Timing of coronary angiography in high-risk non-ST-elevation acute coronary syndrome: results from the Portuguese Registry for Acute Coronary Syndromes (ProACS).

Background: Current guidelines recommend an early invasive coronary angiography (ICA) within 24 h of admission for high-risk patients with non-ST-elevation acute coronary syndrome (NSTE-ACS). Nevertheless, meta-analyses failed to demonstrate a clear advantage of this strategy in reducing hard endpoints such as death or nonfatal myocardial infarction compared to a delayed approach. Thus, the optimal timing of ICA in high-risk NSTE-ACS remains undetermined.

Objective: This study aimed to determine the optimal timing for ICA in high-risk NSTE-ACS, regarding 1-year all-cause mortality and cardiovascular rehospitalizations.

Methods: We conducted a national multicenter retrospective study of high-risk NSTE-ACS patients included in the Portuguese Registry for Acute Coronary Syndromes. Patients were divided into three groups according to the time of ICA: within the first 24 h, between 24 and 48 h, and between 48 and 72 h. The incidence of in-hospital complications and mortality, 1-year mortality, and cardiovascular rehospitalizations were assessed.

Results: Of the 9949 patients included, 46.7% underwent early ICA. This was associated with a lower incidence of acute heart failure (8.5% vs. 11.1% vs. 11.5%, P < 0.001) and shorter length of stay (3 vs. 4 vs. 6 days, P = 0.012). It, however, did not reduce in-hospital complications or mortality (1.2 vs. 0.7 vs. 0.8%, P = 0.066). We also found no significant association with the composite endpoint of 1-year mortality or cardiovascular rehospitalization (15.1 vs. 15.9 vs. 15.7%, P = 0.887).

Conclusions: Early ICA was associated with a lower incidence of acute heart failure and shorter length of stay, without a significant impact on 1-year mortality risk or cardiovascular rehospitalizations.