Prospective validation of a risk score to predict pacemaker implantation after transcatheter aortic valve replacement

INTRODUCTION

The need for pacemaker is a common complication after transcatheter aortic valve replacement (TAVR). We previously described the Emory Risk Score (ERS) to predict the need for new pacemaker implant (PPM) after TAVR. Metrics included in the score are a history of syncope, pre-existing RBBB, QRS duration ≥140 ms, and prosthesis oversizing ≥16%. To prospectively validate the previously described risk score.

METHODS

We prospectively evaluated all patients without pre-existing pacemakers, ICD, or pre-existing indications for pacing undergoing TAVR with the Edwards SAPIEN 3 prosthesis at our institution from March 2019 to December 2020 (n = 661). Patients were scored prospectively; however, results were blinded from clinical decision-making. The primary endpoint was PPM at 30 days after TAVR. Performance of the ERS was evaluated using logistic regression, a calibration curve to prior performance, and receiver operating characteristic (ROC) analysis.

RESULTS

A total of 48 patients (7.3%) had PPM after TAVR. A higher ERS predicted an increased likelihood of PPM (OR 2.61, 95% CI: 2.05-3.25 per point, p < 0.001). There was good correlation between observed and expected values on the calibration curve (slope = 1.04, calibration at large = 0.001). The area under the ROC curve was 0.81 (95% CI [0.74-0.88], p < 0.001).

CONCLUSIONS

The ERS prospectively predicted the need for PPM in a serial, real-world cohort of patients undergoing TAVR with a balloon-expandable prosthesis, confirming findings previously described in retrospective cohorts. Notably, the prospective performance of the score was comparable with that of the initial cohorts. The risk score could serve as a framework for preprocedural risk stratification for PPM after TAVR.

Hemodynamic Performance of Two Current-Generation Transcatheter Heart Valve Prostheses in Severely Calcified Aortic Valve Stenosis

BACKGROUND

Treatment of severely calcified aortic valve stenosis is associated with a higher rate of paravalvular leakage (PVL) and permanent pacemaker implantation (PPI). We hypothesized that the self-expanding transcatheter heart valve (THV) prostheses Evolut Pro (EPro) is comparable to the balloon-expandable Sapien 3 (S3) regarding hemodynamics, PPI, and clinical outcome in these patients.

METHODS

From 2014 to 2019, all patients with very severe calcification of the aortic valve who received an EPro or an S3 THV were included. Propensity score matching was utilized to create two groups of 170 patients.

RESULTS

At discharge, there was significant difference in transvalvular gradients (EPro vs. S3) (dPmean 8.1 vs. 11.1 mmHg, p ≤ 0.001) and indexed effective orifice area (EOAi) (1.1 vs. 0.9, p ≤ 0.001), as well as predicted EOAi (1 vs. 0.9, p ≤ 0.001). Moderate patient prosthesis mismatch (PPM) was significantly lower in the EPro group (17.7% vs. 38%, p ≤ 0.001), as well as severe PPM (2.9% vs. 8.8%, p = 0.03). PPI and the PVL rate as well as stroke, bleeding, vascular complication, and 30-day mortality were comparable.

CONCLUSIONS

In patients with severely calcified aortic valves, both THVs performed similarly in terms of 30-day mortality, PPI rate, and PVL occurrence. However, patient prothesis mismatch was observed more often in the S3 group, which might be due to the intra-annular design.

The effect of the learning curve on paravalvular aortic regurgitation and mid-term mortality in transfemoral transcatheter aortic valve implantation

OBJECTIVE

Paravalvular aortic regurgitation is an important independent mortality predictor in transcatheter aortic valve implantation (TAVI). Our study evaluated the association between paravalvular aortic regurgitation and mid-term mortality in relation with the learning curve, in patients with severe aortic stenosis who underwent transfemoral TAVI in the first 3 years since the establishment of the program.

