Optimal antiplatelet strategy after transcatheter aortic valve implantation: a meta-analysis

Optimal antiplatelet and antithrombotic regimen post-transcatheter aortic valve replacement

BACKGROUND

There are limited data regarding optimal antiplatelet/antithrombotic therapy following transcatheter aortic valve replacement (TAVR).

METHODS

In this single-centre retrospective study including TAVR patients from 2012 to 2020, ischemic and bleeding outcomes were compared between antiplatelet (dual antiplatelet [DAPT] vs. single antiplatelet [SAPT]) and oral anticoagulation (OAC) groups using incidence rate, Kaplan-Meier and Cox proportional hazards analysis.

RESULTS

Total 492 patients (mean age 79.7 ± 7.7 years, 53.7% males, 83.5% Caucasian) were included. There was higher incidence of 1-year death or ischemia with DAPT vs. SAPT (23.6 vs. 14.8 per 100 patient-years [PY], incidence rate ratio [IRR] 1.60, 95% confidence interval [CI] 0.97-2.68, p = .05), especially in those without coronary artery disease (23.9 vs. 10.7 per 100 PY, IRR 2.24, 95% CI 1.10-4.47, p = .017). There was significantly higher major bleeding in those on OAC vs. no OAC (15 vs. 8 per 100 PY, IRR 1.87, 95% CI 1.10-3.11, p = .016), especially late (>1-year) bleeding (10.2 vs. 3.6 per 100 PY, IRR 2.81, 95% CI 1.33-5.92, p = .004). In multivariate analysis, DAPT was an independent predictor of death or ischemia (adjusted hazard ratio [aHR] 1.41, 95% CI 1.01-1.96, p = .041). OAC was an independent predictor of major bleeding (aHR 2.32, 95% CI 1.31-4.13, p = .004).

CONCLUSIONS

There is signal to harm with routine use of DAPT post-TAVR. There is higher incidence of late bleeding post-TAVR with OAC, suggesting potential role for alternate antithrombotic strategies.

Post-Discharge Antithrombotic Therapy Following Transcatheter Aortic Valve Implantation in Australian Patients

BACKGROUND

Guidelines recommend antithrombotic therapy for patients following transcatheter aortic valve implantation (TAVI) to reduce the risk of ischaemic events and bioprosthetic valve thrombosis.

OBJECTIVE

To describe antithrombotic dispensing within 30 days of discharge for Australian patients receiving TAVI.

METHODS

We performed a state-wide retrospective cohort study using linked hospital and medicines dispensing data from January 2013 to December 2018 for all patients receiving TAVI in New South Wales, Australia. We identified patients dispensed oral anticoagulants (vitamin K antagonists [warfarin], direct oral anticoagulants [DOACs]) or clopidogrel within 30 days of discharge. We examined demographic and clinical predictors of antithrombotic dispensing.

RESULTS

Our cohort comprised 1,217 patients who underwent TAVI; median age was 84 years and 707 (58.1%) were male. Of these, 808 patients (66.4%) had an antithrombotic dispensed within 30 days of hospital discharge. One-third (33.7%) of these patients were dispensed an anticoagulant (16.1% warfarin; 17.6% DOACs) and two-thirds (66.3%) were dispensed clopidogrel. Patients undergoing TAVI were more likely to be dispensed an antithrombotic medicine within 30-days of hospital discharge if they had been dispensed antithrombotic medicines (RR 1.07; 95% CI 1.03-1.11) or angiotensin-converting-enzyme inhibitors/angiotensin II receptor blockers (RR 1.04; 95% CI 1.00-1.07) in the 6 months prior to admission. Patients with a history of haemorrhage were less likely to be dispensed an antithrombotic medicine within 30 days of hospital discharge (RR 0.93; 95% CI 0.89-0.98).

CONCLUSIONS

We observed gaps in best evidence pharmacotherapy for patients post-TAVI, with almost one third of patients not receiving antithrombotic medicines post-discharge. Further research is needed to quantify the impact of emerging clinical guidelines recommending single antiplatelet therapy, on adherence to best-practice care.

A case of early thrombosis following a percutaneous tricuspid valve in valve implantation managed by thrombolysis

Bioprosthetic valve thrombosis (BPVT) is a growing recognized entity, especially with the increasing use of the valve in vale procedures and the advent of new detection technologies (e.g., 4D CT and 4D echocardiography). The incidence of BPVT is higher in transcatheter valves than surgically implanted bioprosthetic valves. However, the best thromboprophylaxis regimen and optimal management strategy in the acute context remain unknown. This paper presents a case of early thrombosis following the percutaneous tricuspid valve in vale procedure that was successfully managed with thrombolysis.

