Frequency and predictors of thrombus inside the guiding catheter during interventional procedures: an optical coherence tomography study.

Optical coherence tomography (OCT) is able to identify thrombus. We detect the frequency of thrombus inside the guiding catheter by OCT and its relationship with clinical and procedural factors. We screened 77 patients who underwent OCT pullbacks. Only patients with visible guiding catheter were finally included (35) and divided into thrombus (21) or no-thrombus group (14). Patients within thrombus group were mostly males (100 vs. 71 %, p = 0.05), with acute coronary syndrome (76 vs. 36 %, p = 0.02) and received more frequently percutaneous coronary intervention (86 vs. 43 %, p = 0.01) as compared to other group. A second dose of heparin was more frequently administered in thrombus than in other group (86 vs. 50 %, p = 0.01). Time between first heparin administration and OCT pullback (41[28-57] vs. 20 min [10-32], p = 0.001), time elapsed from second heparin administration and OCT pullback (29 [19-48] vs. 16 min [12-22], p = 0.002) and total procedural time (47 [36-69] vs. 31 min [26-39], p = 0.005) were longer in thrombus compared to other group. At multivariate analysis, total procedural time and time between first heparin administration and OCT pullback were only predictors of intra-catheter thrombus (HR 0.6 [0.3-0.9], p = 0.03 and HR 1.9 [1.1-3.2], p = 0.02, respectively). Thrombus inside guiding catheter may be a frequent finding in long interventional procedure. Future studies are warranted to determine its clinical impact.