IBIS-4: Rosuvastatin Tied to Plaque Stability in STEMI
OCT analysis supplements previous IVUS findings
High-intensity statin therapy is associated with plaque stabilization in the noninfarct-related arteries of STEMI patients, according to a serial multivessel OCT study presented on Tuesday in a Featured Clinical Research at TCT 2015.
For the IBIS-4 study, Lorenz Räber, MD, PhD, of University Hospital Bern, Switzerland, and colleagues used the ILUMIEN OCT console and Dragonfly catheter (both St. Jude Medical) to assess the serial changes in cap thickness and macrophage accumulation as well as the frequency of fibroatheroma in 153 noninfarct-related arteries of 83 STEMI patients taking rosuvastatin 40mg over 13 months. The analysis, which was assisted by software specifically developed for the study that specifically looked for things like “side branches and calcific pools,” was performed at 0.4-mm intervals along the vessels. Mean matched vessel length was 28.4 mm, with a total of 10,710 matched frames.
Minimal cap thickness (co-primary endpoint) increased from baseline to follow-up, as did mean cap thickness. Lipid arc reduced over time (see Figure). Similarly, in a sensitivity analysis of matched 3-mm segments also found increases in minimal and mean cap thickness over the study period (P < .001 for both).
Macrophage angle (co-primary endpoint) decreased by a mean of 35.8% over time, with a 25.9% reduction seen in the maximum macrophage angle (P < .001 for both).
Importantly, Räber said, there was a significant association between LDL reduction and the change in various parameters of atherosclerosis such that “the more you can lower the LDL the more macrophage reduction can be achieved.”
Räber said the limitations of the study include the fact that there was no formal sample size calculation and that it was a serial imaging study that lacked a control group. Also, he said, only selected patients underwent serial imaging since multivessel imaging in “the setting of STEMI is technically demanding and can only be performed in stabilized STEMI patients.”
Panelist Harold L. Dauerman, MD, of the University of Vermont Medical Center, Burlington, said IBIS-4 is a “very detailed analysis that expands upon what IVUS has shown us.”
- Bern reports receiving grant/research support from St. Jude Medical.
- Dauerman reports receiving grant/research support from Medtronic and consultant fees/honoraria/speaker’s fees from Boston Scientific and Medtronic.