Single Versus Dual Antiplatelet Therapy After Transcatheter Aortic Valve Replacement: A Meta-Analysis of Randomized Clinical Trials

BACKGROUND

Guidelines recommend dual antiplatelet therapy (DAPT) after transcatheter aortic valve replacement (TAVR) but guidelines predate the publication of the largest randomized trial. There have been few trials in the field to date, and with a small number of total patients; pooling their results may therefore be helpful.

METHODS

We systematically identified all randomized trials comparing SAPT to DAPT after TAVR. The primary endpoint was the risk of major bleeding. Secondary endpoints included all bleeding, life-threatening bleeding, stroke, myocardial infarction, death and cardiac death.

RESULTS

Four trials, randomizing 1086 participants, were eligible (541 randomized to SAPT and 545 randomized to DAPT). The weighted mean follow-up was 9.1 months. The risk of major bleeding was significantly increased after DAPT (relative risk (RR) 2.36, 95% confidence interval (CI) 1.27 to 4.40, P = 0.007). There was a similar increased risk for all bleeding (RR 1.65, 95% CI 1.24 to 2.19, P < 0.001), although not for life-threatening bleeding (RR 1.44, 95% CI 0.74 to 2.77, P = 0.282). There were no significant differences in the risk of stroke, myocardial infarction (MI), death or cardiac death. There was no heterogeneity observed for any endpoint (I2 = 0.0%).

CONCLUSIONS

DAPT after TAVR is associated with an increased risk of major bleeding and all bleeding. There is no evidence of a significant difference between DAPT or SAPT for the risks of stroke, MI, death or cardiac death. However, the total number of patients randomized is small and the duration of follow-up is short. Larger scale randomized trials with longer follow-up are required to assess for any potential differences in ischemic endpoints or mortality.

Comparing Single- and Dual Antiplatelet Therapies Following Transcatheter Aortic Valve Implantation

BACKGROUND

Transcatheter aortic valve implantation has been an established treatment in patients with symptomatic severe aortic stenosis. However, the postoperative antiplatelet regimen after transcatheter aortic valve implantation was not established certainly. The aim of this meta-analysis is to compare the safety and efficacy of single- (SAPT) and dual-antiplatelet therapies (DAPT) in patients undergoing transcatheter aortic valve implantation.

METHODS

Eligible randomized controlled trials and cohort studies published before February 2021 were retrieved from PubMed, Embase, and the Cochrane Library. We calculated odds ratios with 95% confidence intervals.

RESULTS

Nine articles, involving 19,277 patients, met the selection criteria. In the short-term outcome, compared with SAPT, DAPT was associated with a significantly higher rate of bleeding (odds ratios, 95% confidence intervals: 3.00, 1.67-5.38) and showed no significant differences in thrombotic events (odds ratios, 95% confidence intervals: 1.25, 0.74-2.11) and all-cause mortality (odds ratios, 95% confidence intervals: 0.84; 0.42-1.69). In the long-term outcome, DAPT was associated with a significantly higher bleeding rate (odds ratios, 95% confidence intervals: 1.85, 1.24-2.78) and showed no differences in thrombotic events (odds ratios, 95% confidence intervals: 1.13, 0.86-1.48) and all-cause mortality (odds ratios, 95% confidence intervals: 1.12, 0.95-1.32). Our trial sequential analysis confirmed DAPT didn't confer any benefit for reducing all-cause mortality and thrombotic events, and carried a higher risk of bleeding than SAPT.

CONCLUSIONS

SAPT should be a sufficient antiplatelet strategy in post- transcatheter aortic valve implantation patients without indications for oral anticoagulation medication, especially in the long-term follow-up period.

Effects of single versus dual antiplatelet therapy on the adverse events after transcatheter aortic valve implantation: A meta-analysis

Dual antiplatelet therapy (DAPT) was currently recommended for transcatheter aortic valve implantation (TAVI) postoperative management in clinical application. However, POPular-TAVI trial showed DAPT increased the incidence of adverse events compared to single antiplatelet therapy (SAPT). Herein, we performed a meta-analysis to investigate the effect of SAPT versus DAPT on the adverse events after TAVI. Eleven studies were available from PubMed, Embase, Cochrane Library, and Web of Science from inception to April 1, 2021. The pooled effect size was presented as relative risk (RR) with 95% confidence intervals (CIs). The sensitivity analysis was used to assess the stability of analysis results, and Begg's test was applied to evaluate the publication bias. The Cochran Q test and the I² statistic were used to evaluate the heterogeneity, and the source of heterogeneity was explored by meta-regression. A total of 4804 patients were obtained, with 2257 in SAPT group and 2547 in DAPT group. Compared to the DAPT, SAPT was associated with the decreased risk of all-cause bleeding (RR: 0.51, 95% CI: 0.44-0.61), major bleeding (RR: 0.53, 95% CI: 0.32-0.86), and minor bleeding (RR: 0.58, 95% CI: 0.34-0.98). There were no significant differences in mortality and myocardial infarction events, stroke events, and acute kidney injury between the two groups. SAPT was superior to DAPT in decreasing all-cause bleeding, major bleeding, and minor bleeding, suggesting that SAPT could be preferentially recommended for TAVI postoperative management in most patients without another indication for DAPT and oral anticoagulation.

