Bicuspid valve CT registry of balloon-expandable TAVR: BETTER TAVR registry.

BACKGROUND: The anatomic substrate of bicuspid valves may lead to suboptimal TAVR stent expansion and geometry. AIM: We evaluated determinants of stent geometry in bicuspid valves treated with Sapien transcatheter aortic valve replacement (TAVR) valves. METHODS: A multicenter retrospective registry of patients (February 2019 to August 2022) who underwent post-TAVR computed tomography to determine stent area (vs. nominal valve area) and stent ellipticity (maximum diameter/minimum diameter). Predictors of relative stent expansion (minimum area/average of inflow + outflow area) and stent ellipticity were evaluated in a multivariable regression model, including valve calcium volume (indexed by annular area), presence of raphe calcium, sinus diameters indexed by area-derived annular diameter, and performance of pre-dilation and post-dilation. RESULTS: The registry enrolled 101 patients from four centers. The minimum stent area (vs. nominal area) was 88.1%, and the maximum ellipticity was 1.10, with both observed near the midframe of the valve in all cases. Relative stent expansion ≥90% was observed in 64/101 patients. The only significant predictor of relative stent expansion ≥90% was the performance of post-dilation (OR: 4.79, p = 0.018). Relative stent expansion ≥90% was seen in 86% of patients with post-dilation compared to 57% without (p < 0.001). The stent ellipticity ≥1.1 was observed in 47/101 patients. The significant predictors of stent ellipticity ≥1.1 were the indexed maximum sinus diameter (OR: 0.582, p = 0.021) and indexed intercommisural diameter at 4 mm (OR: 2.42, p = 0.001). Stent expansion has a weak negative correlation with post-TAVR mean gradient (r = -0.324, p < 0.001). CONCLUSION: Relative stent expansion ≥90% was associated with the performance of post-dilation, and stent ellipticity ≥1.1 was associated with indexed intercommisural diameter and indexed maximum sinus diameter. Further studies to determine optimal deployment strategies in bicuspid valves are needed.

Rivaroxaban and apixaban are less effective than enoxaparin for the prevention of catheter-induced clotting in vitro.

BACKGROUND: Central venous catheters are prone to clotting, particularly in patients with cancer. Although low-molecular-weight heparin and direct oral anticoagulants, such as apixaban and rivaroxaban, have been evaluated for the prevention of catheter thrombosis, their efficacy remains uncertain. OBJECTIVES: Compare apixaban and rivaroxaban with enoxaparin for the prevention of catheter-induced clotting in vitro. METHODS: To address this uncertainty, we used a well-established microplate-based assay to compare the effects of enoxaparin, apixaban, and rivaroxaban on catheter-induced thrombosis and thrombin generation in human plasma. RESULTS: Consistent with our previous findings, catheter segments shortened the clotting time and promoted thrombin generation. When compared at concentrations with similar anti-factor Xa activity as enoxaparin, apixaban and rivaroxaban were >20-fold less potent than enoxaparin for the prevention of catheter-induced clotting and thrombin generation. CONCLUSION: The prevention of catheter thrombosis in patients with cancer is challenging. Clinical trials are needed to compare the efficacy of low-molecular-weight heparin with that of direct oral anticoagulants both for the prevention and treatment of catheter thrombosis.

How Did We Get Here? Antithrombotic Therapy after Bioprosthetic Aortic Valve Replacement: A Review.

IMPORTANCE: Aortic stenosis is the most common valvular disease, and more than 90% of patients who undergo aortic valve replacement receive a bioprosthetic valve. Yet optimal antithrombotic therapy after bioprosthetic aortic valve replacement remains uncertain, and guidelines provide contradictory recommendations. OBSERVATIONS: Randomized studies of antithrombotic therapy after bioprosthetic aortic valve replacement are small and underpowered. Observational data present opposing, and likely confounded, results. Historically, changes to guidelines have not been informed by high-quality new data. Current guidelines from different professional bodies provide contradictory recommendations despite citing the same evidence. CONCLUSION: Insufficient antithrombotic therapy after bioprosthetic aortic valve replacement has serious implications: ischemic stroke, systemic arterial thromboembolism, and clinical and subclinical valve thromboses. Unnecessarily intense antithrombotic therapy, however, increases risk of bleeding and associated morbidity and mortality. Professional bodies have used the current low-quality evidence and generated incongruent recommendations. Researchers should prioritize generating high-quality, randomized evidence evaluating the risks and benefits of antiplatelet versus anticoagulant therapy after bioprosthetic aortic valve replacement.

