Incidence, predictors and outcomes in patients with totally occluded culprit artery in NSTEMI.

Abstract

Background

It is unclear whether patients without ST elevation on ECG with totally occluded culprit arteries have poorer outcomes than other Non-ST elevation myocardial infarction patients and compared to ST elevation myocardial infarction

Objectives/Aims

To establish the incidence of patients with Non-ST elevation myocardial infarction (NSTEMI) with occluded culprit artery and compare outcomes versus NSTEMI patients in general and ST-elevation myocardial infarction (STEMI) patients.

Method

Patients admitted with a NSTEMI (excluding out of hospital cardiac arrest) within the Melbourne Interventional Group (MIG) registry between 2005-2017 with single lesion PCI were included. The primary endpoint was major adverse cardiac events (MACE) at 30 days between NSTEMI patients with and without occluded culprit arteries. Secondary endpoints included 12-month mortality and MACE. Secondary analysis compared outcomes between STEMI patients and NSTEMI patients with occluded artery.

Results

6829 patients had single lesion NSTEMIs of which 954 (13.97%) had occluded culprit arteries. Most culprit arteries were non-LAD (RCA 39.2%, LCx 33.2% vs. LAD 25.9%). There were higher rates of cardiogenic shock and left ventricular dysfunction in the occluded artery group. 30-day MACE was higher in the occluded artery group (6.7% vs 3.8%) with a hazard ratio of 1.93 with higher cardiac mortality, target lesion and vessel revascularisation, no-reflow and Glycoprotein IIb/IIIa use. However, long term mortality was not higher than the overall NSTEMI cohort. All-cause mortality and 30-day MACE were higher in the STEMI cohort than the NSTEMI occluded artery group.

Implications/Outcomes for Planned Research Project

This research project suggests that patients with occluded culprit arteries likely require closer observation post PCI and potentially a longer period of observation in hospital post procedure.

Final Thoughts

NSTEMI with occluded artery patients represent a more unstable subgroup early after presentation however with appropriate treatment long term risks are not increased. They represent a lower risk group than STEMI patients despite potential delays in emergent percutaneous intervention due to lack of ST elevation.