Characteristics, management and outcomes of patients with acute coronary syndrome and prior coronary artery bypass surgery: findings from the second Gulf Registry of Acute Coronary Events.

OBJECTIVES: To evaluate the baseline demographic/clinical characteristics, in-hospital treatment and outcomes among patients with or without prior coronary artery bypass graft surgery (CABG) presenting as acute coronary syndrome (ACS) from six Middle East countries.

METHODS: Data was derived from a prospective, multinational, multicenter registry of 7881 consecutive patients hospitalized with ACS in six Middle East countries. Data were analyzed according to their history of prior CABG.

RESULTS: Of 7881 ACS patients, 336 (4.2%) had a history of CABG. Patients with prior CABG were older (mean 63 ± 10.8 vs. 56 ± 12.6 years; P = 0.001) and more frequently to be men (76%) with significantly more prior angina, infarction and percutaneous revascularization. They were more likely to have hypertension, diabetes, hyperlipidemia, prior congestive heart failure, stroke, renal failure, peripheral arterial disease and had higher prevalence of previous treatment with evidence-based medications. They were more likely to present with unstable angina (45.5% vs. 23.4%), followed by non-ST elevation myocardial infarction (STEMI) (43.8% vs. 29.5%), STEMI (10.7% vs. 47.1%) (All P = 0.001) with less prominent peak values of cardiac biomarkers than patients without prior CABG. Patients with prior CABG were more likely to present with significantly worse Killip class (≥ 2), higher Global Registry of Acute Coronary Events (GRACE) risk score, multivessel disease, severe left ventricular (LV) dysfunction (LV ejection fraction ≤ 30%) and developed significantly higher cardiogenic shock and major bleeding. In patients with prior CABG, no significant difference was observed in in-hospital mortality (4.2% vs. 4.6%, P=0.735) or mortality at one month (6.5% vs. 8.2%, P=0.277) or after one year (15% vs. 12.4%, P=0.204) when compared to patients without prior CABG.

CONCLUSIONS: ACS patients from Middle East countries with prior CABG have adverse baseline characteristics, reported higher GRACE risk score, multivessel disease, more severe LV dysfunction, cardiogenic shock, in-hospital major bleeding, but with less incidence of STEMI with less prominent surge of cardiac biomarkers. However, there was no significant difference in mortality during hospitalization, at 30 days and at one year between ACS patients with and without prior CABG. The reasons for this 'risk-mortality' paradox need to be further evaluated.