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.

The importance of the Heart Team evaluation before transcatheter aortic valve replacement: Results from the BRAVO-3 trial

BACKGROUND/OBJECTIVES

Clinicians use validated scores to risk-stratify patients undergoing transcatheter aortic valve replacement (TAVR). However, evaluation by the Heart Team often deems patients to be at higher risk than their formal scores suggest. We sought to assess clinical outcomes of TAVR patients defined as high-risk by the Heart Team's assessment versus the patient's logistic EuroSCORE (LES).

METHODS

The BRAVO-3 trial randomized patients at high risk (LES ≥ 18, or deemed inoperable by the Heart Team) to TAVR with periprocedural anticoagulation with unfractionated heparin versus bivalirudin. Endpoints included net adverse cardiac events (NACE: the composite of all-cause mortality, MI, stroke, or bleeding), major adverse cardiovascular events (MACE: death, MI, or stroke), the individual components of MACE, major vascular complications, BARC ≥ 3b bleeding and VARC life-threatening bleeding at 30 days. We compared patients deemed high-risk based on LES ≥ 18 versus high-risk by the Heart Team despite lower LES.

RESULTS

A total of 467/800 (58.4%) patients were deemed high-risk by the Heart Team despite LES < 18. After multivariable analysis, there were no differences in the odds of endpoints between groups (NACE, OR_LES≥18 : 1.32, 95% CI 0.86-2.02, p = .21; MACE, OR_LES≥18 : 1.27, 95% CI 0.72-2.25, p = .41; major vascular complications, OR_LES≥18 : 0.97, 95% CI 0.65-1.44, p = .88; BARC ≥3b, OR_LES≥18 : 1.38, 95% CI 0.82-2.33, p = .23; and VARC life-threatening bleeding, OR_LES≥18 : 0.99, 95% CI 0.69-1.41, p = .95).

CONCLUSION

Patients undergoing TAVR and labeled high-risk by LES ≥ 18 or Heart Team assessment despite LES < 18 have comparable short-term outcomes. Assignment of high-risk status to over 50% of patients is attributable to Heart Team's clinical assessment.

A Controlled Trial of Rivaroxaban after Transcatheter Aortic-Valve Replacement

BACKGROUND

Whether the direct factor Xa inhibitor rivaroxaban can prevent thromboembolic events after transcatheter aortic-valve replacement (TAVR) is unclear.

METHODS

We randomly assigned 1644 patients without an established indication for oral anticoagulation after successful TAVR to receive rivaroxaban at a dose of 10 mg daily (with aspirin at a dose of 75 to 100 mg daily for the first 3 months) (rivaroxaban group) or aspirin at a dose of 75 to 100 mg daily (with clopidogrel at a dose of 75 mg daily for the first 3 months) (antiplatelet group). The primary efficacy outcome was the composite of death or thromboembolic events. The primary safety outcome was major, disabling, or life-threatening bleeding. The trial was terminated prematurely by the data and safety monitoring board because of safety concerns.

RESULTS

After a median of 17 months, death or a first thromboembolic event (intention-to-treat analysis) had occurred in 105 patients in the rivaroxaban group and in 78 patients in the antiplatelet group (incidence rates, 9.8 and 7.2 per 100 person-years, respectively; hazard ratio with rivaroxaban, 1.35; 95% confidence interval [CI], 1.01 to 1.81; P = 0.04). Major, disabling, or life-threatening bleeding (intention-to-treat analysis) had occurred in 46 and 31 patients, respectively (4.3 and 2.8 per 100 person-years; hazard ratio, 1.50; 95% CI, 0.95 to 2.37; P = 0.08). A total of 64 deaths occurred in the rivaroxaban group and 38 in the antiplatelet group (5.8 and 3.4 per 100 person-years, respectively; hazard ratio, 1.69; 95% CI, 1.13 to 2.53).

CONCLUSIONS

In patients without an established indication for oral anticoagulation after successful TAVR, a treatment strategy including rivaroxaban at a dose of 10 mg daily was associated with a higher risk of death or thromboembolic complications and a higher risk of bleeding than an antiplatelet-based strategy. (Funded by Bayer and Janssen Pharmaceuticals; GALILEO ClinicalTrials.gov number, NCT02556203.).

Reduced Leaflet Motion after Transcatheter Aortic-Valve Replacement

BACKGROUND

Subclinical leaflet thickening and reduced leaflet motion of bioprosthetic aortic valves have been documented by four-dimensional computed tomography (CT). Whether anticoagulation can reduce these phenomena after transcatheter aortic-valve replacement (TAVR) is not known.

