Stentless treatment strategy for left circumflex artery ostial stenosis: Directional coronary atherectomy followed by drug-eluting balloon

Abstract

A 60-year-old man with history of exertional angina pectoris was referred for treatment of an ostial left circumflex (LCX) coronary artery stenosis. The branch angle between left anterior descending artery (LAD) and LCX was shallow, therefore stent implantation seemed at risk of “carina shift” of plaque to the LAD ostium as well as higher in-stent restenosis. Therefore, directional coronary atherectomy (DCA, Atherocut™, L-size, NIPRO, Osaka, Japan) was performed at the ostium of the LCX lesion. After evaluating plaque accumulation using intravascular ultrasound (IVUS), DCA was circumferentially performed 16 times, from 2 atm to 3 atm, using an 8 fr guide system. Although angiogram and IVUS showed excellent results, adjunctive balloon dilatation with 3.5 mm paclitaxel-coated balloon was performed to prevent restenosis. At 8 months, the patient reported being angina-free, and subsequent follow-up angiogram showed no restenosis of LCX. Paclitaxel-coated balloon following DCA for LCX ostial stenosis seems to be safe and effective for both acute and chronic results, suggesting a potential stentless therapeutic option.

<Learning objective: Directional coronary atherectomy in combination with drug-eluting balloon may be a potential stentless therapeutic option, especially for the ostial stenosis of left circumflex artery.>

Introduction

Drug-eluting stents have markedly improved clinical outcomes of patients treated with percutaneous coronary intervention by reducing both restenosis and repeat revascularization rates. However, bifurcation stenting, specifically with involvement of the left main coronary artery, is still challenging due to the possible carina shift or requirement of prolonged dual antiplatelet therapy, and continued restenosis. Recently, directional coronary atherectomy (DCA) has been revived in Japan, and is being combined with drug-eluting balloons (DEB) as a potential treatment strategy to reduce restenosis. We describe a case report of stentless treatment strategy using DEB following DCA for left circumflex artery (LCX) ostial stenosis.

Case report

A 60-year-old man with history of exertional angina pectoris was referred for treatment of an ostial LCX coronary artery stenosis (Fig. 1A and B). His coronary risk factors included hypertension, dyslipidemia, and type 2 diabetes, but no renal dysfunction. Electrocardiography showed sinus rhythm without any abnormal ST-T changes. However, subsequent exercise treadmill study revealed horizontal ST depression in precordial leads. Coronary angiography was then performed and showed a tight stenosis in the ostial LCX. However, the branch angle between the left anterior descending artery (LAD) and LCX was shallow, therefore stent implantation from left main coronary artery to LCX seemed at risk of “carina shift” of plaque to the LAD ostium, as well as higher in-stent restenosis. Therefore, DCA followed by DEB was performed at the ostium of the LCX lesion. Percutaneous coronary intervention was initiated for the ostium of the LCX using an approach via the right femoral artery. An 8-french Launcher JCL 4.0 (Medtronic, Minneapolis, MN, USA) was engaged in the left coronary artery and a Sion guide wire (Asahi Intecc, Nagoya, Japan) was selected into the distal LCX. Intravascular ultrasound (IVUS) was performed to evaluate plaque composition and accumulation of the LCX ostium, and revealed the soft and partially-attenuated plaque at the opposite side of LAD to the slight pericardial side (Fig. 2A, arrow asterisks indicating the ostium of LAD). After exchanging the guide wire to the 300 cm of Grand slam (Asahi Intecc), the DCA procedure using DCA catheter (Atherocut™, L-size, NIPRO, Osaka, Japan) was started. Completing 2 test cuts with 2 atm, IVUS was also performed to confirm the atherectomy direction, suggesting the correct position of plaque resection (Fig. 2B). Thereafter, subsequent atherectomy was circumferentially performed 16 times, from 2 atm to 3 atm (Fig. 2C). Although angiogram and IVUS showed excellent results, adjunctive balloon dilatation with 3.5/15 mm DEB (paclitaxel-coated balloon, SeQuent Please, B. Braun, Melsungen, Germany) was performed to prevent restenosis (Figs. 2D, 3 A and B). Percent plaque area before DCA was 78% and 54% after DCA in IVUS, and radiation time, radiation dose, and amount of contrast was 18 min, 1.6 Gy, and 105 ml, respectively. At 3 months, dual antiplatelet therapy was finished, and at 8 months, the patient reported being angina-free, and subsequent follow-up angiogram showed no restenosis of LCX (Fig. 3C and D).

Fig. 1.

(A and B) Angiogram showing the ostial stenosis of the left circumflex artery.

Fig. 2.

(A) Preintervention intravascular ultrasound (IVUS) imaging shows soft and partially attenuated plaque (arrow). Asterisk indicates the left anterior descending artery (LAD). (B) IVUS imaging after test cut of the left circumflex artery ostial lesion (arrowhead). Asterisk indicates LAD. (C) Angiogram during directional coronary atherectomy (DCA) procedure. (D) IVUS imaging after DCA. Arrows indicate the lumen after DCA, and asterisk indicates LAD.

Fig. 3.

(A and B) Final angiogram after directional coronary atherectomy and drug-eluting balloon index procedure. (C and D) Follow-up angiogram at 8 months.

Discussion

Drug-eluting stents significantly attenuate the cellularity and reduce the requirement for repeat revascularization. Until a few years ago, the treatment choice would have been limited to metallic stents, requiring prolonged dual antiplatelet therapy and potential risk of late thrombotic events or restenosis. Compared with a stent strategy, DEB may have advantages due to absence of a permanent scaffold and polymer, maintaining the original coronary anatomy geometry, and limited inflammatory stimulation, thereby allowing for short‐term dual antiplatelet therapy [1]. Although most applications of DEB have been reported for the treatment of in-stent restenosis or small coronary vessels, several studies have reported the safety and efficacy in terms of long-term vessel patency [2], [3], [4]. Recently, there was a report that late lumen loss was similar between drug-eluting stents and DEB in de novo coronary artery [5]. In addition, a study by Kleber et al. reported that 69% of patients showed luminal enlargement at 4-month follow-up angiogram after treatment with paclitaxel-coated balloon [6], [7]. This additional property of DEB seems particularly intriguing for DCA cases, because of acquiring ideal lesion preparation by atherectomy under IVUS guidance. While the main indication for DCA is soft plaque, having IVUS information available was very helpful for understanding the plaque component as well as achieving lumen area. In addition, effect of plaque reduction is more conclusive in DCA than conventional angioplasty. Despite the requirement for technical skills and limited availability, reports of DCA procedure with IVUS guidance and experienced operators provided excellent acute results without increased risk of complications [8], [9]. Ostial stenoses of LCX are at higher risk for restenosis after stenting [10], therefore, the recent revival of DCA in combination with DEB may be a potential stentless therapeutic option for these patients. The short duration of DAPT is the advantage after DEB compared with drug-eluting stent implantation. However, the duration of DAPT after drug-eluting stent implantation has been shortened recently. The trend of DAPT duration after DEB in the real world has become shortened as well.

Conclusion

We report a case using DCA and IVUS guidance followed by DEB for percutaneous treatment of an LCX ostial stenosis. This case seems safe and effective for both acute and 8-month follow-up results, suggesting a potential stentless therapeutic option.

Conflict of interest

The authors declare that there is no conflict of interest