Bespoke valve sizing avoids annular rupture in patients treated with a balloon-expandable transcatheter heart valve.

BACKGROUND: Annular and left ventricular outflow tract (LVOT) calcification increase the risk of annular rupture following transcatheter aortic valve replacement (TAVR). The outcomes of a strategy of routine use of a balloon-expandable valve (BEV) for all patients irrespective of annular or LVOT calcium is unknown. OBJECTIVES: We evaluated the impact of bespoke sizing on annular rupture in patients treated with a BEV. METHODS: All consecutive patients undergoing TAVR at a single centre (February 2020-February 2022) were treated only with a BEV. No other valve design was used. Annular/LVOT calcification was assessed using a standardized grading system. For each annular area, we determined the percentage valve oversizing with nominal deployment. The balloon deployment volume was then adjusted when required (over-/underfilled) to achieve over-sizing of approximately 5% in the presence of annular/LVOT calcium and 5%-10% in the absence of annular/LVOT calcium. Adjusted valve areas were assumed to change proportionately to the change in balloon deployment volume. RESULTS: Among 533 TAVR treated patients, annular/LVOT calcification was present in 166 (31.1%) and moderate or severe in 90 (16.9%). In patients with annular/LVOT calcification, the adjusted oversizing was 3.5 ± 3.6% and in patients without annular/LVOT calcification, the adjusted oversizing was 6.8 ± 4.7% (p < 0.001). There were no cases of annular rupture and no cases with more than mild paravalvular leak (PVL). Mild PVL was more frequent in patients with annular/LVOT calcium (10.8% vs 4.6%, p = 0.01). CONCLUSION: Bespoke BEV sizing by adjustment of balloon deployment volume avoided annular rupture in patients undergoing TAVR.

New-Onset Atrial Fibrillation After Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

OBJECTIVES: The authors aimed to identify risk factors and outcomes associated with new-onset atrial fibrillation (NOAF) after transcatheter aortic valve replacement (TAVR). BACKGROUND: NOAF is a common complication after TAVR, although estimates of the precise occurrence are variable. This study sought to quantify the occurrence of NOAF after TAVR and to explore the outcomes and predictors associated with this complication. METHODS: We searched Medline, EMBASE, and the Cochrane database from 2016 to 2020 for articles that reported NOAF after TAVR. We extracted data for studies published before 2016 from a previous systematic review. We pooled data using a random effects model. RESULTS: We identified 179 studies with 241,712 total participants (55,271 participants with pre-existing atrial fibrillation (AF) were excluded) that reported NOAF from 2008 to 2020. The pooled occurrence of NOAF after TAVR was 9.9% (95% CI: 8.1%-12%). NOAF after TAVR was associated with a longer index hospitalization (mean difference = 2.66 days; 95% CI: 1.05-4.27), a higher risk of stroke in the first 30 days (risk ratio [RR]: 2.35; 95% CI: 2.12-2.61), 30-day mortality (RR: 1.76; 95% CI: 1.12-2.76), major or life-threatening bleeding (RR: 1.60; 95% CI: 1.39-1.84), and permanent pacemaker implantation (RR: 1.12; 95% CI: 1.05-1.18). Risk factors for the development of NOAF after TAVR included higher Society of Thoracic Surgeons score, transapical access, pulmonary hypertension, chronic kidney disease, peripheral vascular disease, and severe mitral regurgitation, suggesting that the risk for NOAF is highest in more comorbid TAVR patients. CONCLUSIONS: NOAF is common after TAVR. Whether AF after TAVR is a causal factor or a marker of sicker patients remains unclear.

