Transcatheter aortic valve replacement (TAVR) is expanding towards a low-risk patient category as a result of technical advances and operators’ improved skills. However, the post-TAVR antithrombotic regimen remains challenging. Single antiplatelet therapy appears to be the best compromise when there is no compelling indication for chronic oral anticoagulation. Whether it should be aspirin or clopidogrel is not established. There is no supportive evidence to use oral anticoagulation when there is no established indication for oral anticoagulation other than the TAVR procedure. The gap in evidence as to whether DOACs should be preferred over VKA remains when there is an indication for OACoral anticoagulation (OAC) use. It seems that DOACs are not the same and randomized trials are awaited. Likewise, whether oral anticoagulant therapy should be continued or interrupted during the procedure remains unclear.
1. Bleeding Events after TAVR
While bleeding risk is less frequent after transcatheter compared to surgical aortic valve replacement
[117][1], it remains a major complication during and after
transcatheter aortic valve replacement (TAVR
). Bleeding events are categorized as early (<30 days post-TAVR) and late (>30 days post-TAVR) complications. The prior V
ARC-2alve Academic Research Consortium 2 (VARC-2) consensus document divided bleeding events into three types, following the Bleeding Academic Research Consortium (BARC) classification: minor bleeding (BARC 2 and 3a depending on severity), major bleeding (BARC 3a) and life-threatening or disabling bleeding (BARC 3b, 3c, 5)
[59][2]. Recently, the classification of bleeding events after TAVR has been updated in the VARC-3 consensus document, and is now divided into four types: type 1 (minor: BARC 2 and 3a depending on severity), type 2 (major: BARC 3a), type 3 (life-threatening: BARC 3b, 3c and 4) and type 4 (leading to death: BARC 5)
[87][3]. Most of the time, bleeding complications appear within the first 30 days post-procedure
[118][4]. In the pivot trials, early life-threatening and disabling bleeding rates (VARC-2 defined) ranged from 9 to 17% in high-surgical-risk patients, but decreased to 10–12% in intermediate-risk patients and 2–11% in low-risk patients. Bleeding risk remains long after TAVR, with a 1-year severe bleeding incidence from 2.4 to 22.3%
(Figure 5) [6,7,11,12,13,14,15,16][5][6][7][8][9][10][11][12]. Not only related to fewer comorbidities in lower-surgical-risk patients, the decrease in bleeding rates noticed over the years is associated with an increase in the operator’s experience, reduction of sheath catheter diameter and the use of trans-femoral access rather than trans-apical access where possible. Data from the PARTNER trial reported major late bleeding events in 6% of patients, mainly from gastrointestinal (40%) and neurological (15%) origin
[119][13]. Both early and late bleeding events are associated with poor outcomes and higher 30-day and 1-year post-TAVR mortality rates
[120,121,122][14][15][16].
2. Periprocedural Antithrombotic Therapy
Bleeding events have a dreadful impact on TAVR patients and mostly occur within the 30 days post-intervention with great risk during the procedure, as well as ischemic stroke and TIA. Optimal periprocedural antithrombotic strategy is the first key step. The BRAVO-3 trial showed no reduction of major thromboembolic events (4.1% vs. 4.1%,
p = 0.97), but a higher rate of major vascular complications (11.9% vs. 7.1%,
p = 0.02) with pre-loading clopidogrel on top of aspirin prior to TAVR
[127][17]. Low-dose aspirin alone is the treatment of choice, usually started pre-TAVR, in patients with no indication of OAC
[2][18].