METHODS

In a substudy of a large randomized trial, we randomly assigned patients who had undergone successful TAVR and who did not have an indication for long-term anticoagulation to a rivaroxaban-based antithrombotic strategy (rivaroxaban [10 mg] plus aspirin [75 to 100 mg] once daily) or an antiplatelet-based strategy (clopidogrel [75 mg] plus aspirin [75 to 100 mg] once daily). Patients underwent evaluation by four-dimensional CT at a mean (±SD) of 90±15 days after randomization. The primary end point was the percentage of patients with at least one prosthetic valve leaflet with grade 3 or higher motion reduction (i.e., involving >50% of the leaflet). Leaflet thickening was also assessed.

RESULTS

A total of 231 patients were enrolled. At least one prosthetic valve leaflet with grade 3 or higher motion reduction was found in 2 of 97 patients (2.1%) who had scans that could be evaluated in the rivaroxaban group, as compared with 11 of 101 (10.9%) in the antiplatelet group (difference, -8.8 percentage points; 95% confidence interval [CI], -16.5 to -1.9; P = 0.01). Thickening of at least one leaflet was observed in 12 of 97 patients (12.4%) in the rivaroxaban group and in 33 of 102 (32.4%) in the antiplatelet group (difference, -20.0 percentage points; 95% CI, -30.9 to -8.5). In the main trial, the risk of death or thromboembolic events and the risk of life-threatening, disabling, or major bleeding were higher with rivaroxaban (hazard ratios of 1.35 and 1.50, respectively).

CONCLUSIONS

In a substudy of a trial involving patients without an indication for long-term anticoagulation who had undergone successful TAVR, a rivaroxaban-based antithrombotic strategy was more effective than an antiplatelet-based strategy in preventing subclinical leaflet-motion abnormalities. However, in the main trial, the rivaroxaban-based strategy was associated with a higher risk of death or thromboembolic complications and a higher risk of bleeding than the antiplatelet-based strategy. (Funded by Bayer; GALILEO-4D ClinicalTrials.gov number, NCT02833948.).

2349Selatogrel, a novel P2Y12 inhibitor for emergency use, achieves rapid, consistent and sustained platelet inhibition following single-dose subcutaneous administration in stable CAD patients

Background

In the setting of AMI, rapid platelet inhibition is desirable but the onset of pharmacodynamic (PD) effect of oral platelet P2Y12 inhibitors is delayed, sometimes for hours. Subcutaneous (s.c) administration of a rapidly-acting P2Y12 inhibitor would overcome many of the limitations of available therapies. Patients with stable CAD were investigated initially.

Purpose

To characterise the inhibition of platelet aggregation and pharmacokinetics (PK) of a single dose of selatogrel, a novel s.c P2Y12 inhibitor, in patients with stable CAD.

Methods

Patients with stable CAD receiving oral antiplatelet therapy (aspirin and/or oral P2Y12 inhibitor) were randomized to 1 of 8 groups based on treatment (selatogrel or matching placebo), dose (8 mg or 16 mg) and s.c injection site (thigh or abdomen). Venous blood samples were collected into PPACK anticoagulant tubes. Platelet reactivity was assessed by VerifyNow PRU (P2Y12 reaction units) test before and 15 min, 30 min and 1, 2, 4, 8 and 24 h after injection. Light-transmittance aggregometry (LTA; ADP 20 uM) was also performed. PK samples were collected up to 24 h post-dose. Adverse events occurring within 30 days were recorded. Responders were defined as having PRU <100 at 30 min after injection and lasting ≥3 h.

Results

345 patients (mean age 65 y; 20% female; 31% diabetes) received selatogrel 8 mg (n=114), selatogrel 16 mg (n=115) or placebo (n=116). 97% were on background therapy with aspirin (or its derivative carbasalate) and 35% with oral P2Y12 inhibitor (clopidogrel 23%, prasugrel 4%, ticagrelor 8%). 89% of subjects were responders to selatogrel 8 mg, 90% to selatogrel 16 mg and 16% to placebo (P<0.0001). At 15 min post-dose, PRU values (mean±SD) were 10±25 with selatogrel 8 mg, 5±10 with selatogrel 16 mg and 163±73 with placebo (Figure). PRU levels were maintained at 2 and 4 h for both doses and gradually returned to pre-dose levels by 24 h post-dose (Figure). LTA results were consistent with the VerifyNow results. PD responses were similar for thigh and abdomen injection sites. Selatogrel was well tolerated: mild dyspnoea (or moderate dyspnoea, n=1, with 16 mg) occurred in 5% and 9% with selatogrel 8 mg and 16 mg, respectively, vs 0% with placebo; dizziness occurred in 4% and 4% vs 1%, respectively, without significant haemodynamic or ECG changes. Bleeding events occurred in 9.6% and 4.3% with selatogrel 8 mg and 16 mg, respectively, vs 6.9% with placebo. Pharmacokinetic data will be presented.

