Haemodynamic and renal effects of intravenous enalaprilat during coronary artery bypass graft surgery in patients with ischaemic heart dysfunction

Renal dysfunction occurring after open heart surgery is multifactorial in o rigin but activation of the renin-angiotensin system may have a prominent r ole. Fourteen patients with ischaemic heart dysfunction scheduled for elect ive coronary artery bypass graft (CABG) surgery were allocated to a treatme nt group [enalaprilat for 2 days; ACEI (angiotensin-converting enzyme inhib itor) group, =7] or a control group (n=7). The cardiac index was significan tly higher in ACEI-treated patients than in the controls before and after c ardiopulmonary bypass (CPB) (P<0.05) and on postoperative day 2 (P<0.05). T he systemic vascular resistance was significantly lower in the ACEI-treated patients than in the controls before and after CPB (P<0.05). Renal plasma flow, measured as [I-131] orthoiodohippuran clearance (Cl-H), was higher in the ACEI group than in the control group before CPB, as was endogenous cre atinine clearance after CPB (P<0.05). On post-operative day 7, Cl-H was sig nificantly higher in the ACEI group than in the control group (P<0.05). Pla sma renin activity and vasopressin concentration increased in both groups d uring CPB (P<0.05). The study demonstrates that administration of an i.v. A CEI, enalaprilat, improves cardiac output during CABG surgery in patients w ith ischaemic heart dysfunction. Moreover, renal perfusion was better maint ained during surgery, and this effect was sustained up to post-operative da y 7.