Culprit lesion impact on intracoronary thrombus in ACS: insights from the OPTICO-ACS study program

The right coronary artery (RCA) is anatomically predisposed to slower flow, greater curvature, and blood stasis, potentially favoring increased thrombus formation. Recent pivotal trials have shown that routine thrombus aspiration does not improve short- or long-term outcomes in acute coronary syndromes (ACS).

To determine whether culprit vessel location influences thrombus formation, morphology, and procedural outcomes in ACS, and to assess whether the hemodynamic predisposition of the RCA translates into a measurable difference in thrombus characteristics or clinical benefit after thrombus aspiration.

In this substudy of the OPTICO-ACS registry, we included ACS patients undergoing thrombus aspiration and optical coherence tomography (OCT) imaging of the culprit lesion before PCI. Culprit vessels were categorized as RCA or left coronary artery (LCA). Thrombus burden was assessed angiographically, while OCT quantified thrombus score, area, volume, and burden. Procedural and clinical outcomes were compared between groups.

Among 255 patients (RCA = 88, LCA = 167), RCA lesions were independently associated with higher angiographic thrombus burden (adjusted OR 2.10, 95% CI 1.23–3.76; p = 0.007). OCT analysis confirmed greater thrombus area (p = 0.04) and volume (p = 0.01) in RCA compared with LCA lesions. No significant differences were observed in post-procedural TIMI 3 flow (p = 0.73). At 30-day follow-up, rates of non-fatal myocardial infarction (0% vs 2.4%) and target vessel revascularization or hospitalization for angina (2.3% vs 4.2%) numerically favored RCA lesions, without reaching statistical significance (p = 0.14 and 0.43, respectively).

RCA culprit lesions in ACS exhibit a greater thrombus burden, confirmed by both angiographic and OCT-derived measurements. Despite these morphological differences, procedural and clinical outcomes were comparable across coronary territories, suggesting that thrombus aspiration may mitigate—but not eliminate—the higher thrombogenic potential of the right coronary artery. These findings are hypothesis-generating and suggest that vessel-specific differences in thrombus morphology may influence procedural strategies in selected ACS patients, warranting further dedicated studies.