Comparison of the Signal-averaged ECG after Primary Percutaneous Coronary Intervention according to Thrombus Aspiration in ST Elevation Myocardial Infarction

Lee, Jun Young; Choi, Won Suk; Jung, Byung Chun; Lee, Bong Ryeol; Kang, Hyun Jae; Kim, Jae Hee; Kang, Gyoun Eun

Abstract

BACKGROUND/AIMS
Percutaneous coronary intervention (PCI) is the standard method of treating ST-segment elevation myocardial infarction (STEMI). There is continuing uncertainty as to whether reducing the thrombus burden through catheter aspiration improves the arrhythmogenic structure of the myocardium in STEMI. We compared the changes in electrical instability after thrombus aspiration-assisted primary PCI using conventional primary PCI.
METHODS
The study population included 170 consecutive patients with STEMI who underwent primary PCI. The patients were divided into 80 patients who underwent primary PCI only and 90 patients who underwent thrombus aspiration before PCI. The signal-averaged ECG (SAECG) was obtained 5 +/- 2 days after the intervention.
RESULTS
There were no significant differences between the groups in terms of sex, age, cardiovascular risk factors, or time from the onset of symptoms to treatment. The duration of the low amplitude signals less than 40 microV (LAS40), duration of the QRS complex (QRSD), and root mean square voltage of the terminal 40 ms of the QRS complex (RMS40) did not differ between the thrombus aspiration and no thrombus aspiration groups. The incidences of QRSD > 114 ms and RMS40 < 20 microV were significantly lower in the thrombus aspiration group than the no thrombus aspiration group (19 vs. 8, p = 0.011 and 16 vs. 8, p = 0.047, respectively), while the incidence of LAS > 38 ms was significantly higher in the non-thrombus aspiration group (18 vs. 8, p = 0.018).
CONCLUSIONS
Among random patients with STEMI, thrombus aspiration improved all of the parameters of SAECG, which is related to ventricular arrhythmogenesis, although the long-term clinical outcomes need to be assessed.