Cold Blood Versus Crystalloid Cardioplegia for Myocardial Protection in Adult Cardiac Surgery: A Meta-analysis of Randomized Controlled Studies

Objective The purpose of this article was to systematically review randomized controlled trials in which cold blood cardioplegia was compared with cold crystalloid cardioplegia for cardiac surgery. Design Correlation studies were searched independently in the EMBASE, MEDLINE and Cochrane library databases. The primary endpoints of interest were spontaneous sinus rhythm (SSR) after declamping, perioperative myocardial infarction (MI) and mortality (within 30 days). Setting A hospital. Participants Randomized controlled trials. Intervention A meta-analysis of 12 studies. Measurements and Main Results The 12 included trials recruited a total of 2866 participants; 1357 patients received cold crystalloid cardioplegia, and 1509 patients received cold blood cardioplegia. The pooled analysis showed no significant difference favoring either cold crystalloid cardioplegia or cold blood cardioplegia in terms of spontaneous sinus rhythm (SSR) after declamping (789/1028 [76.75%] v 773/1025 [75.41%], relative risk (RR) = 0.92 [0.76, 1.13], p = 0.43 with 6 studies included), mortality (within 30 days) (20/1335 [1.50%] v 24/1469 [1.63%], relati v e risk (RR) = 1.09 [0.62, 1.91], p = 0.77 with 11 studies included), atrial fibrillation (AF) (329/1043 [31.54%] v 365/1040 [35.10%], RR =0.90 [0.80, 1.01], p = 0.08 with 6 studies included) or stroke (45/1114 [4.04%] v 20/1240 [1.61%], RR = 2.18 [0.69, 6.93], p = 0.19 with 4 studies included). The aggregate data showed that the incidence of perioperative myocardial infarction was lower in patients who received cold blood cardioplegia (CB) (32/1310 [2.44%] v 17/1434 [1.19%], RR = 2.30 [1.33, 3.98], p = 0.003 with 11 studies included). Conclusions Cold blood cardioplegia reduced perioperative myocardial infarction when compared with cold crystalloid cardioplegia. No differences in the overall incidence rates of spontaneous sinus rhythm, mortality (within 30 days), atrial fibrillation or stroke were observed.