The Crucial Role of Cardiac Imaging in Transcatheter Aortic Valve Replacement (TAVR): Pre- and Post-procedural Assessment

Preoperative visit-care for transcatheter aortic valve replacement: a review

AIM

The aim of this review is to evaluate and summarize the evidence for preoperative visit-care of transcatheter aortic valve replacement (TAVR) and to provide evidence-based support for clinical intervention.

DESIGN

The review presents an evidence summary report, following the standard of the Fudan University Center for Evidence-based Nursing.

METHODS

Literature related to preoperative visit-care for transcatheter aortic valve replacement have been retrieved based on the "6S" pyramid model of evidence. The types of literature included systematic reviews, expert consensus, evidence summary, and guidelines.

DATA SOURCES

Up To Date, Cochrane Library, Joanna Briggs Institute, National Institute for Health and Care Excellence, Medlive, American Heart Association, Registered Nurses Association of Ontario, Scottish Intercollegiate Guidelines Network, European Society of Cardiology, American College of Cardiology, PubMed, CINAHL, Wanfang database, VIP database, Chinese biomedical literature database, CNKI. The search period is limited to the time when each database was established until February 2024.

RESULTS

A total of 18 articles were included in this review, consisting of 1 systematic review, 1 evidence summary, 3 guidelines and 13 expert consensuses. This review summarized 30 pieces of the best evidence for preoperative visit-care for transcatheter aortic valve replacement, encompassing three evidence themes: multidisciplinary team collaboration, preoperative assessment, and preoperative education.

CONCLUSION

The study has established an ideal foundation of evidence for preoperative visit-care in TAVR. However, throughout the particular application process, it was crucial to assess the feasibility and relevance of the evidence in clinical practice by taking into account elements such as the application setting, recommendations from experts with diverse expertise, and the preferences of the patients.

Balloon Aortic Valvuloplasty in the Modern Era: A Review of Outcomes, Indications, and Technical Advances

Balloon aortic valvuloplasty (BAV) improves the hemodynamics and symptoms of patients with severe aortic stenosis in the short term with low rates of complications, but has not been shown to be an effective destination therapy. Our pooled analysis of >14,300 patients from studies published between January 1, 1991, and April 31, 2022, reported intraprocedural mortality and in-hospital mortality rates as 1.94% (95% CI, 1.39%-2.59%) and 6.02% (95% CI, 4.83%-7.32%), respectively. Hence, BAV is primarily indicated as a bridge to aortic valve replacement/decision with secondary uses as bridge to noncardiac surgery and palliative therapy. Recent advancements in alternative access sites, balloon catheters, and lithotripsy for BAV have opened opportunities for expanded use and further improvements in complication rates. As the utilization of BAV has continually increased since the advent of transcatheter aortic valve replacement, reexamining the role and outcomes of BAV in the era of transcatheter aortic valve replacement has become increasingly important. This review focuses on the outcomes, indications, advances, and technical considerations for BAV.

How to Image and Manage Prosthesis-Related Complications After Transcatheter Aortic Valve Replacement

PURPOSE OF REVIEW

In this review, we provide an overview of potential prosthesis - related complications after transcatheter aortic valve replacement, their incidences, the imaging modalities best suited for detection, and possible strategies to manage these complications.

RECENT FINDINGS

Therapy for severe aortic valve stenosis requiring intervention has increasingly evolved toward transcatheter aortic valve replacement over the past decade, and the number of procedures performed has increased steadily in recent years. As more and more centers favor a minimalistic approach and largely dispense with general anesthesia and intra-procedural imaging by transesophageal echocardiography, post-procedural imaging is becoming increasingly important to promptly detect dysfunction of the transcatheter valve and potential complications. Complications after transcatheter aortic valve replacement must be detected immediately in order to initiate adequate therapeutic measures, which require a profound knowledge of possible complications that may occur after transcatheter aortic valve replacement, the imaging modalities best suited for detection, and available treatment options.

Self-navigated versus navigator-gated 3D MRI sequence for non-enhanced aortic root measurement in transcatheter aortic valve implantation

OBJECTIVES

To prospectively compare image-quality, reliability and graft sizing of a prototype self-navigated and a navigator-gated non-contrast three dimensional (3D) whole-heart magnetic-resonance-angiography (MRA) sequence with computed-tomography-angiography (CTA) for planning transcatheter-aortic-valve-implantation (TAVI).

