Biochemical markers and cardiac troponin I release after radiofrequency catheter ablation: Approach to size of necrosis

Background We designed this study to determine the value of serum levels of several cardiac markers in patients who underwent radiofrequency ablation and to establish the utility of cardiac troponin l (cTnl). After radiofrequ ency ablation there is always a small localized endomyocardial necrosis. Th e volume of the necrosis may be estimated by the rise of several biochemica l marker levels, classically creatinine kinase (CK) and CK-MB. cTnl is a ne wly available biochemical marker with a high cardiac specificity. Methods and Results We analyzed the data from 51 patients who underwent rad iofrequency ablation and from 16 control patients who underwent an electrop hysiologic study without ablation. The levels of CK, CK-MB mass, cTnl, and myoglobin were compared with clinical findings, ST-T wave abnormalities, an d the presence of arrhythmias. The study shows that there is a higher relea se of cTnl compared with the standard markers CK, CK-MB, and myoglobin. A p athologic value of cTnl was found in 92% of the patients of the ablation gr oup. CK-MB had a lower sensitivity (63%). The area under the receiver opera ting characteristic curve for cTnl was 0.9375, significantly superior to th e other biochemical markers (P < .05). We found a moderate level of correla tion between the number of radiofrequency pulses and cardiac cTnl release ( r = 0.69, P < .0001). Conclusions The serum level of cTnl detects the minor myocardial damage pro duced by radiofrequency ablation. This would be useful information to have in patients who might have the potential for other ischemic events. The oth er biochemical or ablation parameters usually reported, including the radio frequency ablation parameters, have no good correlation with the size of th e myocardial necrosis. Therefore we suggest that monitoring of cTnl is the best way to detect and quantify the size of myocardial necrosis created by radiofrequency ablation.