Dual quantitative coronary angiography accurately quantifies intracoronary thrombotic burden in patients with acute coronary syndrome: Comparison with optical coherence tomography imaging

Abstract

Background: Dual quantitative coronary angiography (QCA) has been recently tested for assessment of intracoronary thrombus volume in experimental models. The present study aimed to validate dual QCA in vivo for the assessment of thrombus burden by exploring the correlations between dual QCA-thrombus volume and optical coherence tomography (OCT)-derived indices of thrombotic burden.

Methods and results: Fifty-one patients with ACS and angiographic evidence of thrombus undergoing OCT of the culprit lesion before stenting were included. Dual QCA-thrombus volume was calculated as difference between edge-detection and video-densitometry area functions along the target segment. Culprit lesion was categorized using the Ambrose's and AHA/ACC angiographic classifications. Thrombus volume (mean thrombus area × thrombus length), thrombus burden [(mean thrombus area/mean lumen area) x100] and Prati thrombus score (number of quadrants with thrombus) were measured by OCT, and the presence of plaque rupture (PR) or intact fibrous cap (IFC) was assessed. Dual QCA-thrombus volume correlated significantly with OCT-thrombus volume (R = 0.791), thrombus burden (R = 0.767) and Prati thrombus score (R = 0.600) (all p < 0.001). Dual-QCA thrombus volume was significantly higher in patients with PR compared with those with IFC (3.48 mm³ [1.45-11.26] vs. 1.69 mm³ [0.09-5.02], p = 0.013). Compared with IFC, PR showed higher prevalence of eccentric type II Ambrose lesion (41.7% vs. 7.4%, p = 0.004), complex B2/C lesion (87.5% vs. 55.6%, p = 0.012), and heavy calcification (29.2% vs. 3.7%, p = 0.013).

Conclusions: Dual QCA analysis appears to be a promising tool for quantification of intracoronary thrombus in vivo. This novel methodology may be useful to guide intracoronary thrombus removal during percutaneous coronary intervention and to aid prognostic stratification in patients with ACS.

Keywords: Acute coronary syndrome; Intact fibrous cap; Optical coherence tomography; Plaque rupture; Quantitative coronary angiography; Thrombus.