Photon-Counting Detector CT Virtual Monoenergetic Images for Coronary Artery Stenosis Quantification: Phantom and In Vivo Evaluation.

BACKGROUND. Calcium blooming causes stenosis overestimation on coronary CTA. OBJECTIVE. The purpose of this article was to evaluate the impact of virtual monoenergetic imaging (VMI) reconstruction level on coronary artery stenosis quantification using photon-counting detector (PCD) CT. METHODS. A phantom containing two custom-made vessels (representing 25% and 50% stenosis) underwent PCD CT acquisitions without and with simulated cardiac motion. A retrospective analysis was performed of 33 patients (seven women, 26 men; mean age, 71.3 ± 9.0 [SD] years; 64 coronary artery stenoses) who underwent coronary CTA by PCD CT followed by invasive coronary angiography (ICA). Scans were reconstructed at nine VMI energy levels (40-140 keV). Percentage diameter stenosis (PDS) was measured, and bias was determined from the ground-truth stenosis percentage in the phantom and ICA-derived quantitative coronary angiography measurements in patients. Extent of blooming artifact was measured in the phantom and in calcified and mixed plaques in patients. RESULTS. In the phantom, PDS decreased for 25% stenosis from 59.9% (40 keV) to 13.4% (140 keV) and for 50% stenosis from 81.6% (40 keV) to 42.3% (140 keV). PDS showed lowest bias for 25% stenosis at 90 keV (bias, 1.4%) and for 50% stenosis at 100 keV (bias, -0.4%). Blooming artifacts decreased for 25% stenosis from 61.5% (40 keV) to 35.4% (140 keV) and for 50% stenosis from 82.7% (40 keV) to 52.1% (140 keV). In patients, PDS for calcified plaque decreased from 70.8% (40 keV) to 57.3% (140 keV), for mixed plaque decreased from 69.8% (40 keV) to 56.3% (140 keV), and for noncalcified plaque was 46.6% at 40 keV and 54.6% at 140 keV. PDS showed lowest bias for calcified plaque at 100 keV (bias, 17.2%), for mixed plaque at 140 keV (bias, 5.0%), and for noncalcified plaque at 40 keV (bias, -0.5%). Blooming artifacts decreased for calcified plaque from 78.4% (40 keV) to 48.6% (140 keV) and for mixed plaque from 73.1% (40 keV) to 44.7% (140 keV). CONCLUSION. For calcified and mixed plaque, stenosis severity measurements and blooming artifacts decreased at increasing VMI reconstruction levels. CLINICAL IMPACT. PCD CT with VMI reconstruction helps overcome current limitations in stenosis quantification on coronary CTA.

Transapical Mitral Valve Replacement: 1-Year Results of the Real-World Tendyne European Experience Registry.

BACKGROUND: Early studies of the Tendyne transcatheter mitral valve replacement (TMVR) showed promising results in a small selective cohort. OBJECTIVES: The authors present 1-year data from the currently largest commercial, real-world cohort originating from the investigator-initiated TENDER (Tendyne European Experience) registry. METHODS: All patients from the TENDER registry eligible for 1-year follow-up were included. The primary safety endpoint was 1-year cardiovascular mortality. Primary performance endpoint was reduction of mitral regurgitation (MR) up to 1 year. RESULTS: Among 195 eligible patients undergoing TMVR (median age 77 years [Q1-Q3: 71-81 years], 60% men, median Society of Thoracic Surgeons Predicted Risk of Mortality 5.6% [Q1-Q3: 3.6%-8.9%], 81% in NYHA functional class III or IV, 94% with MR 3+/4+), 31% had "real-world" indications for TMVR (severe mitral annular calcification, prior mitral valve treatment, or others) outside of the instructions for use. The technical success rate was 95%. The cardiovascular mortality rate was 7% at 30 day and 17% at 1 year (all-cause mortality rates were 9% and 29%, respectively). Reintervention or surgery following discharge was 4%, while rates of heart failure hospitalization reduced from 68% in the preceding year to 25% during 1-year follow-up. Durable MR reduction to ≤1+ was achieved in 98% of patients, and at 1 year, 83% were in NYHA functional class I or II. There was no difference in survival and major adverse events between on-label use and "real-world" indications up to 1 year. CONCLUSIONS: This large, real-world, observational registry reports high technical success, durable and complete MR elimination, significant clinical benefits, and a 1-year cardiovascular mortality rate of 17% after Tendyne TMVR. Outcomes were comparable between on-label use and "real-world" indications, offering a safe and efficacious treatment option for patients without alternative treatments. (Tendyne European Experience Registry [TENDER]; NCT04898335).