Con: Viscoelastic Testing Should Not Be Used Routinely but Selectively in Cardiac Surgery.

Viscoelastic testing (VET) has become an important tool in cardiac surgery, particularly within bleeding management algorithms. However, evidence supporting its benefits largely pertains to patients with active bleeding rather than its use in all cases. VET does not reliably predict bleeding or transfusion requirements when performed preoperatively, and its indiscriminate application may lead to unnecessary blood product administration and increased costs. Randomized trials and meta-analyses consistently show that VET improves outcomes when integrated into structured blood management algorithms after bleeding is clinically evident. Established clinical predictors and standard laboratory tests remain effective for assessing bleeding risk, and recent expert guidelines explicitly discourage routine VET for all cardiac surgery patients. Selective use of VET in patients with suspected coagulopathy preserves its clinical benefits, minimizes harm, and aligns with evidence-based practice.