Abstract
Cardiac allograft vasculopathy (CAV) is the most common cause of long-term graft failure after heart transplantation. In the absence of a specific treatment for this condition, percutaneous coronary revascularization (PCI) has been the main palliative treatment. Although long-term results are unknown, use of drug-eluting stents (DES) has been shown to have favorable outcome when used in heart transplant patients for treatment of focal lesions in CAV. We report the case of a 77-year-old male who presented with restenosis secondary to DES stent fracture (SF) after treatment of CAV with sirolimus-eluting stents (SES).
1
Introduction
Cardiac allograft vasculopathy (CAV) remains the main challenge to the long-term survival of heart transplant patients. It is a diffuse inflammatory process that has a prevalence of up to 50% at 5 years post-transplant . CAV contributes to roughly half of allograft dysfunction leading to death . Once it develops, long-term survival is reduced significantly .
Retransplantation remains the most effective treatment for such a diffuse process. However, retransplantation is limited by donor availability and survival compared with the initial transplantation . Although CAV is a diffuse disease that is often not amenable to percutaneous coronary revascularization (PCI), intervention of focal and significant lesions has therapeutic utility in improving prognosis . Balloon angioplasty and bare-metal stents (BMS) have been used for revascularization of focal lesions, but they are associated with a high risk of restenosis . Limited data have shown favorable results with drug-eluting stents (DES) . Several cases of restenosis in DES in association with stent fractures (SFs) were recently reported. Most of these SFs were found to occur in sirolimus-eluting stents (SES) . We present the case of a 77-year-old male who had significant CAV lesions which were treated with SES, presented with restenosis secondary to multiple SFs.
2
Case report
The patient is a 77-year-old male who underwent orthotopic heart transplantation 8 years ago for ischemic cardiomyopathy. His initial clinical course has been free from any graft rejection. Recently, secondary to his long-standing diabetes and hypertension, he developed end-stage renal disease and was considered for renal transplantation. Even though he was asymptomatic from a cardiovascular standpoint, during his preoperative cardiac workup, he was evaluated with a dipyramidole nuclear stress test and found to have moderate to severe lateral wall reversible ischemia without scar with an estimated left ventricular ejection fraction of 70%. Subsequently, he underwent a left heart catheterization with selective coronary angiography. Although there were lesions at the mid- and distal left anterior descending artery as well as at the diagonal branch, further evaluation using fractional flow reserve (FFR) revealed them to be nonsignificant (FFR was 0.97 and 0.95, respectively, with 140 μg/kg per minute of intravenous adenosine infusion). Distal left circumflex artery was diffusely and severely diseased and not suitable for PCI. However, there was a significant stenosis in the large obtuse marginal branch (OM) which was consistent with the lateral wall ischemia on the nuclear study ( Fig. 1 A ). The OM lesion was successfully dilated with two SESs with some area of overlap (3.5×23 and 3.5×13 mm deployed at 16 atm) ( Fig. 1 B). Five months later, he presented with significant dyspnea with mild to moderate exertion. His EKG showed sinus bradycardia with first degree A–V block and left anterior fascicular block and nonspecific ST-T changes. He was evaluated with left heart catheterization and coronary angiography which revealed sequential stenosis of the previously stented segments of OM ( Fig. 1 C and D) with a normal left ventricular function. The restenotic segment was angulated and had significant dynamic motion during systole. Further analysis of his coronary angiogram showed significant SFs of previously placed stents with complete dehiscence from one another circumferentially. Intravascular ultrasound (IVUS) evaluation revealed fewer stent struts consistent with focal stent strut fracture compared to complete circumferential strut coverage of other normally looking stented area ( Figs. 1C and 2 ). Neointimal hyperplasia was most pronounced in the SF and overlap segments with a minimal cross-sectional area of 2.4 mm 2 with focal in-stent restenosis. Although there was a possibility of repeat SF, because of the patient’s significant symptoms and the high mortality of coronary artery bypass graft surgery (CABG) in this population, restenotic and focal lesions were decided to be treated with PCI using a different kind of DES. The lesions were successfully treated with everolimus-eluting stents (3.5×23, 3.5×23, and 3.5×12 mm deployed at 14 atm with some area of overlap) without any residual stenosis ( Fig. 2 ). The patient tolerated the procedure well with no complications.
2
Case report
The patient is a 77-year-old male who underwent orthotopic heart transplantation 8 years ago for ischemic cardiomyopathy. His initial clinical course has been free from any graft rejection. Recently, secondary to his long-standing diabetes and hypertension, he developed end-stage renal disease and was considered for renal transplantation. Even though he was asymptomatic from a cardiovascular standpoint, during his preoperative cardiac workup, he was evaluated with a dipyramidole nuclear stress test and found to have moderate to severe lateral wall reversible ischemia without scar with an estimated left ventricular ejection fraction of 70%. Subsequently, he underwent a left heart catheterization with selective coronary angiography. Although there were lesions at the mid- and distal left anterior descending artery as well as at the diagonal branch, further evaluation using fractional flow reserve (FFR) revealed them to be nonsignificant (FFR was 0.97 and 0.95, respectively, with 140 μg/kg per minute of intravenous adenosine infusion). Distal left circumflex artery was diffusely and severely diseased and not suitable for PCI. However, there was a significant stenosis in the large obtuse marginal branch (OM) which was consistent with the lateral wall ischemia on the nuclear study ( Fig. 1 A ). The OM lesion was successfully dilated with two SESs with some area of overlap (3.5×23 and 3.5×13 mm deployed at 16 atm) ( Fig. 1 B). Five months later, he presented with significant dyspnea with mild to moderate exertion. His EKG showed sinus bradycardia with first degree A–V block and left anterior fascicular block and nonspecific ST-T changes. He was evaluated with left heart catheterization and coronary angiography which revealed sequential stenosis of the previously stented segments of OM ( Fig. 1 C and D) with a normal left ventricular function. The restenotic segment was angulated and had significant dynamic motion during systole. Further analysis of his coronary angiogram showed significant SFs of previously placed stents with complete dehiscence from one another circumferentially. Intravascular ultrasound (IVUS) evaluation revealed fewer stent struts consistent with focal stent strut fracture compared to complete circumferential strut coverage of other normally looking stented area ( Figs. 1C and 2 ). Neointimal hyperplasia was most pronounced in the SF and overlap segments with a minimal cross-sectional area of 2.4 mm 2 with focal in-stent restenosis. Although there was a possibility of repeat SF, because of the patient’s significant symptoms and the high mortality of coronary artery bypass graft surgery (CABG) in this population, restenotic and focal lesions were decided to be treated with PCI using a different kind of DES. The lesions were successfully treated with everolimus-eluting stents (3.5×23, 3.5×23, and 3.5×12 mm deployed at 14 atm with some area of overlap) without any residual stenosis ( Fig. 2 ). The patient tolerated the procedure well with no complications.
