PERIOPERATIVE ISCHEMIA AND CARDIAC COMPLICATIONS IN MAJOR VASCULAR-SURGERY - IMPORTANCE OF THE PREOPERATIVE 12-LEAD ELECTROCARDIOGRAM

Purpose: To investigate the associations between specific preoperative 12-lead electrocardiogram (ECG) abnormalities, perioperative ischemia , and postoperative myocardial infarction or cardiac death in major va scular surgery. Methods: Two prospective studies on perioperative myoc ardial ischemia performed in two tertiary university hospitals were co mbined to include 405 patients. All preoperative ECGs were analyzed ac cording to the Sokolow-Lyon criteria for left ventricular hypertrophy by investigators who were blinded to the patients' perioperative clini cal course. Perioperative myocardial ischemia was detected by continuo us ECG recording, and postoperative cardiac complications included myo cardial infarction and cardiac death. Results: A total of 19 postopera tive cardiac complications occurred (two cardiac deaths and 17 myocard ial infarctions). Voltage criteria for left ventricular hypertrophy (7 8 patients, 19%) and ST segment depression greater than 0.5 mm (98 pat ients, 24.2%) on preoperative ECGs were both significantly associated with postoperative myocardial infarction or cardiac death (odds ratio, 4.2 and 4.7; p = 0.001 and 0.0005, respectively) and with longer intr aoperative and postoperative myocardial ischemia. In each of the two s tudy groups, a preoperative ECG abnormality that involved voltage crit eria, ST segment depression, or both (134 patients, 33.1%) was more pr edictive of postoperative cardiac complications than any other preoper ative clinical variable, including a history of myocardial infarction or angina pectoris, diabetes mellitus, pathologic Q-wave by ECG, or pr eoperative myocardial ischemia. The combined duration of intraoperativ e and postoperative ischemia and the preoperative ECG with either volt age criteria or ST segment depression were the only independent factor s associated with adverse cardiac events by multivariate analysis (p l ess than or equal to 0.0001 and p = 0.02, respectively). Conclusion: L eft ventricular hypertrophy and ST segment depression on preoperative 12-lead ECGs are important markers of increased risk for myocardial in farction or cardiac death after major vascular surgery.