Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves

Self-expanding intra-annular versus commercially available transcatheter heart valves in high and extreme risk patients with severe aortic stenosis (PORTICO IDE): a randomised, controlled, non-inferiority trial

BACKGROUND

Randomised trial data assessing the safety and efficacy of the self-expanding intra-annular Portico transcatheter aortic valve system (Abbott Structural Heart, St Paul, MN, USA) compared with any commercially available valves are needed to compare performance among designs.

METHODS

In this prospective, multicentre, non-inferiority, randomised controlled trial (the Portico Re-sheathable Transcatheter Aortic Valve System US Investigational Device Exemption trial [PORTICO IDE]), high and extreme risk patients with severe symptomatic aortic stenosis were recruited from 52 medical centres experienced in performing transcatheter aortic valve replacement in the USA and Australia. Patients were eligible if they were aged 21 years or older, in New York Heart Association functional class II or higher, and had severe native aortic stenosis. Eligible patients were randomly assigned (1:1) using permuted block randomisation (block sizes of 2 and 4) and stratified by clinical investigational site, surgical risk cohort, and vascular access method, to transcatheter aortic valve replacement with the first generation Portico valve and delivery system or a commercially available valve (either an intra-annular balloon-expandable Edwards-SAPIEN, SAPIEN XT, or SAPIEN 3 valve [Edwards LifeSciences, Irvine, CA, USA]; or a supra-annular self-expanding CoreValve, Evolut-R, or Evolut-PRO valve [Medtronic, Minneapolis, MN, USA]). Investigational site staff, implanting physician, and study participant were unmasked to treatment assignment. Core laboratories and clinical event assessors were masked to treatment allocation. The primary safety endpoint was a composite of all-cause mortality, disabling stroke, life-threatening bleeding requiring transfusion, acute kidney injury requiring dialysis, or major vascular complication at 30 days. The primary efficacy endpoint was all-cause mortality or disabling stroke at 1 year. Clinical outcomes and valve performance were assessed up to 2 years after the procedure. Primary analyses were by intention to treat and the Kaplan-Meier method to estimate event rates. The non-inferiority margin was 8·5% for primary safety and 8·0% for primary efficacy endpoints. This study is registered with ClinicalTrials.gov, NCT02000115, and is ongoing.

FINDINGS

Between May 30 and Sept 12, 2014, and between Aug 21, 2015, and Oct 10, 2017, with recruitment paused for 11 months by the funder, we recruited 1034 patients, of whom 750 were eligible and randomly assigned to the Portico valve group (n=381) or commercially available valve group (n=369). Mean age was 83 years (SD 7) and 395 (52·7%) patients were female. For the primary safety endpoint at 30 days, the event rate was higher in the Portico valve group than in the commercial valve group (52 [13·8%] vs 35 [9·6%]; absolute difference 4·2, 95% CI -0·4 to 8·8 [upper confidence bound {UCB} 8·1%]; p_{non-inferiority}=0·034, p_superiority=0·071). At 1 year, the rates of the primary efficacy endpoint were similar between the groups (55 [14·8%] in the Portico group vs 48 [13·4%] in the commercial valve group; difference 1·5%, 95% CI -3·6 to 6·5 [UCB 5·7%]; p_{non-inferiority}=0·0058, p_superiority=0·50). At 2 years, rates of death (80 [22·3%] vs 70 [20·2%]; p=0·40) or disabling stroke (10 [3·1%] vs 16 [5·0%]; p=0·23) were similar between groups.

INTERPRETATION

The Portico valve was associated with similar rates of death or disabling stroke at 2 years compared with commercial valves, but was associated with higher rates of the primary composite safety endpoint including death at 30 days. The first-generation Portico valve and delivery system did not offer advantages over other commercially available valves.

FUNDING

Abbott.

The role of four-dimensional computed tomography in transcatheter aortic valve replacement prosthesis endocarditis with concurrent leaflet thrombosis: a case report

Background

Transcatheter aortic valve replacement (TAVR) is becoming increasingly utilized for the treatment of severe aortic valvular heart disease. Infective endocarditis of TAVR is rare but associated with higher mortality and morbidity. The potential for leaflet thrombosis following TAVR is also becoming increasingly recognized. Diagnosis of these conditions on echocardiography can be challenging due to prosthesis artefact.

Case summary

An 84-year-old man with a previous transcatheter aortic valve replacement presented with a febrile illness and bacteraemia. Transthoracic and transoesophageal echocardiography demonstrated high transvalvular gradients with features of prosthesis endocarditis, though leaflet morphology could not be fully assessed due to prosthesis artefact. Four-dimensional computed tomography revealed hypo-attenuated leaflet thickening with reduced leaflet motion, consistent with prosthesis leaflet thrombosis. The patient was successfully treated with antibiotics and anticoagulation, with resolution of the infection and normalization of the transvalvular gradient after 6 weeks.

Discussion

Echocardiography should be the first-line investigation for assessing leaflet morphology in suspected prosthetic valve endocarditis or leaflet thrombosis but its accuracy may be limited by artefact. Our case highlights that four-dimensional computed tomography provides further evaluation of prosthesis leaflet morphology/motion, providing valuable diagnostic information.

