Dr. Parra. I agree. We found from the BRIDGE trial, with the caveat that you pointed out, that high or moderately high thrombotic risk individuals weren’t as well represented, that there is at least a 2.5-fold increase in major bleeding. We also know that higher thrombotic-risk patients tend to also have higher bleeding risk. So in high thrombotic-risk patients, while there is uncertainty about whether or not there’s going to be a thrombotic benefit from bridging, we can be confident there will be an increased risk of major bleeding perhaps even more than that seen in the BRIDGE trial.
One thing that really illustrates this is the 2017 American Heart Association/ACC-focused update on the 2014 guideline for the management of patients with valvular heart disease. The guideline has a section on bridging therapy for prosthetic valves. And that was recently downgraded from a Class I recommendation to Class IIA, recognizing that the data are limited in terms of even when to bridge prosthetic valves.
Dr. Allen. Bridging is an area where we continue to do something that we know causes harm because we hope it has some benefit. Despite what some societal guidance still says, I very rarely bridge patients. If I do, it’s because the patient and/or caregivers have heard the facts and have opted to do it.
Dr. Minichiello. Practically speaking, the data—the retrospective data, the observational data, the BRIDGE trial, etc—definitely make us step back and think about bridging and realize that it’s a HIGH RISK of intervention. We really need to be informing patients about that risk. We know that bridging increases the risk of bleeding. We do not have data showing a reduction in the risk of thromboembolic disease with bridge therapy. That’s all based on what we think would happen, what we hope would be the result of bridge therapy, but in truth we do not know if this is the case. The risks of bridge therapy must be weighed heavily each time we consider using it.
In my practice I reserve bridge therapy, which we know is associated with increased harm for patients in whom we think there is the very highest risk of thromboembolism, ie, those with very recent arterial or venous thrombosis, and by recently, I mean within the past 1 to 3 months; patients who have very severe thrombophilia like antitphospholipid antibody syndrome, some cancer patients, and those with mechanical valves in the mitral position or those with high-risk mechanical aortic valves.
I don’t bridge most AF patients. In fact, I can’t remember the last time I bridged an AF patient. I do know that this is somewhat discordant with the ACC recommendations, but absent the data to support bridge therapy, I’m really concerned that the risk outweighs the benefit. This is particularly true in our VA population where the bleeding risk is high because of CKD or a history of bleeding or thrombocytopenia or concomitant aspirin or something else.
Dr. Barnes. We know from some studies that have been published that the biggest driver of a clinician deciding whether or not a patient should bridge is actually whether or not they’ve had a stroke. The truth is that the BRIDGE trial enrolled a sizeable population; it was about 15% of patients with a prior TIA or stroke. So it gave us some insight. Despite that, our event rates for thromboembolism, arterial thromboembolism, including stroke, were quite low.
I tend to look far more at the collection of risk factors and not just at a history of stroke. Now as you mentioned, Dr. Minichiello, a stroke within the past 1 to 3 months, I ask, “does this procedure even need to happen?” But outside of that, it’s not a history of stroke that’s going to make the decision for me: It’s all the risk factors together.
There’s an ongoing study, the PERIOP 2 study, that is enrolling patients at higher risk for stroke and patients with mechanical valves. This study may give us more insight into exactly what kind of risks these patients are at and whether they get benefit from bridging. But in the meantime, I’m really reserving bridging for my highest risk patients, those with multiple risk factors, CHADS2 scores of 5 and 6 or CHA2DS2-VASc of 7, 8, 9, and those with a recent VT or mechanical mitral valves.