HARM is defined as delayed gadolinium enhancement in the subarachnoid space on FLAIR imaging. In this prospective study, Kang’s team looked at 45 patients who underwent either carotid endarterectomy or stenting for stenosis ≥ 70%. Each patient had diffusion-weighted and FLAIR imaging before and 24 hours after carotid revascularization. They found that older age, underlying leukoaraiosis, and post-procedural high blood pressure were associated with symptomatic HARM.
The most meaningful part of their study focuses on the post-procedural blood pressure data. They found that patients with symptomatic HARM showed clinical improvement after strict blood pressure control. If HARM is more likely to occur with elevated blood pressures and if symptoms improve after blood pressure is optimized, why are we not doing a better job controlling pressures?
We have an abundance of data showing that uncontrolled blood pressure after carotid revascularization increases the risk of reperfusion injury. Data is most meaningful when it directly impacts bedside care.
When a patient undergoes carotid revascularization, we cannot change his age or his amount of underlying leukoaraiosis. We can control post-procedural blood pressure. And we have the medications and technology to do it well. The risk of HARM will decrease with improved blood pressure management and this should be the focus of post-carotid revascularization care.