Transcatheter aortic valve implantation: the procedure

Computed tomography imaging in preprocedural planning of transcatheter valvular heart interventions

Cardiac Computed Tomography (CCT) has become a reliable imaging modality in cardiology providing robust information on the morphology and structure of the heart with high temporal and isotropic spatial resolution. For the past decade, there has been a paradigm shift in the management of valvular heart disease since previously unfavorable candidates for surgery are now provided with less-invasive interventions. Transcatheter heart valve interventions provide a real alternative to medical and surgical management and are often the only treatment option for valvular heart disease patients. Successful transcatheter valve interventions rely on comprehensive multimodality imaging assessment. CCT is the mainstay imaging technique for preprocedural planning of these interventions. CCT is critical in guiding patient selection, choice of procedural access, device selection, procedural guidance, as well as allowing postprocedural follow-up of complications. This article aims to review the current evidence of the role of CCT in the preprocedural planning of patients undergoing transcatheter valvular interventions.

Racial Disparity Among Patients Undergoing Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Replacement in the United States

Transcatheter aortic valve replacement (TAVR) has emerged as a minimally invasive alternative to surgical aortic valve replacement (SAVR). However, racial disparities in the utilization of TAVR persist. This meta-analysis attempts to determine whether the prevalence of adverse outcomes (procedure-related complications) represent barriers to the use of TAVR among African Americans (AA). The TAVR cohort consisted of 89.6% Caucasian (C) and 4.7% AA, while the SAVR cohort included 86.9% C and 6.4% AA. The utilization rate (UR) of TAVR was 1.48 and .35 among C and AA, respectively, while the UR of SAVR was 1.44 and .48 among C and AA, respectively. Following TAVR, for AA the odds ratio (OR) was greater for stroke (OR = 1.22, P = .02) and transient ischemic attack (TIA) (OR = 1.57, P < .001) and lower for undergoing the insertion of a permanent pacemaker (OR = .81, P < .001). While there was a significant difference between C and AA in TAVR and SAVR utilization, outcomes between groups following TAVR are comparable; therefore, adverse outcomes do not appear to be a barrier to the use of TAVR among eligible AA.

Left atrial function index (LAFI) and outcome in patients undergoing transcatheter aortic valve replacement

Background

Clinical data regarding the association between the left atrial function index (LAFI) and outcome in patients undergoing transcatheter aortic valve replacement (TAVR) are limited.

Objectives

We aimed to investigate the association between the left atrial function index (LAFI) and outcome in patients undergoing TAVR.

Methods

In this retrospective multicenter study, we assessed baseline LAFI in 733 patients undergoing TAVR for severe aortic stenosis in two German high-volume centers between 2008 and 2019. Based on receiver operating characteristic curves, patients were stratified according to their baseline LAFI into two groups (LAFI ≤ 13.5 vs. LAFI > 13.5) and assessed for post-procedural outcome. The primary endpoint of our study was the 1-year all-cause mortality.

Results

Patients with a LAFI ≤ 13.5 had significantly more often atrial fibrillation (p < 0.001), lower LVEF (p < 0.001) and higher levels of NT-proBNP (p < 0.001). After TAVR, a significant improvement in the LAFI as compared to baseline was observed at 12 months after the procedure (28.4 vs. 32.9; p = 0.001). Compared to patients with a LAFI > 13.5, those with a LAFI ≤ 13.5 showed significantly higher rate of 1-year mortality (7.9% vs. 4.0%; p = 0.03). A lower LAFI has been identified as independent predictor of mortality in multivariate analysis (HR (95% CI) 2.0 (1.1–3.9); p = 0.03).

Conclusion

A reduced LAFI is associated with adverse outcome and an independent predictor of mortality in TAVR patients. TAVR improves LAFI within 12 months after the procedure.

Graphical abstract

Left Atrial Function Index (LAFI) in Patients undergoing Transcatheter Aortic Valve Implantation. A Kaplan–Meier survival analysis of 1-year all-cause mortality in patients with LAFI ≤ 13.5 compared with patients with LAFI > 13.5. Comparing rates of 1-year all-cause mortality between the different LAFI groups, we found a significant association between left atrial function and mortality. LAFI Left atrial function index. B Comparison of the mean LAFI before and after TAVR. After long-term follow-up the LAFI improved significantly. LAFI Left atrial function index; FU follow-up. C Assessment of the left atrial function index using the pre-procedural transthoracic echocardiography. A Measurement of the minimal left atrial volume (LAEDV). B Assessment of the maximal left atrial volume (LAESV).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-022-02010-5.

Transcatheter aortic valve replacement in patients with severe comorbidities: A retrospective cohort study

OBJECTIVE

To investigate the long-term outcomes of patients with severe comorbidities (sCM) undergoing transcatheter aortic valve replacement (TAVR).

BACKGROUND

The benefit of TAVR may be limited among patients with sCM due to a lack of mortality- or quality-of-life-benefit.

METHODS

All TAVR patients in the Allina Health System between January 1, 2011 and August 7, 2018 were included (n = 890, 82 ± 8 years, 55% men). sCM included: severe lung disease, severe liver disease, end-stage renal disease, severe, severe dementia, severe dilated cardiomyopathy, and frailty. Outcomes between patients with (n = 215, 24%) and without (n = 675, 76%) sCM were compared.