Hemodynamics inside the neo- and native sinus after TAVR: Effects of implant depth and cardiac output on flow field and coronary flow

Transcatheter aortic valve replacement (TAVR) has emerged as a widely used therapy for aortic valve diseases. With TAVR, flow hemodynamics may change leading to areas of flow stagnation prone to thrombosis risk. The neo-sinus, created by introducing a prosthesis inside the diseased native valve, may prompt leaflet thrombosis due to areas of flow stasis. This study attempted to understand the effect of different prosthesis implant depths on the flow field within the neo- and native sinus and on the coronary perfusion. Experiments were performed inside an in vitro pulse duplicator producing physiological conditions according to ISO 5840-1:2015 standard. Flow fields were obtained for two cardiac outputs (CO) using particle image velocimetry (PIV). Washout was calculated as a measure of flow stasis. The two main results are: a lower implant position and a lower CO/frequency led to better native sinus washout, but worsened neo-sinus washout. In contrast, a higher implant position led to higher coronary flow (for higher CO/frequency). No significant effect of implant depth on coronary flow was observed for lower CO/frequency. In summary, a higher implant position using this self-expanding prosthesis is associated with reduced neo-sinus flow stasis. Hereby, washout of the native sinus, as well as coronary flow, are dependent on cardiac output.

Utility of CT in the diagnosis of prosthetic valve abnormalities

BACKGROUND

Patients with prosthetic heart valves (PHV) are at an increased risk of endocarditis and dysfunction. Knowledge about the etiology of dysfunction and extent of endocarditis can have distinct treatment implications. Echocardiography has limitations due to PHV-related artifacts. We hypothesized that computed tomography (CT) will have incremental value over echocardiography for evaluation of PHV abnormalities with surgical findings as the reference standard.

METHODS

Consecutive patients with PHV that had a reoperation for valve replacement, had a contrast chest CT and echocardiogram within 1 year of the reoperation, between 2010 and 2018 at a single academic center formed the study cohort. CTs and echocardiograms were assessed for potential etiologies of dysfunction (valve degeneration, pannus and thrombus); and for extent of endocarditis (vegetation, abscess, and pseudoaneurysm).

RESULTS

Seventy-three patients (65.8% male, mean age 62.1 ± 16.5 years) formed the study cohort. The indication for reoperation was PHV dysfunction in 51 and PHV endocarditis in 22. Compared to echocardiography, CT diagnosed the etiology of PHV dysfunction in 17 (33.3%) more patients (9 valve degeneration, 8 pannus). In the PHV endocarditis cohort, CT failed to detect one vegetation and one abscess, whereas echocardiography failed to detect 1 abscess. In combination, CT and echocardiography demonstrated all the vegetations and abscesses.

CONCLUSION

CT may provide superior characterization in comparison to echocardiography for the identification of the cause of prosthetic valve dysfunction, and complementary information to echocardiography for the evaluation of prosthetic valve endocarditis.

Utility of Three-Dimensional (3D) Modeling for Planning Structural Heart Interventions (with an Emphasis on Valvular Heart Disease)

PURPOSE OF REVIEW

Advanced imaging has played a vital role in the contemporary, rapid rise of structural heart interventions. 3D modeling and printing has emerged as one of the most recent imaging tools and the implementation of 3D modeling is expected to increase with further advances in imaging, print hardware, and materials.

RECENT FINDINGS

3D modeling can be used to educate patients and clinical teams, provide ex vivo procedural simulation, and improve outcomes. Intra-procedural success rates may be improved, and post-procedural complications can be predicted more robustly with appropriate application of 3D modeling. Recent advances in technology have increased the availability of this tool, such that there can be more ready adoption into a routine clinical workflow. Familiarity with 3D modeling and its current utilization and role in structural interventions will help inform how to approach and adapt this exciting new technology.

Inorganic-polymerization crosslinked tissue-siloxane hybrid as potential biomaterial for bioprosthetic heart valves

Bioprosthetic heart valve (BHV) replacement is increasingly used for treating valve-related diseases worldwide but the current commercially used BHVs treated with glutaraldehyde (Glut) often failed within 12-15 years due to degradation, thrombosis, inferior biocompatibility, and calcification. Herein, 3-glycidyloxypropyl trimethoxysilane (GPTMS) was used to crosslink porcine pericardium (PP) at the concentration (vol/vol) of 0.25%, 1%, 2%, and 4% and their performance for potential application in BHVs was evaluated. The crosslinking mechanism mainly involved the ring-opening of epoxide by amine attack and silanol poly-condensation. The stability of collagen in higher concentration (1%, 2%, and 4%) GPTMS crosslinked PPs (GPTMS-PPs) was clearly increased. GPTMS-PPs showed no cytotoxicity and supported the growth of endothelial cells while Glut-PP did not. GPTMS-PPs were less prothrombotic than Glut-PP. GPTMS-PP crosslinked at 1% concentration showed comparable mechanical properties to Glut-PP while had better anti-tearing performance. The subcutaneous implantation in rat for 30 days showed that GPTMS crosslinking was able to effectively inhibit the calcification of BHV.

The Issue of Subclinical Leaflet Thrombosis After Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has been considered an important therapy for the treatment of symptomatic severe aortic stenosis. Although the devices and the techniques have been improved some complications may occur and several issues still need to be addressed. The issue of subclinical leaflet thrombosis (SLT) has been recognized as a complication after TAVI, and its incidence ranges from 0% to 40%. Nowadays, computed tomography is considered as the standard method for diagnosis of SLT. The concept of hypoattenuated leaflet thickening (HALT), reduced leaflet motion (RELM), and hypoattenuation affecting motion (HAM) have been used in this topic. Most patients who had SLT were taking single or dual antiplatelet therapy. In addition, these medications were not effective in resolving this complication after TAVI. However, there is a suggestion that oral anticoagulants have a protective and therapeutic effect. With the increasing use of TAVI, it is necessary to have better knowledge about several aspects of this complication, because it may have impact on prognosis. Therefore, some aspects of SLT diagnosis, management, and prognosis are not yet fully understood.

