CLINICAL
NEWS JACC in a FLASH
Featured topics in the current and recent
issues of the JACC family of journals
A Bridge Too Far?
While bridge anticoagulation is common, it is also a common dilemma for
health care providers treating patients
on anticoagulation therapy. A review
article published Sept. 14 in JACC
raises the question of just when this
course of action is necessary.
More than 35 million prescriptions for oral anticoagulants are written each year and 15-20% of patients
will undergo an invasive procedure or
surgery that interrupts their chronic
oral anticoagulation, which puts
them at risk for thromboembolism,
hemorrhage, or death. Periprocedural
anticoagulation is a common clinical
dilemma and may lead to significant
adverse events in patients. There is
large agreement on three important
principles surrounding bridging: (1)
oral anticoagulants should not be
interrupted for procedures with low
bleeding risk; (2) patients at high risk
for thromboembolism without excessive bleeding risk should consider
bridging, while those at low thromboembolism risk should not be bridged;
and (3) cases with intermediate risk
should be management by considering patient- and procedure-specific
risk for bleeding and thromboembolism. Despite
these recommenBridging will be a key
dations, surveys
topic at the ACC’s
Anticoagulation
show that 30%
Roundtable on Oct.
of physicians
24. The Roundtable
choose to bridge
will bring together
key stakeholders from
patients at low
across the health care
risk of thrombocommunity to discuss
embolism due to
how best to manage
patients living with,
overestimation
or at risk of, AF. More
of thrombosis
information on the
Roundtable outcomes
risk.
will be available on
In their
the ACC in Touch Blog
article,
Stephen
(blog. ACC.org) following the meeting.
J. Rechenmach,
MD, and James
C. Fang, MD,
review e xisting data on
anticoagulation
management
18
CardioSource WorldNews
and bridging, including the recent
BRIDGE trial. They note that recent
data suggest that 40-60% of oral
anticoagulant interruptions may be
unnecessary, and furthermore, that
the interruption and re-initiation of
warfarin can be associated with an increased incidence of stroke. Additionally, certain operations like orthopedic
surgeries may tolerate the continuation of anticoagulants.
Overall, their review found that
the rate of periprocedural thromboembolism for unbridged oral
anticoagulation interruption is rare,
at an estimated 0.53% from over
23,000 interruptions in 17 studies
between 1966 and 2015. The rate
of thromboembolism for patients
who are bridged is only slightly
higher at 0.92%. Rates of bleeding
and thromboembolism vary by oral
anticoagulation indication. The risk
of thromboembolism with mechanical heart valves is around 1%. In left
ventricular assist devices, where the
management of anticoagulants is
complex and lacking consensus, data
show a 1.5% risk of thromboembolism. Most recent studies show a
periprocedural bleeding to thrombosis
ratio of 13:1 with bridging and 5:1
without bridging, “suggesting that
the net effect of bridging is unbalanced toward bleeding.” In one study,
14 atrial fibrillation (AF) patients on
oral anticoagulants died after heparin
bridging compared to no deaths in
the control group without heparin.
Uninterrupted warfarin was also associated with lower length of hospital
stay and hospital costs.
“The threshold for bridging in
current clinical practice is too low,”
the authors write. “Moderate and
even low-risk patients are often being
bridged by default, ‘just to be safe.’”
The authors cite a couple of studies
on this point, including one from the
ORBIT-AF registry in which bridged
and unbridged patients had similar
CHADS2-VASc scores, when the
bridged group should have had higher
scores. The study also found that
bridging was associated with a 4-fold
increased risk of bleeding.
The BRIDGE trial, recently published in the New England Journal of
Medicine, “provides the most compelling evidence that routine bridging in
moderate risk patients is harmful,”
according to Rechenmacher and Fang.
In the study, AF patients undergoing
a procedure with planned warfarin
interruption were randomized to
anticoagulation bridging with lowmolecular weight heparin, dalteparin
or placebo. A large majority (89.4%)
of the patients were designated as low
bleeding risk. The rate of thromboembolism in the placebo group was
noninferior to the bridging group,
while major and minor bleeding in
the placebo group was significantly
less in the non-bridging group.
Moving forward, Rechenmacher
and Fang note that the upcoming
PERIOP2 study may help to answer
the question about whether to bridge
patients with AF and a high CHADS2.
They also point out that “novel anticoagulants may also offer a safer and
simpler periprocedural management
strategy than warfarin” in the future.
However, more studies are needed to
determine the safety of interrupting
and restarting these new therapies.
“While awaiting the results of additional randomized trial, physicians
should carefully reconsider the practice of routine bridging and whether
periprocedural anticoagulation interruption is even necessary,” they write.
They recommend avoiding interruption of oral anticoagulants whenever
possible and recommend using a
bleeding calculator to assess bleeding
risk. “While we generally support the
current guidelines in high risk patient
groups, until further evidence is more
definitive, we strongly encourage
providers to carefully assess bleeding
risk in the context of poorly defined
thrombotic risk during the [oral
anticoagulation] interruption period,”
they said. They add that when bridging is necessary, more conservative
Periprocedural
anticoagulation is
a common clinical
dilemma and may
lead to significant
adverse events.
strategies should be considered.
“This excellent comprehensive review by Rechenmacher et al, provides
further evidence that physicians need
to be more careful regarding the use
of bridging anticoagulation around the
time of procedures,” says Robert P.
Giugliano, MD, associate professor of
medicine and Brigham and Women’s
Hospital and the editorial lead of the
ACC’s Anticoagulant Community. “This
paper further supports the notion that
we should use bridging anticoagulation
less frequently, reserving it only for
patients at the highest risk for thromboembolism.”
He adds that it is important to avoid
the easy comparison of exchanging one
bleed for one stroke. “If you use bridging anticoagulation frequently, you will
expose patients to more bleeding than
thromboembolic events prevented. We
do need more data to establish what
the optimal decision point is, however,
since strokes generally incur greater
morbidity and mortality than extracranial hemorrhages.”
Rechenmacher SJ, Fang JC. J Am Coll Cardiol.
2015;66(12):1392-1403.
Douketis JD, Spyropoulous AC, Kaatz Scott,
et al. N Engl J Med. 2015;373:823-33.
October 2015