A Computed Tomography Protocol to Evaluate Coronary Artery Disease Before Transcatheter Aortic Valve Replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) computed tomographic angiography (CTA) images can be used to evaluate coronary artery disease (CAD). METHODS: We conducted a prospective cohort study of consecutive TAVR patients from November 2019 to February 2021 to evaluate TAVR CTA assessment of CAD on the rate of pre-TAVR invasive angiography. Patients had CTA first or invasive angiography first at the discretion of their treating physicians. TAVR CTA scans were categorised as normal/mild CAD, single-vessel disease, high risk (multivessel or left main disease), or nondiagnostic in patients without previous coronary artery bypass grafting (CABG) and as low risk or high risk in patients with previous CABG. Invasive angiography was recommended before TAVR for high-risk or nondiagnostic CTA findings. RESULTS: TAVR was performed on 354 patients; CTA first was performed in 273 and invasive angiography first in 81. Among 231 patients without previous CABG who had CTA first, 22.1% (51/231) had pre-TAVR invasive angiography and 1.3% (3/231) had pre-TAVR revascularisation. Normal/mild CAD or single-vessel disease was found on CTA in 174 patients, of whom 0.5% (1/174) had high-risk disease on invasive angiography. Among 42 patients with previous CABG who had CTA first, 14.3% (6/42) had pre-TAVR invasive angiography and 2.4% (1/42) had pre-TAVR revascularisation. CONCLUSION: TAVR CTA CAD evaluation can avoid pre-TAVR invasive angiography in more than 70% of patients while rarely missing high risk findings. A CTA-first strategy to assess CAD should be considered, especially among patients where conservative management of CAD is preferred.

Clinical practice guideline for transcatheter versus surgical valve replacement in patients with severe aortic stenosis in Latin America

In elderly (75 years or older) patients living in Latin America with severe symptomatic aortic stenosis candidates for transfemoral approach, the panel suggests the use of transcatheter aortic valve implant (TAVI) over surgical aortic valve replacement (SAVR). This is a conditional recommendation, based on moderate certainty in the evidence. This recommendation does not apply to patients in which there is a standard of care, like TAVI for patients at very high risk for cardiac surgery or inoperable patients, or SAVR for non-elderly patients (eg, under 65 years old) at low risk for cardiac surgery. The suggested age threshold of 75 years old is based on judgement of limited available literature and should be used as a guide rather than a determinant threshold. The conditional nature of this recommendation means that the majority of patients in this situation would want a transfemoral TAVI over SAVR, but some may prefer SAVR. For clinicians, this means that they must be familiar with the evidence supporting this recommendation and help each patient to arrive at a management decision integrating a multidisciplinary team discussion (Heart Team), patient's values and preferences through shared decision-making, and available resources. Policymakers will require substantial debate and the involvement of various stakeholders to implement this recommendation.

Clinical practice guideline for transcatheter versus surgical valve replacement in patients with severe aortic stenosis in Latin America.

In elderly (75 years or older) patients living in Latin America with severe symptomatic aortic stenosis candidates for transfemoral approach, the panel suggests the use of transcatheter aortic valve implant (TAVI) over surgical aortic valve replacement (SAVR). This is a conditional recommendation, based on moderate certainty in the evidence (⨁⨁⨁Ο).This recommendation does not apply to patients in which there is a standard of care, like TAVI for patients at very high risk for cardiac surgery or inoperable patients, or SAVR for non-elderly patients (eg, under 65 years old) at low risk for cardiac surgery. The suggested age threshold of 75 years old is based on judgement of limited available literature and should be used as a guide rather than a determinant threshold.The conditional nature of this recommendation means that the majority of patients in this situation would want a transfemoral TAVI over SAVR, but some may prefer SAVR. For clinicians, this means that they must be familiar with the evidence supporting this recommendation and help each patient to arrive at a management decision integrating a multidisciplinary team discussion (Heart Team), patient's values and preferences through shared decision-making, and available resources. Policymakers will require substantial debate and the involvement of various stakeholders to implement this recommendation.