Distinguishing aortic valve thrombus from Libman-Sacks endocarditis in antiphospholipid syndrome: imaging and management

Aortic valve (AV) thrombus, a rare complication of antiphospholipid syndrome (APLS), is important to distinguish from Libman-Sacks endocarditis because of its responsiveness to anticoagulation. This may be attributed to immunopathologic differences underpinning their development. We present the case of a 45-year-old woman with high-risk primary APLS who developed an AV mass and was taken for valvular repair surgery but found to have pure thrombus and normal valve leaflets. In such cases, a trial of conservative management with anticoagulation may be adequate. Echocardiography, computed tomography and MRI findings suggestive of thrombus without endocarditis are presented. A literature review of histopathologic, imaging and treatment implications of pure AV thrombus in the context of APLS is included.

Valve-in-Valve for Degenerated Transcatheter Aortic Valve Replacement Versus Valve-in-Valve for Degenerated Surgical Aortic Bioprostheses: A 3-Center Comparison of Hemodynamic and 1-Year Outcome

Background

As transcatheter aortic valve replacement (TAVR) is expected to progress into younger patient populations, valve‐in‐TAVR (ViTAVR) may become a frequent consideration. Data on ViTAVR, however, are limited. This study investigated the outcome of ViTAVR in comparison to valve in surgical aortic valve replacement (ViSAVR), because ViSAVR is an established procedure for higher‐risk patients requiring repeated aortic valve intervention.

Methods and Results

Clinical and procedural data of patients who underwent ViTAVR at 3 sites in the United States and Germany were retrospectively compared with data of patients who underwent ViSAVR at Cedars‐Sinai Medical Center, according to Valve Academic Research Consortium‐2 criteria. A total of 99 consecutive patients, 52.5% women, with a median Society of Thoracic Surgeons score of 7.2 were identified. Seventy‐four patients (74.7%) underwent ViSAVR, and 25 patients (25.3%) underwent ViTAVR. Balloon‐expandable devices were used in 72.7%. ViSAVR patients presented with smaller index devices (21.0 versus 26.0 mm median true internal diameter; P<0.001). Significantly better postprocedural hemodynamics (median prosthesis mean gradient, 12.5 [interquartile range, 8.8–16.2] versus 16.0 [interquartile range, 13.0–20.5] mm Hg; P=0.045) were observed for ViTAVR compared with the ViSAVR. Device success, however, was not different (79.2% and 66.2% for ViTAVR and ViSAVR, respectively; P=0.35), as were rates of permanent pacemaker implantation (16.7% versus 5.4%; P=0.1). One‐year‐mortality was 9.4% and 13.4% for ViTAVR and ViSAVR, respectively (log‐rank P=0.38).

Conclusions

Compared with ViSAVR, ViTAVR provides acceptable outcomes, with slightly better hemodynamics, similar device success rates, and similar 1‐year mortality.

Sinus of Valsalva Thrombosis Detected on Computed Tomography after Transcatheter Aortic Valve Replacement

BACKGROUND AND OBJECTIVES

Leaflet thrombosis after transcatheter aortic valve replacement (TAVR) has been reported recently, whereas thrombus formation in sinus of Valsalva has yet to be fully evaluated. This study describes clinical and cardiac computed tomography (CT) findings of patients with sinus of Valsalva thrombosis.

METHODS

Between March 2011 and Aug 2019, 192 patients underwent cardiac CT after TAVR. After a retrospective review of CT images, 9 patients (82 years, male:female=2:7) who had sinus of Valsalva thrombosis identified by cardiac CT were selected for this study. Patient demographics, interval between TAVR and cardiac CT scan, location and CT attenuation of sinus of Valsalva thrombosis, and presence of concurrent leaflet thrombosis were evaluated.

RESULTS

The median interval between TAVR and cardiac CT was 11 days. Sinus of Valsalva thrombosis was frequently detected in the non-coronary sinus (89%, 8/9), and predominantly located in the bottom of the sinus extending upward towards the sinotubular junction. Three patients had concomitant leaflet thrombosis, and 3 patients had subclinical embolic stroke noted on brain magnetic resonance imaging. All patients had been prescribed aspirin and clopidogrel after TAVR for at least 6 months without anticoagulants.

CONCLUSIONS

Cardiac CT after TAVR can detect sinus of Valsalva thrombosis, and attention should be paid to this potential source of subsequent systemic embolization.

Impact of dual energy cardiac CT for metal artefact reduction post aortic valve replacement

PURPOSE

Assess image quality of dual-energy (DE) and single-energy (SE) cardiac multi-detector computed tomographic (MDCT) post aortic valve replacement (AVR) on a dual source MDCT scanner.

METHODS

Eighty patients with cardiac MDCT acquisitions (ECG gated, dual-source) post-surgical and transcatheter AVR were retrospectively identified. Forty DE (cohort 1) and 40 SE acquisitions (cohort 2; 100 or 120 kVp) were reviewed. Metal artefact at valve coaptation (VC) and valve insertion site (VIS), and contrast enhancement were assessed. Valve leaflet edge definition was graded on a 4-point scale by three radiologists.

RESULTS

The mean percentage valve area obscured by metal artifact differed between the cohorts; cohort 1 DE blended, high keV and low keV: 14.8 %, 11.1 % and 17.8 % at VC and 16.4 %, 13 %, 20.4 % at VIS respectively. Cohort 2: 25.8 % and 33.6 % (VC and VIS); each DE reconstruction vs SE: P < 0.0001. Average contrast opacification and coefficient of variance for cohort 1: 562.9 ± 144.7, 281.1 ± 60.3 and 1132.7 ± 300.8 Hounsfield Units (HU) and 9.6 %, 10 % and 8.9 %. For cohort 2: 437.2 ± 119.2 HU and 10.8 % (P < 0.01). Average leaflet edge definition cohort 1: 2.3 ± 0.4, 2.7 ± 0.2 and 2.3 ± 0.2, and cohort 2: 2.9 ± 0.2.

