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Coronary artery aneurysm formation 7 months after bare-metal stent implantation: Intravascular ultrasound and optical coherence tomography observation
Journal of Cardiology Cases (2011) 3, e115—e118
available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/jccase
Case Report
Coronary artery aneurysm formation 7 months after bare-metal stent implantation: Intravascular ultrasound and optical coherence tomography observation Tsuyoshi Nakata (MD) a, Kenichi Fujii (MD) a,∗, Masashi Fukunaga (MD) a, Mitsumasa Ohyanagi (MD, FJCC) b, Tohru Masuyama (MD, FJCC) a a b
Cardiovascular Division, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 6638501, Japan Division of Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan
Received 19 January 2011; accepted 26 January 2011
KEYWORDS Optical coherence tomography; Coronary aneurysm; Bare-metal stent
Summary Late-acquired angiographic coronary aneurysm formation after drug-eluting stent implantation is a rare phenomenon but potentially life-threatening event that has become a major cause of concern. Optical coherence tomography (OCT) is a high-resolution imaging method that allows detailed evaluation of stent strut coverage and characterization of neointimal tissue. This case report describes the possible mechanism of late-acquired angiographic coronary aneurysm formation after bare-metal stent implantation using OCT and intravascular ultrasound. © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Introduction Recently, several cases of late acquired coronary aneurysm formation leading to stent thrombosis after drug-eluting stent deployment were reported. Several mechanisms of coronary aneurysm formation after drug-eluting stent were elucidated with the use of intracoronary imaging modalities, including intravascular ultrasound (IVUS) and optical coherence tomography (OCT) [1]. However, there have been a
∗ Corresponding author. Tel.: +81 0798 45 6553; fax: +81 0798 45 6551. E-mail address: [email protected] (K. Fujii).
few reported cases using OCT to assess coronary aneurysm formation after bare-metal stent implantation. This case report describes IVUS and OCT findings of coronary aneurysm formation after bare-metal stent implantation.
Case report An 80-year-old male with a history of arterial hypertension and dyslipidemia was admitted to our institution presenting with ST-segment elevation inferior acute myocardial infarction. Coronary angiography revealed total occlusion with thrombus in the proximal right coronary artery (RCA) (Fig. 1A). Primary percutaneous coronary intervention of
1878-5409/$ — see front matter © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jccase.2011.01.005
e116
Figure 1 stenting.
T. Nakata et al.
(A) Angiography of the right coronary artery showing the total occlusion at the proximal segment. (B) Final result after
the proximal RCA was performed. The lesion was predilated with a 3.0 mm × 15 mm balloon and a 3.5 mm × 30 mm bare-metal stent (Driver stent, Medtronic CardioVascular, Santa Rosa, CA, USA) was deployed at 14 atm with a good
angiographic result (Fig. 1B). IVUS and OCT examinations were not attempted after stent implantation. The patient was discharged without in-hospital events and remained asymptomatic on dual antiplatelet therapy. One month later,
Figure 2 (A) Seven-month follow-up coronary angiography showing coronary artery aneurysm formation at previously stented site (arrows). (B) Intravascular ultrasound appearance of complete strut apposition and neointimal coverage at the distal part of the stent. (C) Intravascular ultrasound imaging of coronary artery aneurysm formation.
Coronary artery aneurysm formation 7 months after bare-metal stent implantation
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Figure 3 (A) Optical coherence tomography showing intimal tissue with layered structure and predominant low backscatter (arrow heads). (B) Incomplete stent apposition and poor strut coverage at the site of coronary aneurysm (arrows).
