Temporal trends in the type of recurrent acute coronary syndrome

Introduction

Different pathogenic mechanisms have been suggested for acute coronary syndrome (ACS) with ST segment elevation (STEMI) or without ST segment elevation (NSTEMI) and for unstable angina (UA). Our objective was to analyze the incidence of different types of ACS in relation to the temporal occurrence, as first or recurrent ACS.

Methods

Six hundred and twenty consecutive patients admitted to a cardiology ward due to ACS during 12 months were studied. The ACS were divided into UA, STEMI and NSTEMI. Previous ACS episodes, the clinical profile and angiographic information were recorded.

Results

The mean age was 67.4 ± 14 years, 447 (72%) males. The ACS type was 251 (40%) UA, 168 (27%) STEMI and 201 (32%) NSTEMI. In 408 (66%) patients it was the first admission due to ACS, 120 (29%) UA, 146 (36%) STEMI and 142 (35%) NSTEMI. The incidence of STEMI was higher in the first episode than among 213 second episodes (169 [27%] UA, 244 [39%] STEMI and 181 [29%] NSTEMI vs 140 [66%] UA, 20 [9%] STEMI and 53 [25%] NSTEMI, P < 0.001). The average time between first and second ACS was 51.9 ± 60 months. Patients with recurrent ACS presented more incidence of male sex (174 [82%] vs 273 [67%], P < 0.001), diabetes mellitus (69 [33%] vs 102 [25%], P = 0.045), hypercholesterolemia (123 [58%] vs 153 [37%], P < 0.001), hypertension (124 [58%] vs 202 [49%], P = 0.034) and peripheral arterial disease (40 [20%] vs 31 [8%], P < 0.001) than patients without recurrent ACS. Patients with recurrent ACS also presented less ejection fraction (52.8 ± 14 vs 56 ± 13, P = 0.007) and less incidence of one-vessel disease (46 [22%] vs 140 [34%], P = 0.001).

Conclusion

STEMI appears more frequently in a first ACS rather than in a recurrent ACS. Patients who suffer from recurrent ACS demonstrated a worst cardiovascular profile.