Additional ST-segment elevation during thrombolytic therapy in patients with acute ST-elevation myocardial infarction: Impact on myocardial salvage and final infarct sizeFortschreitende ST-streckenelevation während der Thrombolyse bei Patienten mit akutem ST-Streckenhebungsinfarkt: Der Einfluss auf die Rettung von Myokard und die endgültige Infarktgröße

The aim of the study was to investigate the clinical significance of additional ST-segment elevation that occurs during thrombolytic therapy. Therefore, we classified 153 patients with a first acute myocardial infarction (MI) into two groups: Group A, 55 patients with additional ST-segment elevation >-1 mm above the initial ST elevation during thrombolytic therapy and Group B, 98 patient without this electrocardiographic pattern. Among the patients with anterior MI, Group A (n=33) had no reduction from ST-predicted to final QRS-estimated infarct size (+12% versus −27%; p=0.0005) and a larger final infarct size (QRS-score; 18% versus 12%: p=0.0002) than Group B (n=41). Among the patients with inferior MI, Group A (n=22) had a smaller reduction from ST-predicted to final QRS-estimated infarct size (−30% versus −53%; p=0.03) and a larger final infarct size (QRS-score; 15% versus 9%; p=0.03) than Group B (n=57). The area under the curve (AUC) of CK and CK-MB was higher in patients from Group A compared with those from Group B (anterior MI: AUC-CK: 22048 versus 19490 U.h.I−1; p=0.07; AUC-MB: 2227 versus 2016 U.h.l−1; p=0.11; inferior MI: AUC-CK: 17206 versus 11004 U.h.l.−1; p=0.01; AUC-MB: 2193 versus 1046 U.h.l−1; p-0.007). Both global left ventricular function and ST-segment elevation resolution were significantly better in Group B. Two and three vessel disease was observed more frequently in Group A. Additional ST-segment elevation during thrombolytic therapy suggests reduced myocardial salvage by thrombolytic therapy and thus may result in larger final infarct size.