Conclusions

Selatogrel has a rapid PD effect following s.c injection in patients with stable CAD, within 15 min in most patients. The consistent and high levels of P2Y12 inhibition with a single 8 mg or 16 mg dose are sustained for over 4 hours, following which platelet reactivity progressively recovers over 24 h. Selatogrel was well tolerated, with mostly mild, transient dyspnoea observed in <10% patients. These data support further studies of selatogrel for emergency treatment of AMI patients.

Acknowledgement/Funding

Fully funded by Idorsia Pharmaceuticals Ltd

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.

Transfemoral PCI skill: Use it or lose it.….But #RadialFirst

Despite, earlier concerns, is the article by Badri et al., there was no apparent increase in the rate of vascular complications with transfemoral percutaneous coronary intervention (PCI) associated with increasing levels of adoption of transradial PCI by individuals initially identified as primarily femoral operators (> 90% of PCI's via the femoral artery). Compared with the 2010-2011 period, patients undergoing PCI in the United States in 2014-2015 tended to be generally sicker. This fact, coupled with a liberalization in bleeding definition, likely led to an overall increase in the observed rate of vascular complications post-transfemoral PCI (from 1.3 to 1.64%) across the study time period. Despite the extensive body of evidence supporting the use of transradial over transfemoral PCI access, the vast majority (>80%) of primarily femoral operators in the United States have remained low radial adopters and the overall proportion of PCIs performed transradially across this time period by primarily transfemoral operators increased significantly, yet modestly (from 1.3 to 17.8%).

Geographical Variations in Patterns of DAPT Cessation and Two-Year PCI Outcomes: Insights from the PARIS Registry

BACKGROUND

Data on geographical variations in dual antiplatelet therapy (DAPT) cessation and the impact on outcomes after percutaneous coronary intervention (PCI) are limited. We sought to evaluate geographical patterns of DAPT cessation and associated outcomes in patients undergoing PCI in the United States versus Europe.

METHODS

Analyzing data from the PARIS registry, we studied 3,660 U.S. patients (72.9%) and 1,358 European patients (27.1%) that underwent PCI with stent implantation. DAPT cessation was classified as physician-recommended discontinuation, interruption (< 14 days), or disruption due to bleeding or noncompliance. The primary endpoint was 2-year major adverse cardiovascular events (MACE) defined as a composite of cardiac death, stent thrombosis, myocardial infarction, or target lesion revascularization.

RESULTS

Cardiovascular risk factors were more common in the United States, whereas procedural complexity was greater in Europe. The incidence of 2-year DAPT discontinuation was significantly lower in U.S. versus European patients (30.7% vs. 65.6%; p < 0.001); however, rates of interruption (13.7% vs. 1.5%, p < 0.001) and disruption (17.7% vs. 5.1%, p < 0.001) were higher. DAPT discontinuation was associated with lower adjusted risk, whereas DAPT disruption was associated with greater risk for 2-year MACE, without interaction by region. After adjustment for baseline characteristics and DAPT cessation, 2-year MACE risk was not statistically different between regions (10.3% for Europe vs. 11.9% for U.S., adjusted hazard ratio 0.81, 95% confidence interval 0.65-1.01, p = 0.065).

CONCLUSION

DAPT cessation patterns, along with clinical and angiographic risk, vary substantially between PCI patients in the U.S. versus Europe. Despite such differences, cardiovascular risk associated with DAPT cessation remains uniform.

Impact of Diabetes Mellitus in Women Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents

BACKGROUND

Data examining the impact of diabetes mellitus (DM) on ischemic risk after percutaneous coronary intervention in women are limited as most clinical trial participants are male. We evaluated (1) the impact of DM on ischemic outcomes in women undergoing drug-eluting stent (DES) implantation and (2) whether the outcomes of new- versus early-generation DES vary by DM status.