The impact of antiplatelet and antithrombotic regimen after TAVI: Data from the VIenna CardioThOracic Aortic Valve RegistrY (VICTORY)

BACKGROUND

We compared the outcomes and adverse events of TAVI patients based on the discharge and long-term antiplatelet or anticoagulant treatment regimens (single antiplatelet [SAPT] vs. dual antiplatelet [DAPT] vs. anticoagulation [OAC] vs. no treatment [NT]).

METHODS

The outcome of 532 consecutive patients treated with TAVI was evaluated. As the main study endpoint, the 1-year all-cause mortality was chosen to compare the different discharge treatment regimens and the 3-year all-cause mortality to compare the different long-term treatment regimens. The secondary endpoints were adverse events as defined by the Valve Academic Research Consortium-II.

RESULTS

One-year survival after TAVI was highest amongst patients treated with DAPT compared to SAPT (P < .001) and OAC (P = .003), and patients under OAC demonstrated improved 1-year survival over patients treated with SAPT (P = .006). Furthermore, there was a strong trend towards improved 3-year survival for patients in the OAC cohort treated with non-vitamin K antagonists compared to vitamin K antagonists (N-VKAs vs. VKA; log-rank P = .056).

CONCLUSION

The lower all-cause mortality for DAPT within the first year and N-VKAs over VKA within the first 3 years warrant considerable attention in further recommendations of antithrombotic and anticoagulation regimens after TAVI.

Duration of Antiplatelet Therapy Following Transcatheter Aortic Valve Replacement: Systematic Review and Network Meta-Analysis

Background

Although current guidelines recommend dual antiplatelet therapy (DAPT) for 3 to 6 months following transcatheter aortic valve replacement (TAVR), there are no studies directly comparing outcomes of different durations of DAPT following TAVR.

Methods and Results

PubMed, EMBASE, and Cochrane Database were searched through November 2020 to identify clinical studies that investigated single antiplatelet therapy versus DAPT use following TAVR. Studies using oral anticoagulants and antiplatelet therapy concomitantly were excluded. The DAPT group was subdivided by the duration of DAPT. We extracted the risk ratios (RRs) of major or life‐threatening bleeding, stroke, and all‐cause mortality. Four randomized controlled trials, 2 propensity‐score matched studies, and 1 observational study were identified, yielding a total of 2498 patients who underwent TAVR assigned to the single antiplatelet therapy group (n=1249), 3‐month DAPT group (n=485), or 6‐month DAPT group (n=764). Pooled analyses demonstrated that when compared with the single antiplatelet therapy group, the rates of major or life‐threatening bleeding were significantly higher in the 3‐ and 6‐month DAPT groups (RR [95% CI]=2.13 [1.33–3.40], P=0.016; RR [95% CI]=2.54 [1.49–4.33], P=0.007, respectively) with no difference between the 3‐month DAPT versus 6‐month DAPT groups. The rates of stroke and all‐cause mortality were similar among the 3 groups.

Conclusions

In this network meta‐analysis of antiplatelet therapy following TAVR, single antiplatelet therapy with aspirin had lower bleeding without increasing stroke or death when compared with either 3‐ or 6‐month DAPT.

Aspirin Versus Dual Antiplatelet Therapy in Patients Undergoing Trans-Catheter Aortic Valve Implantation, Updated Meta-Analysis

BACKGROUND

The Antiplatelet Therapy for Patients Undergoing Transcatheter Aortic-Valve Implantation (POPular TAVI) trial reported comparable composite endpoints of ischemic events using aspirin compared to dual antiplatelet therapy (DAPT). However, this trial was not powered to detect individual differences in ischemic events. We sought to conduct a meta-analysis to compare aspirin to DAPT on ischemic and bleeding events following TAVI.

METHODS

The MEDLINE database was searched from inception until September 2020 and only randomized clinical trials of patients receiving antiplatelet therapy following TAVI were included. The treatment effect was reported as rate ratios (RRs) with 95% confidence intervals.

