Propofol-supplemented cardioplegia: a multi-center blinded three-group randomized trial (ProMPT2)

Abstract

Objective: Coronary artery bypass grafting using cardiopulmonary bypass and cardioplegic arrest is an effective treatment for coronary artery disease. Research suggests supplementing the cardioplegia solution with propofol may be cardioprotective. The aim was to compare the safety and efficacy of supplementing the cardioplegia solution with different doses of propofol in adults undergoing first-time surgery.

Methods: A blinded, parallel group randomized controlled trial conducted in 3 hospitals in the UK comparing a cardioplegia solution supplemented with high-dose propofol (concentration 12mcg/mL), low-dose propofol (concentration 6mcg/mL) or placebo (saline). Primary outcome was cardiac troponin T measurements over the first 48 hours after surgery. Participants were followed-up for 12 months.

Results: 240 participants, median age 66 years, 90% male, were randomly allocated; 78 to high-dose propofol, 80 to low-dose propofol and 82 to placebo. 239 participants were included in the primary analysis. Geometric mean cardiac troponin release at 48 hours (95% confidence interval) was 145ng/L (125-168), 162ng/L (138-191) and 150ng/L (125-180) in the high-dose propofol, low-dose propofol and placebo groups respectively (adjusted geometric mean ratio 1.06; 95% confidence interval 0.97-1.15; P=0.20, for pairwise comparisons between high and low-dose propofol and between low-dose propofol and placebo). 96 adverse events which prolonged the hospital stay, or were life-threatening were reported (33, 26 and 37 in the high-dose propofol, low-dose propofol and placebo groups respectively) and four deaths (1 low-dose propofol group, 3 placebo group).

Conclusions: Propofol supplementation of warm blood cardioplegia at both the lower and higher concentrations is safe but there is no evidence to suggest either dose is cardioprotective.

Keywords: cardioplegia; cardiopulmonary bypass; coronary artery bypass surgery; ischemia; propofol; randomized; reperfusion.