Plaque regression associated with everolimus administration after heart transplantation

Open ArchivePublished:March 20, 2013DOI:https://doi.org/10.1016/j.jccase.2013.02.003

      Abstract

      A 45-year-old male who had suffered from refractory non-ischemic heart failure treated with a left ventricular assist device received heart transplantation in February 2008. He underwent coronary angiography (CAG) and intravascular ultrasound (IVUS) at 3 months, and 1, 2, and 3 years after surgery. At 3 months, neither significant stenosis on CAG nor plaque on 3 coronary arteries, as assessed by IVUS were observed. However, focal eccentric plaque on proximal left anterior descending artery has developed up to 2 years, despite the fact that risk factors for cardiac allograft vasculopathy were well controlled. At 2 years, everolimus 2.5 mg/day was added to the patient's existing regimen consisting of corticosteroids, mycophenolate mofetil, and cyclosporine. Then mycophenolate mofetil was withdrawn. At 3 years, concomitant with plaque regression, a decreased plaque volume index, enlarged lumen volume index, and increased minimum lumen area were observed. We experienced a case with plaque regression associated with everolimus administration. Further investigations are needed to explore the mechanism of plaque regression associated with everolimus, as well as to confirm our observation in randomized controlled trials for patients after heart transplantation.
      <Learning objective: We experienced a case with plaque regression associated with everolimus administration. Further investigations are needed to explore the mechanism of plaque regression associated with everolimus, as well as to confirm our observation in randomized controlled trials for patients after heart transplantation.>

      Keywords

      Introduction

      Cardiac allograft vasculopathy is an ongoing issue after heart transplantation, even though treatment regimen consisting of calcineurin inhibitors, mycophenolate mofetil and glucocorticoids has been established in patients after heart transplantation.
      We report a case with plaque regression associated with Everolimis administration after heart transplantation.
      A 45-year old male who had suffered from refractory non-ischemic heart failure treated with a left ventricular assist device received heart transplantation in February 2008. At 3 months, and 1, 2, and 3 years after surgery, he underwent coronary angiography (CAG) (Fig. 1) and intravascular ultrasound (IVUS) (Fig. 2) examinations to evaluate cardiac allograft vasculopathy (CAV). No significant rejection episodes, as assessed by right ventricular biopsy, were observed during the follow-up period. Although his lipid and diabetic profiles were well controlled until 2 years after heart transplantation, those parameters were worsened at 3 years, even under statin administration, subcutaneous insulin injection, and oral anti-diabetic drugs (Table 1 and Fig. 4). There was no cytomegalovirus infection during the follow-up periods.
      Figure thumbnail gr1
      Fig. 1Serial changes in angiogram for left coronary artery after heart transplantation. No obvious stenosis on the coronary artery tree was observed following intracoronary injection of nitrate after heart transplantation at (a) 3 months, (b) 1 year, (c) 2 years, and (d) 3 years, even though increased plaque thickness was detected up to 2 years, as assessed by intravascular ultrasound (IVUS). Arrows indicate the site corresponding to plaque progression and regression observed by IVUS.
      Figure thumbnail gr2
      Fig. 2Serial changes in plaque thickness in the proximal left anterior descending coronary artery assessed by intravascular ultrasound (IVUS). Single (*), double (**), and triple (***) asterisks indicate the left circumflex artery, first diagonal branch, and first septal branch, respectively. Focusing on the site between the first diagonal branch to second septal branch where plaque progression and regression took place, we measured maximum plaque thickness, minimum lumen area as well as lumen and plaque volume indices using Simpson's method. (a) No obvious plaque was detected at 3 months. (b) At 1 year, longitudinal and cross-sectional images showed that a focal eccentric plaque was observed in an area distal to first diagonal branch. (c) The plaque thickness had increased by 2 years, as shown in both the longitudinal and cross-sectional images, with decreased lumen area. (d) Although it was difficult to see the first diagonal branch due to wire artifact after transplantation, at 3 years, both the longitudinal and cross-sectional images showed decreased plaque thickness with enlarged lumen area, which was associated with everolimus administration. We note that IVUS was performed in a standard fashion using an automated and motorized 1.0 mm/s pullback with a commercially available imaging system with a 20-MHz IVUS catheter (Volcano Corp, Rancho Cordova, CA, USA) at 3 months, 1 year, and 2 years after surgery, and an automated motorized 0.5 mm/s pullback with a 40-MHz IVUS catheter (Boston Scientific Corp., Natick, MA, USA) at 3 years after surgery, respectively.
      Table 1Laboratory data after heart transplantation.
      3 months1 year2 years3 years
      HbA1c (%)5.15.75.67.0
      Total cholesterol (mg/dL)154193182219
      LDL-cholesterol (mg/dL)90112100128
      HDL-cholesterol (mg/dL)36414957
      Triglycerides (mg/dL)118190165134
      HDL, high-density lipoprotein; LDL, low-density lipoprotein.
      At 3 months, neither significant stenosis on CAG nor plaque on 3 coronary arteries, as assessed by IVUS, were observed. The maximum plaque thickness at 3 months on the proximal left anterior descending (LAD) coronary artery was 0.42 mm (Fig. 2, Fig. 3). At 1 year, IVUS revealed that an eccentric focal plaque had developed with a maximum thickness of 1.06 mm at the same area in the LAD with an increased plaque volume index (4.6 mm3/mm), and decreased lumen volume index (12.2 mm3/mm) and minimum lumen area (10.9 mm2) (Fig. 2, Fig. 3). At 2 years, the eccentric plaque had further developed, reaching a maximum plaque thickness of 1.79 mm, with increased plaque volume index (7.0 mm3/mm), and decreased lumen volume index (6.9 mm3/mm), and minimum lumen area (5.6 mm2) (Fig. 2, Fig. 3).
      Figure thumbnail gr3
      Fig. 3Serial changes in intravascular ultrasound parameters.
      Subsequently, everolimus was added at an initial dose of 1.5 mg/day to the patient's existing regimen consisting of corticosteroids (2.5 mg/day), cyclosporine (450 mg/day), and mycophenolate mofetil (250 mg/day). As the patient displayed no adverse effects to everolimus in the first week of administration, the dosage was increased to 2.5 mg/day in order to maintain a drug concentration of 3–8 ng/ml and mycophenolate mofetil was withdrawn (Fig. 4). At 3 years after transplantation surgery, IVUS showed that the eccentric plaque in the proximal LAD had regressed, with a maximum plaque thickness of 1.11 mm (Fig. 2, Fig. 3). Concomitant with plaque regression, a decreased plaque volume index (5.1 mm3/mm), enlarged lumen volume index (9.0 mm3/mm), and increased minimum lumen area (8.1 mm2) were observed (Fig. 2, Fig. 3). Coronary narrowing assessed by CAG exhibited marginal progression and regression during the follow-up period (Fig. 1).
      Figure thumbnail gr4
      Fig. 4Medications after heart transplantation surgery.