CONCLUSION

DE high keV renderings can result in up to 17.2 % less metal artefact compared to standard SE acquisition for cardiac CT. Contrast opacification and homogeneity is higher for DE blended and low keV renderings compared to SE acquisition with leaflet visibility preferred for low keV and blended DE renderings.

Influence of prosthesis-related factors on the occurrence of early leaflet thrombosis after transcatheter aortic valve implantation

Aims

Early leaflet thrombosis (LT) is a well-described phenomenon after transcatheter aortic valve implantation (TAVI) with an incidence around 15%. Data about predictors of LT are scarce. The purpose of the study was to investigate the influence of prosthesis-related factors on the occurrence of LT.

Materials and results

Fusion imaging of pre- and post-procedural computed tomography angiography was performed in 55 TAVI patients with LT and 140 selected patients as control groups (85 patients in an unmatched and 55 in a matched control) to obtain a 3D reconstruction of the transcatheter heart valve (THV) within the native annulus region. All patients received a balloon-expandable Sapien 3 THV. The THV length above and below the native annulus was measured within the fused images to assess the implantation depth. The deployed THV area was quantified on three heights (left ventricular outflow tract end, stent centre, and aortic end) to determine the average expansion of the prosthesis as percent of the nominal area. We also calculated the extent of prosthesis waist in percent of maximum area. After multivariate adjustment, the extent of THV waist [odds ratio (OR) per 10% (confidence interval, CI) 0.636 (0.526–0.769), P &lt; 0.001] as prosthesis-related factor and previous oral anticoagulation [OR (CI) 0.070 (0.020–0.251), P &lt; 0.001] had significant, independent influence on the occurrence of LT. The implantation depth showed no influence on LT manifestation (P = 0.704).

Conclusion

Besides the absence of previous oral anticoagulation, a less pronounced waist of the implanted THV was a prosthesis-position-related independent predictor of LT after TAVI using the Sapien 3.

The Beneficial Effect of Anticoagulation in Aortic Bioprosthesis is Associated with its Size

OBJECTIVE

To evaluate the clinical and echocardiographic outcomes in aortic valve replacement (AVR) patients with aortic bioprosthesis under oral anticoagulation (OA).

METHODS

Patients who underwent AVR with bioprosthesiswere prospectively enrolled. They were classified based on postoperative use of OA. Clinical and operative variables were collected. Echocardiographic and clinical follow-ups were performed two years after surgery. The primary outcome evaluated was change in transprosthetic gradient. Secondary outcomes analyzed were change in New York Heart Association (NYHA) class, major bleeding episodes, hospitalization, stroke, and transient ischemic attack.

RESULTS

We included 103 patients (61 without OA and 42 with OA). Clinical characteristics were similar among groups, except for younger age (76±6.3 vs. 72.4±8.1 years, P=0.016) and higher prevalence of atrial fibrillation (0% vs. 23.8%, P<0.001) in the OA group. Mean (21.4±10 mmHg vs. 16.8±7.7 mmHg, P=0.037) and maximum (33.4±13.7 mmHg vs. 28.4±10.2 mmHg, P=0.05) transprosthetic gradients were higher in patients without OA. Improvement in NYHA class was more frequent in patients with OA (73% vs. 45.3%, P=0.032). Major bleeding, stroke, and hospitalization were similar among groups. OA was the only independent predictor for improvement of NYHA class after multivariate logistic regression analysis (odds ratio [OR]: 5.9, 95% confidence interval [CI]: 1.2-29.4; P=0.028). Stratification by prosthesis size showed that patients with ≤ 21 mm prosthesis benefited from OA.

CONCLUSION

Early anticoagulation after AVR with bioprosthesis was associated with significant decrease of transprosthesis gradient and improvement in NYHA class. These associations were seen mainly in patients with ≤ 21 mm prosthesis.

Endocarditis risk with bioprosthetic and mechanical valves: systematic review and meta-analysis

OBJECTIVE

Bioprosthetic valves are being used with increased frequency for valve replacement, with controversy regarding risk:benefit ratio compared with mechanical valves in younger patients. However, prior studies have been too small to provide comparative estimates of less common but serious adverse events such as infective endocarditis. We aimed to compare the incidence of infective endocarditis between bioprosthetic valves and mechanical valves.

METHODS

We searched PubMed, Cochrane, EMBASE, Scopus and Web of Science from inception to April 2018 for studies comparing left-sided aortic and mitral bioprosthetic to mechanical valves for randomised trials or observational studies with propensity matching. We used random-effects model for our meta-analysis. Our primary outcome of interest was the rate of infective endocarditis at follow-up.

RESULTS

13 comparison groups with 43 941 patients were included. Mean age was 59±7 years with a mean follow-up of 10.4±5.0 years. Patients with bioprosthetic valves had a higher risk of infective endocarditis compared with patients receiving mechanical valves (OR 1.59, 95% CI 1.35 to 1.88, p<0.001) with an absolute risk reduction of 9 per 1000 (95% CI 6 to 14). Heterogeneity within the included studies was low (I²=0%). Exclusion of the study with maximum weight did not change the results of the analysis (OR 1.57, 95% CI 1.14 to 2.17, p=0.006). A meta-regression of follow-up time on incidence of infective endocarditis was not statistically significant (p=0.788) indicating difference in follow-up times did not alter the pooled risk of infective endocarditis.

CONCLUSIONS

Bioprosthetic valves may be associated with a higher risk of infective endocarditis. These data should help guide the discussion when deciding between bioprosthetic and mechanical valves in individual patients.

