Myocardial consequences of remifentanil in patients with coronary artery disease

Remifentanil may be an alternative to conventional opioids for minimally in vasive direct coronary artery bypass surgery because of its extremely short duration of action. The aim of this study was to investigate the effects o f remifentanil on myocardial blood flow, metabolism and systemic haemodynam ic variables in patients with coronary artery disease. After approval by th e local ethics committee, 12 male patients were investigated before electiv e coronary artery bypass grafting. Systemic haemodynamic variables, myocard ia[ blood flow and metabolism were measured when patients were awake and wh en they were anaesthetized with high-dose remifentanil (2.0 mu g kg(-1) min (-1)), or with remifentanil 0.5 mu g kg(-1) min(-1) combined with propofol (target-controlled infusion aiming at a plasma concentration of 2.0 mu g ml (-1)). Myocardial blood flow was measured using a modified Kety-Schmidt tec hnique. High-dose remifentanil anaesthesia significantly reduced cardiac in dex (Cl) (-25%) as a consequence of a decrease in stroke volume index (SVI) (-14%) and heart rate (-13%). Mean arterial pressure (MAP) was 30% lower t han that in the awake patient. Myocardial blood flow and myocardial oxygen uptake (MVo(2)) decreased by 30% and 42%, respectively. In contrast to high -dose remifentanil anaesthesia, systemic vascular resistance index (-14%) d uring remifentanil/propofol anaesthesia was significantly lower than that i n the awake patient. Other haemodynamic variables, and myocardial blood flo w and MVo(2), did not significantly differ from the high-dose remifentanil period. In conclusion, high-dose remifentanil reduces SVI, heart rate, MAP, myocardial blood flow and MVo(2) and its effects do not differ from those of remifentanil/propofol anaesthesia.