Anticoagulation and ACS Practice Test

In ACS with significant renal impairment, the goal is anticoagulation that is effective yet easily controllable and reversible. Unfractionated heparin fits this need because its effect can be rapidly titrated with an IV infusion and monitored with aPTT, and if bleeding occurs or urgent reversal is required, protamine sulfate can largely neutralize its effect. It is not primarily cleared by the kidneys, so the risk of drug accumulation and prolonged bleeding is lower than with agents that rely on renal clearance.

LMWH and fondaparinux, in contrast, are renally cleared and can accumulate in severe kidney failure, increasing bleeding risk; fondaparinux lacks a reliable reversal option. DOACs are not standard for ACS management and have limited reversibility in this setting, especially in severe renal impairment. So the combination of controllability, reversibility, and minimal renal accumulation makes unfractionated heparin the preferred approach in this scenario.