Variability in opioid prescribing practices among cardiac surgeons and trainees.

BACKGROUND AND AIM: The opioid epidemic has become a major public health crisis in recent years. Discharge opioid prescription following cardiac surgery has been associated with opioid use disorder; however, ideal practices remain unclear. Our aim was to examine current practices in discharge opioid prescription among cardiac surgeons and trainees. METHODS: A survey instrument with open- and closed-ended questions, developed through a 3-round Delphi method, was circulated to cardiac surgeons and trainees via the Canadian Society of Cardiac Surgeons. Survey questions focused on routine prescription practices including type, dosage and duration. Respondents were also asked about their perceptions of current education and guidelines surrounding opioid medication. RESULTS: Eighty-one percent of respondents reported prescribing opioids at discharge following routine sternotomy-based procedures, however, there remained significant variability in the type and dose of medication prescribed. The median (interquartile range) number of pills prescribed was 30 (20-30) with a median total dose of 135 (113-200) Morphine Milligram Equivalents. Informal teaching was the most commonly reported primary influence on prescribing habits and a lack of formal education regarding opioid prescription was associated with a higher number of pills prescribed. A majority of respondents (91%) felt that there would be value in establishing practice guidelines for opioid prescription following cardiac surgery. CONCLUSIONS: Significant variability exists with respect to routine opioid prescription at discharge following cardiac surgery. Education has come predominantly from informal sources and there is a desire for guidelines. Standardization in this area may have a role in combatting the opioid epidemic.

Rivaroxaban and Dabigatran for Suppression of Mechanical Heart Valve-Induced Thrombin Generation.

BACKGROUND: Patients with mechanical heart valves (MHVs) require warfarin to prevent thromboembolism. Dabigatran was less effective than warfarin in patients with MHVs, which prompted a black box warning against the use of direct oral anticoagulants for this indication. However, rivaroxaban and apixaban, which inhibit factor Xa, have not been evaluated in patients with MHVs. To determine whether rivaroxaban and apixaban would be effective, we used MHV-induced thrombin generation assays to compare them with warfarin either alone or in combination with dabigatran. METHODS: Thrombin generation in the absence or presence of MHV leaflets or sewing ring segments (SRSs) was quantified. Studies were done in control plasma; plasma from patients on warfarin; plasma containing varying concentrations of rivaroxaban, apixaban, or dabigatran alone; or plasma containing rivaroxaban plus dabigatran. RESULTS: Mean endogenous thrombin potential (ETP) increased 1.2-fold, 1.5-fold, and 1.8-fold in the presence of leaflets, Teflon (Terumo Aortic (Sunrise, FL)) SRSs, or Dacron (Terumo Aortic (Sunrise, FL)) SRSs, respectively. Rivaroxaban and apixaban reduced ETP at concentrations above 50 ng/mL but were less effective than warfarin. When rivaroxaban and dabigatran were combined, they suppressed ETP in a more than additive manner. CONCLUSIONS: Whereas warfarin suppresses MHV-induced thrombin generation, MHVs induce the generation of factor Xa in concentrations that overwhelm clinically relevant concentrations of rivaroxaban or apixaban. When used in combination, rivaroxaban and dabigatran are more effective than either agent is alone, suggesting that concomitant inhibition of factor Xa and thrombin is better than inhibition of either clotting enzyme alone.

How Did We Get Here?: A Historical Review and Critical Analysis of Anticoagulation Therapy Following Mechanical Valve Replacement.

Managing severe valvular heart disease with mechanical valve replacement necessitates lifelong anticoagulation with a vitamin K antagonist. Optimal anticoagulation intensity for patients with mechanical valves remains uncertain; current recommendations are inconsistent across guideline bodies and largely based on expert opinion. In this review, we outline the history of anticoagulation therapy in patients with mechanical heart valves and critically evaluate current antithrombotic guidelines for these patients. We conclude that randomized trials evaluating optimal anticoagulation intensity in patients with mechanical valves are needed, and that future guidelines must better justify antithrombotic treatment recommendations.

