Cardiac thrombotic stability determined by contrast-enhanced echocardiography: investigative protocol and preliminary results

Abstract

Objective This study’s intent was to test a new system for scoring cardiac thrombotic stability, based on contrast-enhanced ultrasound (CEUS). Methods We used human whole blood for an in vitro thrombotic model involving 1-h (T1h) and 7-day (T7d) subsets. The T1h group was monitored for 1 h continuously to observe for the formation of a new thrombus on the original thrombus base. Changes in thrombotic CEUS images, histologic features, and shear wave elastography were recorded over time. We also studied 28 patients diagnosed with cardiac thrombi, each examined by transthoracic echocardiography and CEUS.Thrombi were scored for substrate (Ts) and hardness (Th) based on the visualized degree of contrast penetration into the thrombi. Statistical analyses of Ts and Th reflected thrombolytic time and risk of embolism to other organs. Results Histologically, the loosely constructed ends of in vitro thrombi solidified over time. In addition, the average Young’s modulus of thrombi over time indicated a progressive increase in hardness. Contrast-enhancing agents were able to penetrate fresh, loose thrombi only, not chronic, stable thrombi. As Ts and Th increased, prolonged thrombolytic time and greater risk of embolism to other organs were apparent. Conclusions Our data suggest that this new CEUS scoring system correlates well with cardiac thrombotic hardness and the quality of its underlying substrate, serving to quantify thrombotic stability.

The diagnostic accuracy of contrast echocardiography in patients with suspected cardiac masses: A preliminary multicenter, cross-sectional study

“…However, three cases had a much higher A1/A2 (1.91, 2.12, and 1.85, respectively), likely because these three cases were fresh thrombi. The loose texture of a fresh thrombus and the ability of the ultrasound-enhancing agents to enter from the periphery at the beginning of CE result in a higher A1/A2, which is consistent with a previous study (19). Conversely, the texture of an old thrombus is dense, and the microbubbles of the ultrasound-enhancing agents cannot enter, resulting in A1/A2 values close to zero.…”

“…All patients were adults. Exclusion criteria included allergies to albumin, blood products, and ultrasound enhancing agents; severe heart failure (New York Heart Association Class IV) and severe arrhythmia patients; respiratory failure; severe liver or kidney dysfunction; and mental illness or epilepsy (19).…”