NEW YORK (Reuters Health) – Elevated C-reactive protein (CRP) levels are linked with an increased risk of stent thrombosis and cardiovascular events in patients with drug-eluting stents, say researchers from Korea in the November 17th Circulation.

“CRP can be a very simple, easily measurable, and very useful bio-marker to identify high-risk patients and guide preventive or therapeutic measures to significantly reduce infrequent, but deadly, stent thrombosis,” Dr. Duk-Woo Park from University of Ulsan College of Medicine, Seoul told Reuters Health by email.

Dr. Park and colleagues followed 2691 patients with drug-eluting stents for a median of 3.9 years. In 970 patients, baseline CRP was elevated (3 mg/L or higher).

In general, thrombosis was infrequent. Twenty-six patients had definite stent thrombosis (0.96%), 6 (0.22%) had probable thrombosis, and 34 (1.26%) had possible thrombosis.

Overall, 137 patients (5.09%) died during the course of the study, 227 (8.43%) had myocardial infarctions, and 195 (7.24%) had target vessel revascularization.

According to the article, increasing rates of stent thrombosis over time were significantly higher in patients with elevated CRP. On multivariate analysis, elevated CRP was significantly associated with an increased risk of stent thrombosis (hazard ratio, 3.86).

Patients with elevated CRP also had significantly higher risks of death (HR, 1.61), myocardial infarction (HR, 1.63), and the composite of death or myocardial infarction (HR, 1.61), compared to patients with nonelevated CRP levels.

In contrast, the authors report, there was no association between CRP levels and the risk of target vessel revascularization.

Incorporation of CRP level into a model with clinical, lesion, and procedural risk factors significantly improved the risk prediction for stent thrombosis and death or myocardial infarction, the investigators say.

“Patients with high CRP should be classified as high-risk patients,” Dr. Park said. “For these patients, less invasive stent implantation or more aggressive pharmacologic therapy (especially, anti-platelet drugs or other CRP-modulating drugs) would be recommended to reduce these catastrophic events.”

“Our study identifies a very interesting, novel relationship,” Dr. Park added. “Further larger and longer-term follow-up study may be needed to confirm this phenomenon.”

Reference:
Circulation 2009;120:1987-1995.