METHODS

Patients with severe aortic stenosis who underwent transfemoral TAVI between 2017 and 2020 were included in the analysis. Paravalvular aortic regurgitation was assessed by transthoracic echocardiography at 48 hours after the procedure. All-cause mortality was evaluated after 30 days and at mid-term follow-up.

RESULTS

Paravalvular aortic regurgitation ≥grade II was associated with mid-term all-cause mortality (OR 4.4; 95%CI 1.82-11.55; p < 0.001), their prevalence declining after the first 60 cases. Baseline characteristics did not significantly differ in the first 60 patients from the rest of the cohort. Male sex (p = 0.006), advanced age (p = 0.04), coronary artery disease (p = 0.003), or elevated STS Score (p = 0.02) influenced mid-term survival. When adjusting for the presence of these factors, only age (OR 1.1; 95%CI 1.0-1.2), paravalvular aortic regurgitation ≥grade II (OR 3.9; 95%CI 1.3-12.9), and the number of days spent in the intensive care unit (OR 1.4; 95%CI 1.1-1.8) were independent predictors of mid-term all-cause mortality.

CONCLUSIONS

In a group of patients with severe aortic stenosis who underwent transfemoral TAVI in the first 3 years since the establishment of the program, paravalvular aortic regurgitation ≥grade II was associated with mid-term mortality, both declining after the first 60 cases.

Conduction delays after transcatheter aortic valve implantation with balloon-expandable prosthesis and high implantation technique

Performing transcatheter aortic valve implantation with high implantation technique, i.e. with an aorto-ventricular ratio > 60/40, reduces the need of permanent pacemaker implantation. Valve calcification and prosthesis oversizing are predictors of permanent pacemaker implantation, but there are no available data on their role when transcatheter aortic valve implantation is performed with an aorto-ventricular ratio > 60/40. The aim of this study was to evaluate the effect of leaflets/annulus calcification and prosthesis oversizing on the incidence of permanent pacemaker implantation after transcatheter aortic valve implantation with a high implantation technique. Transcatheter aortic valve implantation was performed in 48 patients implanting a balloon-expandable transcatheter heart valve with an aorto-ventricular ratio > 60/40. Calcium burden was assessed by preprocedural multidetector computed tomography. An invasive electrophysiological study was performed before and after transcatheter aortic valve implantation. Five patients (10.4%) needed permanent pacemaker implantation. At univariate analysis, baseline right bundle branch block and postprocedural PR, QRS and His-ventricular interval elongation significantly predicted permanent pacemaker implantation (p < 0.05). Receiver-operating characteristic curve analysis showed a correlation between transcatheter heart valve oversizing and permanent pacemaker implantation need, with the best cut-off being 17% (AUC = 0.72, p = 0.033). Linear regression analysis demonstrated that QRS complex elongation was related to total, left and non-coronary leaflet calcification (p < 0.05). This study demonstrates that, when transcatheter aortic valve implantation is performed using a balloon-expandable transcatheter heart valve deployed with an aorto-ventricular ratio > 60/40, the presence of leaflets/annulus calcification or the need to oversize the prosthesis correlate with the occurrence of pathological cardiac conduction delays.

Degree of valve calcification in patients undergoing transfemoral transcatheter aortic valve implantation with and without balloon aortic valvuloplasty: Findings from the multicenter EASE-IT TF registry

AIMS

We aimed to assess whether the level of aortic root calcification is associated with BAV performance/omission during transcatheter aortic valve implantation (TAVI), and to explore related outcomes.

