"The results are very positive for the 8 million patients worldwide who have received DES and are concerned by the risk of death and adverse events,” principal investigator Stefan James (Uppsala Clinical Research Centre, Sweden) said in Clinical Trial Update session yesterday. “But physicians should be concerned that we’ve not solved the problem of late stent thrombosis. They need to think carefully about patient selection.”
The SCAAR registry, which included data on 294,000 procedures, was derived from the Swedish Personal Registry, which records all health events occurring in each Swedish individual. In the registry data 13,786 patients received a DES and 21,480 a BMS. Analysis of events showed that, within the entire study between 2002 and 2006, 2957 MIs and 1424 deaths occurred - and these provided the outcome measures for the statistical analysis.
An analysis based on the 18,967 patients receiving only one stent at the index revascularisation showed an absolute reduction in the rate of restenosis of 3.5% after four years in favour of the DES group compared with the BMS group. However, there was a continuous low risk of 0.5 % annually of in-stent thrombosis in the DES group, which did not seem to occur in the BMS group.
“So our results show the risk of late events in DES is counterbalanced by a early gains,” said James.
The results reported yesterday add a year of enrolment and an additional year of follow-up to data published in February (NEJM 2007:356:1009-19), which showed a higher mortality among the DES patients.
“We speculate that in the later cohort clinicians were more aware of the risk of DES and prolonged antiplatelet therapy. They may also have improved techniques with use of higher balloon pressures and more accurate stent sizing,” said James, adding that clinicians need to think carefully about patient selection.
Patients with large vessels, increased risk of bleeding and compliance issues should have BMS stents, he said, while those with bifurcations, lesions longer than 8mm, narrow stents, and diabetics may benefit from DES.
A prospective large scale randomised trial of DES versus BMS is needed that includes different durations of dual antiplatelet treatment, he added
After the uproar in ESC in Barcelona 2006 and publication of the BASKET trial, use of DES dropped from 60% to 15% in Sweden, but has now stabilised at around 20% after publication of randomised trials and meta-analyses, and the NORDIC trial showed a good response in bifurcation patients.
Read the SCAAR Drug Eluting Stents Clinical Trial Update