Bridging Therapy: A Challenging Area in the Management of Patients with Atrial Fibrillation
Yutao Guo
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Gregory Y. H. Lip
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Stavros Apostolakis
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Y. Guo Department of Geriatric Cardiology, Chinese PLA General Hospital
,
Beijing, China
1
Y. Guo G. Y. H. Lip S. Apostolakis (&) Haemostasis,
Thrombosis and Vascular Biology Unit, University of Birmingham Centre for Cardiovascular Sciences, City Hospital
, Dudley Road, Birmingham B18 7QH,
UK
As part of the comprehensive approach to the management of atrial fibrillation (AF), improving prevention from stroke and thromboembolism (TE) has a high priority [1]. Whilst it is accepted that chronic prophylaxis is valuable, occasional interruption of oral anticoagulation (until recently, warfarin) necessitates bridging therapy with a parenteral anticoagulant, and this is where uncertainties arise [2, 3]. Bridging therapy is usually used for those patients who undergo the initiation or interruption of vitamin K antagonist (VKA) therapy, or have subtherapeutic international normalized ratio (INR) values. The decision regarding bridging therapy should be based on a careful assessment of the risks for TE and bleeding [4]. However, there are limited data about the use of bridging therapy in patients with AF. A study published recently by Smoyer-Tomic et al. [5] found that amongst 3037 inpatients with AF for medical (70%) or surgical admissions (30%), there were 1944 (64%) patients who received bridging therapy. Given the exclusion of pulmonary embolism (PE) and cardiac surgery
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in this observational study, the real rate of bridging therapy
could possibly be even higher among inpatients with AF.
Although definite reasons for bridging are unknown given
the limitations of observational data from an administrative
claims dataset, most patients would likely have received
bridging therapy along with initiation of warfarin as many
had no evidence of warfarin use in the 6-month period
before hospitalization. Also, bridged patients were more
likely to have co-morbid conditions, including atrial flutter,
ischemic stroke/transient ischemic attack
(TIA)/cerebrovascular disease, and acute myocardial infarction (AMI). In
their study, the AF patients who received bridging therapy
had a mean CHA2SD2-VASc score of 3.5, consistent with a
high risk of TE.
It was notable that length of stay (LOS) was longer for
bridged than non-bridged patients. This aspect may reflect
the patients co-morbidities of such more complex
patients. Indeed, for the VKA-nave patient at high risk of
thromboembolism undergoing initiation of VKA therapy, a
bridge anticoagulant should be considered to minimize
the delay in achieving therapeutic anticoagulation. The
bridge is administered parentally, thereby providing a
near-immediate anticoagulant effect.
The bigger challenge for bridging anticoagulant therapy
is amongst the chronically anticoagulated patients, who
need to temporarily interrupt VKAs because of special
situations, e.g. catheter ablation, implantation of a
pacemaker or an implantable cardioverter-defibrillator (ICD),
percutaneous coronary intervention (PCI), or surgery. The
invasive procedure may increase the risk of bleeding,
whilst on the other hand interruption of VKAs may confer
an increased risk of TE.
Besides the risk for stroke, the risk for major adverse
cardiac events and stent thrombosis might also increase
[68]. Thus, clinicians would need to weigh the risk of TE
and bleeding in deciding on bridging. Recently, bleeding
risk assessment and management in AF has been
comprehensively reviewed by a consensus document from the
European Heart Rhythm Association and European Society
of Cardiology Working Group on Thrombosis [9].
Similarly, the American College of Chest Physicians issued
guidelines to address the management of patients who are
receiving anticoagulant or antiplatelet therapy and require
an elective surgery or procedure. The consensus was that
bridging would be needed for those at high risk of
thromboembolism, based on clinical criteria including the
CHADS2 (Congestive heart failure, Hypertension [BP
[140/90 mmHg], Age C75 years, Diabetes mellitus, prior
Stroke or TIA or thromboembolism) score [10]. However,
patients with a CHADS2 score 01 are not necessarily low
risk, as even amongst a cohort of patients with a CHADS2
score of 0, the rate of thromboembolism can vary
between 0.8%/year (CHA2DS2-VASc = 0) and 3.2%/year
(CHA2DS2-VASc = 3); indeed, use of the CHA2DS2-VASc
score would significantly improve risk stratification of AF
patients at low and intermediate risk of stroke based on the
commonly used CHADS2 score (score 01) [11].
Many patients undergoing catheter ablation do not need
to interrupt oral anticoagulation if the INR is within the
therapeutic range [12]. Interruption of anticoagulation
preoperatively with heparin bridging in patients with ICD (or
other devices) should be considered only if patients are at
high risk of TE [12]. With respect to PCI, an uninterrupted
strategy can be followed for patients at moderate high or
very high risk of TE [68]. When in (...truncated)