The association between preoperative blood calcium and postoperative blood loss in patients undergoing heart valve replacement surgery.

Abstract

Bleeding after heart valve surgery is a serious clinical challenge. Hypocalcemia has been associated with the extent of bleeding in patients with spontaneous intracerebral hemorrhage. However, the association between blood calcium levels and bleeding extent in heart valve replacement patients has not been clearly established. This study aimed at determining the association between blood calcium levels and perioperative hemorrhage after heart valve replacement therapy. Based on preoperative blood calcium levels, patients were grouped into the hypocalcemia group and normocalcemia group. Postoperative bleeding, blood product use, and complications were monitored during hospitalization. The association between blood calcium levels and major bleeding was determined by multivariable logistic regression models. In the first 12h after surgery, bleeding in hypocalcemia group was significantly larger than that of the normocalcemia group (338 ± 234mL vs 232 ± 96mL; p = .024). The outcome was the same when the overall chest tube output was considered (950 ± 447mL vs 738 ± 220mL; p = .038). The incidence of major bleeding was 65.91% in the hypocalcemia group and 18.97% in the normocalcemia group (p = .001). Postoperative complications in the two groups were similar. After adjusting for multiple covariates, the adjusted odds ratios (OR) for participants in hypocalcemia group was 10.01 (95% CI 3.35-34.82), compared with that in normocalcemia group (p < .001). In patients undergoing heart valve surgery, preoperative blood concentrations of calcium are associated with postoperative blood loss. Hypocalcemia before operation may increase the risk of postoperative bleeding. When patients with valvular heart disease present with hypocalcemia before surgery, prompt intervention may lead to better control of postoperative bleeding.