Antiplatelet Therapy and Coronary Artery Bypass Grafting: Analysis of Current Evidence With a Focus on Acute Coronary Syndrome.

This review was undertaken to summarize and discuss the current evidence around antiplatelet therapy and coronary artery bypass grafting (CABG). Aspirin (ASA) monotherapy remains the standard of care among patients before and after CABG. The role of more intense antiplatelet therapy-specifically, P2Y12 inhibitors-in improving clinical outcomes and graft patency is becoming increasingly apparent. As such, we provide an overview of a variety of antiplatelet regimens. The review discusses the evidence around preoperative management of antiplatelet therapies, with a particular focus on timing of cessation. It also evaluates the current literature to elucidate the best antiplatelet therapy regimen after CABG, focusing on acute coronary syndrome (ACS). Whenever possible, data are presented from randomized controlled trials (RCTs) and meta-analyses. Although guidelines recommend use of dual antiplatelet therapy (DAPT) after CABG for patients with ACS, available evidence is limited to small RCTs, and meta-analyses are of substudies of larger RCTs. There is also considerable heterogeneity in patient population of these studies; a significant number of patients underwent off-pump CABG (OPCAB) in trials that demonstrate graft-patency benefit with DAPT. With this limited evidence, DAPT remains underused in the CABG population, even among patients presenting after ACS.

The blood compatibility challenge. Part 1: Blood-contacting medical devices: The scope of the problem.

Blood-contacting medical devices are an integral part of modern medicine. Such devices may be used for only a few hours or may be implanted for life. Despite advances in biomaterial science, clotting on medical devices remains a common problem. Systemic administration of antiplatelet drugs or anticoagulants is often needed to reduce the risk of clotting. Although effective, such therapy increases the risk of bleeding, which can be fatal. This chapter (a) describes some of the commonly used blood-contacting devices and their potential complications, (b) provides an overview of the mechanisms that drive device-associated clotting, and (c) reviews the strategies employed to attenuate clotting on blood-contacting medical devices. STATEMENT OF SIGNIFICANCE: This paper is part 1 of a series of 4 reviews discussing the problem of biomaterial associated thrombogenicity. The objective was to highlight features of broad agreement and provide commentary on those aspects of the problem that were subject to dispute. We hope that future investigators will update these reviews as new scholarship resolves the uncertainties of today.

Antiplatelet Therapy versus Anticoagulation after Surgical Bioprosthetic Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

BACKGROUND: The optimal antithrombotic therapy after surgical bioprosthetic aortic valve replacement (BAVR) is uncertain. We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs) comparing antiplatelet therapy and anticoagulation in patients with surgical BAVR. METHODS: We searched Cochrane CENTRAL, MEDLINE and EMBASE from inception to 3 November 2017 for studies evaluating antiplatelet therapy versus anticoagulation early after surgical BAVR. We performed title and abstract screening, full-text review, risk of bias evaluation and data collection independently and in duplicate. We evaluated overall quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework, and pooled data using a random effects model. RESULTS: We identified 2 RCTs (n = 397) and 5 observational studies (n = 2,012) meeting our eligibility criteria. The mean follow-up for all outcomes was 3 months in RCTs, and 10 months for observational studies. Antiplatelet compared with anticoagulant therapy demonstrated a trend towards fewer major bleeds in RCTs (relative risk [RR], 0.34; 95% confidence interval [CI], 0.11-1.04, p = 0.06, I 2 = 0%, low quality evidence), and significantly fewer major bleeds in observational studies (RR, 0.34; 95% CI, 0.20-0.58, p ≤ 0.0001, I 2 = 0%, very low quality evidence), but stroke, thromboembolism and mortality did not show a significant difference in either RCTs or observational studies. CONCLUSION: Antiplatelet therapy demonstrated reduced bleeding risk with no negative effects on stroke, thromboembolism or mortality compared with anticoagulation therapy after surgical BAVR. Our confidence in the results is reduced by the low quality of the available evidence.

