FD-OCT identifies predictors of MI before and after stenting

8 February 2012

MedWire News: Thin-cap fibroatheroma assessed prior to percutaneous coronary intervention (PCI) is associated with an increased risk for periprocedural myocardial infarction (MI), research shows.

The study, led by Italo Porto (Catholic University of the Sacred Heart, Rome, Italy), also identified in-stent thrombus and intra-stent dissection as independent predictors of periprocedural MI.

Two of these predictors are not apparent during pre-PCI optical coherence tomography (OCT) imaging, the group points out.

Periprocedural type IVa MI is an MI associated with PCI. It is a known complication in stable and unstable patients and is associated with adverse short- and long-term adverse outcomes.

In the current study, which is published in Circulation: Cardiovascular Interventions, the researchers examined frequency-domain (FD)-OCT-defined plaque features, measured before and after PCI, to evaluate their effect on periprocedural MI.

FD-OCT was performed in 50 patients with non-ST-segment elevation MI (NSTEMI) or unstable angina and periprocedural MI was diagnosed in 21 patients. The remaining 29 patients served as the control arm.

As assessed by FD-OCT prior to PCI, thin-cap fibroatheroma was present in 76.4% of the MI patients and 41.4% of the control arm (p=0.03).

Similarly, post-PCI FD-OCT revealed that in-stent thrombus and intra-stent dissection was evident in 61.9% of the MI patients, respectively, compared with 20.7% and 31.0% of the control patients. In both instances, the difference was statistically significant.

"The most novel part of our results lies in the identification of intrastent thrombus and intrastent dissection at post stenting FD-OCT analysis as predictors of type IVa MI," according to Porto and colleagues.

In addition, the lack of an observed association with plaque rupture, presenting thrombus, and plaque "prolapse" through the stent struts with MI is also novel and significant, they state. These variables have been linked with periprocedural MI in previous studies.

Multivariate analysis showed that patients with thin-cap fibroatheroma undergoing PCI were nearly 30 times more likely to have a periprocedural MI compared with those with the atheroma.

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Circ Cardiovasc Intv 2012; Advance online publication