Dr Claudio Rabbia, Torino-Molinette, Italy, recently presented two-year results from the GREAT study, which was designed to assess the results of renal stenting with the sirolimus-eluting (SE) 0.18 Palmaz Genesis stainless steel balloon expandable stent, compared to a bare metal stents (BMS) for the treatment of renal artery stenosis (RAS).
The following entrance criteria were used: Inclusion Criteria: age > over 30 years, clinical indication for renal artery revascularisation (stenosis >50%) reference vessel renal artery must be >4mm and <8mm by visual estimate, the patient must have a baseline serum creatinine of <5.0mg/dl, patient is willing and able to comply with the specified follow-up evaluation, the patient must provide written informed consent prior to the procedure. Exclusion Criteria were: more than one index lesion in a renal artery, including tandem had any known complication (e.g. guidewire perforation) following balloon angioplasty, lesions which are in arteries to transplanted or bypassed kidneys, any patient allergic or intolerant to aspirin and/or sirolimus, any patient with a co-existing condition with a life expectancy of less than two years, patients with a known bleeding or hypercoagulation disorder, absolute contraindication to administration of intravenous contrast material, heparin, or known allergy to 316L stainless steel or any of its components, abdominal aortic aneurysm >4.0cm in diameter, major surgical or interventional procedures within 30 days prior to this study or planned surgical or interventional procedures within 30 days of entry into this study, patients with ASA classification =4, life expectancy of less than two years or factors making clinical follow-up difficult, imprisoned persons, patients enrolled in this or other clinical trials or anticipated to be included into a trial which may interfere with this study, or patients already enrolled in this trial before.
A sequential approach was used with 52 patients receiving a bare Palmaz Genesis stent followed by 50 additional patients receiving the sirolimus-eluting Palmaz Genesis stent. The primary endpoint was an angiographic determination of the minimal lumen diameter in the stent at six months comparing the uncoated and the coated stents. Patients with >50% stenosis were subsequently treated with BMS vs SES. Primary endpoint was angiographic in-stent percentage diameter stenosis at six months. Secondary endpoints included absence of major events of up to two tears post procedure.
Angiographic follow-up revealed a procedural success rate of 100% for SES and 98% for BMS. In addition, there was no significant difference in the binary restenosis rate (14.3% in the BMS group and 6.7% for the SES group) or late lumen loss (0.92mm in the BMS group and 0.62mm for the SES group).
The results revealed that in the BMS group mean in-stent percentage diameter stenosis was 23.9+22.9 and 18.7+15.6 for the SES group (p=0.39). Up to 12 months, six patients (11.5%) in the BMS group required a revascularisation and two (3.7%) in the SES (p=0.16). that a worsening of renal function occurred in two (3.8%) and five patients respectively (9.4%), respectively.
Rabbia commented that although there was no significant difference using SES, there was a general trend in favour of SES, so it would seem that the addition of drug-eluting properties appears beneficial. He concluded that the 0.18 Palmaz Genesis stent appears to be a safe and effective device in the treatment of RAS.
In discussion, Roger Greenhalgh, Imperial College, London, UK, commented that the trial was not designed to show efficacy and therefore challenged the conclusion that DES for renals is effective.