METHODS AND RESULTS

EASE-IT TF was a prospective, observational, multicenter registry of patients undergoing TF-TAVI with the Edwards SAPIEN 3, with or without BAV predilation. Valvular calcification was quantified from pre-procedural multi-slice computed tomography images and compared between BAV and no BAV patients. Data for 178 patients (55 BAV; 123 no BAV) were analyzed. There were no significant differences between groups in terms of regional/leaflet sector calcification volumes, maximum asymmetry between the different leaflet sectors, or total calcification scores. Overall, a greater-than-average leaflet calcification volume was independently predictive of ≥mild PVL (OR: 5.116; 95% CI: 1.042-38.35) and the need for post-dilation (OR: 3.592; 95% CI: 1.173-12.14). The latter effect was abated in patients with BAV (OR: 1.837; 95% CI: 0.223-18.00) and intensified in those without BAV (OR: 5.575; 95% CI: 1.114-38.74). No other BAV-dependent effects of calcification on outcomes were observed.

CONCLUSIONS

In the majority of transfemoral valve implantations, calcification does not appear to be the main driving factor in the decision to perform/omit BAV. Predilation may be valuable for reducing post-dilation requirements in patients only with a greater degree of leaflet calcification.

The role of echocardiography in transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is an effective and less invasive treatment for the increasing population of individuals with severe aortic stenosis (AS). Echocardiography is crucial in the assessment of AS patients from pre- to post-procedure. Transthoracic echocardiography (TTE) may be used to assess patient suitability for TAVI, as well as evaluate the severity of AS, the aortic valve complex, aortic valve morphology, mitral regurgitation (MR), and left ventricular function. Transesophageal echocardiography (TEE) is usually used as an intra-procedural monitoring tool to provide feedback during the procedure, to assess prosthetic valve function, and to detect complications rapidly before and after balloon aortic valvuloplasty (BAV) or transcatheter heart valve (THV) deployment. In this review, the role of echocardiography in the pre-, intra-, and post-TAVI procedure periods is described in detail.

Clinical utility of a predictive model for paravalvular aortic regurgitation after transcatheter aortic valve implantation with a self-expandable prosthesis

Background

Methods

Results

Conclusion

A correlation between long-term in vitro dynamic calcification and abnormal flow patterns past bioprosthetic heart valves

In this paper, a long-term in vitro dynamic calcification of three porcine aortic heart valves was investigated using a combined approach that involved accelerated wear testing of the valves in the rapid calcification solution, hydrodynamic assessment of the progressive change of effective orifice area (EOA) along with the transaortic pressure gradient, and quantitative visualization of the flow. The motivation for this study was developing a standardized, economical, and feasible in vitro testing methodology for bioprosthetic heart valve calcification, which would address both the hydrodynamic performance of the valves as well as the subsequent changes in the flow field. The results revealed the failure of the test valves at 40 million cycles mark, associated with the critical decrease in the EOA, followed by the increase in the maximum value of viscous shear stress of up to 52%, compared to the values measured at the beginning of the study. The decrease in the EOA was subsequently followed by the rapid increase in the maximum streamwise velocity of the central orifice jet up to the value of about 2.8 m/s, compared to the initial value of 2 m/s, and to the value of 2.2 m/s in the case of a control valve along with progressive narrowing of the velocity profile for two test valves. The significance of the current work is in demonstrating a correlation between calcification of the aortic valve and spatial as well as the temporal development of abnormal flow features.

Prediction of paravalvular leakage after transcatheter aortic valve implantation

Significant paravalvular leakage (PVL) after transcatheter aortic valve implantation (TAVI) is related to patient mortality. Predicting the development of PVL has focused on computed tomography (CT) derived variables but literature targeting CoreValve devices is limited, controversial, and did not make use of standardized echocardiographic methods. The study included 164 consecutive patients with severe aortic stenosis that underwent TAVI with a Medtronic CoreValve system©, with available pre-TAVI CT and pre-discharge transthoracic echocardiography. The predictive value for significant PVL of the CT-derived Agatston score, aortic annulus size and eccentricity, and “cover index” was assessed, according to both echocardiographic Valve Academic Research Consortium (VARC) criteria and angiographic Sellers criteria. Univariate predictors for more than mild PVL were the maximal diameter of the aortic annulus size (for both angiographic and echocardiographic assessment of PVL), cover index (for echocardiographic assessment of PVL only), and Agatston score (for both angiographic and echocardiographic assessment of PVL). The aortic annulus eccentricity index was not predicting PVL. At multivariate analysis, Agatston score was the only independent predictor for both angiographic and echocardiographic assessment of PVL. Agatston score is the only independent predictor of PVL regardless of the used imaging technique for the definition of PVL.