Reversal of Bioprosthetic Aortic Valve Thrombosis Using Rivaroxaban-A Case Report

Background: Bioprosthetic valve thrombosis (BPVT) is a rare but recognized complication causing valve dysfunction. In subacute valve thrombosis, systemic oral anticoagulation is recommended. However, there is little data comparing the efficacy of warfarin and novel oral anticoagulant (NOAC) therapy in this setting.

Case Summary: A patient developed subacute BPVT 11 years post-implantation. The patient was initially treated with warfarin for a period of 6 months, with limited effect. Following replacement of warfarin with rivaroxaban, there was significant reversal of the BPVT, as represented by a reduction in transaortic maximal velocity (Vmax) from 4.1 to 3 m/s over 7 months.

Discussion: Systemic oral anticoagulation can be an effective treatment for subacute valve thrombosis. Guidelines currently recommend warfarin as first line but NOACs can be considered in such patients and may be more effective than warfarin. Randomized controlled trials are required to further establish the optimal anticoagulation for patients with subacute BPVT.

Three-dimensional extent of flow stagnation in transcatheter heart valves

The recent unexpected discovery of thrombosis in transcatheter heart valves (THVs) has led to increased concerns of long-term valve durability. Based on the clinical evidence combined with Virchow's triad, the primary hypothesis is that low-velocity blood flow around the valve could be a primary cause for thrombosis. However, due to limited optical access in such unsteady three-dimensional biomedical flows, measurements are challenging. In this study, for the first time, we employ a novel single camera volumetric velocimetry technique to investigate unsteady three-dimensional cardiovascular flows. Validation of the novel volumetric velocimetry technique with standard planar particle image velocimetry (PIV) technique demonstrated the feasibility of adopting this new technique to investigate biomedical flows. This technique was used to quantify the three-dimensional velocity field in the vicinity of a validated, custom developed, transparent THV in a bench-top pulsatile flow loop. Large volumetric regions of flow stagnation were observed in the neo-sinus throughout the cardiac cycle, with stagnation defined as a velocity magnitude lower than 0.05 m s^-1. The volumetric scalar viscous shear stress quantified via the three-dimensional shear stress tensor was within the range of low shear-inducing thrombosis observed in the literature. Such high-fidelity volumetric quantitative data and novel imaging techniques used to obtain it will enable fundamental investigation of heart valve thrombosis in addition to providing a reliable and robust database for validation of computational tools.

Coronary Artery Disease and Transcatheter Aortic Valve Replacement: JACC State-of-the-Art Review

About one-half of transcatheter aortic valve replacement (TAVR) candidates have coronary artery disease (CAD), and controversial results have been reported regarding the effect of the presence and severity of CAD on clinical outcomes post-TAVR. In addition to coronary angiography, promising data has been recently reported on both the use of computed tomography angiography and the functional invasive assessment of coronary lesions in the work-up pre-TAVR. While waiting for the results of ongoing randomized trials, percutaneous revascularization of significant coronary lesions has been the routine strategy in TAVR candidates with CAD. Also, scarce data exists on the incidence, characteristics, and management of coronary events post-TAVR, and increasing interest exist on potential coronary access challenges in patients requiring coronary angiography/intervention post-TAVR. This review provides an updated overview of the current landscape of CAD in TAVR recipients, focusing on its prevalence, clinical impact, pre- and post-procedural evaluation and management, unresolved issues and future perspectives.

Effect of concomitant aortic regurgitation on early hypo-attenuated leaflet thickening after transcatheter aortic valve replacement in patients with symptomatic severe aortic stenosis

OBJECTIVE

We hypothesize that different degree of pre-existing aortic regurgitation (AR) may affect the presence of hypo-attenuated leaflet thickening (HALT) after transcatheter aortic valve replacement (TAVR).

BACKGROUND

The mechanism of the presence of HALT post-TAVR is not fully understood.

METHODS

We retrospectively evaluated the post-procedural multi-slice computed tomography (MSCT) before discharge for evidence of HALT. Patients were grouped according to the degree of pre-existing AR. Baseline, native anatomy and procedure details were compared, then multivariate regression was performed.

RESULTS

MSCT analyzed was performed at a median of 6 days post-TAVR in 179 patients. HALT was detected in 10.6% of patients. After adjusting for variables that were significantly different between groups, pre-existing ≥ moderate AR was protective to the risk of HALT (OR 0.15, 95% CI 0.03-0.84, p = .03). Stratifying for factors that might explain the impact of pre-existing AR on HALT, patients with a small Sinus of Valsalva, non-eccentric remodeling and receiving a large bioprosthesis experienced a sevenfold higher risk for HALT (OR 7.16, 95% CI 2.05-25.08, p = .002).

CONCLUSIONS

Patients underwent TAVR with pre-existing ≥ moderate AR appeared to experience a lower incidence of early HALT compared to those patients with less than moderate AR, which may be explained by a larger Sinus of Valsalva and a higher proportion of LV eccentric remodeling.

Anticoagulation After Surgical or Transcatheter Bioprosthetic Aortic Valve Replacement

BACKGROUND

There is paucity of evidence on the impact of anticoagulation (AC) after bioprosthetic aortic valve replacement (AVR) on valve hemodynamics and clinical outcomes.

OBJECTIVES

The study aimed to assess the impact of AC after bioprosthetic AVR on valve hemodynamics and clinical outcomes.

METHODS

Data on antiplatelet and antithrombotic therapy were collected. Echocardiograms were performed at 30 days and 1 year post-AVR. Linear regression model and propensity-score adjusted cox proportional model were used to assess the impact of AC on valve hemodynamics and clinical outcomes, respectively.

