Thin-cap fibroatheroma and large calcification at the proximal stent edge correlate with a high proportion of uncovered stent struts in the chronic phase.

OBJECTIVE: A high proportion of uncovered stent struts is associated with late stent thrombosis after drug-eluting stent (DES) implantation, which frequently results in myocardial infarction or death. However, the predictors of uncovered stent struts remain unknown. Here, using optical coherence tomography (OCT), we studied the baseline tissue characteristics of the target coronary segment and evaluated their influence on the neointimal coverage of the strut in the chronic phase. METHODS: We analyzed 118 coronary lesions treated with OCT-guided DES implantation. OCT examinations of target lesions were performed before and after DES implantation, and tissue characteristics were evaluated within 5 mm outer segment of both stent edges. At follow-up, stent strut coverage was assessed within 5 mm inner segment from each stent edge. On the basis of the proportion of uncovered stent struts in the chronic phase, target segments were divided into poorly covered (the highest quartile with % uncovered struts, n=29) and well-covered (the remaining lower quartiles with % uncovered struts, n=89) groups. RESULTS: Clinical parameters were similar between the two groups. On baseline OCT images, thin-cap fibroatheroma (TCFA) and large calcification were more frequently observed in the poorly covered group than the well-covered group (10.3 vs. 0.0%, P=0.0032, and 27.6 vs. 9.0%, P=0.017, respectively). Furthermore, multivariable analysis showed TCFA and large calcification at the proximal edge, but not at the distal edge, were predictors of uncover stent struts. CONCLUSION: TCFA and large calcification at the proximal stent edge are strong predictors of uncovered stent struts. OCT is useful for selecting stent landing sites in terms of future occurrence of uncovered stent struts.

Changes in the reference lumen size of target lesions before and after coronary stent implantation: Evaluation with frequency domain optical coherence tomography.

OBJECTIVE: In optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI), stent size is usually determined according to the pre-PCI lumen size of either the distal or proximal reference site. However, the effect of the OCT imaging catheter crossing the target lesion on the reference lumen measurements has not been studied. We evaluated changes in the reference lumen size before and after PCI using frequency domain OCT. METHODS: For 100 consecutive patients with PCI, mean lumen diameter (LD) and lumen area (LA) were measured at the proximal and distal reference sites before and after coronary stent implantation with OCT. RESULTS: Mean LD and LA of the distal reference site were significantly increased after PCI with stent implantation (2.57 ± 0.6 to 2.62 ± 0.64 mm, p < 0.01 and 5.20 ± 2.66 to 5.41 ± 2.54 mm2, p < 0.01, respectively). By contrast, these indices at the proximal reference site were significantly decreased. ROC curve analysis selected MLA of 1.50 mm2 as the best cutoff value for changes in mean LD. Distal mean LD was markedly increased after PCI in lesions with MLA < 1.50 mm (2.28 ± 0.48 to 2.40 ± 0.17 mm, P < 0.001), but did not change in lesions with MLA > 1.50 mm2. Tissue characteristics were not correlated with changes in reference lumen size. CONCLUSIONS: When we select the stent size during OCT-guided PCI, we need to pay attention to the decrease in the luminal measurement of the reference sites, especially in lesions with tight stenosis.

Primary cardiac lymphoma: echocardiography and F-18-fluorodeoxyglucose positron emission tomography in selection of a biopsy site.

A 63-year-old man was referred to our hospital because of a cardiac tumor. Transthoracic echocardiography revealed a rough, mobile tumor in the dilated right atrium, and transesophageal echocardiography showed that the tumor consisted of small, botryoidal masses. Catheter-based biopsy carried a high risk of embolism. Therefore, we used F-18-fluorodeoxyglucose positron emission tomography (FDG-PET), which revealed an abnormal accumulation in the right cervical lymph nodes, as well as in the heart. We safely performed biopsy of the lymph nodes and diagnosed the patient with primary cardiac lymphoma. We concluded that echocardiography and FDG-PET are useful for selecting an appropriate biopsy site in primary cardiac lymphoma.