Threshold for calcium volume evaluation in patients with aortic valve stenosis: correlation with Agatston score

Abstract

Background The evaluation of aortic valve calcium burden is important when planning for transcatheter aortic valve implantation (TAVI). Although a robust golden standard methodology is available for calcium evaluation on noncontrast-enhanced (NCE) computed tomographic (CT) series, a standard reference for calcium assessment on contrast-enhanced CT series is currently lacking. Methods Two hundred and forty-four preprocedural CT scans from patients who had received TAVI were analysed. We correlated the aortic calcium volumes obtained on CE series at three thresholds [450, 850, and ‘probe + 100’ Hounsfield Units (HU)] with the Agatston score obtained on NCE scans. A subgroup analysis was performed taking into account the contrast enhancement of the left ventricular outflow tract (LVOT), with a prespecified cut-off of 300 HU. Results The overall population analysis showed higher correlation with the Agatston score using the 850 HU threshold (r = 0.45, P < 0.0001); no correlation was found with the 450 HU threshold, whilst the ‘probe + 100’ HU threshold showed a weaker correlation (r = 0.30, P < 0.0001). In patients with LVOT enhancement less than 300 HU, 450 HU showed the highest accuracy in calcium identification (r = 0.70, P < 0.0001), whereas in patients with LVOT enhancement of at least 300 HU, the most accurate threshold was 850 HU (r = 0.46, P < 0.0001). Conclusion The thresholds for correct calcium identification using the automatic 3Mensio software depend on the contrast enhancement of aortic and cardiac structures, which can be estimated by measuring the HU in the LVOT. In patients with LVOT HU of less than 300, the correct threshold to be set in the software is 450 HU, whereas in patients with LVOT HU of at least 300 the correct threshold is 850 HU.

Acute expansion of nitinol-based self-expandable device in patients undergoing transfemoral aortic valve implantation

“…Transcatheter aortic valve replacement (TAVR) is the treatment of choice for patients with severe symptomatic aortic stenosis and has become the preferred strategy in patients at intermediate/high surgical risk 1–5 . In the last decade, many efforts have been made to improve patient selection for TAVR, and reduce procedural complications and adverse outcomes 6–13 . In patients undergoing TAVR, prosthesis adaptation to the aortic root is of paramount importance to avoid severe paravalvular leaks, achieve an effective orifice area and minimize patient–prosthesis mismatch 14,15 …”

“…[1][2][3][4][5] In the last decade, many efforts have been made to improve patient selection for TAVR, and reduce procedural complications and adverse outcomes. [6][7][8][9][10][11][12][13] In patients undergoing TAVR, prosthesis adaptation to the aortic root is of paramount importance to avoid severe paravalvular leaks, achieve an effective orifice area and minimize patientprosthesis mismatch. 14,15 Of interest, it is widely described that TAVR with a balloon-expandable valve was systematically associated with a certain degree of valve stent recoil.…”

Cardiovascular imaging updates and future perspectives

“…25 The calcium score assessment by using the Agatston score before TAVI is essential; in patients with LV outflow tract (LVOT) Hounsfield unit (HU) of less than 300, the correct threshold to be set in the CT software is 450 HU, whereas in patients with LVOT HU of at least 300 the correct threshold is 850 HU. 26 It has also been shown that psoas muscular attenuation CT measurement (mean HU and high-density/low-density muscle) are independent and incremental predictors of allcause mortality in patients undergoing TAVI. 27 CT is also crucial for the success of transcatheter valve replacement, allowing a complete evaluation of mitral and tricuspid apparatus and biventricular anatomy.…”

“…The calcium score assessment by using the Agatston score before TAVI is essential; in patients with LV outflow tract (LVOT) Hounsfield unit (HU) of less than 300, the correct threshold to be set in the CT software is 450 HU, whereas in patients with LVOT HU of at least 300 the correct threshold is 850 HU 26 …”

Overinflation of balloon‐expandable valves for transcatheter treatment of pure noncalcified native aortic regurgitation: How much oversizing is needed and achievable?

“…Abbreviations: AR, aortic regurgitation; AV, aortic valve; CT, computerized tomography; LVEF, left ventricular ejection fraction; Pt, patient; RCC, right coronary cusp; STS, Society of Thoracic Surgeons; THV, transcatheter heart valve; VBR, virtual basal ring. a Measured at 850 HU using automated 3mensio Structural Heart 10.2 software 9. …”