      Discussion

      CAV has been reported to be a main cause of death after heart transplantation. Previous studies have shown that numerous recipient factors, including male sex, older age, early severe rejection, cytomegalovirus infection, diabetes, hypertension, hyperlipidemia, and higher body mass index, are associated with an increased risk of CAV [
      • Zimmer R.J.
      • Lee M.S.
      Transplant coronary artery disease.
      ]. Although the patient did not experience any rejection episodes or viral infection, he had several risk factors for CAV, including male sex, diabetes, and hyperlipidemia. In addition, a plaque with a thickness of >0.5 mm had developed within 1 year after transplantation, which is considered to be a surrogate value of high risk for CAV [
      • Tuzcu E.M.
      • Kapadia S.R.
      • Sachar R.
      • Ziada K.M.
      • Crowe T.D.
      • Feng J.
      • Magyar W.A.
      • Hobbs R.E.
      • Starling R.C.
      • Young J.B.
      • McCarthy P.
      • Nissen S.E.
      Intravascular ultrasound evidence of angiographically silent progression in coronary atherosclerosis predicts long-term morbidity and mortality after cardiac transplantation.
      ]. A randomized clinical trial comparing the efficacy and safety between patients assigned either to low- (1.5 mg/day) or high-dose everolimus (3.0 mg/day) or azathioprine revealed that maximal plaque thickness 12 months after transplantation, as assessed by IVUS, was significantly smaller in the two everolimus groups than that in the azathioprine group [
      • Eisen H.J.
      • Tuzcu E.M.
      • Dorent R.
      • Kobashigawa J.
      • Mancini D.
      • Valantine-von Kaeppler H.A.
      • Starling R.C.
      • Sorensen K.
      • Hummel M.
      • Lind J.M.
      • Abeywickrama K.H.
      • Bernhardt P.
      Everolimus for the prevention of allograft rejection and vasculopathy in cardiac-transplant recipients.
      ]. As the everolimus-treated group exhibited lower plaque progression, it is possible that everolimus potentially promotes plaque regression, resulting in a reduced risk of vasculopathy after heart transplantation. Although the mechanism underlying everolimus-related plaque regression after heart transplantation remains unknown, anti-immunosuppression [
      • Schuler W.
      • Sedrani R.
      • Cottens S.
      • Haberlin B.
      • Schulz M.
      • Schuurman H.J.
      • Zenke G.
      • Zerwes H.G.
      • Schreier M.H.
      SDZ RAD, a new rapamycin derivative: pharmacological properties in vitro and in vivo.
      ] as well as anti-inflammatory effects [
      • Mueller M.A.B.F.
      • Teupser D.
      • Ceglarek U.
      • Thiery J.
      Prevention of atherosclerosis by the mTOR inhibitor everolimus in LDLR−/− mice despite severe hypercholesterolemia.
      ] may play a role in the phenomenon.
      In summary, we experienced a case with plaque regression associated with the administration of everolimus following heart transplantation, despite having a high risk for developing CAV. If we encounter transplantation patients with high CAV risks, we may need to consider administering everolimus. Further investigations are needed to explore the mechanism of plaque regression associated with everolimus, as well as to confirm our observation in randomized controlled trials for patients after heart transplantation.

      Conflict of interest

      None of the authors have conflicts of interest that should be declared.

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      Linked Article

      • The role of everolimus in treatment of cardiac allograft vasculopathy
        Journal of Cardiology CasesVol. 7Issue 6
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          Cardiac allograft vasculopathy (CAV) remains one of the most important causes of late graft failure and death in heart transplant recipients [1]. CAV is a progressive coronary artery disease characterized by diffuse and progressive thickening of the intima along the entire length of the epicardial and intramyocardial arteries [2]. CAV is largely caused by various immunologic factors, which act on the wall of the graft coronary vessels damaging the endothelium and triggering the release of proliferative substances and the adhesion of platelets and mononuclear cells [3].
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          We appreciate the time and effort Park et al. took to read and think about our case report, as well as share some of your thought with us and the Journal of Cardiology Cases reader. His point is an extremely important one: that is, the new nomenclature of the double-lumen right coronary artery (DLRCA) distinguishes from double right coronary artery (DRCA).
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