clopidogrel was withdrawn, maintaining aspirin treatment. Follow-up coronary angiography was performed 7 months after the initial procedure. During the follow-up period, the patient had no recurrence of clinical symptoms. Coronary angiography demonstrated a large pool of contrast medium external to the stented site suggestive of coronary aneurysm formation of the proximal stented segment of the RCA (Fig. 2A). The patient subsequently underwent IVUS (Atlantis SR Pro2TM , Boston Scientific Corp., Natick, MA, USA) and OCT (ImagingWire, LightLab Imaging Inc., Westford, MA, USA) examinations. The IVUS examination was performed after injection of 200 g nitroglycerin and imaging included stents and the 5-mm stent edges with a 0.5 mm/sec pullback. IVUS showed adequate stent expansion and complete stent apposition with neointimal coverage of stent struts in the distal part of the stent (Fig. 2B). In the proximal part of the stent, IVUS found that there were giant gaps between stent struts and vessel wall and the localized dilation exceeded 1.5 times the vessel crosssectional area of the proximal reference segment, indicating stent malapposition and an aneurysm formation (Fig. 2C). At this segment, neointima formation on the mallaposed strut could not be visualized by IVUS. Then, OCT examination was also attempted with a conventional occlusion technique. An imaging run was performed with a 0.016in. wire-type imaging wire from the distal segment to the proximal segment of the stent using automated transducer pullback at 1.0 mm/s during automated injection of lactated Ringer’s solution at 0.5 ml/s from the distal tip of the occlusion balloon catheter. OCT showed a layered intimal tissue structure with predominant low backscatter in the distal part of the stent (Fig. 3A). At the site of coronary aneurysm on the IVUS image, OCT showed stent struts separated from the vessel wall and strut coverage was incomplete (Fig. 3B). There was a normal structure composed of three layers that may suggest true aneurysm on OCT images (Fig. 3B). This case presented late-acquired aneurysm formation following bare-metal stent implantation for the treatment
of ST-segment elevation inferior acute myocardial infarction.
Discussion The occurrence of angiographic coronary aneurysm formation after drug-eluting stent implantation is rare [2], but may lead to serious, potentially life-threatening clinical problems, including stent thrombosis and death [3]. Although the underlying mechanism for aneurysm formation after drug-eluting stent implantation remains unknown, several hypotheses may be postulated. Extensive acute vessel damage during the initial procedure [4], infectious processes [5], hypersensitivity reactions [6], and phenomena resembling extreme cases of late acquired malapposition may all be implicated [7]. The incidence of coronary aneurysm formation after bare-metal stent deployment is relatively lower than that of drug-eluting stents. In the TAXUS VI trial [8], involving long and complex lesions, the occurrence of late-acquired aneurysms tended to be higher in the paclitaxel-eluting stent than in the bare-metal stent group (1.4% versus 0.5%). A previous IVUS study demonstrated that late-acquired stent malapposition after bare-metal stent implantation was associated with primary stenting in acute myocardial infarction and directional coronary atherectomy before stenting [9]. This finding indicated that the potential mechanisms of aneurysm formation after bare-metal stent implantation were thrombus resolution and acute deep vessel wall injury promoting outward vessel remodeling. In the current case, however, OCT demonstrated a normal structure composed of three layers that may suggest true aneurysm. Furthermore, OCT images showed abnormal tissue proliferation in the stent. Therefore, we speculate the mechanisms for appearance of this coronary aneurysm are the combination of thrombus resolution and local hypersensitivity reaction to the stent metal. Long-term follow-up studies with large populations would be required to confirm the clinical significance of these findings obtained from OCT examinations.
e118
References [1] Rathore S, Terashima M, Suzuki T. Late-acquired stent malapposition after sirolimus-eluting stent implantation following acute coronary syndrome: angiographic, IVUS, OCT and coronary angioscopic observation. J Invasive Cardiol 2009;21:666—7. [2] Alfonso F, Pérez-Vizcayno MJ, Ruiz M, Suárez A, Cazares M, Hernández R, Escaned J, Ba˜ nuelos C, Jiménez-Quevedo P, Macaya C. Coronary aneurysms after drug-eluting stent implantation: clinical, angiographic, and intravascular ultrasound findings. J Am Coll Cardiol 2009;53:2053—60. [3] Alfonso F, Suárez A, Pérez-Vizcayno MJ, Moreno R, Escaned J, Ba˜ nuelos C, Jiménez P, Bernardo E, Angiolillo DJ, Hernández R, Macaya C. Intravascular ultrasound findings during episodes of drug-eluting stent thrombosis. J Am Coll Cardiol 2007;21:2095—9. [4] Aoki J, Kirtane A, Leon MB, Dangas G. Coronary artery aneurysm after drug-eluting stent implantation. J Am Coll Cardiol Intv 2008;1:14—21. [5] Alfonso F, Moreno R, Vergas J. Fatal infection after rapamycineluting coronary stent implantation. Heart 2005;91:e51—2.
