Thrombocytopenia After Cardiac Surgery: A Single-Center Retrospective Study.

BACKGROUND: Postoperative thrombocytopenia is a frequent complication in cardiac surgery, associated with increased morbidity and mortality. Our study aimed to describe platelet count after cardiac surgery and identify predictors of postoperative thrombocytopenia. METHODS: We conducted a retrospective, single-center study including 519 adult patients who underwent cardiac surgery without operative platelet transfusion. The primary outcome was the incidence of postoperative thrombocytopenia, defined using three thresholds: <150 G/L, <100 G/L, and <50 G/L. Platelet counts were recorded daily from preoperative day to postoperative day 7. Independent predictors were identified using multivariate logistic regression for a threshold of 100 G/L. RESULTS: Thrombocytopenia < 150 G/L occurred in 306 patients (59%), <100 G/L in 92 (18%), and < 50 G/L in 35 (7%). The incidence of thrombocytopenia depended on the type of surgery (P < 0.0001). Mitral valve surgery, ascending aorta procedures, and the use of sutureless aortic valve prostheses were associated with increased thrombocytopenia rates. Platelet counts were higher in patients who have had off-pump coronary surgery within the first five days (P < 0.0001). Five independent predictors were identified: older age (P = 0.022), lower baseline platelet count (P < 0.0001), higher creatinine (P = 0.04), operative transfused units of red blood cells (P = 0.015), and higher autotransfusion volume (P = 0.02). The model using only preoperative variables achieved an AUC of 0.83. Finally, thrombocytopenia <100 G/L was associated with more blood loss (P = 0.001), more postoperative transfusions (P < 0.0001), and longer intensive care unit stay (P = 0.001). CONCLUSION: Our study differentiates pre- and perioperative risk factors for thrombocytopenia in cardiac surgery to define a targeted, individualized platelet management strategy.