Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: Thank you.Do you always do a heparin bridge or is this contraindicated under certain situations?Does a patient history of a-fib affect the outcome of the risk calculus?. ### Response: When considering the decisions here, you need to weigh the benefits and risks of anticoagulation.His stroke risk from afib can be estimated with the CHADS2-VASC score. Look this calculator up online. Most people stand an annualized risk of 2-11% of experiencing stroke. On a day to day basis, that risk is super small. Like 0.001% chance of having a stroke every day he's off anticoagulation, and even that is probably an overestimate of his stroke risk.The risks of bleeding are obvious. He's bleeding into his GU tract. This could occlude his bladder. He could bleed into the wound bed in ways that make his recovery worse. The chance of bleeding while anticoagulated is 100%.The last nail in the coffin is that we have multiple large and well-designed trials (BRIDGE and PERIOP2) that show no benefit to bridging pre or postoperatively in any population we've looked at this far, including mechanical valves in the post-op setting.At this point the only cases where bridging might be worth it is acute DVT/PE within 3 months of surgery, and maybe mechanical mitral valve..