T. Nakata et al. [6] Virmani R, Guagliumi G, Farb A, Musumeci G, Grieco N, Motta T, Mihalcsik L, Tespili M, Valsecchi O, Kolodgie FD. Localized hypersensitivity and late coronary thrombosis secondary to a sirolimus-eluting stent. Should we be cautious? Circulation 2004;109:701—5. [7] Li SSL, Cheng BC, Lee SH. Giant coronary aneurysm formation after sirolimus-eluting stent implantation in Kawasaki disease. Circulation 2005;112:e105—7. [8] Dawkins KD, Grube E, Guagliumi G, Banning AP, Zmudka K, Colombo A, Thuesen L, Hauptman K, Marco J, Wijns W, Popma JJ, Koglin J, Russell ME, TAXUS VI Investigators. Clinical efficacy of polymer-based paclitaxel-eluting stents in the treatment of complex, long coronary artery lesions from a multicenter, randomized trial: support for the use of drug-eluting stents in contemporary clinical practice. Circulation 2005;112: 3306—13. [9] Hong MK, Mintz GS, Lee CW, Kim YH, Lee SW, Song JM, Han KH, Kang DH, Song JK, Kim JJ, Park SW, Park SJ. Incidence, mechanism, predictors, and long-term prognosis of late stent malapposition after bare-metal stent implantation. Circulation 2004;109:881—6.
available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/jccase
Case Report
Coronary artery aneurysm formation 7 months after bare-metal stent implantation: Intravascular ultrasound and optical coherence tomography observation Tsuyoshi Nakata (MD) a, Kenichi Fujii (MD) a,∗, Masashi Fukunaga (MD) a, Mitsumasa Ohyanagi (MD, FJCC) b, Tohru Masuyama (MD, FJCC) a a b
Cardiovascular Division, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, 6638501, Japan Division of Coronary Heart Disease, Hyogo College of Medicine, Nishinomiya, Japan
Received 19 January 2011; accepted 26 January 2011
KEYWORDS Optical coherence tomography; Coronary aneurysm; Bare-metal stent
Summary Late-acquired angiographic coronary aneurysm formation after drug-eluting stent implantation is a rare phenomenon but potentially life-threatening event that has become a major cause of concern. Optical coherence tomography (OCT) is a high-resolution imaging method that allows detailed evaluation of stent strut coverage and characterization of neointimal tissue. This case report describes the possible mechanism of late-acquired angiographic coronary aneurysm formation after bare-metal stent implantation using OCT and intravascular ultrasound. © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Introduction Recently, several cases of late acquired coronary aneurysm formation leading to stent thrombosis after drug-eluting stent deployment were reported. Several mechanisms of coronary aneurysm formation after drug-eluting stent were elucidated with the use of intracoronary imaging modalities, including intravascular ultrasound (IVUS) and optical coherence tomography (OCT) [1]. However, there have been a
∗ Corresponding author. Tel.: +81 0798 45 6553; fax: +81 0798 45 6551. E-mail address: [email protected] (K. Fujii).
few reported cases using OCT to assess coronary aneurysm formation after bare-metal stent implantation. This case report describes IVUS and OCT findings of coronary aneurysm formation after bare-metal stent implantation.
