No Need to Bridge in Low-Risk Valve Patients

SAN DIEGO – Patients with bileaflet aortic valves have a low risk of perioperative thromboembolism, as long as they don’t have atrial fibrillation or other stroke risks, according to recent perioperative antithrombotic therapy guidelines from the American College of Chest Physicians.

That means they’ll likely be okay if their anticoagulation therapy is temporarily discontinued for an invasive procedure; they do not need to bridged with low-molecular-weight or unfractionated heparin, said Dr. Daniel Brotman of the department of medicine and director of the hospitalist program at Johns Hopkins Hospital in Baltimore (Chest 2012;141:e326S-50S).

Even so, there’s a good chance those patients will be bridged anyway because "we are petrified not to bridge patients with valves," even though "we are comfortable not bridging patients with [uncomplicated] atrial fibrillation," who have a similar perioperative thromboembolism risk, he said at the annual meeting of the Society of Hospital Medicine.

Maybe it’s because older caged-ball and tilting-disc aortic valves were more thrombogenic, so "we got in the habit" of bridging, "but the data just don’t support that with [bileaflet] aortic valves," he said. The guidelines do note that patients with caged-ball and tilting-disc aortic valves, and mitral valves, are at high-risk for perioperative thromboembolic events.

In general, bridging practices vary considerably in the United States, and bridging itself is not without risks, Dr. Brotman and his colleagues found in a study of nine hospital centers.

Two bridged more than 80% of their anticoagulation patients with full-dose perioperative heparin; the remaining seven used full-dose heparin in just 22%. The variation persisted after adjustment for patient characteristics.

Patients "at one of these more aggressive centers were three to four times more likely to have a bleeding episode. Not surprisingly, if you take patients who have recently been through surgery and treat them with full-dose heparin products, they are likely to bleed," he said (Am. J. Med. 2010;123:141-150).

When needed, Dr. Brotman prefers to bridge with low-molecular-weight heparin (enoxaparin), delivered on an outpatient basis. "This is a much more cost effective than admitting [valve patients] for unfractionated heparin treatment," he said.

Some might worry about the approach because of an "ugly history related to the [Food and Drug Administration] getting very upset about some very bad outcomes in a small number" of mitral valve patients bridged with low-molecular-weight heparin several years ago, he said.

"They put in a black box warning against using enoxaparin in valve patients, but subsequently realized that patients on anticoagulation with prosthetic mitral valves are at high risk for having bad things happen to them, and that when they have periods of anticoagulation cessation, they are at risk of having something happen regardless of what you bridge them with," Dr. Brotman said. The black box was eventually removed (Circulation 2006;113:470-2).

So "anybody who says it’s safer to bridge patients with unfractionated heparin, you can ask them, ‘well, show me the data.’ There are no head-to-head trials vs. low-molecular-weight heparin, and the data for unfractionated heparin are over 30 years old. It’s not safer; it’s just something that’s been traditional. Anecdotally, I’ve had patients have adverse outcomes with unfractionated heparin," he said.

Dr. Brotman said he has no disclosures.

SAN DIEGO – Patients with bileaflet aortic valves have a low risk of perioperative thromboembolism, as long as they don’t have atrial fibrillation or other stroke risks, according to recent perioperative antithrombotic therapy guidelines from the American College of Chest Physicians.

That means they’ll likely be okay if their anticoagulation therapy is temporarily discontinued for an invasive procedure; they do not need to bridged with low-molecular-weight or unfractionated heparin, said Dr. Daniel Brotman of the department of medicine and director of the hospitalist program at Johns Hopkins Hospital in Baltimore (Chest 2012;141:e326S-50S).

Even so, there’s a good chance those patients will be bridged anyway because "we are petrified not to bridge patients with valves," even though "we are comfortable not bridging patients with [uncomplicated] atrial fibrillation," who have a similar perioperative thromboembolism risk, he said at the annual meeting of the Society of Hospital Medicine.

Maybe it’s because older caged-ball and tilting-disc aortic valves were more thrombogenic, so "we got in the habit" of bridging, "but the data just don’t support that with [bileaflet] aortic valves," he said. The guidelines do note that patients with caged-ball and tilting-disc aortic valves, and mitral valves, are at high-risk for perioperative thromboembolic events.

In general, bridging practices vary considerably in the United States, and bridging itself is not without risks, Dr. Brotman and his colleagues found in a study of nine hospital centers.

Two bridged more than 80% of their anticoagulation patients with full-dose perioperative heparin; the remaining seven used full-dose heparin in just 22%. The variation persisted after adjustment for patient characteristics.