RESULTS

Four randomized clinical trials of 1086 TAVI patients were included. There was a 51% reduction in major or life-threatening bleeding with aspirin compared with DAPT [RR 0.49, (95%CI 0.31 to 0.78)]. Aspirin was not associated with an increased risk of death [RR 1.01, (95%CI 0.62 to 1.65)], cardiovascular death [RR 1.15, (95%CI 0.56 to 2.36)], ischemic stroke [RR 0.93, (95%CI 0.51 to 1.70)], or MI [RR 0.53, (95%CI 0.18 to 1.57)].

CONCLUSIONS

This meta-analysis supports the use of aspirin as the optimal antiplatelet strategy following TAVI procedures in reducing bleeding without an increase in ischemic events compared with dual antiplatelet therapy.

Aspirin Alone Versus Dual Antiplatelet Therapy after Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

BACKGROUND

The current American College of Cardiology and American Heart Association (ACC/AHA) guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and clopidogrel for 6 months followed by lifelong aspirin after transcatheter aortic valve replacement (TAVR). However, studies that have DAPT with aspirin following TAVR have questioned this recommendation as DAPT has been associated with more bleeding events compared to aspirin. We performed a systematic review and meta-analysis of all the RCTs comparing DAPT (aspirin plus clopidogrel) with aspirin alone as antithrombotic treatment following transcatheter aortic valve replacement.

METHODS

The databases of Embase, PubMed, and Cochrane library were searched from inception to Oct 1, 2020, and randomized controlled trials (RCTs) reporting aspirin plus clopidogrel with aspirin alone as antithrombotic treatment after TAVI were included. Revman 5.3 was used to conduct the analysis.

RESULTS

After screening 152 articles, four studies involving 1086 patients (541 patients in the aspirin group and 545 patients in the DAPT group) were included. The results demonstrated that, at 30 days follow-up, compared with DAPT, aspirin was not associated with a statistically significant difference in the rate of bleeding events (RR = 1.22, 95% CI 0.62 to 2.39, P = 0.57), all-cause mortality (RR = 1.21, 95% CI 0.52 to 2.84, P = 0.66), stroke (RR = 0.81, 95% CI 0.24 to 2.79, P = 0.74), and MI (RR = 4.00, 95% CI 0.45 to 35.22, P = 0.21). However, at the 6 to 12 months follow-up, DAPT appeared to increase the risk of bleeding events compared with aspirin alone (RR = 1.67, 95% CI 1.24 to 2.24, P < 0.001), and there was no significant difference in the rate of all-cause mortality (RR = 0.89, 95% CI 0.53 to 1.48, P = 0.65), stroke (RR = 1.04, 95% CI 0.57 to 1.92, P = 0.90), and MI (RR = 1.65, 95% CI 0.52 to 5.26, P = 0.40) among the two groups.

CONCLUSIONS

Our systematic review and meta-analysis suggested that aspirin alone could decrease the risk of bleeding and was not associated with higher risk of mortality, stroke or myocardial infarction compared with DAPT.

Adjunctive Antithrombotic Therapy for Patients With Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Importance

Transcatheter aortic valve replacement (TAVR) is an established alternative to surgery for patients with severe symptomatic aortic stenosis. Adjunctive antithrombotic therapy used to mitigate thrombotic risks in patients undergoing TAVR must be balanced against bleeding complications, since both are associated with increased mortality.

Observation

Stroke risk associated with TAVR is lower than that associated with surgical aortic valve replacement in recent trials including patients at intermediate or low risk, but it is constant beginning at the time of implant and accrues over time based on patient risk factors. Patients with aortic stenosis undergoing TAVR also have a sizable risk of life-threatening or major bleeding. Although dual antiplatelet therapy for 3 to 6 months after TAVR is the guideline-recommended regimen, this practice is not well supported by current evidence. In patients with no indication for oral anticoagulation, current registry-based evidence suggests that single antiplatelet therapy may be safer than dual antiplatelet therapy. Similarly, oral anticoagulation monotherapy appears superior to anticoagulation plus antiplatelet therapy in those where oral anticoagulant use is indicated. To date, no risk prediction models have been established to guide antithrombotic therapy.

Conclusions and Relevance

Despite the growing volume of TAVR procedures to treat patients with severe aortic stenosis, evidence for adjunctive antithrombotic therapy remains rather scarce. Ongoing clinical trials will provide better understanding to guide antithrombotic therapy.

Antithrombotic selection in patients undergoing transcatheter aortic valve replacement

PURPOSE

Clinical controversy regarding the most appropriate antithrombotic regimen after transcatheter aortic valve replacement remains. Current evidence, guidelines, and recommendations are discussed.

