Perioperative myocardial infarction can be predicted by preoperative electrocardiography

Preoperative identification of the predictors of perioperative myocardial infarction following noncardiac surgery (PMI) may help decrease its high mortality rate. In previous studies, atrial and ventricular rhythm abnormalities in the preoperative ECG have been identified to be risk factors for PMI. We performed this prospective study to determine whether or not other ECG findings may also predict PMI. Adults with significant comorbid conditions admitted to the SICU following high-risk noncardiac operations and who underwent workup to rule out PMI were studied. PMI workup consisted of a 12-lead ECG, CK-MB, and later troponin determination at 6–8 hour intervals for 24 hours. Data collection included patient demographics, comorbid conditions, preoperative work up including 12-lead ECG, surgical diagnoses, type and duration of anesthesia and operations, preoperative, intraoperative, and postoperative vital signs and clinical events, results of PMI workup, incidence of PMI and final outcome. The data was analyzed using SPSS statistical software.

There were 356 patients; 168 males and 188 females with the mean age of 62.9 years. The preoperative ECG was normal in 85 (23.9%) and abnormal in 271 (76.1%) patients. Normal sinus rhythm was present in 254/356 (71.3%), premature atrial complexes in 11/356 (3.1%), atrial fibrillation in 14/356 (3.9%), premature ventricular complexes (PVC) in 26/356 (7.3%), left ventricular hypertrophy (LVH) in 72/356 (20.2%), T-wave abnormality in 156/356 (46.3%), ST segment abnormality in 97/356 (27.2%), and a Q wave in 53/356 (14.9%). PMI developed in 31/356 (8.7%) patients, and three (9.7%) died as a result.

Comparison of the preoperative ECG findings of patients without and with PMI showed sinus tachycardia in 45/325 (13.8%) without PMI and in 7/31 (22.6%) with PMI, atrial fibrillation in 13/325 (4%) without PMI and in 1/31 (3.2%) with PMI, PVCs in 22/325 (6.8%) without PMI and in 4/31 (12.9%) with PMI, LVH in 61/325 (18.8%) without PMI and in 11/31 (35.5%) with PMI, and ST segment abnormality in 83/325 (25.5%) without PMI and in 14/31 (45.2%) with PMI. Logistic regression analysis showed LVH and ST segment abnormality to be significant predictors of PMI.

Conclusion

LVH or ST segment abnormality on the preoperative ECG are predictors of PMI.