RESULTS

A total of 4,832 patients undergoing bioprosthetic AVR (transcatheter aortic valve replacement [TAVR], n = 3,889 and surgical AVR [SAVR], n = 943) in the pooled cohort of PARTNER2 (Placement of Aortic Transcatheter Valves) randomized trials and nonrandomized registries were studied. Following adjustment for valve size, annular diameter, atrial fibrillation, and ejection fraction at the time of assessment of hemodynamics, there was no significant difference in aortic valve mean gradients or aortic valve areas between patients discharged on AC vs. those not discharged on AC, for either TAVR or SAVR cohorts. A significantly greater proportion of patients not discharged on AC had an increase in mean gradient >10 mm Hg from 30 days to 1 year, compared with those discharged on AC (2.3% vs. 1.1%, p = 0.03). There was no independent association between AC after TAVR and adverse outcomes (death, p = 0.15; rehospitalization, p = 0.16), whereas AC after SAVR was associated with significantly fewer strokes (hazard ratio [HR]: 0.17; 95% confidence interval [CI]: 0.05-0.60; p = 0.006).

CONCLUSIONS

In the short term, early AC after bioprosthetic AVR did not result in adverse clinical events, did not significantly affect aortic valve hemodynamics (aortic valve gradients or area), and was associated with decreased rates of stroke after SAVR (but not after TAVR). Whether early AC after bioprosthetic AVR has impact on long-term outcomes remains to be determined. (Placement of AoRTic TraNscathetER Valves [PARTNERII A]; NCT01314313).

2019 Canadian Cardiovascular Society Position Statement for Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) or replacement has rapidly changed the treatment of patients with severe symptomatic aortic stenosis. It is now the standard of care for patients believed to be inoperable or at high surgical risk, and a reasonable alternative to surgical aortic valve replacement for those at intermediate surgical risk. Recent clinical trial data have shown the benefits of this technology in patients at low surgical risk as well. This update of the 2012 Canadian Cardiovascular Society TAVI position statement incorporates clinical evidence to provide a practical framework for patient selection that does not rely on surgical risk scores but rather on individual patient evaluation of risk and benefit from either TAVI or surgical aortic valve replacement. In addition, this statement features new wait time categories and treatment time goals for patients accepted for TAVI. Institutional requirements and recommendations for operator training and maintenance of competency have also been revised to reflect current standards. Procedural considerations such as decision-making for concomitant coronary intervention, antiplatelet therapy after intervention, and follow-up guidelines are also discussed. Finally, we suggest that all patients with aortic stenosis might benefit from evaluation by the heart team to determine the optimal individualized treatment decision.

Hypo-attenuated leaflet thickening in surgically-implanted mitral bioprosthesis

Background

Hypo-attenuated leaflet thickening (HALT) in bioprosthetic aortic valve has been studied, but its equivalent in bioprosthetic mitral valve (bMV) remains uncharacterized. We sought to identify the prevalence, hemodynamic characteristics, and significance of anticoagulation therapy in bMV HALT.

Methods

A single-center cross-sectional study of 53 consecutive patients who underwent mitral valve replacement (MVR) with bMV between 2007 and 2017 was conducted. Cardiac-gated contrasted CT scans were obtained. Anticoagulant and antiplatelet therapy use were ascertained at the time of hospital discharge and CT scanning. Patient characteristics, postoperative stroke, and hemodynamic profile by echocardiogram were obtained to descriptively characterize the prevalence and characteristics associated with bMV HALT.

Results

Three patients (5.7%) were found to have a HALT on bMV. The mean time from index MVR to CT scan was 3.4 ± 0.8 years in HALT cohort and 3.4 ± 2.7 years in non-HALT cohort. Fifty patients (94.3%) were discharged on warfarin, and 37 patients (69.8%) were on warfarin at the time of CT scans. One patient with HALT was on therapeutic warfarin at the time of the CT scan that identified HALT. All three patients were asymptomatic at the time of CT scan. In patients with HALT, mean transmitral pressure gradient were 8, 5, and 2.7 mmHg, all with trivial or mild mitral regurgitation.

Conclusions

In this study, the prevalence of HALT was low at 5.7%, all presenting without symptoms. One patient presented with HALT while on therapeutic oral anticoagulation, which may suggest thrombotic etiology may not adequately explain HALT.

Assessment of Long-Term Structural Deterioration of Transcatheter Aortic Bioprosthetic Valves Using the New European Definition

BACKGROUND

The durability of transcatheter aortic bioprosthetic valves is a crucial issue, but data are scarce, especially beyond 5 years of follow-up. We aimed to assess long-term (7 years) structural valve deterioration (SVD) and bioprosthetic valve failure of transcatheter aortic bioprosthetic valves.

METHODS AND RESULTS

Consecutive patients with at least 5-year follow-up available undergoing transcatheter aortic valve implantation from April 2002 to December 2011 in 5 French centers were included. Incidence of SVD and bioprosthetic valve failure were defined according to newly standardized criteria of the European Association of Percutaneous Cardiovascular Interventions/European Society of Cardiology/European Association for Cardio-Thoracic Surgery and reported as cumulative incidence function to account for the competing risk of death. One thousand four hundred three consecutive patients were included with a mean age of 82.6±7.5 years and with a mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) of 21.3±7.5%. A balloon-expandable valve was used in 83.7% of cases. Survival rates were 83.5% (95% CI, 81.4%-85.5%) and 18.6% (95% CI, 15.3%-21.8%) at 1 and 7 years, respectively. Median duration of follow-up was 3.9 years. Bioprosthetic valve failure occurred in 19 patients with a 7-year cumulative incidence of 1.9% (95% CI, 1.4%-2.4%). SVD occurred in 49 patients (moderate, n=32; severe, n=17) with a 7-year cumulative incidence of moderate and severe SVD of 7.0% (95% CI, 5.6%-8.4%) and 4.2% (95% CI, 2.9%-5.5%), respectively. Five patients had aortic valve reintervention (1.0%; 95% CI, 0.4%-1.6%) including 1 case of surgical aortic valve replacement and 4 redo-transcatheter aortic valve implantation. The incidences of SVD and bioprosthetic valve failure were not significantly different between balloon and self-expandable prostheses.

