In this episode of Hospital Medicine Unplugged, we hit the brakes on routine bridging—who actually needs LMWH/UFH when you stop warfarin, and who is safer with no bridge at all?

We start by nailing the definition: bridging = temporarily swapping a long-acting oral anticoagulant (usually warfarin) for short-acting heparin (UFH/LMWH) during interruptions for procedures or bleeding. Then we zoom out to the core tension: tiny peri-procedural thromboembolic risk vs a 3–4× jump in major bleeding with bridging.

We walk through thromboembolic risk stratification—AF with CHA₂DS₂-VASc, recent VTE timing, mechanical valves, and severe thrombophilia—and pair it with procedure and patient bleeding risk (neurosurgery vs dental work, HAS-BLED factors, renal/liver disease, prior bleeds).

Then comes the evidence gut-punch:

• BRIDGE: in AF on warfarin, no reduction in thromboembolism, but major bleeding triples with LMWH bridging.

• Meta-analyses: no thrombotic benefit, big bleeding signal across mixed AF/VTE/mechanical valve cohorts.

• PAUSE & DOAC data: rapid onset/offset means DOACs almost never need bridging.

From there we carve out the true bridging exceptions—the “maybe yes” group:
• Mechanical mitral or older-generation mechanical valves
• Very recent (<3 months) VTE or stroke/systemic embolism
• Severe thrombophilia or high-risk cancer-associated VTE

Everywhere else, guidelines increasingly say: “Don’t bridge.” Most AF, remote VTE, bileaflet mechanical AVR without extra risk factors, and all DOAC-treated patients go down a simple interrupt-and-restart pathway instead of heparin drips and syringes.

We close with a practical, ward-ready playbook:
• Step 1: Classify thromboembolic risk (AF/VTE/valve).
• Step 2: Classify procedure + patient bleeding risk.
• Step 3: If DOAC → timed hold based on drug + kidney function, no bridge.
• Step 4: If warfarin and truly very high thrombotic risk → consider LMWH/UFH, but delay/avoid post-op therapeutic dosing when bleeding risk is high.
• Step 5: Use prophylactic-dose LMWH as VTE prophylaxis, not as a stealth “mini-bridge.”

By the end, you’ll have a clean mental algorithm for “bridge vs no bridge” that lines up with ACCP, AHA/ACC, and AF guidelines—less bleeding, same stroke protection, and far fewer unnecessary heparin shots.