A revised methodology for aortic-valvar complex calcium quantification for transcatheter aortic valve implantation

AIMS

We sought to optimize a method for quantification of the calcium in the aortic-valvar complex for the prediction of significant paravalvular leak (PVL) after transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

All patients had severe symptomatic aortic stenosis and were treated with balloon-expandable TAVI (Sapien/Sapien-XT, Edwards Lifesciences LLC, Irvine, CA, USA). In order to correct for precise annular sizing, only patients with available contrast computed tomography (CT) data for measurements were included (n = 198). Paravalvular leak was quantified using peri-procedural transoesophageal echocardiography by Valve Academic Research Consortium-2 (VARC-2) criteria (grade ≥ moderate was considered significant). A detailed region-of-interest methodology separated quantification of calcium in each of the aortic leaflets to that in the left ventricular outflow tract (LVOT) and was used to predict PVL in receiver operator characteristic curve analyses. For non-contrast scans, the greatest discriminatory value for PVL was seen at the 450 Hounsfield Unit (HU) threshold for detection (volume ≥626 mm(3)), whereas for contrast scans it was at 850 HU (≥235 mm(3)). Left ventricular outflow tract calcium predicted PVL but only as a binary variable with no incremental value of quantification. In a multivariable binary logistic regression model, annulus area ≥ prosthesis area (OR 3.5, 95% CI 1.5-8.2, P = 0.005), contrast leaflet calcium volume (850-HU threshold) ≥235 mm(3) (OR 2.8, 95% CI 1.2-6.7, P = 0.023), and presence of LVOT calcium (OR 2.8, 95% CI 1.2-7.0, P = 0.022) were independent predictors for PVL ≥ moderate.

CONCLUSION

Both leaflet and LVOT calcium are significant predictors of PVL and exert an important synergistic influence on this complication, even in appropriately sized valves. With careful attention to thresholds for detection, clinically relevant leaflet calcium volumes can be identified with either non-contrast or contrast CT scans.

Aortic regurgitation after transcatheter aortic valve implantation: mechanisms and implications

In recent years, transcatheter aortic valve implantation (TAVI) has become an established treatment option for selected high-risk patients with severe aortic stenosis (AS). Favorable results with regard to both hemodynamics and clinical outcome have been achieved with transcatheter valves. Aortic regurgitation (AR) remains a major concern after TAVI. Echocardiography is the imaging modality of choice to assess AR in these patients due to its wide accessibility and low cost. Mostly mild residual AR has been observed in up to 70% of patients. However, as even a mild degree of AR has been associated with a decreased survival up to two years after TAVI, accurate evaluation and classification of AR is important. AR in transcatheter valves can be divided into three types according to different pathophysiological mechanisms. Besides the well-known transvalvular and paravalvular forms of regurgitation, a third form termed supra-skirtal has recently been observed. A thorough understanding of AR in transcatheter valves may allow to improve device design and implantation techniques to overcome this complication. The aim of this review is to provide an overview of the three types of AR after TAVI focussing on the different pathophysiological mechanisms.

Transcatheter aortic valve replacement in patients with severe aortic stenosis who are at high risk for surgical complications: summary assessment of the California Technology Assessment Forum

BACKGROUND

The California Technology Assessment Forum is dedicated to assessment and public reporting of syntheses of available data on medical technologies. In this assessment, transcatheter aortic valve replacement (TAVR) was evaluated for patients with severe aortic stenosis (AS) who are at high risk for complications.