METHODS AND RESULTS

We pooled patient-level data of 10 448 women undergoing percutaneous coronary intervention with DES from 26 randomized trials. Baseline characteristics and 3-year clinical outcomes were stratified according to DM status (noninsulin-dependent and insulin-dependent) and DES generation. The primary end point was the composite of all-cause death or myocardial infarction. Secondary end points were definite or probable stent thrombosis and target lesion revascularization. Compared with women without DM (n=7154, 68.5%), adjusted risks (adjusted hazard ratios [95% CI]) for death or myocardial infarction among women with noninsulin-dependent DM (n=2241, 21.4%) and insulin-dependent DM (n=1053, 10.1%) were 1.30 (1.11-1.53) and 1.71 (1.41-2.07), respectively ( P_trend<0.001). Similar trends were observed for def/prob stent thrombosis and target lesion revascularization. Compared with early-generation DES, use of newer-generation DES was associated with significant reductions in death or myocardial infarction in the absence of DM whereas differences were nonsignificant in the presence of DM, with similar findings for def/prob stent thrombosis and target lesion revascularization.

CONCLUSIONS

The presence of DM is associated with substantial, graded, and durable risks for ischemic events among women undergoing percutaneous coronary intervention with DES. The safety and efficacy profile of newer-generation DES is preserved among women without DM, while benefits are nonsignificant among women with DM.

Ischemia-reperfusion injury and ischemic post-conditioning in acute myocardial infarction: Lost in translation

Ischemic post-conditioning (IPoC) has been proposed as a strategy to mitigate the risk of ischemia-reperfusion injury during primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). In this comprehensive and updated meta-analysis of randomized controlled trials, IPoC during primary PCI for STEMI had no significant effect on all-cause mortality, re-infarction, or new-onset heart failure compared with no post-conditioning. Further strategies need to be prospectively evaluated to improve outcomes in patients with STEMI undergoing primary PCI.

Long-term Safety and Efficacy of New-Generation Drug-Eluting Stents in Women With Acute Myocardial Infarction: From the Women in Innovation and Drug-Eluting Stents (WIN-DES) Collaboration

Importance

Women with acute myocardial infarction (MI) undergoing mechanical reperfusion remain at increased risk of adverse cardiac events and mortality compared with their male counterparts. Whether the benefits of new-generation drug-eluting stents (DES) are preserved in women with acute MI remains unclear.

Objective

To investigate the long-term safety and efficacy of new-generation DES vs early-generation DES in women with acute MI.

Design, Setting, and Participants

Collaborative, international, individual patient-level data of women enrolled in 26 randomized clinical trials of DES were analyzed between July and December 2016. Only women presenting with an acute coronary syndrome were included. Study population was categorized according to presentation with unstable angina (UA) vs acute MI. Acute MI included non-ST-segment elevation MI (NSTEMI) or ST-segment elevation MI (STEMI).

Interventions

Randomization to early- (sirolimus- or paclitaxel-eluting stents) vs new-generation (everolimus-, zotarolimus-, or biolimus-eluting stents) DES.

Main Outcomes and Measures

Composite of death, MI or target lesion revascularization, and definite or probable stent thrombosis at 3-year follow-up.

Results

Overall, the mean age of participants was 66.8 years. Of 11 577 women included in the pooled data set, 4373 (37.8%) had an acute coronary syndrome as clinical presentation. Of these 4373 women, 2176 (49.8%) presented with an acute MI. In women with acute MI, new-generation DES were associated with lower risk of death, MI or target lesion revascularization (14.9% vs 18.4%; absolute risk difference, -3.5%; number needed to treat [NNT], 29; adjusted hazard ratio, 0.78; 95% CI, 0.61-0.99), and definite or probable stent thrombosis (1.4% vs 4.0%; absolute risk difference, -2.6%; NNT, 46; adjusted hazard ratio, 0.36; 95% CI, 0.19-0.69) without evidence of interaction for both end points compared with women without acute MI (P for interaction = .59 and P for interaction = .31, respectively). A graded absolute benefit with use of new-generation DES was observed in the transition from UA, to NSTEMI, and to STEMI (for death, MI, or target lesion revascularization: UA, -0.5% [NNT, 222]; NSTEMI, -3.1% [NNT, 33]; STEMI, -4.0% [NNT, 25] and for definite or probable ST: UA, -0.4% [NNT, 278]; NSTEMI, -2.2% [NNT, 46]; STEMI, -4.0% [NNT, 25]).

