS: One hundred consecutive patients with severe AS and indication for TAVR were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multidetector computed tomography, and left ventricular endomyocardial biopsies at the time of TAVR. The final study cohort consisted of 92 patients with a completed study protocol, 39 (42.4%) of whom showed a normal ejection fraction (EF) high-gradient (NEFHG) AS, 13 (14.1%) a low EF high-gradient (LEFHG) AS, 25 (27.2%) a low EF low-gradient (LEFLG) AS, and 15 (16.3%) a paradoxical low-flow, low-gradient (PLFLG) AS. The high-gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807 ± 421 and 813 ± 281 mm3 , respectively) as compared with the low-gradient phenotypes (LEFLG and PLFLG; 503 ± 326 and 555 ± 594 mm3 , respectively, P < 0.05). Conversely, MF was most prevalent in low-output phenotypes (LEFLG > LEFHG > PLFLG > NEFHG, P < 0.05). This was paralleled by a greater cardiovascular (CV) mortality within 600 days after TAVR (LEFLG 28% > PLFLG 26.7% > LEFHG 15.4% > NEFHG 2.5%; P = 0.023). In patients with a high MF burden, a higher AVC was associated with a lower mortality following TAVR (P = 0.045, hazard ratio 0.261, 95% confidence interval 0.07-0.97). CONCLUSIONS: MF is associated with adverse CV outcome following TAVR, which is most prevalent in low EF situations. In the presence of large MF burden, patients with large AVC have better outcome following TAVR. Conversely, worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy. The better survival rates in large AVC patients following TAVR indicate TAVR induced relief of severe AS-associated pressure overload with subsequently improved outcome.

Impact of observer experience on multi-detector computed tomography aortic valve morphology assessment and valve size selection for transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) has become the standard treatment for aortic stenosis in older patients. It increasingly relies on accurate pre-procedural planning using multidetector computed tomography (MDCT). Since little is known about the required competence levels for MDCT analyses, we comprehensively assessed MDCT TAVR planning reproducibility and accuracy with regard to valve selection in various healthcare workers. 20 randomly selected MDCT of TAVR patients were analyzed using dedicated software by healthcare professionals with varying backgrounds and experience (two structural interventionalists, one imaging specialist, one cardiac surgeon, one general physician, and one medical student). Following the analysis, the most appropriate Edwards SAPIEN 3™ and Medtronic CoreValve valve size was selected. Intra- and inter-observer variability were assessed. The first structural interventionalist was considered as reference standard for inter-observer comparison. Excellent intra- and inter-observer variability was found for the entire group in regard to the MDCT measurements. The best intra-observer agreement and reproducibility were found for the structural interventionalist, while the medical student had the lowest reproducibility. The highest inter-observer agreement was between both structural interventionalists, followed by the imaging specialist. As to valve size selection, the structural interventionalist showed the highest intra-observer reproducibility, independent of the brand of valve used. Compared to the reference structural interventionalist, the second structural interventionalist showed the highest inter-observer agreement for valve size selection [ICC 0.984, 95% CI 0.969-0.991] followed by the cardiac surgeon [ICC 0.947, 95%CI 0.900-0.972]. The lowest inter-observer agreement was found for the medical student [ICC 0.507, 95%CI 0.067-0.739]. While current state-of-the-art MDCT analysis software provides excellent reproducibility for anatomical measurements, the highest levels of confidence in terms of valve size selection were achieved by the performing interventional physicians. This was most likely attributable to observer experience.

Head-to-Head Comparison of Different Software Solutions for AVC Quantification Using Contrast-Enhanced MDCT.

Aortic valve calcification (AVC) in aortic stenosis patients has diagnostic and prognostic implications. Little is known about the interchangeability of AVC obtained from different multidetector computed tomography (MDCT) software solutions. Contrast-enhanced MDCT data sets of 50 randomly selected aortic stenosis patients were analysed using three different software vendors (3Mensio, CVI42, Syngo.Via). A subset of 10 patients were analysed twice for the estimation of intra-observer variability. Intra- and inter-observer variability were determined using the ICC reliability method, Bland-Altman analysis and coefficients of variation. No differences were revealed between the software solutions in the AVC calculations (3Mensio 941 ± 623, Syngo.Via 948 mm3 ± 655, CVI42 941 ± 637; p = 0.455). The best inter-vendor agreement was found between the CVI42 and the Syngo.Via (ICC 0.997 (CI 0.995-0.998)), followed by the 3Mensio and the CVI42 (ICC 0.996 (CI 0.922-0.998)), and the 3Mensio and the Syngo.Via (ICC 0.992 (CI 0.986-0.995)). There was excellent intra- (3Mensio: ICC 0.999 (0.995-1.000); CVI42: ICC 1.000 (0.999-1.000); Syngo.Via: ICC 0.998 (0.993-1.000)) and inter-observer variability (3Mensio: ICC 1.000 (0.999-1.000); CVI42: ICC 1.000 (1.000-1.000); Syngo.Via: ICC 0.996 (0.985-0.999)) for all software types. Contrast-enhanced MDCT-derived AVC scores are interchangeable between and reproducible within different commercially available software solutions. This is important since sufficient reproducibility, interchangeability and valid results represent prerequisites for accurate TAVR planning and its widespread clinical use.