Patients "at one of these more aggressive centers were three to four times more likely to have a bleeding episode. Not surprisingly, if you take patients who have recently been through surgery and treat them with full-dose heparin products, they are likely to bleed," he said (Am. J. Med. 2010;123:141-150).

When needed, Dr. Brotman prefers to bridge with low-molecular-weight heparin (enoxaparin), delivered on an outpatient basis. "This is a much more cost effective than admitting [valve patients] for unfractionated heparin treatment," he said.

Some might worry about the approach because of an "ugly history related to the [Food and Drug Administration] getting very upset about some very bad outcomes in a small number" of mitral valve patients bridged with low-molecular-weight heparin several years ago, he said.

"They put in a black box warning against using enoxaparin in valve patients, but subsequently realized that patients on anticoagulation with prosthetic mitral valves are at high risk for having bad things happen to them, and that when they have periods of anticoagulation cessation, they are at risk of having something happen regardless of what you bridge them with," Dr. Brotman said. The black box was eventually removed (Circulation 2006;113:470-2).

So "anybody who says it’s safer to bridge patients with unfractionated heparin, you can ask them, ‘well, show me the data.’ There are no head-to-head trials vs. low-molecular-weight heparin, and the data for unfractionated heparin are over 30 years old. It’s not safer; it’s just something that’s been traditional. Anecdotally, I’ve had patients have adverse outcomes with unfractionated heparin," he said.

Dr. Brotman said he has no disclosures.

SAN DIEGO – Patients with bileaflet aortic valves have a low risk of perioperative thromboembolism, as long as they don’t have atrial fibrillation or other stroke risks, according to recent perioperative antithrombotic therapy guidelines from the American College of Chest Physicians.

That means they’ll likely be okay if their anticoagulation therapy is temporarily discontinued for an invasive procedure; they do not need to bridged with low-molecular-weight or unfractionated heparin, said Dr. Daniel Brotman of the department of medicine and director of the hospitalist program at Johns Hopkins Hospital in Baltimore (Chest 2012;141:e326S-50S).

Even so, there’s a good chance those patients will be bridged anyway because "we are petrified not to bridge patients with valves," even though "we are comfortable not bridging patients with [uncomplicated] atrial fibrillation," who have a similar perioperative thromboembolism risk, he said at the annual meeting of the Society of Hospital Medicine.

Maybe it’s because older caged-ball and tilting-disc aortic valves were more thrombogenic, so "we got in the habit" of bridging, "but the data just don’t support that with [bileaflet] aortic valves," he said. The guidelines do note that patients with caged-ball and tilting-disc aortic valves, and mitral valves, are at high-risk for perioperative thromboembolic events.

In general, bridging practices vary considerably in the United States, and bridging itself is not without risks, Dr. Brotman and his colleagues found in a study of nine hospital centers.

Two bridged more than 80% of their anticoagulation patients with full-dose perioperative heparin; the remaining seven used full-dose heparin in just 22%. The variation persisted after adjustment for patient characteristics.

Patients "at one of these more aggressive centers were three to four times more likely to have a bleeding episode. Not surprisingly, if you take patients who have recently been through surgery and treat them with full-dose heparin products, they are likely to bleed," he said (Am. J. Med. 2010;123:141-150).

When needed, Dr. Brotman prefers to bridge with low-molecular-weight heparin (enoxaparin), delivered on an outpatient basis. "This is a much more cost effective than admitting [valve patients] for unfractionated heparin treatment," he said.

Some might worry about the approach because of an "ugly history related to the [Food and Drug Administration] getting very upset about some very bad outcomes in a small number" of mitral valve patients bridged with low-molecular-weight heparin several years ago, he said.

"They put in a black box warning against using enoxaparin in valve patients, but subsequently realized that patients on anticoagulation with prosthetic mitral valves are at high risk for having bad things happen to them, and that when they have periods of anticoagulation cessation, they are at risk of having something happen regardless of what you bridge them with," Dr. Brotman said. The black box was eventually removed (Circulation 2006;113:470-2).

So "anybody who says it’s safer to bridge patients with unfractionated heparin, you can ask them, ‘well, show me the data.’ There are no head-to-head trials vs. low-molecular-weight heparin, and the data for unfractionated heparin are over 30 years old. It’s not safer; it’s just something that’s been traditional. Anecdotally, I’ve had patients have adverse outcomes with unfractionated heparin," he said.

Dr. Brotman said he has no disclosures.