Acute coronary occlusion with vs. without ST elevation: impact on procedural outcomes and long-term all-cause mortality.

Background: Acute total occlusion (ATO) is diagnosed in a substantial proportion of patients with non-ST-elevation myocardial infarction (NSTEMI). We compared procedural outcomes and long-term mortality in patients with STEMI with NSTEMI with vs. without ATO.

Methods and results: We included patients with acute myocardial infarction (AMI) undergoing invasive coronary angiography between 2004 and 2019 at our centre. Acute total occlusion was defined as thrombolysis in myocardial infarction (TIMI) 0-1 flow in the infarct-related artery or TIMI 2-3 flow with highly elevated peak troponin (>100-folds the upper reference limit). Association between presentation and long-term mortality was evaluated using multivariable adjusted Cox regression analysis. From 2269 AMI patients (mean age 66 ± 13.2 years, 74% male), 664 patients with STEMI and 1605 patients with NSTEMI (471 [29.3%] with ATO) were included. ATO(+)NSTEMI patients had a higher frequency of cardiogenic shock and no reflow than ATO(-)NSTEMI with similar rates compared with STEMI patients (cardiogenic shock: 2.76 vs. 0.27 vs. 2.86%, P < 0.0001, P = 1; no reflow: 4.03 vs. 0.18 vs. 3.17%, P < 0.0001, P = 0.54). ATO(+)NSTEMI and STEMI were associated with 60 and 55% increased incident mortality, respectively, as compared with ATO(-)NSTEMI (ATO(+)NSTEMI: 1.60 [1.27-2.02], P < 0.0001, STEMI: 1.55 [1.24-1.94], P < 0.0001). Likewise, left ventricular ejection fraction (48.5 ± 12.7 vs. 49.1±11 vs. 50.6 ± 11.8%, P = 0.5, P = 0.018) and global longitudinal strain (-15.2 ± -5.74 vs. -15.5 ± -4.84 vs. -16.3 ± -5.30%, P = 0.48, P = 0.016) in ATO(+)NSTEMI were comparable to STEMI but significantly worse than in ATO(-)NSTEMI.

Conclusion: Non-ST-elevation myocardial infarction patients with ATO have unfavourable procedural outcomes, resulting in increased long-term mortality, resembling STEMI. Our findings suggest that the occlusion perspective provides a more appropriate classification of AMI than differentiation into STEMI vs. NSTEMI.