Abstract 13738: Release Kinetic of Troponin T Measured With a High Sensitive Assay in Patients With Acute Myocardial Ischemia
Background: High sensitive troponin T (hsTnT) assays have been shown to improve diagnostic sensitivity in patients presenting with symptoms suggestive for an acute coronary syndrome (ACS). However, no unequivocal data are available on the exact release kinetic of cardiac troponin T levels measured with conventional and high sensitive assay after induction of myocardial ischemia. Therefore, in the present study we aimed to analyse the release kinetic of conventional troponin T (cTnT), hsTnT and CK-MB in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing transcoronary ablation of septal hypertrophy (TASH) as a method uniquely offering a clearly defined onset of myocardial ischemia.
Methods and Results: Consecutive patients (n=21) with HOCM undergoing TASH were included into the study. TASH was performed according to standard interventional practice. Plasma samples for measurements of cTnT, hsTNT and CK-MB were collected before as well as 15 min, 30 min, 45 min, 60 min, 75 min, 90 min, 105 min, 2 hours, 4 hours, 8 hours and 24 hours after TASH. Using the 99th percentile cut off point for a healthy population hsTnT levels raised steadily after induction of myocardial ischemia and were significantly increased already after 15 minutes (21.4 pg/ml [13.3-39.7] vs. 11.3 pg/ml [6.0-18.8]; p=0.031). CTnT levels showed the first significant increase only after 60 min (0.03 ng/ml [0.018-0.03] vs. <0.01 ng/ml [<0.01.-0.01];p<0.0001). CK-MB levels showed a continuous increase with a significant rise over the upper normal limit after 60 minutes (37.5 U/l [31.0-43.0] vs. 7.0 U/l [6.0-9.0]; p<0.0001). The measurement of CK before and 12 h after intervention showed a significant difference (935.0 U/l [545.5-1115.0] vs. 80.0 U/l [63.5-109.0]; p<0.0001).
Conclusion: HsTnT shows a continuous rise after onset of myocardial ischemia during all prespecified time points. The first significant difference compared to baseline hsTnT values occurs already 15 minutes after induction of myocardial ischemia, whereas cTnT shows the first significant increase only after 60 min. These results demonstrate that acute myocardial ischemia can be detected significantly earlier with high sensitive troponin T assays as compared to conventional troponin assays.
- © 2011 by American Heart Association, Inc.