Conclusions and Relevance

New-generation DES are associated with consistent and durable benefits over 3 years in women presenting with acute MI. The magnitude of these benefits appeared to be greater per increase in severity of acute coronary syndrome.

Effect of Short Procedural Duration With Bivalirudin on Increased Risk of Acute Stent Thrombosis in Patients With STEMI: A Secondary Analysis of the HORIZONS-AMI Randomized Clinical Trial

Importance

Bivalirudin has been associated with reduced bleeding and mortality during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). However, increased rates of acute stent thrombosis (AST) have been noted when bivalirudin is discontinued at the end of the procedure, which is perhaps related to this medication's short half-life.

Objectives

To evaluate the clinical effect of procedure duration on AST when either bivalirudin or heparin plus glycoprotein IIb/IIIa receptor inhibitor (GPI) is used.

Design, Setting, and Participants

An ad hoc analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) clinical trial was performed between March 1, 2015, and April 30, 2016, on patients who underwent primary percutaneous coronary intervention with stents and were randomized 1:1 to bivalirudin or heparin plus GPI. Defined as the difference between the patient's arrival at the catheterization laboratory and the patient's final angiogram. Participants included 3602 patients with STEMI, aged 18 years or older, who were undergoing primary percutaneous coronary intervention and presenting less than 12 hours from symptom onset.

Main Outcomes and Measures

Clinical events committee-adjudicated definite AST (occurring ≤24 hours after percutaneous coronary intervention).

Results

Among patients included in this analysis, procedure time was identified in 1286 receiving bivalirudin and 1412 receiving heparin plus GPI. Shorter procedures were defined as the lowest quartile of duration (<45 minutes). Patients undergoing shorter procedures were younger and less likely to be hypertensive and smokers. Shorter procedures were less complicated with fewer stents implanted, less multivessel stenting, less thrombus, and less no-reflow. An increased risk of definite AST was associated with shorter than with longer procedures with bivalirudin (7 [2.1%] vs 7 [0.7%]; relative risk, 2.87; 95% CI, 1.01-8.17; P = .04) but not with heparin plus GPI (0 vs 3 [0.3%]; P = .30).

Conclusions and Relevance

Despite less procedural complexity, shorter primary percutaneous coronary intervention time was associated with an increased risk of AST in patients treated with bivalirudin but not patients treated with heparin plus GPI, possibly because of the rapid offset of bivalirudin's antithrombotic effect during a window of limited oral antiplatelet action.

Trial Registration

clinicaltrials.gov Identifier: NCT00433966.

Temporal Trends in Statin Prescriptions and Residual Cholesterol Risk in Patients With Stable Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

Intensive low-density lipoprotein cholesterol (LDL-C) reduction with statins is recommended after elective percutaneous coronary intervention (PCI). We aimed to evaluate adherence to guideline-recommended statin therapy (GRST) and the rate of residual cholesterol risk (RCR) at follow-up after elective PCI. All patients who underwent elective PCI between January 2010 and May 2016 were prospectively included in this single-center study. GRST was defined as high-intensity statin (HIS) therapy for patients ≤75 years old and moderate-intensity statin (MIS) or HIS therapy for patients >75 years. RCR at follow-up was defined as <50% decrease in LDL-C with HIS or <30% with MIS for statin-naïve patients and as LDL-C >70 mg/dL for nonstatin-naïve patients. A total of 2,653 patients were included, with 1,304 (49.2%) discharged with GRST. There was a significant increase in the number of patients discharged with GRST over time from 44.2% in 2010 to 63.0% in 2016 (p <0.001). Conversely, RCR at follow-up was present in 1,120 patients (42.2%) overall and remained stable over time. Risk factors of RCR at follow-up were female gender (odds ratio [OR]: 1.38; 95% confidence interval [CI] 1.13 to 1.70), previous myocardial infarction (OR: 1.37; 95% CI 1.12 to 1.64), smoking (OR: 1.30; 95% CI 1.01 to 1.67), higher LDL-C level at baseline (OR: 1.22; 95% CI 1.18 to 1.25). The presence of RCR was associated with an increased adjusted risk of death within 1 year of the second LDL-C measurement (adjHR: 2.78; 95% CI 1.15 to 6.67). In conclusion, although the rate of GRST at discharge has improved significantly over time in patients who underwent elective PCI, the prevalence of RCR at follow-up has not changed appreciably suggesting that further implementation of guidelines as well as novel or more intensive pharmacotherapy may be warranted.