CONCLUSIONS

The long-term assessment of transcatheter aortic bioprosthetic valves durability is limited by the poor survival of our population beyond 5 years. Further studies are warranted, particularly in younger and lower-risk patients.

New Insights into Valve Hemodynamics

Heart valve diseases are common disorders with five million annual diagnoses being made in the United States alone. All heart valve disorders alter cardiac hemodynamic performance; therefore, treatments aim to restore normal flow. This paper reviews the state-of-the-art clinical and engineering advancements in heart valve treatments with a focus on hemodynamics. We review engineering studies and clinical literature on the experience with devices for aortic valve treatment, as well as the latest advancements in mitral valve treatments and the pulmonic and tricuspid valves on the right side of the heart. Upcoming innovations will potentially revolutionize treatment of heart valve disorders. These advancements, and more gradual enhancements in the procedural techniques and imaging modalities, could improve the quality of life of patients suffering from valvular disease who currently cannot be treated.

Obstructive bioprosthetic mitral valve thrombosis

Bioprosthetic valve thrombosis (BPVT) is not uncommon but can be under diagnosed due to the lack of awareness and technical limitations of echocardiography. When suspecting BPVT, it is imperative to consider multimodality imaging to establish the diagnosis as early treatment can alter the clinical course. Here we present a case series of two patients with a history of rheumatic heart disease status post bioprosthetic mitral valve replacement who presented with acute heart failure symptoms. In both cases, supplemental imaging with real-time 3D echocardiography was critical in establishing a diagnosis of BPVT, resulting in timely treatment. These cases support updating current guidelines for the management of patients with bioprosthetic valve replacement to include more frequent surveillance imaging even if patients are asymptomatic.

Thrombosis of a Percutaneous Transcatheter Mitral Valve Implant and Its Treatment

Bioprosthetic heart valves do not usually require formal anticoagulation as they are less thrombogenic than their mechanical counterparts. However, valve thrombosis has been reported after both transcatheter and surgical aortic bioprosthesis implantation. Short-term anticoagulation after surgical bioprosthesis implantation is often recommended while endothelialisation of the prosthesis takes place, particularly for mitral valve implants. There have been no reports of tissue heart valve thrombosis in transcatheter mitral valve replacement. We describe our experience and successful treatment of such a case.

A Finite Element Analysis Study from 3D CT to Predict Transcatheter Heart Valve Thrombosis

Background: Transcatheter aortic valve replacement has proved its safety and effectiveness in intermediate- to high-risk and inoperable patients with severe aortic stenosis. However, despite current guideline recommendations, the use of transcatheter aortic valve replacement (TAVR) to treat severe aortic valve stenosis caused by degenerative leaflet thickening and calcification has not been widely adopted in low-risk patients. This reluctance among both cardiac surgeons and cardiologists could be due to concerns regarding clinical and subclinical valve thrombosis. Stent performance alongside increased aortic root and leaflet stresses in surgical bioprostheses has been correlated with complications such as thrombosis, migration and structural valve degeneration. Materials and Methods: Self-expandable catheter-based aortic valve replacement (Medtronic, Minneapolis, MN, USA), which was received by patients who developed transcatheter heart valve thrombosis, was investigated using high-resolution biomodelling from computed tomography scanning. Calcific blocks were extracted from a 250 CT multi-slice image for precise three-dimensional geometry image reconstruction of the root and leaflets. Results: Distortion of the stent was observed with incomplete cranial and caudal expansion of the device. The incomplete deployment of the stent was evident in the presence of uncrushed refractory bulky calcifications. This resulted in incomplete alignment of the device within the aortic root and potential dislodgment. Conclusion: A Finite Element Analysis (FEA) investigation can anticipate the presence of calcified refractory blocks, the deformation of the prosthetic stent and the development of paravalvular orifice, and it may prevent subclinical and clinical TAVR thrombosis. Here we clearly demonstrate that using exact geometry from high-resolution CT scans in association with FEA allows detection of persistent bulky calcifications that may contribute to thrombus formation after TAVR procedure.

Experimental analysis of pulsatile flow characteristics in prosthetic aortic valve models with stenosis

Bioprosthetic valves are widely used for aortic valve replacements for patients with severe aortic diseases. However, tissue-engineered leaflets normally deteriorate over time due to calcification, leading to life-threatening conditions that would require re-operation. The hemodynamics induced by a prosthetic stenosis is complicated and not fully understood. This in vitro experimental study focuses on the fluid dynamics of two aortic valve models with different prosthetic stenosis conditions. An in vitro cardiovascular flow simulator was utilized to provide the pulsatile physiological flow conditions. Phase-locked particle image velocimetry (PIV) and high-frequency pressure sensors were employed to measure the flow fields and pressure waveforms. Pressure data were evaluated for the two models representing moderate and severe stenosis conditions, respectively. The severe prosthetic stenosis induced a prolonged ejection period and increased acceleration time ratio. PIV results suggest the severe prosthetic stenosis resulted in a two-fold increase in peak jet velocity and a three-fold increase in peak turbulence kinetic energy compared to the moderate stenosis case. The severe stenosis also caused rapid expansion of the jet downstream of the valve orifice and increased eccentricity of the jet flow. The maximum Reynolds shear stress in the severe stenosis case was found similar to the bileaflet mechanical valve reported by previous literature, which was below the risk threshold of blood cell damage but could potentially increase the risks of platelet activation and aggregation.