Case report An 80-year-old male with a history of arterial hypertension and dyslipidemia was admitted to our institution presenting with ST-segment elevation inferior acute myocardial infarction. Coronary angiography revealed total occlusion with thrombus in the proximal right coronary artery (RCA) (Fig. 1A). Primary percutaneous coronary intervention of
1878-5409/$ — see front matter © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jccase.2011.01.005
e116
Figure 1 stenting.
T. Nakata et al.
(A) Angiography of the right coronary artery showing the total occlusion at the proximal segment. (B) Final result after
the proximal RCA was performed. The lesion was predilated with a 3.0 mm × 15 mm balloon and a 3.5 mm × 30 mm bare-metal stent (Driver stent, Medtronic CardioVascular, Santa Rosa, CA, USA) was deployed at 14 atm with a good
angiographic result (Fig. 1B). IVUS and OCT examinations were not attempted after stent implantation. The patient was discharged without in-hospital events and remained asymptomatic on dual antiplatelet therapy. One month later,
Figure 2 (A) Seven-month follow-up coronary angiography showing coronary artery aneurysm formation at previously stented site (arrows). (B) Intravascular ultrasound appearance of complete strut apposition and neointimal coverage at the distal part of the stent. (C) Intravascular ultrasound imaging of coronary artery aneurysm formation.
Coronary artery aneurysm formation 7 months after bare-metal stent implantation
e117
Figure 3 (A) Optical coherence tomography showing intimal tissue with layered structure and predominant low backscatter (arrow heads). (B) Incomplete stent apposition and poor strut coverage at the site of coronary aneurysm (arrows).
clopidogrel was withdrawn, maintaining aspirin treatment. Follow-up coronary angiography was performed 7 months after the initial procedure. During the follow-up period, the patient had no recurrence of clinical symptoms. Coronary angiography demonstrated a large pool of contrast medium external to the stented site suggestive of coronary aneurysm formation of the proximal stented segment of the RCA (Fig. 2A). The patient subsequently underwent IVUS (Atlantis SR Pro2TM , Boston Scientific Corp., Natick, MA, USA) and OCT (ImagingWire, LightLab Imaging Inc., Westford, MA, USA) examinations. The IVUS examination was performed after injection of 200 g nitroglycerin and imaging included stents and the 5-mm stent edges with a 0.5 mm/sec pullback. IVUS showed adequate stent expansion and complete stent apposition with neointimal coverage of stent struts in the distal part of the stent (Fig. 2B). In the proximal part of the stent, IVUS found that there were giant gaps between stent struts and vessel wall and the localized dilation exceeded 1.5 times the vessel crosssectional area of the proximal reference segment, indicating stent malapposition and an aneurysm formation (Fig. 2C). At this segment, neointima formation on the mallaposed strut could not be visualized by IVUS. Then, OCT examination was also attempted with a conventional occlusion technique. An imaging run was performed with a 0.016in. wire-type imaging wire from the distal segment to the proximal segment of the stent using automated transducer pullback at 1.0 mm/s during automated injection of lactated Ringer’s solution at 0.5 ml/s from the distal tip of the occlusion balloon catheter. OCT showed a layered intimal tissue structure with predominant low backscatter in the distal part of the stent (Fig. 3A). At the site of coronary aneurysm on the IVUS image, OCT showed stent struts separated from the vessel wall and strut coverage was incomplete (Fig. 3B). There was a normal structure composed of three layers that may suggest true aneurysm on OCT images (Fig. 3B). This case presented late-acquired aneurysm formation following bare-metal stent implantation for the treatment
of ST-segment elevation inferior acute myocardial infarction.
