Early versus Delayed Angiography in Non-ST-Elevation Myocardial Infarction – Insights from ACSIS

Background:
Despite scarce and conflicting clinical evidence, an early invasive approach is recommended for patients with non-ST-elevation myocardial infarction (NSTEMI). The aim of this study was to describe real-world treatment practices and long-term outcomes in NSTEMI patients with respect to timing of angiography, including temporal trends.

Methods:
We analyzed data from the Acute Coronary Syndrome Israeli Survey (ACSIS) from the years 2000 to 2013 which included 2,536 NSTEMI patients that were admitted to cardiology departments and underwent coronary angiography with available information on its timing. Patients were divided into early (within the first 24 hours from admission) and delayed angiography group (>24 hours from admission). The primary outcome was all-cause mortality at 1, 2, and 5 years.

Results:
A total of 1,737 (68%) patients underwent delayed angiography. These were older (65±12 vs. 62±12, p<0.001), had more cardiovascular comorbidity, and a higher GRACE score >140 (37% vs. 27%, p<0.001). Percutaneous coronary intervention (PCI) rates were lower in the delayed group compared to the early group: 65% vs. 75% (p<0.001), respectively. Predictors for early angiography were male gender (OR=1.34, 95% CI 1.06-1.69) and ACSIS years 2008-2013 (OR=1.83, 95% CI 1.06-1.69), whereas age >75, GRACE >140, and admission during weekends were predictors for delayed angiography (OR=0.67, 95% CI 0.51-0.87; OR=0.77, 95% CI 0.62-0.95; OR=0.47, 95% CI 0.38-0.57, respectively). Upon multivariate analysis, delayed angiography was associated with a significantly higher risk of death at 5 years (HR=1.53, 95% CI 1.15-2.04), with the difference becoming significant only from the third year of follow-up (2-year mortality HR=1.16, 95% CI 0.85-1.59, Figure).

Conclusions:
Delayed angiography was more likely to be performed in patients with high risk features and was independently associated with increased 5-year mortality.