The clinical relevance of raised cardiac troponin I in the absence of significant angiographic coronary artery disease.

OBJECTIVES: Cardiac troponins are highly sensitive and specific markers of myocardial cell injury. We wished to determine the clinical relevance of raised troponins in the absence of significant angiographic coronary artery disease. DESIGN AND METHODS: We assessed patients admitted to our hospital over the past 3 years with troponin-positive chest pain and no angiographically significant coronary disease. RESULTS: The study included 67 patients, all of whom had symptoms of "chest pain" and elevated (>0.2 microg/L) troponin I on admission. Thirty-four (51%) patients had alternative causes for myocyte injury other than coronary ischaemia. In the remaining 33 (49%) patients we could find no other associated features or diagnoses. Follow up was obtained in 29 (88%) of these 33 patients (mean follow up 58+/-13 weeks, range 17-156 weeks). During the follow up period, three (4.5%) patients were readmitted with further ischaemic events. CONCLUSIONS: Myocardial damage can occur in the absence of significant angiographic coronary disease and other causes of raised troponins should be considered according to the clinical presentation. Troponin-positive cases with angiographically "normal" coronary arteries can re-present with future cardiac events and should still be considered for aggressive risk management.

Direct stenting may limit myocardial injury during percutaneous coronary intervention.

BACKGROUND: Direct coronary stenting has been shown to be safe and feasible, with a demonstrable reduction in cost, procedural time and radiation exposure. Direct stenting may limit distal embolization of atherosclerotic plaque and consequently reduce myocardial cell injury following percutaneous coronary intervention, which may have important prognostic implications. METHODS AND RESULTS: We assessed cardiac troponin I (cTnI) release in the 24 hours following direct coronary stenting (DS) as compared to stenting with balloon predilatation (PD) in a total of 311 patients and 440 vessels/lesions (vessel to lesion ratio = 1:1) (DS: n = 107 patients and 149 vessels/lesions; PD: n = 204 patients and 291 vessels/lesions). The 2 groups were well matched except for a greater proportion of diabetic patients in the PD group (21%) compared to the DS group (11%) (p < 0.05). There were no significant differences in the distribution of target lesion site or angiographic complexity between the 2 groups. Primary angiographic success was achieved in 97% of vessels in the DS group and 98% of vessels in the PD group (p = NS). DS failed in 7/114 patients (6%) deemed suitable for DS by the operator, but all stents were subsequently successfully deployed following balloon predilatation. Abciximab (ReoPro , Eli Lilly Company, Indianapolis, Indiana) was used in 11 patients (10%) in the DS group and 24 patients (12%) in the PD group ( p = 0.68). The post-procedural median (IQR) peak cTnI concentrations were 0.2 0.1 g/L in the DS group and 0.5 0.3 g/L in the PD group (p = 0.02). Post-procedural cTnI concentrations were > 0.2 g/L in 11 patients (10%) in the DS group and in 53 patients (26%) in the PD group (X2 = 58.6; p < 0.0001). The rate of major adverse cardiac events at 6 18 month follow-up was 8% in the DS group and 15% in the PD group (X2 = 38.5; p = 0.02). CONCLUSION: Direct stenting without balloon predilatation is associated with lower post-procedural cTnI concentrations and lower incidence of major adverse events compared to traditional stenting with predilatation.