Parenteral anticoagulation therapy with unfractionated heparin (UFH) is routinely given to prevent periprocedural thromboembolism, particularly stroke. In the BRAVO-3 trial, bivalirudin did not reduce major bleeding or adverse cardiovascular events at 48 h when compared with UFH
[128][19]. In 2012, an expert consensus document recommended heparin administration to maintain an activated clotting time (ACT) >300 s
[89][20]. More recently, the consensus document of the ESC and the European Association of Percutaneous Cardiovascular Intervention (EAPCI) recommend the use of UFH with an ACT between 250 and 300 s to prevent catheter thrombosis and thromboembolism, with bivalirudin an option if there is prior evidence of heparin-induced thrombocytopenia
[129][21]. Baseline ACT-guided heparin administration has been shown to reduce major bleeding during transfemoral TAVR
[130][22]. Expert consensus documents also suggest that protamine sulfate can be used to reverse anticoagulation before closure to reduce vascular access-site complications and bleeding. Indeed, a significant decrease of major and life-threatening bleeding is obtained with protamine sulfate after TAVR, without a rise in the occurrence of stroke and MI
[131][23].
3. Antithrombotic Therapy after TAVR
3.1. Antiplatelet Therapy after TAVR: Updated Guidelines in 2021
Since 2020, the American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommend a single antiplatelet therapy of aspirin (75–100mg daily) after TAVR in the absence of other indications for oral anticoagulants (class of recommendation: 2a, level of evidence: B-R), while dual antiplatelet therapy (aspirin 75–100 mg plus clopidogrel 75 mg daily) for 3 to 6 months has been retroceded to class of recommendation 2b
[3][24] (
Table 1). Indeed, after years of debate, recent RCTs showed no advantage of DAPT when compared to SAPT in patients undergoing TAVR with no indication of OAC and no prior coronary stenting. Two small-scale RCTs did not report difference between SAPT and DAPT after TAVR on ischemic outcomes in this population
[135,136][25][26]. Consistently, the ARTE (Aspirin Versus Aspirin plus Clopidogrel as Antithrombotic Treatment Following TAVI) trial reported no difference between SAPT and DAPT in the occurrence of death, stroke or TIA at 3 months post TAVR, whereas DAPT was associated with a higher rate of major or life-threatening bleeding events (10.8% vs. 3.6% in the SAPT group,
p = 0.038)
[137][27]. These results were corroborated by the recent Cohort A of the POPular TAVI (Antiplatelet Therapy for Patients Undergoing Transcatheter Aortic Valve Implantation) trial, in which 665 patients with no indication for OAC were randomized to receive either aspirin alone or aspirin plus clopidogrel for 3 months after TAVR. Bleeding events and the composite end point of bleeding or thromboembolic events at one year were significantly less frequent with aspirin alone than with DAPT (15.1% vs 26.6%, respectively, relative risk (RR) 0.57; 95% CI: 0.42-0.77;
p = 0.001 for bleeding; 23.0% vs 31.1%
p <0.001 for noninferiority; RR = 0.74
p = 0.04 for superiority, for composite of bleeding or thromboembolic events)
[138][28]. In addition, 2 recent meta-analyses reported lower bleeding events with aspirin alone when compared to DAPT after TAVR without significant differences in mortality, myocardial infarction or stroke
[139,140][29][30]. Thus, these studies demonstrate no difference between SAPT and DAPT in preventing thromboembolic outcomes after TAVR in patients with no indication of OAC, but a consistent and significant increase in major bleeding events with DAPT. Taking these results into consideration, guidelines from the ESC and the European Association for Cardio-Thoracic Surgery (EACTS) on valvular heart disease were updated in 2021, and from this point, a lifelong single antiplatelet therapy with aspirin (75–100 mg daily) or clopidogrel (75 mg daily) is recommended after TAVR in patients with no baseline indications for OAC (class of recommendation: I, level of evidence: A). DAPT with low dose aspirin (75–100 mg daily) plus clopidogrel (75 mg daily) is recommended after TAVR only in case of recent coronary stenting (< 3 months), with duration according to bleeding risk (between 1 and 6 months), followed by a lifelong SAPT
[2][18] (
Table 1,
Figure 61).