SUMMARY

Antithrombotic selection following transcatheter aortic valve replacement depends on a variety of patient-specific factors. For patients without a preexisting indication for anticoagulation, initial trials employed dual antiplatelet therapy as the postprocedural therapy of choice. Newer studies in this patient population, however, suggest single antiplatelet therapy reduces bleeding events without sacrificing ischemic protection. In patients with a preexisting indication for anticoagulation, warfarin plus single antiplatelet therapy, as opposed to triple antithrombotic therapy, offered similar ischemic protection while reducing clinically significant bleeding. Warfarin monotherapy was associated with a further reduction in bleeding events. One trial demonstrated the safety and efficacy of using apixaban in patients with concomitant atrial fibrillation; however, routine use of rivaroxaban increased adverse cardiac and bleeding events, leaving the utility of direct-acting oral anticoagulants in question.

CONCLUSION

Available evidence and current guidelines point to a lack of consensus regarding antithrombotic selection after transcatheter aortic valve replacement. Patient-specific factors and comorbidities must be considered when tailoring therapy, with an emphasis on balancing thrombotic and bleeding risks.

Leaflet thrombosis after valve-in-valve transcatheter aortic valve implantation: a case series

Background

Valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) in degenerated surgical aortic valve replacement (SAVR) is an alternative to redo-SAVR. However, reports on leaflet thrombosis following ViV-TAVI are emerging and subclinical thrombosis has gained recent attention. Although the incidence of transcatheter heart valve (THV) thrombosis after TAVI for native aortic valve disease is low, current imaging studies suggest the incidence of subclinical THV thrombosis may be significantly higher. While anticoagulation strategies for THV patients for native aortic stenosis presenting with symptomatic obstructive thrombosis has been described, the optimal management and anticoagulation therapy of patients with THV thrombosis following ViV-TAVI are less evident.

Case summary

We report a case series of three patients presenting with early and late THV thrombosis after ViV-TAVI. Two patients presented clinically on single antiplatelet therapy and one patient presented with subclinical valve thrombosis whilst taking a non-vitamin K oral anticoagulation agent.

Discussion

Leaflet thrombosis after ViV-TAVI is an important cause of THV degeneration and may present subclinically. Imaging modalities such as serial transthoracic echocardiograms and multidetector computerized tomography aid diagnosis and guide management. Patient-individualized risk- vs. -benefit prophylactic post-procedural oral anticoagulation may be indicated.

Short-term dual anti-platelet therapy decreases long-term cardiovascular mortality after transcatheter aortic valve replacement

No data are available on extended dual anti-platelet therapy (DAPT) duration which may influence long-term prognosis (later than 1 year) after transcatheter aortic valve replacement (TAVR). Therefore, this study is aimed to evaluate whether discontinuing DAPT within 1 year had an impact on adverse events after TAVR. Using data from the OCEAN-TAVI registry, we assessed 1008 patients who survived the first year after TAVR with DAPT since discharge. Patients were divided into 'DAPT group' (n = 462), comprising patients who took DAPT at both discharge and 1 year, and 'stop-DAPT group' (n = 546), comprising patients who took DAPT at discharge and single anti-platelet therapy (SAPT) at 1 year. We compared the incidence of cardiovascular (CV) death, major and minor bleeding, and ischemic stroke later than 1 year after TAVR between the two groups. A total of 28 CV deaths were observed later than 1 year after TAVR. The stop-DAPT group had a significantly lower incidence of CV death than the DAPT group (1.8% vs. 4.9%, log-rank P = 0.029). Stop DAPT was associated with lower CV death later than 1 year of TAVR in Cox regression analysis (adjusted hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.20-0.99), and in analysis with inverse probability of treatment weighting method using propensity score (adjusted HR, 0.45; 95% CI, 0.20-0.98). Our study demonstrated that switching from DAPT to SAPT within 1 year of TAVR was significantly associated with a lower CV death later than 1 year after TAVR.

Antithrombotic Therapy After Transcatheter Aortic Valve Replacement

The performance of transcatheter aortic valve replacement has expanded considerably during the past decade. Technological advances and refinement in implantation techniques have resulted in improved procedural outcomes, whereas indications are progressively extending toward lower-risk patients. Ischemic/embolic complications and major bleeding remain important and strongly correlate to mortality. In this regard, the optimal antithrombotic regimen after successful transcatheter aortic valve replacement remains unclear, in the absence of randomized trials. For patients without an indication for oral anticoagulation, empirical treatment with dual antiplatelet therapy (aspirin plus clopidogrel) for 3 to 6 months is currently recommended. However, dual antiplatelet therapy has been preliminarily associated with increased risk of bleeding compared with single antiplatelet therapy without significant ischemic benefit. Non-vitamin K oral anticoagulants and warfarin have also entered clinical investigation, to address the issue of preexisting or new-onset of atrial fibrillation and potentially attenuate subclinical leaflet thrombosis. Clinical trials are necessary to systematically address the risks and benefits of these approaches. In this review, we present the pathophysiological mechanisms of post-transcatheter aortic valve replacement complications and provide updated insights on the rationale behind the various antithrombotic regimens being currently evaluated in large randomized trials.

