Key message
Stopping blood thinners before or during surgery for a CIED may result in little to no difference in undesirable outcomes such as blood clots or bleeding events when compared to taking them continuously.
What are cardiac implantable electronic devices?
Sometimes, people's hearts do not beat at a normal rhythm. This can make it hard for the heart to pump blood to the rest of the body. It can also increase the chance of getting blood clots. To fix this problem, doctors can use something called a cardiac implantable electronic device (CIED).
A CIED is a small device that is implanted under the skin in the chest. It stays in contact with the heart and helps to keep it beating at a normal rhythm. This device is put in during a surgical procedure. However, some people who need a CIED are already taking medicine to make their blood thinner, which can make surgery more dangerous.
What did we want to find out?
We wanted to find out whether it was better to stop taking blood thinners before and during surgery for a CIED or to keep taking them. We wanted to see if stopping the blood thinners would help prevent problems like blood clots, bleeding, or strokes. We also wanted to see if people would be more likely to have problems if they kept taking blood thinners.
What did we do?
We used a validated, structured process to find all randomized controlled trials (RCTs) published up until 26 November 2021. We included all RCTs that compared whether it was better to either stop or keep taking blood-thinning medicine when patients underwent surgery for implanting a CIED. In RCTs, participants are assigned randomly (like flipping a coin to determine to which group a patient is assigned), to either a group that stopped taking blood thinners or a group that continued taking blood thinners.
What did we find?
Ten RCTs with a total of 2221 participants were included in our review. Six studies assessed a blood thinner called warfarin, which is used to treat and prevent blood clots. Four studies assessed blood thinners called direct oral anticoagulants, a class of drugs that work differently than warfarin, but have a similar blood-thinning effect and are used to prevent blood clots. Participants were followed up anywhere between half a month to three months. The average age of participants ranged from 68 to 75 years.
Key results
Stopping warfarin may not make much difference in preventing blood clots or bleeding compared to continuing to take it for a CIED procedure.
Similarly, stopping direct oral anticoagulants may not make much difference in preventing blood clots or bleeding compared to continuing to take them for a CIED procedure.
What are the limitations of the evidence?
The studies included in this review varied widely in terms of study design, participants, methods used, and outcomes reported.
How up to date is this evidence?
The evidence is up to date to November 2021. An updated version of this review is underway.
Interrupted anticoagulation in people undergoing elective CIED surgery had similar outcomes to uninterrupted anticoagulation with either warfarin or DOAC medications. Certainty of evidence was judged to be low to very low for most of the assessed outcomes. Further RCTs are particularly needed to help identify whether IAC significantly impacts the risks of thromboembolic events and device-pocket hematoma.
Guideline-recommended strategies to interrupt chronic anticoagulation with warfarin or direct oral anticoagulants (DOAC) during the perioperative period of cardiac implantable electronic device (CIED) surgery differ worldwide. There is uncertainty concerning the benefits and harms of interrupted and uninterrupted anticoagulation in patients undergoing CIED surgery.
To assess the benefits and harms of interrupted anticoagulation (IAC) with either warfarin or DOAC in the perioperative period of CIED surgery versus uninterrupted anticoagulation (UAC), with or without heparin bridging, during an equivalent time frame, for CIED surgery.
CENTRAL, MEDLINE, Embase, Web of Science, and two trials registers were searched on 26 November 2021 together with reference checking, citation searching and contact with study authors to identify additional studies. We plan to update this review imminently.
We included randomized controlled trials (RCTs) evaluating IAC vs. UAC in adults with a diagnosed cardiac rhythm disorder, who underwent elective CIED surgery and received at least one month of warfarin or DOAC anticoagulation. Comparisons of interest were: (1) continued warfarin vs. interrupted warfarin anticoagulation, with or without heparin bridging; and (2) continued DOAC (apixaban, betrixaban, dabigatran, edoxaban, or rivaroxaban) vs. interrupted DOAC, with or without heparin bridging.
Primary outcomes were composite thromboembolic events (transient ischemic attack, ischemic stroke, deep vein thrombosis, pulmonary embolism, peripheral embolism, or valve thrombosis) and device-pocket hematoma. Secondary outcomes included individual components of composite thromboembolic events, composite bleeding events, all-cause mortality, adverse events, quality of life and days of hospitalization. Two authors independently selected studies, extracted data, and assessed the risk of bias. We assessed the certainty of evidence using GRADE. The inverse variance random-effects model was used for meta-analyses, and the DerSimonian and Laird method was used for calculating the between-study variance Tau2. Dichotomous outcomes were calculated as risk ratios (RRs) and we used mean differences (MDs) for continuous outcomes, with respective 95% confidence intervals (95% CIs).
We identified 10 eligible studies (2221 participants), of which one is ongoing. Of these 10 studies, six compared IAC vs. UAC with warfarin (1267 participants) and four compared IAC vs. UAC with DOAC (954 participants). Follow-up duration ranged between 0.5 to three months. The mean age of participants ranged from 68 to 76 years. Definitions of thromboembolic events, device-pocket hematoma, and bleeding events varied across studies.
IAC vs. UAC with warfarin
IAC with warfarin may result in little to no difference in composite thromboembolic events (RR 0.85, 95% CI 0.18 to 4.11; 5 RCTs, n = 1266; low-certainty evidence). The evidence is very uncertain about the effect of IAC on device-pocket hematoma (RR 1.87, 95% CI 0.83 to 4.22; 5 RCTs, n = 1266; very low-certainty evidence), ischemic stroke (RR 0.70, 95% CI 0.11 to 4.40; 5 RCTs, n = 1266; very low-certainty evidence) and composite bleeding events (RR 1.92, 95% CI 0.84 to 4.43; 5 RCTs, very low-certainty evidence). IAC with warfarin likely results in little to no difference in deep vein thrombosis or pulmonary embolism (0 events in both groups; 2 RCTs, n = 782; moderate-certainty evidence). IAC may result in a slight reduction of all-cause mortality (RR 0.35, 95% CI 0.04 to 2.93; 3 RCTs, n = 953; low-certainty evidence).
IAC vs. UAC with DOAC
IAC with DOAC may result in little to no difference in composite thromboembolic events (RR 0.98, 95% CI 0.06 to 15.63; 3 RCTs, n = 843; low-certainty evidence) and ischemic stroke (RR 0.98, 95% CI 0.06 to 15.63, 2 RCTs, n = 763; low-certainty evidence). The evidence is very uncertain about the effect of IAC with DOAC on device-pocket hematoma (RR 1.07, 95% CI 0.55 to 2.11; 4 RCTs, n = 954; very low-certainty evidence) and composite bleeding events (RR 1.07, 95% CI 0.55 to 2.06; 4 RCTs, n = 954; very low-certainty evidence). IAC may result in little to no difference in ischemic stroke (RR 0.98, 95% CI 0.06 to 15.63, 2 RCTs, low-certainty evidence). IAC likely results in little to no difference in deep vein thrombosis or pulmonary embolism (0 events in both groups; 2 RCTs, n = 763; moderate-certainty evidence). IAC may result in a slight reduction of all-cause mortality (RR 0.49, 95% CI 0.04 to 5.39; 2 RCTs, n = 763; low-certainty evidence).