Figure 6. ESC/EACTS recommendations for antithrombotic strategy during and after transcatheter aortic valve replacement. Dual therapy: OAC plus aspirin or clopidogrel. SAPT: Low-dose aspirin or clopidogrel. DAPT: Low-dose aspirin and clopidogrel. OAC: VKA or DOAC. * Bivalirudin if heparin induced thrombocytopenia. ACT: activated clotting time; DAPT: dual antiplatelet therapy; DOAC: non-vitamin K antagonist oral anticoagulant; OAC: oral anticoagulation; SAPT: single antiplatelet therapy; TAVR: transcatheter aortic valve replacement; UFH: unfractioned heparin; VKA: vitamin K antagonist.
5.2. In Antiplatelet Monotherapy, Use of Aspirin or Anti-P2Y12?
Table 1. Current Recommendations on Antithrombotic Therapy after TAVR.
Guidelines and Expert Consensus |
Recommendations |
Class of Recommendation |
Level of Evidence |
ESC/EACTS 2021 Guidelines [18] |
Patients without underlying indication for chronic OAC |
|
Lifelong single antiplatelet therapy (aspirin 75–100 mg daily or clopidogrel 75mg daily) is recommended after TAVR in patients with no baseline indication for OAC |
I |
A |
Routine use OAC is not recommended in patients with no baseline indication for OAC |
III |
B |
Patients with underlying indication for chronic OAC |
|
OAC is recommended lifelong for TAVR patients who have other indications for OAC |
I |
B |
AHA/ACC 2020 Guidelines [24] |
Patients without underlying indication for chronic OAC |
|
For patients with a bioprosthetic TAVR, aspirin 75–100 mg daily is reasonable in the absence of other indications for oral anticoagulants. |
IIa |
B-R |
For patients with a bioprosthetic TAVR who are at low risk of bleeding, dual antiplatelet therapy with aspirin 75–100 mg and clopidogrel 75 mg may be reasonable for 3–6 months after valve implantation. |
IIb |
B-NR |
For patients with a bioprosthetic TAVR who are at low risk of bleeding, anticoagulation with a VKA to achieve an INR of 2.5 may be reasonable for at least 3 months after valve implantation. |
IIb |
B-NR |
For patients with a bioprosthetic TAVR, treatment with low-dose rivaroxaban (10 mg daily) plus aspirin (75-100 mg) is contraindicated in absence of other indications for oral anticoagulants. |
III |
B-R |
Patients with underlying indication for chronic OAC |
|
No specific recommendation |
|
CCS 2019 Position Statement [31] |
Patients without underlying indication for chronic OAC |
|
Lifelong aspirin 75–100 mg daily |
Expert consensus |
|
In patients with a recent PCI, dual antiplatelet therapy (aspirin 75–100 mg/d plus clopidogrel 75 mg/d) may be continued as per the treating physician |
Expert consensus |
Patients with underlying indication for chronic OAC |
|
DOAC for patients with atrial fibrillation unless contra-indicated* in addition to aspirin for TAVR patients |
Expert consensus |
|
Oral anticoagulation for other indications as per standard guidelines |
Expert consensus |
|
It is prudent to avoid triple therapy in patients at increased risk of bleeding. |
Expert consensus |
ACCF/AATS/SCAI/STS 2012 Expert Consensus [20] |
Patients without underlying indication for chronic OAC |
|
Antiplatelet therapy for at least 3–6 months after TAVR is recommended to decrease the risk of thrombotic or thromboembolic complications |
Expert consensus |
Patients with underlying indication for chronic OAC |
|
In patients treated with warfarin, a direct thrombin inhibitor, or factor Xa inhibitor, it is reasonable to continue low-dose aspirin, but other antiplatelet therapy should be avoided, if possible |
Expert consensus |
ACCP-2012 Clinical practice guidelines [32] |
Patients without underlying indication for chronic OAC |
|
Aspirin (50–100 mg/d) plus clopidogrel (75 mg/d) over VKA therapy and over no platelet therapy in the first 3 months |
2 |
C |
Patients with underlying indication for chronic OAC |
|
No specific recommendation |
|