Background: S-(+)-ketamine anaesthesia carries potential benefits for the cardiovascularly compromised patient. However, the use of S-(+)-ketamine in ischaemic coronary artery disease is controversial. In a prospective, randomized, clinical trial, we have investigated whether an S-(+)-ketamine-based anaesthetic protocol leads to increased cardiac troponin T levels (cTnT) after coronary artery bypass grafting (CABG).
Methods: Two hundred and nine patients undergoing elective CABG were randomized to receive either i.v. anaesthesia with sufentanil-midazolam-propofol (SMP; n=108) or S-(+)-ketamine-midazolam-propofol (KMP; n=101). Haemodynamic variables were maintained within the normal range. Invasive haemodynamic monitoring was performed using a pulmonary artery catheter. Plasma cTnT levels were sampled before induction and 1, 6, and 24 h after aortic unclamping. Cardiovascular adverse events, such as electrocardiographic signs of ischaemia, perioperative myocardial infarction, and death, were recorded.
Results: Patient characteristics, cardiac profile, intraoperative management, and the incidence of cardiovascular adverse events were comparable between the groups. Plasma cTnT levels increased after operation in both groups. cTnT levels were significantly lower in the KMP group 6 h after aortic unclamping compared with the SMP group (P=0.004), but did not differ 24 h after aortic unclamping [median (range): SMP 0.4 (0.01-3.9) vs KMP 0.4 (0.07-6.6) microg litre(-1), P=0.338].
Conclusions: S-(+)-ketamine does not accentuate postoperative cTNT rises in haemodynamically stable elective CABG patients.