Bivalirudin versus unfractionated heparin for residual thrombus burden: a frequency-domain optical coherence tomography study.

ABSTRACT

OBJECTIVES: This study aimed to compare the effect of bivalirudin and unfractionated heparin (UFH) on residual thrombus burden assessed by frequency-domain optical coherence tomography (FD-OCT), and on angiographic indices of microvascular obstruction (MVO). BACKGROUND: The efficacy of bivalirudin to inhibit thrombus formation inside the stent during percutaneous coronary interventions (PCI) as compared to UFH is unknown. METHODS: Sixty patients with coronary artery disease who underwent post-PCI FD-OCT were studied, including 20 patients treated with bivalirudin and 40 control patients treated with UFH, matched by clinical presentation, stent characteristics, and periprocedural medications. In-stent thrombus volume, thrombus score (number of quadrants with thrombus), and thrombus type (white/red) were assessed by FD-OCT. Thrombolysis in myocardial infarction (TIMI) flow grade, corrected TIMI frame count (cTFC), and Quantitative Blush Evaluator (QuBE) score were recorded. RESULTS: Patients treated with bivalirudin showed similar thrombus volume (0.14 mm(3) [0.00-0.88] vs. 0.13 mm(3) [0.00-0.63], P = 0.962), thrombus score (10 [0-25] vs. 8 [0-21], P = 0.849) and thrombus length (1.70 mm [0.00-4.10] vs. 1.40 mm [0.00-4.05], P = 0.968], as compared with patients treated with UFH. Patients in the bivalirudin group showed lower proportion of white thrombus (55.5% vs. 78.6%, P = 0.016). There was no significant difference in TIMI flow grade, cTFC, and QuBE score between the two groups. CONCLUSIONS: The present study showed similar residual thrombus burden and angiographic indices of MVO immediately after PCI between patients treated with bivalirudin and those treated with UFH.