Bridge therapy is a temporary medical strategy used as a transitional intervention to maintain a patient’s health and stability. It is employed when the ideal, long-term treatment cannot be implemented immediately. This approach provides a controlled environment for the patient while awaiting a permanent solution, ensuring their condition does not worsen in the interim. This broad concept is used across diverse medical fields to manage patient risk during a period of procedural or therapeutic delay.
The Underlying Medical Necessity
Bridge therapy becomes necessary when a patient faces a therapeutic gap, where proceeding with definitive treatment is either too dangerous or logistically impossible. Clinicians must balance the risk of disease progression against the risk of immediate, definitive intervention. The primary goal is risk mitigation, maintaining the patient in a stable state until conditions are right for the next step in their care. Delays might be due to the need for organ availability, the manufacturing time for a customized drug, or the requirement to reduce a patient’s immediate surgical risk.
Bridge Therapy in Anticoagulation
Bridge therapy is commonly used in the perioperative management of patients on long-term oral anticoagulants. Individuals with conditions like mechanical heart valves or chronic atrial fibrillation are at high risk for blood clot formation (thromboembolism). Their long-term medications, such as warfarin or Direct Oral Anticoagulants (DOACs), must be interrupted before invasive procedures to prevent severe bleeding.
The dilemma is that stopping the oral agent increases the risk of stroke or clot, while continuing it increases the risk of hemorrhage during surgery. To manage this, the patient is transitioned to a short-acting, injectable medication, typically low molecular weight heparin (LMWH). This transition process constitutes the bridge.
Warfarin, due to its long half-life, must be stopped approximately five days before a major procedure to allow the International Normalized Ratio (INR) to fall. LMWH is then started a few days prior, offering a rapid onset and shorter half-life. The final dose of LMWH is given about 24 hours before surgery, ensuring its anticoagulant effect has worn off by the time the incision is made.
After the procedure, LMWH is restarted 12 to 72 hours later, depending on the bleeding risk, to immediately protect against clots. The patient then resumes the long-acting oral agent, and the medications are overlapped until the oral agent’s therapeutic effect is re-established. This complex strategy is generally reserved for patients at the highest risk for clot formation, as the process itself carries a slight risk of bleeding complications.
Bridge Therapy for Organ Support
In advanced heart or lung failure, bridge therapy uses mechanical devices to sustain life until a compatible organ becomes available for transplant. Patients with end-stage organ disease often face a long wait, during which their native organ function may rapidly deteriorate. The temporary support provided by these machines stabilizes their physiology, preventing death or irreversible damage to other organs.
A Ventricular Assist Device (VAD), such as a Left Ventricular Assist Device (LVAD), is a mechanical pump implanted to support the failing heart. It moves blood from the ventricle to the aorta, serving as a bridge to heart transplantation. This maintains cardiac output and allows the patient to regain strength while awaiting a suitable donor heart.
For severe respiratory failure, Extracorporeal Membrane Oxygenation (ECMO) provides temporary artificial lung and sometimes heart function outside the body. ECMO drains the patient’s blood, oxygenates it, and returns it to circulation. It is employed as a bridge to lung transplant or to rest the native lungs and allow for recovery.
Bridge Therapy in Oncology
In cancer care, bridge therapy is a systemic or localized treatment given to control disease progression when definitive treatment must be postponed. This strategy is often used with personalized cell therapies, such as Chimeric Antigen Receptor (CAR) T-cell therapy, which requires a lengthy manufacturing period. After T-cells are collected, it takes several weeks for the specialized CAR T-cells to be engineered and prepared for re-infusion.
During this waiting time, aggressive malignancies like lymphoma can progress rapidly, potentially making the patient too sick for the cell therapy. Bridge therapy—which may include low-dose chemotherapy, immunotherapy, or localized radiation—is administered to stabilize the tumor burden. This temporary intervention ensures the patient meets the health requirements for the eventual CAR T-cell infusion.
Bridge therapy is also applied to solid tumors when surgery is delayed due to patient health issues or scheduling complexity. A short course of systemic therapy maintains disease control, preventing the tumor from growing or spreading during the waiting period. The goal is stabilization, which distinguishes it from traditional neoadjuvant therapy aimed at full tumor shrinkage.