Assessment of Platelet REACtivity After Transcatheter Aortic Valve Replacement: The REAC-TAVI Trial

OBJECTIVES

The REAC-TAVI (Assessment of platelet REACtivity after Transcatheter Aortic Valve Implantation) trial enrolled patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) pre-treated with aspirin + clopidogrel, aimed to compare the efficacy of clopidogrel and ticagrelor in suppressing high platelet reactivity (HPR) after TAVI.

BACKGROUND

Current recommendations support short-term use of aspirin + clopidogrel for patients with severe AS undergoing TAVR despite the lack of compelling evidence.

METHODS

This was a prospective, randomized, multicenter investigation. Platelet reactivity was measured at 6 different time points with the VerifyNow assay (Accriva Diagnostics, San Diego, California). HPR was defined as (P2Y₁₂ reaction units (PRU) ≥208. Patients with HPR before TAVR were randomized to either aspirin + ticagrelor or aspirin + clopidogrel for 3 months. Patients without HPR continued with aspirin + clopidogrel (registry cohort). The primary endpoint was non-HPR status (PRU <208) in ≥70% of patients treated with ticagrelor at 90 days post-TAVR.

RESULTS

A total of 68 patients were included. Of these, 48 (71%) had HPR (PRU 273 ± 09) and were randomized to aspirin + ticagrelor (n = 24, PRU 277 ± 08) or continued with aspirin + clopidogrel (n = 24, PRU 269 ± 49). The remaining 20 patients (29%) without HPR (PRU 133 ± 12) were included in the registry. Overall, platelet reactivity across all the study time points after TAVR was lower in patients randomized to ticagrelor compared with those treated with clopidogrel, including those enrolled in the registry (p < 0.001). The primary endpoint was achieved in 100% of patients with ticagrelor compared with 21% with clopidogrel (p < 0.001). Interestingly, 33% of clopidogrel responder patients at baseline developed HPR status during the first month after TAVR.

CONCLUSIONS

HPR to clopidogrel is present in a considerable number of patients with AS undergoing TAVR. Ticagrelor achieves a better and faster effect, providing sustained suppression of HPR to these patients. (Platelet Reactivity After TAVI: A Multicenter Pilot Study [REAC-TAVI]; NCT02224066).

Determining the Predominant Lesion in Patients With Severe Aortic Stenosis and Coronary Stenoses: A Multicenter Study Using Intracoronary Pressure and Flow

Patients with severe aortic stenosis (AS) often have coronary artery disease. Both the aortic valve and the coronary disease influence the blood flow to the myocardium and its ability to respond to stress; leading to exertional symptoms. In this study, we aim to quantify the effect of severe AS on the coronary microcirculation and determine if this is influenced by any concomitant coronary disease. We then compare this to the effect of coronary stenoses on the coronary microcirculation.

Adjunct Pharmacotherapy After Transcatheter Aortic Valve Replacement: Current Status and Future Directions

Transcatheter aortic valve replacement (TAVR) is a validated treatment option for severe aortic stenosis. Ischemic and thrombotic complications remain important and strongly correlate with mortality. The optimal postprocedural antithrombotic strategy for prevention of thrombotic events remains unclear. The international guidelines for medical management following TAVR are discordant, allowing for significant variance in prescribing habits. The optimal treatment strategy has yet to be delineated. Clinical trials are ongoing to assess the risks and benefits of various strategies. We discuss the pathobiology and rationale for antithrombotic therapy after TAVR, review current evidence and guidelines, and offer a concise evidence-based approach to this subject.

Clinical Outcomes after Transcatheter Aortic Valve Replacement in Cancer Survivors Treated with Ionizing Radiation

BACKGROUND

Improved cancer survival in patients treated with thoracic ionizing radiation (XRT) has resulted in unanticipated surge of aortic stenosis. Transcatheter aortic valve replacement (TAVR) has revolutionized the management of severe aortic stenosis. However, long-term clinical outcomes in radiation-exposed cohorts undergoing TAVR are unknown. We compared the all-cause mortality and major adverse cardiac events (MACE) in patients with prior chest XRT (C-XRT) undergoing TAVR.

METHODS

This is an observational cohort study in subjects who underwent TAVR for symptomatic severe aortic stenosis from 2012 to 2017 in a tertiary care referral center. We examined the all-cause mortality and MACE using cox proportional hazard analysis to identify the clinical predictors of survival in the cohort of patients who had a history of prior C-XRT for malignancy.

