Prognostic Value of R-Wave Voltage in Patients With Anterior Wall ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Abstract

SummaryThe prognostic value of integrated R-wave voltages of precordial leads (V 1 -V 6 ) in patients with acute anterior wall ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) was investigated.Between July 2006 and October 2009, 292 patients with anterior wall STEMI with presentation < 12 hours underwent primary PCI. Thirty-four patients with electrocardiographic presentation of either complete right bundle branch block (BBB) or complete left BBB were categorized into group A, while the remaining 258 patients without BBB served as group B that was further subdivided into those with lower R-wave voltage (summation of V 1 -V 6 ≤ 1.7 mV) (group 1) and higher voltage (> 1.7 mV) (group 2) according to the ROC curve (sensitivity = 66.3%, specificity = 66%, P < 0.0001).While the procedural success rate was similar between groups A and B and groups 1 and 2, 30-day mortality was higher in group A than B (P ≤ 0.0001). Additionally, left ventricular ejection fraction (LVEF) was lower, whereas peak level of creatine phosphopkinase (CPK), incidence of advanced congestive heart failure, and 30-day mortality were higher in group 1 than 2 (P < 0.01). Multivariate analysis revealed that lower R-wave voltage, multivessel disease, leukocyte count, peak CPK, and creatinine level were predictive of 30-day unfavorable clinical outcomes (all P < 0.01). Rwave voltage in precordial leads was a significant independent predictor of 30-day prognostic outcome in patients with anterior wall STEMI undergoing primary PCI. (Int Heart J 2010; 51: 325-330) Key words: Electrocardiogram, Acute myocardial infarction, R-wave voltage, 30-day major adverse cardiac events I t is well known that the electrocardiogram (ECG), which was first developed more than 100 years ago, 1) is a useful noninvasive tool for the diagnosis of various cardiac disorders in daily clinical practice.2-5) Some distinctive ECG findings, including new onset of complete left bundle branch block (CLBBB), 6) combined expression of pathological Q-wave and complete right bundle branch block (CRBBB), 7) ST-segment elevation ≥ 1 mV in aVR lead, 8) inferior wall myocardial infarction (MI) complicated by right ventricular infarction, 9) and simultaneous inferior wall and anterior wall ST-segment elevation, 10) have been shown to be useful ECG features for the prediction of prognosis after acute myocardial infarction (AMI). Recently, the resolution of elevated ST-segments in patients with acute ST-elevation MI (STEMI) undergoing primary percutaneous coronary intervention (PCI) has also been identified as an important marker of ECG for assessing left ventricular (LV) function and prognostic outcome.11-13) Baseline Q waves 14,15) in STEMI patients treated with primary PCI have also been reported to be an independent prognostic marker of clinical outcome.Although the peak serum level of creatinine phosphokinase, 16) myocardial thallium scan, 17) and the evaluation of LV function using transthoracic echocardiography 18) are all useful t...