Impact of Short-Term Complications on Mortality and Quality of Life After Transcatheter Aortic Valve Replacement

OBJECTIVES

The aim of this study was to examine the independent association of short-term complications of transcatheter aortic valve replacement (TAVR) with survival and quality of life at 1 year.

BACKGROUND

Prior studies have examined the mortality and cost implications of various complications of TAVR. However, many of these complications may primarily affect patients' quality of life after TAVR, which has not been previously studied.

METHODS

Among patients at intermediate or high surgical risk who underwent TAVR as part of the PARTNER (Placement of Aortic Transcatheter Valve) 2 studies and survived 30 days, the association between complications within the 30 days after TAVR and mortality and quality of life at 1 year was examined. Quality of life was assessed using the Kansas City Cardiomyopathy Questionnaire and the Short-Form 12. Complications assessed included major and minor stroke, life-threatening and major bleeding, vascular injury, stage 3 acute kidney injury, new pacemaker implantation, and mild and moderate or severe paravalvular leak (PVL). Multivariable models that included all complications as well as baseline clinical factors were used to examine the independent association of each complication with outcomes.

RESULTS

Among 3,763 TAVR patients, major stroke and stage 3 acute kidney injury were associated with markedly increased risk for 1-year mortality, with adjusted hazard ratios of 5.4 (95% confidence interval [CI]: 3.1 to 9.5) and 4.9 (95% CI: 2.7 to 8.8), respectively, as well as poorer quality of life among survivors (reductions in 1-year Kansas City Cardiomyopathy Questionnaire overall summary score of 15.1 points [95% CI: 24.8 to 5.3 points] and 14.7 points [95% CI: 25.6 to 3.8 points], respectively). Moderate or severe PVL, life-threatening bleeding, and major bleeding were each associated with a more modest increase in mortality and decrement in quality of life, whereas mild PVL was associated with a small decrease in quality of life. After adjusting for baseline characteristics and other complications, need for a new pacemaker, minor stroke, and vascular injury were not independently associated with poor outcomes.

CONCLUSIONS

Among patients undergoing TAVR, similar events are associated with increased mortality and impaired quality of life at 1 year. These results suggest that despite considerable progress, efforts to further reduce stroke, acute kidney injury, bleeding, and moderate or severe PVL are likely to yield important clinical benefits and remain key targets for device iteration and procedural improvement.

Trends in vascular complications and associated treatment strategies following transfemoral transcatheter aortic valve replacement

OBJECTIVE

Vascular complications (VC) and bleeding complications impact morbidity and mortality after transfemoral transcatheter aortic valve replacement (TF-TAVR). Few contemporary studies have detailed these complications, associated treatment strategies, or clinical outcomes. We examined the incidence, predictors, treatment strategies, and outcomes of VCs in a multicenter cohort of patients undergoing TF-TAVR.

METHODS

We performed a retrospective registry and chart review of all nonclinical trial TF-TAVR patients from seven centers within a five-state hospital system from 2012 to 2016. Bleeding and VC were recorded as defined by the Valve Academic Research Consortium recommendations. Procedural and 30-day outcomes and 1-year mortality were compared between patients with no, minor, or major VC. Multivariable logistic and Cox regressions were used to identify predictors of major VC and mortality, respectively.

RESULTS

Over the study period, 1573 patients underwent TF-TAVR, with 96 (6.1%) experiencing a major VC and 77 (4.9%) experiencing a minor VC. The majority of VCs were access site related (74.2%), occurred intraoperatively (52.6%), and required interventional treatment (73.2%). The site, timing, and treatment method of VCs did not significantly change over the study period. Patients with VCs had a greater need for blood transfusion, longer postoperative length of stay, higher rates of cardiac events, increased vascular-related 30-day readmission, and higher 30-day mortality. Female sex (odds ratio [OR], 3.00; 95% CI, 1.91-4.72) and prior percutaneous coronary intervention (OR, 2.14 ; 95% CI, 1.38-3.31) were the strongest predictors of major VC. VCs modestly decreased over the study period: every 90-day increase in surgery date decreased the odds of major VC by 6% (95% CI, 1%-10%). Patients with major VCs had worse 1-year survival (OR, 79%; 95% CI, 69%-86%) compared with patients with minor VCs (OR, 92%; 95% CI, 82%-96%) or no VCs (OR, 88%; 95% CI, 87%-90%; P = .002). However, for patients who survived more than 30 days, the 1-year survival did not differ between groups For patients who survived more than 30 days, male sex (hazard ratio, 1.84; 95% CI, 1.30-2.60) and the logit of STS mortality risk score (hazard ratio, 1.98; 95% CI, 1.48-2.65) were the strongest predictors of mortality. After adjusting for other factors, minor and major VC were not predictors of 1-year mortality for patients who survived more than 30 days.

CONCLUSIONS

In our contemporary cohort, VCs after TF-TAVR have modestly decreased in recent years, but continue to impact perioperative outcomes. Patient selection, consideration of alternative access routes, and prompt recognition and treatment of VCs are critical elements in optimizing early clinical outcomes after TF-TAVR.

Antithrombotic Therapy After Transcatheter Aortic Valve Implantation

The development of transcatheter aortic valve implantation has represented one of the greatest advances in the cardiology field in recent years and has changed clinical practice for patients with aortic stenosis. Despite the continuous improvement in operators’ experience and techniques, and the development of new generation devices, thromboembolic and bleeding complications after transcatheter aortic valve implantation remain frequent, and are a major concern due to their negative impact on prognosis in this vulnerable population. In addition, the optimal antithrombotic regimen in this scenario is not known, and current recommendations are mostly empirical and not evidence based. The present review aims to provide an overview of the current status of knowledge, including relevant on-going randomised trials, on antithrombotic treatment strategies after transcatheter aortic valve implantation.