Gruppo Italiano Di Studio Sullo Stent Nelle Occlusioni - GISSOC
GISSOC was a multicenter, randomized trial to evaluate the outcomes associated with Palmaz-Schatz stent implantation following successful balloon angioplasty (PTCA) vs. PTCA alone for the treatment of chronic total occlusions.
Compared to PTCA alone for the treatment of chronic total occlusions, stent implantation following PTCA would be associated with an improved minimum lumen diameter at 9 month angiography.
Patients Screened: 111
Patients Enrolled: 110
Mean Follow Up: 9 months for the initial study; 6 years for the long-term follow-up
Mean Patient Age: mean 58 years
Both absolute (TIMI flow grade 0) and “functional” (TIMI flow grade 1) occlusions were included. Symptomatic patients or those with inducible ischemia in the territory supplied by the occluded artery were included. The patients were required to be suitable candidates for CABG.
Acute myocardial infarction within 30 days; chest pain at rest within 7 days; contraindication to aspirin or warfarin; total occlusion at a site of a previous PTCA; occlusion <30 days in duration; significant left main disease; vessel <3 mm in diameter or with severe tortuosity; lesion >13 mm or involving a major side branch; evidence after recanalization of diffuse disease, additional stenosis >50% of the lumen diameter in the distal segment following the intervention, or complex dissection.
Minimum lumen diameter at 9 month angiographic follow-up
Binary restenosis at follow-up; major ischemic events (death, myocardial infarction, CABG, repeat angioplasty, target lesion revascularization); symptomatic status at follow-up; hemorrhagic events (intracranial bleeding or complications requiring vascular surgery or blood transfusion)
The target occlusion was treated by conventional PTCA. In case of successful recanalization, defined as restoration of anterograde TIMI grade 2 or 3 flow with a residual stenosis <50% of the lumen diameter, the angiogram was immediately evaluated to establish whether all the angiographic inclusion criteria were met.
Stent Implantation: a standard Palmaz-Schatz stent was manually crimped onto a conventional balloon catheter and deployed with post-dilation. 4-8 hours following sheath removal, warfarin and intravenous heparin infusion were started. Heparin infusion was continued until an INR of 2.5-3.5 was obtained at which point patients were transitioned to warfarin, which was continued for 1 month.
PTCA alone: further balloon dilatations aimed to optimize the angiographic result were allowed. Crossover to stent implantation was allowed in the case of worsening of the residual stenosis to <50% of the lumen diameter.
Aspirin (150 to 325 mg daily) and a calcium channel blocking agent starting at least 24 h before PTCA. During the procedure, heparin was given to maintain the activated clotting time >250 seconds.
110 patients were included in the analysis. Baseline characteristics were well-matched among the two study groups; approximately 10% of the study population was diabetic, and the estimated duration of occlusion was 11 weeks. Approximately 35% of patients in the study had a “functional” occlusion with TIMI Grade 1 flow. Only one patient in the PTCA group crossed over to the stent group.
Follow-up angiography was performed in 88% of patients at a mean follow-up of 9 months. Patients assigned to stent implantation had larger minimum lumen diameters (1.74 mm vs. 0.85 mm, p<0.00001) and a lower rates of binary restenosis (32.0% vs. 68.1%, p=0.0008) and re-occlusion (8.0% vs. 34.0%, p=0.0035) compared to patients assigned to PTCA alone. In multivariate analysis, stent implantation was independently associated with greater minimum lumen diameter, and diabetes and post-procedural diameter stenosis were negatively associated with follow-up lumen diameter.
Among patients assigned to stent implantation, 9-month rates of target lesion revascularization (5.3% vs. 22.0%, p=0.038) and recurrent ischemia (14.0% vs. 46.0%, p=0.002) were lower than in patients assigned to PTCA alone. Rates of other clinical endpoints were similar in both study groups. At 6 year follow-up, the difference in rates of target lesion revascularization remained (14.9% among stent patients vs. 34.5% in PTCA alone, p=0.017).
In this randomized trial of PTCA vs. stent implantation for the treatment of chronic total occlusions, stenting was associated with larger minimum lumen diameters, reduced rates of re-occlusion, and reduced rates of target lesion revascularization at 9-month and long-term follow-up. These findings are similar to those of the SICCO and TOSCA trials, which confirm the efficacy of stenting in lowering rates of restenosis, re-occlusion, and target lesion revascularization when treating chronic total occlusions.
1. Rubartelli P, Niccoli L, Verna E, et al. Stent implantation versus balloon angioplasty in chronic coronary occlusions: results from the GISSOC trial. Gruppo Italiano di Studio sullo Stent nelle Occlusioni Coronariche. J Am Coll Cardiol 1998;32:90-6 (Initial study results)
2. Rubartelli P, Verna E, Niccoli L, et al. Coronary stent implantation is superior to balloon angioplasty for chronic coronary occlusions: six-year clinical follow-up of the GISSOC trial. J Am Coll Cardiol 2003;41:1488-92 (Six year follow-up).
Keywords: Multivariate Analysis, Warfarin, Dilatation, Heparin, Coronary Disease, Constriction, Pathologic, Angioplasty, Balloon, Coronary, Diabetes Mellitus, Stents
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