WASHINGTON – Consistent with experimental and recent clinical studies, a meta-analysis of 69 randomized controlled trials found that increasing strut thickness correlated with increasing risk of stent thrombosis as well as risk of myocardial infarction.
The report was presented at CRT 2018, sponsored by the Cardiovascular Research Institute at Medstar Washington (D.C.) Hospital Center.
In the meta-analysis, which compared four categories of strut thickness, the relationship between strut thickness and rates of stent thrombosis was almost linear, according to Micaela Iantorno, MD, a clinical fellow in interventional cardiology at the hospital center.
Thirty-six of the studies compared devices with thin struts to those with thick struts, 15 studies compared devices with ultrathin struts to devices with thin struts, and 11 compared devices with thin struts to devices with struts in the intermediate category. The remaining seven studies compared other strut thicknesses, such as ultrathin to intermediate.
When compared to devices with the thickest struts, there was a stepwise reduction in risk of strut thrombosis for each grade reduction in thickness. Expressed as an odds ratio, devices with intermediate struts were associated with 33% risk reduction, devices with thin struts were associated with a 42% risk reduction, and devices with ultrathin struts were associated with a 57% risk reduction. Each was statistically significant based on the 95% confidence interval, although P values were not reported.
When devices with ultrathin struts were compared to those with thin struts or to those with intermediate thickness struts, the differences in stent thrombosis were not statistically significant, but there were trends favoring the devices with thinner struts. However, the lower risk of stent thrombosis for devices with thin struts relative to those with intermediate thickness was modest and did not approach significance.