International Normalized Ratio Targets for Left-Sided Mechanical Valve Replacement.

BACKGROUND: Guidelines recommend higher international normalized ratio (INR) targets for patients with mechanical valves believed to be at higher risk for thromboembolism. Higher INR targets are associated with increased bleeding risk. We performed a systematic review and meta-analysis assessing effects of lower and higher INR targets on thromboembolic and bleeding risk in patients with mechanical heart valves. METHODS: We searched Cochrane CENTRAL, MEDLINE and EMBASE for randomized controlled trials (RCTs) evaluating lower versus higher INR targets for adults with bileaflet mechanical valves. We performed title and abstract screening, full-text review, risk of bias evaluation and data collection independently and in duplicate. We pooled data using a random effects model and used the Grading of Recommendations Assessment, Development and Evaluation framework to evaluate overall quality of evidence. RESULTS: We identified six RCTs (n = 5,497). Lower INR targets were associated with significantly less bleeding-22% versus 40% (relative risk [RR]: 0.54, 95% confidence interval [CI]: 0.31, 0.93, p = 0.03, very low quality). There was no difference in thromboembolism-2% in both groups (RR: 1.28, 95% CI: 0.88, 1.85, p = 0.20, very low quality) or mortality-5.5% with lower INR targets versus 8.5% (RR: 1.00, 95% CI: 0.82, 1.21, p = 0.47, moderate quality). CONCLUSION: In patients with mechanical valves, higher INR targets are not supported by current evidence, which is of very low quality. In fact, our systematic review suggests that lower INR targets offer significantly lower bleeding risks with no significant difference in thromboembolic risk.

Surgical ablation of atrial fibrillation: a systematic review and meta-analysis of randomized controlled trials.

Aims: The aim of this review was to assess the effect of concomitant surgical atrial fibrillation (AF) ablation on postoperative freedom from AF and patient-important outcomes. Methods and results: We searched Cochrane CENTRAL, MEDLINE, and EMBASE databases from inception to May 2016 for randomized controlled trials (RCTs) evaluating surgical AF ablation using any lesion set vs. no surgical AF ablation in adults with AF undergoing cardiac surgery. We performed screening, risk-of-bias evaluation, and data collection independently and in duplicate. We evaluated risk of bias with the modified Cochrane tool, quality of evidence using GRADE framework, and pooled data with a random-effects model. Of the 23 included studies, only one was considered at low risk of bias. Surgical AF ablation was associated with more freedom from AF at 12 months [relative risk (RR) = 2.32, 95% confidence interval (CI) 1.92-2.80; P < 0.001, low quality]. However, no significant difference was seen in mortality (RR = 1.07, 95% CI 0.72-1.52; P = 0.41, moderate quality), stroke (RR = 1.19, 95% CI 0.59-2.39; P = 0.63, moderate quality), or pacemaker implantation (RR = 1.28, 95% CI 0.85-1.95; P = 0.24, high quality). Comparing biatrial and left-sided lesion sets showed no difference in mortality (P-interaction = 0.60) or stroke (P-interaction = 0.12). At 12 months, biatrial procedures led to more freedom from AF (RR = 2.80, 95% CI 2.13-3.68; P < 0.0001) when compared with left-sided ablation (RR = 2.00, 95% CI 1.68-2.39; P < 0.0001) (P-interaction = 0.04) Biatrial procedures appear to increase the risk for pacemaker (RR = 2.68, 95% CI 1.41-5.11; P = 0.002) compared with no ablation while left-sided ablation does not (RR = 1.08, 95% CI 0.67-1.74; P = 0.76) (P-interaction = 0.03). Conclusion: Surgical AF ablation during cardiac surgery improves freedom from AF. However, impact on patient-important outcomes including mortality and stroke has not shown statistical significance in current RCT evidence. Biatrial compared with left-sided lesion sets showed no difference in mortality or stroke but were associated with significantly increased freedom from AF and risk for pacemaker requirement.