[Early invasive strategy in non-ST-segment elevation acute coronary syndrome. The paradox continues]

Abstract

Objective: Observational studies have reported a paradoxical inverse relationship between the use of an early invasive strategy (EIS) and the risk of events in patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS). The study objectives are: 1) to examine the association between baseline risk in patients with NSTE ACS and the use of EIS; and 2) to identify some of the factors independently associated to the use of EIS.

Design: Retrospective cohort study.

Setting: Intensive care units participating in the SEMICYUC ARIAM Registry.

Patients: Consecutive patients admitted with a diagnosis of NSTE-ACS within 48 hours of evolution between the months of April-July 2010.

Interventions: None.

Main outcomes: Coronary angiography with or without angioplasty within 72 hours, risk stratification using the GRACE scale.

Results: We analyzed 543 patients with NSTE-ACS, of which 194 were of low risk, 170 intermediate risk and 179 high risk. The EIS was used in 62.4% of the patients at low risk, in 60.2% of those with intermediate risk, and in 49.7% of those at high risk (p for tendency 0.0144). The EIS was used preferentially in patients with low severity and comorbidity. In the logistic regression model, EIS was independently associated to the availability of a catheterization laboratory (OR 2.22 [CI 95% 1.55 to 3.19]), the presence of ST changes on ECG (OR 1.80 [1.23 to 2.64]), or the existence of a low risk of bleeding (OR 0.76 [0.66 to 0.88)]. Conversely, EIS was less prevalent in patients with diabetes (OR 0.60 [0.41 to 0.88]) or tachycardia upon admission (OR 0.54 [0 36 to 0.82]).

Conclusions: In 2010 there remained a lesser relative use of EIS in patients at high risk, due in part to an increased risk of bleeding in these patients.