METHODS AND RESULTS

In this assessment, 5 criteria were used: Regulatory approval, sufficient scientific evidence to allow conclusions on effectiveness, evidence that the technology improves net health outcomes, evidence that the technology is as beneficial as established methods, and availability of the technology outside investigational settings. In this assessment, all 5 criteria were judged to have been met. The primary benefit of TAVR is the ability to treat AS in patients who would otherwise be ineligible for surgical aortic valve replacement. It may also be useful for patients at high surgical risk by potentially reducing periprocedural complications and avoiding the morbidity and recovery from undergoing heart surgery. Potential harms include the need for conversion to an open procedure, perioperative death, myocardial infarction, stroke, bleeding, valve embolization, aortic regurgitation, heart block that requires a permanent pacemaker, renal failure, pulmonary failure, and major vascular complications such as cardiac perforation or arterial dissection. Potential long-term harms include death, stroke, valve failure or clotting, and endocarditis. As highlighted at the February 2012 California Technology Assessment Forum meeting, the dispersion of this technology to new centers across the United States must proceed with careful thought given to training and proctoring multidisciplinary teams to become new centers of excellence.

CONCLUSIONS

TAVR is a potentially lifesaving procedure that may improve quality of life for patients at high risk for surgical AVR. However, attention needs to be paid to appropriate patient selection, their preoperative evaluation, surgical techniques, and postoperative care to preserve and improve on the results attained in the Placement of Aortic Transcatheter Valve trial. Specialty societies are collaborating to ensure that this happens in a rational and comprehensive manner.

Impact of aortic valve calcification severity and impaired left ventricular function on 3-year results of patients undergoing transcatheter aortic valve replacement

OBJECTIVES

To evaluate clinical pre-interventional predictors of 3-year outcome and mortality in high-risk patients with severe aortic valve stenosis treated with transcatheter aortic valve implantation (TAVI).

METHODS

Among 367 patients included in the Aachen TAVI registry, 76 patients with baseline dual-source computed tomography (DSCT) for the quantification of aortic valve calcification (AVC) and a 3-year follow-up were identified.

RESULTS

Survival at 30 days was 91 %, and it was 75 %, 66 % and 64 % at 1, 2 years and 3 years, respectively. Non-survivors at 3 years showed a significantly higher Agatston AVC score (2,854 ± 1,651) than survivors (1,854 ± 961, P = 0.007). Multivariate analysis including age, logistic EuroScore, glomerular filtration rate, Agatston AVC score, ejection fraction < 40 %, NYHA class, baseline medication, chronic lung disease and aortic regurgitation revealed that only the Agatston AVC score (P = 0.03) and impaired left ventricular function (P = 0.001) was significantly associated with mortality. Patients with Agatston AVC scores >2,000 had a significantly lower 3-year survival rate compared with patients with scores <2,000 (47 % vs 79 %, P = 0.004).

CONCLUSIONS

In patients referred for TAVI, aortic valve calcification severity and impaired left ventricular function may serve as a predictor of long-term mortality. Therefore, AVC scores easily determined from pre-procedural CT datasets may be used for patient risk stratification.

The evolving role of cardiac imaging in percutaneous valvular intervention

Surgical therapies have represented the primary evidence-based intervention to alter the natural history of valvular heart disease (VHD), however, the increasing incidence of patients at high surgical risk due to age and related co-morbid conditions has given rise to the need for alternative strategies. Thus, percutaneous approaches to VHD therapy have emerged as an important therapeutic option. Cardiovascular imaging plays a critical role in patient screening for percutaneous valvular interventions, during the procedure itself, and as part of follow-up for the identification of implant success/failure and complications. The technical demands on imaging in this context are highly specific. Although imaging has a significant role in the broader evaluation of valvular heart disease mechanism and severity, the purpose of this paper is to summarise the particular goals of cardiovascular imaging in the work-up for, during, and in the follow-up of percutaneous valvular intervention.