METHODS

Self- and navigator-gated 1.5 T MRA were performed in 27 patients (aged 83 ± 5 years, 41 % male) for aortic root sizing and coronary ostia height measurements; 15 (56 %) patients underwent additional CTA. Subjective-image quality was graded on a 4-point Likert scale, objective MRA image-quality was assessed by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Continuous MRA and CTA measurements were analyzed with regression and Bland-Altman analysis, valve sizing by kappa statistics.

RESULTS

Median image-quality as rated by two observers was 1.5 [interquartile range (IQR) 1-3] for self-navigated MRA and 1 [IQR 1-2] for navigator-gated MRA (p = 0.059). SNR and CNR were comparable between MRA sequences (p = 0.471 and 0.445, respectively). Acquisition time was shorter for self-navigated MRA compared to navigator-gated MRA (5.5 ± 1 min vs, 6.5 ± 2 min, p = 0.029). Inter-observer correlation of aortic root measurements was high to very high for both self- and navigator-gated MRA (r = 0.75 to 0.94 and r = 0.85 to 0.96, respectively, all p < 0.0001). Theoretical prosthetic valve sizing of self-navigated MRA and CTA was equivalent (κ = 1). However, in four patients (15 %) one coronary ostium each (right coronary artery 3, left main artery 1) was not clearly definable on self-navigated MRA.

CONCLUSION

Self-navigated MRA enables aortic annulus TAVI measurements without significant difference to navigator-gated MRA at shortened acquisition time. Prosthesis sizing by self-navigated MRA measurements is equivalent to navigator-gated MRA and CTA-based choice.

Non-contrast MRI protocol for TAVI guidance: quiescent-interval single-shot angiography in comparison with contrast-enhanced CT

Objectives

To prospectively compare unenhanced quiescent-interval single-shot MR angiography (QISS-MRA) with contrast-enhanced computed tomography angiography (CTA) for contrast-free guidance in transcatheter aortic valve intervention (TAVI).

Methods

Twenty-six patients (mean age 83 ± 5 years, 15 female [58%]) referred for TAVI evaluation underwent QISS-MRA for aortoiliofemoral access guidance and non-contrast three-dimensional (3D) “whole heart” MRI for prosthesis sizing on a 1.5-T system. Contrast-enhanced CTA was performed as imaging gold standard for TAVI planning. Image quality was assessed by a 4-point Likert scale; continuous MRA and CTA measurements were compared with regression and Bland-Altman analyses.

Results

QISS-MRA and CTA-based measurements of aortoiliofemoral vessel diameters correlated moderately to very strong (r = 0.572 to 0.851, all p ≤ 0.002) with good to excellent inter-observer reliability (intra-class correlation coefficient (ICC) = 0.862 to 0.999, all p < 0.0001) regarding QISS assessment. Mean diameters of the infrarenal aorta and iliofemoral vessels differed significantly (bias 0.37 to 0.98 mm, p = 0.041 to < 0.0001) between the two modalities. However, inter-method decision for transfemoral access route was comparable (κ = 0.866, p < 0.0001). Aortic root parameters assessed by 3D whole heart MRI strongly correlated (r = 0.679 to 0.887, all p ≤ 0.0001) to CTA measurements.

Conclusion

QISS-MRA provides contrast-free access route evaluation in TAVI patients with moderate to strong correlations compared with CTA and substantial inter-observer agreement. Despite some significant differences in minimal vessel diameters, inter-method agreement for transfemoral accessibility is strong. Combination with 3D whole heart MRI facilitates unenhanced TAVI guidance.

Key Points

• QISS-MRA and CTA inter-method agreement for transfemoral approach is strong.

• QISS-MRA is a very good alternative to CTA and MRA especially in patients with Kidney Disease Outcomes Quality Initiativestages 4 and 5.

• Combination of QISS-MRA and 3D “whole heart” MRI facilitates fully unenhanced TAVI guidance.

