Is early intervention beneficial for patients with non-ST-elevation acute coronary syndrome?

The long-term clinical outcomes from the registry, published in EuroIntervention, showed that the basis of the timing of invasive management should be individualized decisions integrating symptoms and risk panorama rather than strictly defined time intervals.

Episodes of chest pain characterize a non-ST-elevation acute coronary syndrome at rest or with minimal exertion, increasing severity or frequency with dynamic ECG changes. Unlike in ST-segment elevation myocardial infarction patients, where the occlusion is of the culprit coronary artery, causing transmural ischemia, patients presenting with NSTE-ACS usually have a patent culprit vessel with subendocardial ischemia. An invasive approach is beneficial compared with a conservative approach in NSTE-ACS patients. However, it is less specific whether early/urgent angiography is advantageous in NSTE-ACS patients.

Currently, the guidelines stress the importance of early invasive assessment of NSTE-ACS patients, especially those at high risk. However, the evidence supporting the same is limited. Kai M. Eggers, Department of Medical Sciences and Uppsala Clinical Research Center, Uppsala University, Uppsala, Sweden, and associates aimed to examine the prognostic impact of coronary angiography timing in a large cohort of patients with non-ST-elevation acute coronary syndrome.

For this purpose, the researchers conducted a retrospective analysis of 34,666 NSTE-ACS patients registered in the SWEDEHEART registry from 2013 to 2018. Cox regression analyses were used for assessing the prognostic implications of coronary angiography timing on a continuous scale and within <24 vs. 24-72 hours.

Based on the study, the authors found the following:

• The median time interval from admission to invasive assessment was 32.8 (25th, 75th percentiles 20.4-63.8) hours.
• No apparent time window within 96 hours from the admission provided prognostic benefit.
• Coronary angiography within 24-72 hours (vs. <24 hours) was not associated with worse outcomes overall (all-cause mortality: hazard ratio 1.01; major adverse events: hazard ratio 1.04).
• Interaction analyses indicated a more significant relative benefit of coronary angiography <24 hours in some lower-risk groups (women, non-diabetics, and patients with minor troponin elevation) but neutral effects in higher-risk groups (defined by age or the GRACE 2.0 score).

"Long-term clinical outcomes from the nationwide SWEDEHEART registry do not provide support for an early invasive strategy in NSTE-ACS, particularly in those at high risk," the researchers wrote. "Our findings indicate that the timing of invasive assessment should be based on individualized decisions integrating symptoms and risk panorama rather than on strictly defined time intervals."

Reference:

The study, "Timing of coronary angiography in patients with non-ST-elevation acute coronary syndrome: long-term clinical outcomes from the nationwide SWEDEHEART registry," was published in the journal EuroIntervention.

DOI: 10.4244/EIJ-D-21-00982