Author + information
- Received October 30, 2014
- Accepted November 6, 2014
- Published online April 20, 2015.
- Hiroki Ikenaga, MD,
- Satoshi Kurisu, MD, PhD∗ (, )
- Ken Ishibashi, MD, PhD,
- Yoshihiro Dohi, MD, PhD,
- Yukihiro Fukuda, MD, PhD and
- Yasuki Kihara, MD, PhD
- Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
- ↵∗Reprint requests and correspondence:
Dr. Satoshi Kurisu, Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
- coronary angioscopy
- optical coherence tomography
- paclitaxel-coated balloon angioplasty
- slow-flow phenomenon
In case 1, a 60-year-old man underwent a 4.0-mm × 12-mm bare-metal stent (BMS) implantation in the proximal left anterior descending coronary artery. Six months after BMS implantation, a coronary angiogram demonstrated in-stent restenosis (ISR) at the proximal portion of the stent (Figure 1A-a). Frequency-domain optical coherence tomography (FD-OCT) revealed homogeneous neointima (Figure 1B-a) and coronary angioscopy (CAS) revealed white neointimal coverage at the ISR site (Figure 1C-a). The lesion was dilated using a 3.5 × 13-mm conventional balloon catheter at 16 atm. After balloon angioplasty, Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 was achieved, and intracoronary electrocardiography did not change (Figure 1D-a). Subsequently, angioplasty with a 3.5-mm × 30-mm paclitaxel-coated balloon (PCB) (SeQuent Please, B. Braun Melsungen AG, Melsungen, Germany) was performed at the lesion at 9 atm for 30 s (Figure 1A-b). Just after the PCB deflation, ST-segment elevation was recorded in leads V1 to V3 on a surface electrocardiogram, and the slow-flow phenomenon was observed. Similarly, intracoronary electrocardiography showed ST-segment elevation (Figure 1D-b). Intracoronary administration of nitroprusside (90 μg) improved ST-segment elevation. Then, FD-OCT revealed superficial high signals with backscattering indicating paclitaxel, which was released from the PCB (Figure 1B-b, red arrows). CAS revealed white granular materials that might indicate undissolved drugs on the neointima (Figure 1C-b). Finally, TIMI flow grade 3 was achieved (Figure 1A-c).
In case 2, a 80-year-old man with BMS-ISR 17 years after BMS implantation in the proximal left anterior descending coronary artery underwent a PCB angioplasty. FD-OCT revealed lipid-rich neointima (Figure 2B-a), and CAS revealed yellow neointimal coverage at the ISR site (Figure 2C-a). As with case 1, just after the PCB deflation, slow-flow phenomenon was observed. In this case, CAS revealed that undissolved drugs were floating and flowed distally (Figure 2C-c, blue arrow, Online Video 1).
Corrected TIMI frame count in these 2 cases was not changed before PCB angioplasty. However, just after PCB angioplasty, the corrected TIMI frame count became higher, which might demonstrate slow-flow phenomenon (Figure 3).
PCB has been used for BMS-ISR because previous studies have shown that PCB angioplasty is safe and effective in treating BMS-ISR (1). Although PCB is now widely used, there are few reports on intracoronary imaging of the drug-coated neointima after PCB angioplasty. In the current report, slow-flow phenomenon after PCB angioplasty was observed, and OCT and CAS nicely revealed drug-coated neointimal plaque after PCB angioplasty. To our knowledge, this is the first report of the case that slow-flow phenomenon occurred after PCB angioplasty and drug-coated neointimal plaque was evaluated by OCT and CAS. It was reported that PCB angioplasty was associated with diminished endothelial-dependent vasomotor function (2) and acute decrease in coronary flow reserve (3). In these cases, the slow-flow phenomenon after PCB angioplasty was partly caused by an impaired microvascular response as a result of drugs. In addition, CAS revealed white granular materials that might indicate undissolved drugs on the neointima. Furthermore, CAS revealed that these materials flowed distally in case 2. Histopathological study reported that PCB angioplasty led to the possibility of distal embolization (4). Although the exact pathophysiological mechanism leading to acutely slow-flow phenomenon remains unclear, it could be thought that distal embolization of drugs after PCB angioplasty led to slow-flow phenomenon. We think that such intracoronary findings might have significant implications for further refining PCB angioplasty.
For an accompanying video, please see the online version of this article.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received October 30, 2014.
- Accepted November 6, 2014.
- American College of Cardiology Foundation
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