RESULTS

Of the 610 patients who underwent TAVR for symptomatic severe aortic stenosis, 75 had prior C-XRT. The majority of C-XRT patients had prior breast cancer (44%) followed by Hodgkin's lymphoma (31%), with the median time from XRT to TAVR of 19.0 years. During a mean follow up of 17.1 months after TAVR, all-cause mortality was 17%. Those with prior C-XRT had higher all-cause mortality (XRT: 29%; non-XRT:15%, p<0.01) and MACE (XRT: 57%; non-XRT: 27%, p<0.001) after TAVR. Patients with prior XRT had a higher incidence of atrial fibrillation (XRT: 48 %; non-XRT: 2.4%, p<0.01) and high-grade heart block (XRT: 20%; non-XRT: 9.1%, p=0.007) requiring pacemaker implant after TAVR. On multivariate cox proportional hazard analysis, prior XRT (HR: 2.07, p=0.003), poor renal function (HR: 1.29, p<0.001) and post-operative anemia requiring transfusion (HR: 1.16, p:0.001) were the strongest predictors of reduced survival.

CONCLUSIONS

Cancer survivors with prior C- XRT have higher incidence of all-cause mortality and MACE after TAVR. Careful patient selection and follow-up strategies are needed to improve outcomes.

Association Between Transcatheter Aortic Valve Replacement and Early Postprocedural Stroke

IMPORTANCE

Reducing postprocedural stroke is important to improve the safety of transcatheter aortic valve replacement (TAVR).

OBJECTIVE

This study evaluated the trends of stroke occurring within 30 days after the procedure during the first 5 years TAVR was used in the United States, the association of stroke with 30-day mortality, and the association of medical therapy with 30-day stroke risk.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study including 101 430 patients who were treated with femoral and nonfemoral TAVR at 521 US hospitals in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry from November 9, 2011, through May 31, 2017. Thirty-day follow-up ended June 30, 2017.

EXPOSURES

TAVR.

MAIN OUTCOMES AND MEASURES

The rates of 30-day transient ischemic attack and stroke were assessed. Association of stroke with 30-day mortality and association of antithrombotic medical therapies with postdischarge 30-day stroke were assessed with a Cox proportional hazards model and propensity-score matching, respectively.

RESULTS

Among 101 430 patients included in the study (median age, 83 years [interquartile range {IQR}, 76-87 years]; 47 797 women [47.1%]; and 85 147 patients [83.9%] treated via femoral access), 30-day postprocedure follow-up data was assessed in all patients. At day 30, there were 2290 patients (2.3%) with a stroke of any kind (95% CI, 2.2%-2.4%), and 373 patients (0.4%) with transient ischemic attacks (95% CI, 0.3%-0.4%) . During the study period, 30-day stroke rates were stable without an increasing or decreasing trend in all patients (P for trend = .22) and in the large femoral access subgroup (P trend = .47). Among cases of stroke within 30 days, 1119 strokes (48.9%) occurred within the first day and 1567 (68.4%) within 3 days following TAVR. The occurrence of stroke was associated with a significant increase in 30-day mortality: 383 patients (16.7%) of 2290 who had a stroke vs 3662 patients (3.7%) of 99 140 who did not have a stroke died (P < .001; risk-adjusted hazard ratio [HR], 6.1 [95% CI, 5.4-6.8]; P < .001). After propensity-score matching, 30-day stroke risk was not associated with whether patients in the femoral cohort were (0.55%) or were not (0.52%) treated with dual antiplatelet therapy at hospital discharge (HR, 1.04; 95% CI, 0.74-1.46) nor was it associated with whether patients in the nonfemoral cohort were (0.71%) or were not (0.69%) treated with dual antiplatelet therapy (HR, 1.02; 95% CI, 0.54-1.95). Similarly, 30-day stroke risk was not associated with whether patients in the femoral cohort were (0.57%) or were not (0.55) treated with oral anticoagulant therapy at hospital discharge (HR, 1.03; 95% CI, 0.73-1.46) nor was it associated with whether patients in the nonfemoral cohort were (0.75%) or were not (0.82%) treated with an oral anticoagulant (HR, 0.93; 95% CI, 0.47-1.83).

CONCLUSIONS AND RELEVANCE

Between 2011 and 2017, the rate of 30-day stroke following transcatheter aortic valve replacement in a US registry population remained stable.

