Non-ST Elevation Myocardial Infarction With Occluded Culprit Artery: A Continuum of Mortality Risk Across the Spectrum of Acute Myocardial Infarction.

BACKGROUND: Non-ST segment elevation myocardial infarction (NSTEMI) patients presenting with occluded culprit artery (OCA) may be at higher risk for worse outcomes. We sought to compare in-hospital (IH) mortality between patients presenting with NSTEMI with and without OCA, and ST-segment elevation myocardial infarction (STEMI). METHODS: This retrospective analysis studied 14,037 patients enrolled in the Portuguese National Registry of Acute Coronary Syndromes. Three groups were defined: (A) STEMI (n = 8616); (B) OCA-NSTEMI (n = 1309); and (C) non-OCA NSTEMI (n = 4112). Baseline characteristics, therapeutic strategies, and outcomes were compared. Multivariate analysis was performed to assess the risk of IH all-cause mortality across the prespecified groups. RESULTS: Twenty-four percent of NSTEMI patients presented with OCA. The left circumflex artery was more frequently the culprit artery in group B (12.4% A vs 34.5% B vs 26.0% C; P<.001) and this group was also less likely to receive percutaneous revascularization (95.2% A vs 69.7% B vs 83.2% C; P<.001). The incidence of left ventricular systolic dysfunction was higher in group A and lower in group C (19.9% A vs 12.2% B vs 8.1% C; P<.001). The adjusted risk of IH mortality was significantly higher in group A when compared with group B (3.9% A vs 1.8% B; odds ratio, 2.34; 95% confidence interval, 1.34-4.07; P<.01) and in group B when compared with group C (1.8% B vs 0.9% C; odds ratio, 2.25; 95% confidence interval, 1.17-4.35; P=.02). CONCLUSION: OCA-NSTEMI patients had worse IH outcomes than non-OCA NSTEMI patients and better IH outcomes than STEMI patients, suggesting the existence of a continuum of increased risk of IH mortality across these groups.

Acute coronary syndrome with a totally occluded culprit artery: relation of the ST injury vector with ST-elevation and non-ST elevation ECGs.

BACKGROUND: In acute coronary syndrome (ACS), ST-segment elevation (STE), often associated with a completely occluded culprit artery, is an important ECG criterion for primary percutaneous coronary intervention (PCI). However, several studies showed that in ACS a completely occluded culprit artery can also occur with a non-ST-elevation (NSTE) ECG. In order to elucidate reasons for this discrepancy we examined ST injury vector orientation and magnitude in ACS patients with and without STE, all admitted for primary PCI and having a completely occluded culprit artery. METHODS: We studied the ECGs of 300 ACS patients (214/86 STE/NSTE; 228/72 single/multivessel disease) who had a completely occluded culprit artery during angiography prior to primary PCI. The J+60 injury vector orientation and magnitude were computed from Frank XYZ leads derived from the 10-s standard 12-lead ECG. RESULTS: Demographic and anthropomorphic characteristics of the STE and NSTE patients did not differ. STE patients had a higher rate of right coronary artery occlusions, and a lower rate of left circumflex occlusions than NSTE patients (43 vs. 31%, and 13 vs. 22%, respectively; P<0.05). Injury vector elevation and magnitude were larger in STE than in NSTE patients (32° ± 37° vs. 6° ± 39°, and 304 ± 145 µV vs. 134 ± 72 µV, respectively; P<0.0001). CONCLUSION: STE criteria favor certain injury vector directions and larger injury vector magnitudes. Obviously, several ACS patients with complete culprit artery occlusions requiring primary PCI do not fulfill these criteria. Our study suggests that STE-NSTE-based ACS stratification needs further enhancement.