Abstract 10703: Can the Universal Definition of Myocardial Infarction’s Electrocardiogram Criteria for Prior Myocardial Infarction be Simplified?
Background: The Third Universal Definition of Myocardial Infarction (UDMI) includes electrocardiogram (ECG) criteria for prior myocardial infarction, which are any Q wave in leads V2-V3 ≥0.02 seconds or QS complex in leads V2 and V3; or Q wave ≥0.03 seconds and ≥0.1 mV deep or QS complex in leads I, II, aVL, aVF or V4-V6 in any two leads of a contiguous lead grouping. Since these criteria are largely based on expert opinion, require precise measurements, and are complicated, we compared the UDMI criteria to the simplified criteria of any Q wave ≥0.04 seconds in a single lead other than V1, III, and aVR, using the surrogate of cardiovascular (CV) death. Additionally, we compared Q waves that meet the UDMI criteria in contiguous leads to a single lead in order to assess the need for contiguous ECG changes.
Methods: We evaluated computerized Q wave duration and amplitude measurements, in different leads, from the resting ECGs of 43,689 patients collected from 1987 to 1999 at the Palo Alto VA. The average age was 56 (±15) years, 90% were male, 12% were of African descent, and 74% were outpatients. There were 3,929 (9.0%) CV deaths over a mean follow-up of 7.6 (±3.8) years. Cox hazards were calculated with CV death as the endpoint.
Results: We found that the relative risk of CV death, when the UDMI criteria were present in contiguous leads, ranged from 1.87 - 3.16 (depending on the lead grouping) (p <0.001 for each individual relative risk). When the UDMI criteria were present in single leads, the relative risk of CV death ranged from 1.22 - 3.08 (depending on the lead) (p <0.001 for each individual relative risk). When Q waves ≥0.04 seconds in a single lead other than V1, III, and aVR were present, the relative risk of CV death ranged from 1.63 - 6.59 (depending on the lead) (p <0.001 for each individual relative risk).
Conclusions: Using an endpoint of CV death, the simplified Q wave criteria of ≥0.04 seconds in a single lead other than V1, III, and aVR, outperformed the UDMI criteria, suggesting that the UDMI criteria for Q waves can be simplified and improved. Furthermore, the UDMI criteria for Q waves in contiguous leads were only minimally superior to UDMI criteria for Q waves in a single lead, suggesting that requiring ECG changes to be in contiguous leads is unnecessary.
- © 2013 by American Heart Association, Inc.