Usefulness of Clopidogrel Loading in Patients Who Underwent Transcatheter Aortic Valve Implantation (from the BRAVO-3 Randomized Trial)

P2Y₁₂-inhibitor initiation with clopidogrel using a loading dose (LD) versus no LD (NLD) provides more rapid inhibition of platelet activation and reduced risk of ischemic events after coronary stenting. Whether a similar beneficial effect is achieved in the setting of transcatheter aortic valve implantation (TAVI) is unknown. We evaluate the effects of preprocedural clopidogrel LD versus no NLD on 48-hour and 30-day clinical outcomes after TAVI. In the BRAVO-3 trial, 802 patients with severe aortic stenosis who underwent transfemoral TAVI were randomized to intraprocedural anticoagulation with bivalirudin or unfractionated heparin. Administration of clopidogrel LD was left to the discretion of the treating physician. For this analysis, patients were stratified according to receiving clopidogrel LD (n = 294, 36.6%) or NLD (n = 508, 63.4%) before TAVI. LD patients more often received a self-expandable prosthesis using larger sheaths. P2Y₁₂-inhibitor maintenance therapy pre-TAVI was similar in patients with LD versus NLD (28.2% vs 33.1%, p = 0.16). LD versus NLD was associated with similar incidences of major adverse cardiovascular events (i e., death, myocardial infarction, or stroke) (4.1% vs 4.1%, p = 0.97) and major bleeding (8.5% vs 7.7%, p = 0.68), but a higher rate of major vascular complications (11.9% vs 7.1%, p = 0.02). Multivariable adjustment showed that clopidogrel LD did not affect any of the studied clinical events, including major vascular complications (odds ratio 0.91, 95% confidence interval 0.60 to 1.39, p = 0.67). Also patients on clopidogrel maintenance therapy and thus considered in steady state were not at reduced risk of major adverse cardiovascular events compared with patients not on clopidogrel (3.7% vs 5.2%, p = 0.36). In conclusion, in patients who underwent TAVI, use of clopidogrel LD was associated with higher vascular complications and otherwise similar clinical events compared to NLD patients.

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.

Left Atrial Appendage Occlusion in High Bleeding Risk Patients

Objectives

The aim of this study was to investigate the outcomes of left atrial appendage occlusion (LAAO) in high bleeding risk patients suffering atrial fibrillation (AF) and to analyze the different antithrombotic therapies following the intervention.

Background. Methods

This monocentric study included 68 patients with nonvalvular AF with an absolute contraindication to OAT or at high bleeding risk. Follow-up was done with a clinical visit at 3-6-12 months.

Results

Successful LAAO was achieved in 67/68 patients. At discharge, 32/68 patients were on dual antiplatelet therapy (APT), 34/68 were without any antithrombotic therapy or with a single antiplatelet drug, and 2/68 were on anticoagulant therapy. At three-month follow-up visit, 73.6% of the patients did not receive dual APT, of whom 14.7% had no thrombotic therapy and 58.9% were on single antiplatelet therapy. During a follow-up of 1.4 ± 0.9 years, 3/62 patients had late adverse effects (2 device-related thrombus without clinical consequences and 1 extracranial bleeding). The device-related thrombosis was not related to the antithrombotic therapy.

Conclusions

LAAO is feasible and safe and prevents stroke in patients with AF with contraindication to oral anticoagulant therapy. After LAAO, single antiplatelet therapy seems to be a safe alternative to dual antiplatelet therapy, especially in patients at high bleeding risk. No benefit has been observed with dual APT.

Dual antiplatelet therapy after TAVR: A drop in the bucket?

Current guidelines recommend a three- to six-months dual antiplatelet therapy (DAPT) in patients undergoing transcatheter aortic valve replacement (TAVR) or to continue with oral anticoagulant agents (OAC) if already indicated before procedure. However, recent studies showed that treatment with aspirin has the same efficacy of DAPT but it was associated with a significant reduction of major bleeding. Furthermore, half of cerebrovascular events, occurring >24 h after procedure, may be related to new onset of atrial fibrillation or to subclinical leaflets thrombosis and they may be prevented by use of OAC rather than antiplatelet therapy. In absence of very high bleeding risk and of recent percutaneous coronary intervention, the use of OAC over SAPT or DAPT might theoretically be considered in patients undergoing TAVR waiting for results of ongoing clinical trials.

Simplification and optimization of transcatheter aortic valve implantation - fast-track course without compromising safety and efficacy

Transcatheter aortic valve implantation (TAVI) has become an established therapeutic option for patients with symptomatic, severe aortic valve stenosis. Ageing of the Western and Asian population and expansion of indications for TAVI will lead to a substantial increase in the number of TAVI procedures performed worldwide within the next decades. In line with the maturation of TAVI over the past few years, there has also been a significant simplification and optimisation of the TAVI procedure. A minimalist TAVI procedure and fast-track TAVI course have been shown to have distinct advantages over the more traditional TAVI approach. The aim of this manuscript is to discuss strategies of TAVI simplification and optimization, with special focus on fast-track TAVI, without compromising safety and efficacy.