Sustained postoperative anaemia is associated with an impaired outcome after coronary artery bypass graft surgery: insights from the IMAGINE trial.

OBJECTIVE: To investigate the association between sustained postoperative anaemia and outcome after coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective analysis of the IMAGINE trial, which tested the effect of the ACE inhibitor quinapril on cardiovascular events after CABG. SETTING: Thoracic surgery clinic/outpatient department. PATIENTS: 2553 stable patients with left ventricular ejection fraction >40% 2-7 days after scheduled CABG. INTERVENTIONS: Randomisation to quinapril or placebo. MAIN OUTCOME MEASURES: Cox regression analysis for the association between postoperative anaemia and cardiovascular events and the effect of quinapril on the incidence of anaemia. RESULTS: Postoperative anaemia was sustained for >50 days in 44% of patients. Sustained postoperative anaemia was associated with an increased incidence of cardiovascular events during the first 3 months (adjusted HR (adjHR) 1.77, 95% CI 1.10 to 2.85, p=0.012) and during the maximum follow-up of 43 months (adjHR 1.37, 95% CI 1.14 to 1.65, p=0.008). When haemoglobin (Hb) was considered as a continuous variable, every 1 mg/dl decrease in Hb was associated with a 13% increase in cardiovascular events (adjHR 0.87, 95% CI 0.81 to 0.95, p=0.003) and a 22% increase in all-cause mortality (adjHR 0.78, 95% CI 0.60 to 0.99, p=0.034). Quinapril was associated with a slower postoperative recovery of Hb levels and a higher incidence of cardiovascular events in patients with anaemia (adjHR 1.60, 95% CI 1.1 to 2.4, p=0.024). CONCLUSIONS: Postoperative anaemia is common, frequently persists for months after CABG surgery and is associated with an impaired outcome. In patients with anaemia, ACE inhibitors slowed recovery from postoperative anaemia and increased the incidence of cardiovascular events after CABG.

Impact of previous percutaneous transluminal coronary angioplasty and/or stenting revascularization on outcomes after surgical revascularization: insights from the imagine study.

AIM: To determine the impact of previous coronary artery revascularization by percutaneous transluminal coronary angioplasty and/or stenting (PCI) on outcome after subsequent coronary artery bypass grafting (CABG). METHODS AND RESULTS: The ischaemia management with Accupril post-bypass Graft via Inhibition of the coNverting Enzyme (IMAGINE) trial, conducted between November 1999 and September 2004, tested whether early initiation of an angiotensin-converting enzyme inhibitor post-CABG, in stable patients with LVEF >or=40%, would reduce cardiovascular events. Of the 2489 patients included in the IMAGINE trial, undergoing their first operation, 430 had a history of PCI prior to surgery (PCI group), and 2059 were referred to surgery without previous PCI (non-PCI group). There was a significant increase in the primary IMAGINE endpoint in the PCI group, HR = 1.53 [1.17-1.98], P = 0.0016. Coronary revascularization, HR = 1.80 [1.13-2.87], P = 0.014, unstable angina requiring hospitalization, HR = 2.43 [1.52-3.89], P = 0.0002, were the two individual components that significantly increased in the PCI group, even when adjusted for baseline characteristics (age, sex, history of myocardial infarction or stroke, diabetes, treatment group, or off-pump surgery). CONCLUSION: Patients with left ventricular ejection fraction >or=40% having a history of PCI prior to surgery had a worse outcome post-CABG than those with no prior PCI. Further studies are needed to investigate whether these results apply for drug eluting stents.

Effects of angiotensin-converting enzyme inhibition in low-risk patients early after coronary artery bypass surgery.

BACKGROUND: Early after coronary artery bypass surgery (CABG), activation of numerous neurohumoral and endogenous vasodilator systems occurs that could be influenced favorably by angiotensin-converting enzyme inhibitors. METHODS AND RESULTS: The Ischemia Management with Accupril post-bypass Graft via Inhibition of the coNverting Enzyme (IMAGINE) trial tested whether early initiation (< or = 7 days) of an angiotensin-converting enzyme inhibitor after CABG reduced cardiovascular events in stable patients with left ventricular ejection fraction > or = 40%. The trial was a double-blind, placebo-controlled study of 2553 patients randomly assigned to quinapril, target dose 40 mg/d, or placebo, who were followed up to a maximum of 43 months. The mean (SD) age was 61 (10) years. The incidence of the primary composite end point (cardiovascular death, resuscitated cardiac arrest, nonfatal myocardial infarction, coronary revascularization, unstable angina or heart failure requiring hospitalization, documented angina, and stroke) was 13.7% in the quinapril group and 12.2% in the placebo group (hazard ratio 1.15, 95% confidence interval 0.92 to 1.42, P=0.212) over a median follow-up of 2.95 years. The incidence of the primary composite end point increased significantly in the first 3 months after CABG in the quinapril group (hazard ratio 1.52, 95% confidence interval 1.03 to 2.26, P=0.0356). Adverse events also increased in the quinapril group, particularly during the first 3 months after CABG. CONCLUSIONS: In patients at low risk of cardiovascular events after CABG, routine early initiation of angiotensin-converting enzyme inhibitor therapy does not appear to improve clinical outcome up to 3 years after CABG; however, it increases the incidence of adverse events, particularly early after CABG. Thus, early after CABG, initiation of angiotensin-converting enzyme inhibitor therapy should be individualized and continually reassessed over time according to risk.