Discussion The occurrence of angiographic coronary aneurysm formation after drug-eluting stent implantation is rare [2], but may lead to serious, potentially life-threatening clinical problems, including stent thrombosis and death [3]. Although the underlying mechanism for aneurysm formation after drug-eluting stent implantation remains unknown, several hypotheses may be postulated. Extensive acute vessel damage during the initial procedure [4], infectious processes [5], hypersensitivity reactions [6], and phenomena resembling extreme cases of late acquired malapposition may all be implicated [7]. The incidence of coronary aneurysm formation after bare-metal stent deployment is relatively lower than that of drug-eluting stents. In the TAXUS VI trial [8], involving long and complex lesions, the occurrence of late-acquired aneurysms tended to be higher in the paclitaxel-eluting stent than in the bare-metal stent group (1.4% versus 0.5%). A previous IVUS study demonstrated that late-acquired stent malapposition after bare-metal stent implantation was associated with primary stenting in acute myocardial infarction and directional coronary atherectomy before stenting [9]. This finding indicated that the potential mechanisms of aneurysm formation after bare-metal stent implantation were thrombus resolution and acute deep vessel wall injury promoting outward vessel remodeling. In the current case, however, OCT demonstrated a normal structure composed of three layers that may suggest true aneurysm. Furthermore, OCT images showed abnormal tissue proliferation in the stent. Therefore, we speculate the mechanisms for appearance of this coronary aneurysm are the combination of thrombus resolution and local hypersensitivity reaction to the stent metal. Long-term follow-up studies with large populations would be required to confirm the clinical significance of these findings obtained from OCT examinations.
e118
References [1] Rathore S, Terashima M, Suzuki T. Late-acquired stent malapposition after sirolimus-eluting stent implantation following acute coronary syndrome: angiographic, IVUS, OCT and coronary angioscopic observation. J Invasive Cardiol 2009;21:666—7. [2] Alfonso F, Pérez-Vizcayno MJ, Ruiz M, Suárez A, Cazares M, Hernández R, Escaned J, Ba˜ nuelos C, Jiménez-Quevedo P, Macaya C. Coronary aneurysms after drug-eluting stent implantation: clinical, angiographic, and intravascular ultrasound findings. J Am Coll Cardiol 2009;53:2053—60. [3] Alfonso F, Suárez A, Pérez-Vizcayno MJ, Moreno R, Escaned J, Ba˜ nuelos C, Jiménez P, Bernardo E, Angiolillo DJ, Hernández R, Macaya C. Intravascular ultrasound findings during episodes of drug-eluting stent thrombosis. J Am Coll Cardiol 2007;21:2095—9. [4] Aoki J, Kirtane A, Leon MB, Dangas G. Coronary artery aneurysm after drug-eluting stent implantation. J Am Coll Cardiol Intv 2008;1:14—21. [5] Alfonso F, Moreno R, Vergas J. Fatal infection after rapamycineluting coronary stent implantation. Heart 2005;91:e51—2.
T. Nakata et al. [6] Virmani R, Guagliumi G, Farb A, Musumeci G, Grieco N, Motta T, Mihalcsik L, Tespili M, Valsecchi O, Kolodgie FD. Localized hypersensitivity and late coronary thrombosis secondary to a sirolimus-eluting stent. Should we be cautious? Circulation 2004;109:701—5. [7] Li SSL, Cheng BC, Lee SH. Giant coronary aneurysm formation after sirolimus-eluting stent implantation in Kawasaki disease. Circulation 2005;112:e105—7. [8] Dawkins KD, Grube E, Guagliumi G, Banning AP, Zmudka K, Colombo A, Thuesen L, Hauptman K, Marco J, Wijns W, Popma JJ, Koglin J, Russell ME, TAXUS VI Investigators. Clinical efficacy of polymer-based paclitaxel-eluting stents in the treatment of complex, long coronary artery lesions from a multicenter, randomized trial: support for the use of drug-eluting stents in contemporary clinical practice. Circulation 2005;112: 3306—13. [9] Hong MK, Mintz GS, Lee CW, Kim YH, Lee SW, Song JM, Han KH, Kang DH, Song JK, Kim JJ, Park SW, Park SJ. Incidence, mechanism, predictors, and long-term prognosis of late stent malapposition after bare-metal stent implantation. Circulation 2004;109:881—6.