Author + information
- Abdur R. Khan,
- Fadi Alreefi,
- Sarthi R. Shah,
- Faraz Khan Luni,
- Mujeeb A. Sheikh and
- George V. Moukarbel
Routine electrocardiogram is unable to detect ST elevation in all patients who present with myocardial infarction due to acute total coronary occlusion. Our aim was to evaluate the incidence, distribution of the involved vessel and extent of cardiac injury in patients with non-ST elevation myocardial infarction (NSTEMI) who have acutely occluded infarct related artery (IRA).
Total occlusion of IRA was evaluated in 535 consecutive patients who presented with NSTEMI and underwent angiography. Patients were divided into groups based on the distribution of the occluded vessel; infero-lateral (left circumflex and right coronary artery) and anterior distribution (left anterior descending). Demographic and clinical characteristics were compared between these groups. The extent of cardiac injury was measured by the peak level of cardiac enzymes.
The IRA was completely occluded in 78 (15%) of patients. The median time from presentation to coronary intervention was 18 hours. The occluded vessels were more common in the infero-lateral (73%) as compared to the anterior (27%) distribution. There was no significant difference between the two groups (Table 1).
About 15% of NSTEMI are due to a totally occluded artery; more commonly in the infero-lateral distribution. These patients represent STEMI equivalents and likely benefit from an early invasive strategy. There is need for better triage and earlier identification of these subgroups.
|Characteristics||Anterior (n = 21, 27%)||Infero-lateral (n = 57, 73%)||P value|
|Age, yrs||57.1 ± 9.9||59.5 ± 12.8||0.452|
|Systolic Blood Pressure, mmHg||126.4 ± 33.3||137.8 ± 37.5||0.546|
|TIMI Score at presentation||3.2 ± 1.2||3.0 ± 1.0||0.522|
|Peak CK-MB, (Median, 25th and 75th Percentile)||73 (18, 238)||117 (19, 196)||0.952|
|Peak Troponin, (Median, 25th and 75th Percentile)||11 (3, 31)||12 (4, 47)||0.670|
|Ejection Fraction, (Median, 25th and 75th Percentile||45 (40, 52)||50 (30, 55)||0.627|
Difference between means and medians compared by t-test and Matt-Whitney test respectively.