Abstract 6013: Troponin I, High sensitive C-reactive protein and Neopterin in Percutaneous Coronary Interventions: insight from Cardiac Magnetic Resonance Imaging
Background. Cardiac Magnetic Resonance Imaging (CMR) can identify myocardial damage due to embolization after percutaneous coronary interventions (PCI). Late Gadolinium Enhancement (LGE) can non-invasively detect myocardial fibrosis however the association of High sensitive C-reactive protein (HS-CRP) or Neopterin levels with myocardial damage in PCI is currently unknown.
Methods. Patients admitted with potential PCI were enrolled. LGE CMR scan was performed 24hours pre- and 24 hours post-PCI. Fourty five patients were enrolled, 61±12 yrs old, 33(73%) male. CMR performed pre PCI failed to show LGE in the area of the target vessel. TnI were not elevated at baseline. New LGE areas in the 2nd CMR scan were classified in distal (> 10 mm downstream from the stent) or adjacent (close to the stent). Troponin I was assessed at baseline and at 12 and 24 hours after PCI.
Results. In 35 out of 45 pts, baseline levels of HS-CRP and neopterin were measured.Troponin I elevation occurred in 26 (58%) patients, 0.56 ng/ml (0.26 –1.23). New areas of LGE were detected in 15/45 (33%) patients, 0.83 grams (0.32–1.3), all with troponin rise after PCI. In 7 out of 15 (47%) patients new LGE areas were distal to the stent, in 8 (53%) patients adjacent. Grams of myocardial damage correlated with troponin levels after PCI, r = 0.64, p<0.001, in the overall population, although there was no linear relationship. Patients with new distal LGE showed a trend toward higher levels of baseline CRP compared to the remaining patients [7.4 mg/L (2.5– 62.9) vs 2.5 mg/L (0.9 – 6.3), p=0.08]. HS-CRP was a weak predictor of new distal LGE (odds ratio 1.03, 95% confidence interval (0.99 –1.06, p=0.07)). There was no significant difference in the neopterin levels between patients with or without new distal LGE [7.1 nmol/L (6.1– 8.3) vs 6.1 nmol/L (4.4 –9.0), p=0.39]
Conclusions. Patients who develop myocardial damage due to distal embolization show a trend toward higher baseline CRP levels. This suggests that increased systemic inflammation may be a marker of higher friability of coronary plaques and/or of enhanced inflammatory response of myocardium to embolizing particles, responsible for subsequent myocardial damage. Larger studies are needed to confirm these preliminary hypothesis generating data.