Normal values for Doppler echocardiographic assessment of prosthetic valve function after transcatheter aortic valve replacement: a systematic review and meta-analysis

Transcatheter aortic valve replacement has emerged as valuable treatment modality for patients with severe aortic stenosis and an unacceptable risk/benefit ratio for open heart surgery, but particularities specific to TAVR and a rapidly growing number of available TAVR prosthesis make post-procedural assessment of valve function challenging. Aim of the present analysis was to collect and pool all available data currently in the literature regarding normal doppler values for transcatheter prosthetic heart valves and to provide a comprehensive overview. A PRISMA checklist-guided systematic review and meta-analysis of prospective observational studies or national and device specific registries or randomized clinical trials was conducted. Studies were identified by searching PUBMED, SCOPUS, Cochrane Central Register of Controlled Trials and LILACs from January 2000 to March 2017. Out of 240 abstracts, 155 studies reporting echocardiographic parameter for twelve different valves prosthesis in a total of 27,159 patients were in included in this meta-analysis. The means and standard deviations of peak velocity, peak gradient, mean gradient and effective orifice were extracted and pooled from the included studies. The pooled means and standard deviations for all available TAVR prosthesis were classified according to implanted valve size and time since implantation. The present study firstly describes a pooled analysis of normal values for all available TAVR prosthesis in order to empower treating physicians with a reliable tool to perform follow-up echocardiographic assessment in TAVR patients and to safely identify patients with prostheses dysfunction.

Age, comorbidity, life expectancy, and pulmonary nodule follow-up in older veterans

Background

Pulmonary nodule guidelines do not indicate how to individualize follow-up according to comorbidity or life expectancy.

Objectives

To characterize comorbidity and life expectancy in older veterans with incidental, symptom-detected, or screen-detected nodules in 2008–09 compared to 2013–14. To determine the impact of these patient factors on four-year nodule follow-up among the 2008–09 subgroup.

Design

Retrospective cohort study.

Setting

Urban Veterans Affairs Medical Center.

Participants

243 veterans age ≥65 with newly diagnosed pulmonary nodules in 2008–09 (followed for four years through 2012 or 2013) and 446 older veterans diagnosed in 2013–14.

Measurements

The primary outcome was receipt of any follow-up nodule imaging and/or biopsy within four years after nodule diagnosis. Primary predictor variables included age, Charlson-Deyo Comorbidity Index (CCI), and life expectancy. Favorable life expectancy was defined as age 65–74 with CCI 0 while limited life expectancy was defined as age ≥85 with CCI ≥1 or age ≥65 with CCI ≥4. Interaction by nodule size was also examined.

Results

From 2008–09 to 2013–14, the number of older veterans diagnosed with new pulmonary nodules almost doubled, including among those with severe comorbidity and limited life expectancy. Overall among the 2008–09 subgroup, receipt of nodule follow-up decreased with increasing comorbidity (CCI ≥4 versus 0: adjusted RR 0.61, 95% CI 0.39–0.95) with a trend towards decreased follow-up among those with limited life expectancy (adjusted RR 0.69, 95% CI 0.48–1.01). However, we detected an interaction effect with nodule size such that comorbidity and life expectancy were associated with decreased follow-up only among those with nodules ≤6 mm.

Conclusions

We found some individualization of pulmonary nodule follow-up according to comorbidity and life expectancy in older veterans with smaller nodules only. As increased imaging detects nodules in sicker patients, guidelines need to be more explicit about how to best incorporate comorbidity and life expectancy to maximize benefits and minimize harms for patients with nodules of all sizes.

Computed Tomography Assessment for Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement has become a mainstream therapeutic option for patients with severe aortic stenosis who are at intermediate risk or high risk for surgical valve replacement. Computed tomography (CT) is now the standard imaging modality for preoperative vascular access planning an aortic annular sizing. This article reviews the established and potential future roles of CT in transcatheter aortic valve replacement.

Standard imaging techniques in transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has become a widely accepted therapeutic option for patients with severe, symptomatic aortic stenosis at intermediate, high, or extreme risk for conventional surgery as determined through a heart team approach. Two valve prostheses are currently available and the Food and Drug Administration (FDA) approved in the United States for TAVR: the self-expandable Medtronic CoreValve (Medtronic, Inc., Minneapolis, MN, USA) and the balloon-expandable Edwards Sapien Valve (Edwards Lifesciences, Irvine CA, USA). The preoperative evaluation for TAVR includes transthoracic echocardiography (TTE) for the diagnosis of aortic stenosis. Cardiac computed tomography (CTA) has become the imaging modality of choice for annular sizing. Aortic root dimensions and coronary ostia height, and the degree of annular and left ventricular outflow tract calcification are also assessed to estimate the risk of coronary obstruction, annular rupture, and postoperative aortic regurgitation. Finally, CTA is essential to determine the adequacy of the peripheral vasculature for a transfemoral approach. Intraoperatively, fluoroscopy is mandatory for valve positioning, whereas the use of TTE or transesophageal echocardiography (TEE) varies by center. TTE is used for postoperative surveillance of valve function.