CTA-derived Hounsfield units >105 distinguish leaflet fibrosis from thrombosis with 84% sensitivity and 91% specificity in patients with bioprosthetic heart valve dysfunction.
Observational (n=141)
Blinded image analysis
No
Does computed tomography angiography-derived Hounsfield unit measurement differentiate between thrombosis and leaflet fibrosis in patients with bioprosthetic heart valve dysfunction?
CTA-derived Hounsfield units can accurately differentiate between bioprosthetic valve thrombosis and fibrosis, with values >105 HU strongly suggesting fibrosis that is unresponsive to oral anticoagulation.
Effect estimate: AUC 0.94 (95% CI 0.897–0.983)
Absolute Event Rate: 137% vs 87%
p-value: p=<0.001
Abstract Purpose Our hypothesis was that computed tomography angiography (CTA)-derived Hounsfield units (HU) can differentiate between thrombosis and leaflet fibrosis (defined by a lack of response to oral anticoagulation) in patients with bioprosthetic heart valve dysfunction. Materials and methods Valvular leaflet HU were retrospectively assessed in 95 patients (derivation cohort) undergoing CTA 35 days after bioprosthetic heart valve (BHV) implantation showing signs of subclinical leaflet thrombosis (hypoattenuated leaflet thickening, HALT). A second (validation) cohort included 46 patients undergoing CTA for suspected BHV dysfunction 2 years interquartile range IQR 1.5–5.0 after valve replacement. This study included CTA between May 2012 and December 2017. Results In the derivation cohort, the median HU (95 patients) was 87 (IQR 77; 96). In the validation cohort, patients with resolution of findings in a follow-up CTA after newly initiated anticoagulation (“thrombosis” subgroup, 19 patients) similarly demonstrated HU of 87 (IQR 74; 100) ( p = 0.816). In contrast, patients without improvement under oral anticoagulation (“fibrosis” subgroup, 27 patients) exhibited a median of 137 HU (IQR 116, 164; p < 0.001 vs. thrombosis subgroup). In multivariable Cox regression analysis, lower HU were an independent predictor of thrombosis. C-statistics demonstrated an area under the receiver operating characteristic curve of 0.94 ± 0.02 (CI 0.897–0.983, p < 0.001) with a value of 105 HU resulting in a sensitivity of 84% and a specificity of 91% for the differentiation between thrombosis and fibrosis. Conclusion A value of 105 HU on CTA provides good discriminatory power to distinguish between leaflet fibrosis (as defined by a lack of response to oral anticoagulation) and thrombosis after bioprosthetic valve replacement and may help in choosing optimal treatment. Graphical Abstract
Schmitt et al. (Thu,)는 판막 혈전증 또는 판막 섬유증이 의심되는 생체 재료 심장판막 기능 장애 환자(n=141)를 대상으로 관찰 연구를 수행했습니다. 컴퓨터 단층촬영 angiography에서 유도된 Hounsfield 단위 평가 대 혈전증에 대한 진단 대 경구 항응고제 반응으로 정의된 판막 섬유증의 구분이 평가되었습니다 (AUC 0.94, 95% CI 0.897–0.983, p=<0.001). CTA에서 유도된 Hounsfield 단위 >105는 생체 재료 심장판막 기능 장애 환자에서 혈전증과 판막 섬유증을 84% 민감도 및 91% 특이도로 구분합니다.