Lysine analog antifibrinolytics (LAAF) like tranexamic acid (TXA) and aminocaproic acid (EACA) reduce intraoperative blood loss, especially in cardiac surgery where bleeding risks are high. These LAAFs inhibit fibrinolysis and have been proven to decrease bleeding and transfusion volume. In cardiac surgery, frequent transfusions raise the risk of infections, extend hospital stays and reoperations, and carry higher morbidity and mortality. Current guidelines recommend intravenous antifibrinolytics; however, the objective of this review was to determine whether topical administration in cardiac surgery reduces blood loss, with or without intravenous LAAF.

PubMed, Embase, MEDLINE, Cochrane CENTRAL, and Clarivate WoS were searched from inception to August 31, 2024, for randomized controlled trials and observational studies comparing topical TXA or EACA to placebo in cardiac surgery. Data extraction was done independently, and RoB2/ROBINS-I was used for quality assessment. A derSimmonian-Laird random-effects model was applied. Mean differences were used for continuous outcomes, and OR/RR was used for binary. I² statistics measure heterogeneity. Sensitivity analysis and GOSH plotting assessed heterogeneity; trial sequential analysis was performed. The certainty of the evidence followed GRADE guidelines.

The meta-analysis included 26 studies with 2,624 patients, 24 focused on adults. Given the pragmatic approach to this meta-analysis, a wide variety of surgical procedures were included, with coronary artery bypass grafting and valvular procedures being the most prevalent. LAAF administration reduced postoperative blood loss by 174 mL (MD –173.99, 95% CI –238.20 to –109.78, p < 0.00001), and the effect remained constant through subgroup analysis (coronary artery bypass grafting, high- v low-dose, dual-route administration). No significant differences were found in transfusion rates for packed red blood cells (PRBC) and platelets, though LAAF reduced PRBC volume (MD –0.6 units, 95% CI –0.88 to –0.24, p = 0.00006) and fresh frozen plasma requirements (RR 0.69, 95% CI: 0.5 to 0.95, p = 0.03). No differences in hematological change scores or complication rates were observed. The analysis showed high heterogeneity, but the overall effect remained consistent. A trial sequential analysis suggests there is enough data to confirm this effect.

Topical LAAF administration reduces postoperative blood loss up to 24 hours postoperatively. Secondary analyses showed reductions in PRBC transfusion volume and fresh frozen plasma transfusion rate, without increased complications.