RESULTS

At baseline, patients with sCM had worse symptoms, higher STS-PROM and a lower Kansas City Cardiomyopathy Questionnaire (KCCQ) score compared to those without. During a median follow-up of 15 months (IQR, 7-29 months), there were 208 (23%) deaths. Patients with sCM had a lower 3-year survival free from all-cause mortality (40% vs. 79%, p < .001), and lower 3-year survival free from the composite endpoint of all-cause mortality, re-hospitalization for heart failure, myocardial infarction or stroke (31% vs. 64%, p < .001) compared to those without sCM. The estimated monthly increase in KCCQ scores following TAVR was 1.5, 95%CI (1.3, 1.7), p < .001 irrespective of sCM grouping. From Cox regression analysis, severe comorbidities, with the exception of liver disease, were associated with an increased risk of all-cause mortality and any additional comorbidity was associated with a multiplicative increase in risk of mortality of 2.8 (95%CI 2.3, 3.6), p < .001.

CONCLUSIONS

TAVR patients with sCM have poor 3-year outcomes but may experience improvements in their quality of life.

[Management of non-rhythmic complications of TAVI procedures]

Transcatheter aortic valve (TAVI) is the treatment of choice in patients with severe symptomatic aortic stenosis at high surgical risk. Recent data have also shown favorable results in patients considered to have an intermediate operative risk, which broadens the application of this new technology. Despite its success, the TAVI procedure has been associated with life-threatening complications. Advances in preoperative screening and patient selection have reduced the incidence of these complications. When these complications occur, early recognition and rapid management are essential. The purpose of this review is to describe non-rhythmic mechanical complications attributable to TAVI procedures with their predictive factors, how to prevent and manage them.

Prospective Evaluation for Hypoattenuated Leaflet Thickening Following Transcatheter Aortic Valve Implantation

Prospective investigations for the frequency of hypoattenuated leaflet thickening (HALT) and its clinical implications in transcatheter aortic valve implantation (TAVI) patients are limited. We initiated a prospective screening program of TAVI patients for HALT beginning in July 2015. Eligible patients were evaluated with gated, contrast-enhanced multidetector computed tomography within 30 days of TAVI, and examined for HALT and clinical outcomes. During the study period, 287 patients (81 ± 8 years; 53% men) who underwent TAVI with commercially approved devices were examined. Overall, 26 patients (9.1%) had occurrence of HALT, and only one of these patients had detectable hemodynamic changes on echocardiography at diagnosis. Notably, 9 of 26 HALT patients had been receiving warfarin, however, the HALT patients more often had subtherapeutic international normalized ratio whereas using warfarin than patients without HALT on index multidetector computed tomography imaging (p = 0.01). Patients who developed HALT had lower baseline aortic gradient, valvuloarterial impedance, and peak aortic velocity, and more commonly had been treated with balloon-expandable valves (73% of all HALT cases) with a higher incidence among those who received larger prostheses. All patients with HALT were placed on anticoagulation at diagnosis, and valvular function remained unchanged at follow-up. Two patients with HALT (7.7%) experienced ischemic stroke. A statistical trend for more major adverse clinical events was present in HALT patients. In conclusion, HALT was detected in 9% of TAVI cases in this prospective observational cohort, with a greater frequency in patients with large, balloon-expandable prostheses. Prospective screening may be considered as early HALT is reversible by timely therapeutic anticoagulation.

Feasibility and Outcomes of Transcatheter Aortic Valve Implantation Using the Left Axillary Artery as Primary Access Site

BACKGROUND

The femoral artery is generally used as primary access for transcatheter aortic valve implantation. However, peripheral artery disease often precludes femoral access. The purpose of this study was to describe clinical outcome of transcatheter aortic valve implantation using the left axillary artery (LAA) as primary access site.

METHODS

From December 2008 until June 2016, data on all consecutive patients treated with a Medtronic device through the LAA at our hospital were registered, and outcome was prospectively collected according to the updated Valve Academic Research Consortium-2 criteria. Mortality check was performed nationally.

RESULTS

In total, 362 patients were included (median age 80 years [range, 76 to 84]; logistic European System for Cardiac Operative Risk Evaluation 17% ± 12%). Successful axillary access was achieved in 99%. Medtronic CoreValve (86%) and Evolut R (14% [Medtronic, Minneapolis, MN]) were implanted. Major vascular complications occurred in 5% of patients, 1% was LAA related. Life-threatening bleeding and major bleeding were observed in 2% and 10%, respectively. Additional complications were new left bundle branch blood (30%), new permanent pacemaker (11%), and stroke (1%). There were 6 procedural deaths (2%) and 19 deaths (5%) within 30 days. One-year mortality rate was 19%.

CONCLUSIONS

This is the first study reporting outcome after transcatheter aortic valve implantation using the LAA as default access. We conclude that it is highly feasible and safe with low rates of major vascular complications, bleeding, and stroke.

Updates on transcatheter aortic valve replacement: Techniques, complications, outcome, and prognosis

Transcatheter aortic valve replacement (TAVR) initially emerged as a therapeutic option for high-risk patients with severe aortic stenosis. Advancement in technologies since the first era of TAVRs, experience from previous obstacles, and lessons learned from complications have allowed the evolution of this procedure to the current state. This review focuses on the updates on the most current devices, complications, and outcomes of TAVR.

Impact of coronary artery disease in patients undergoing transfemoral transcatheter aortic valve implantation

BACKGROUND

The impact of coronary artery disease (CAD) and revascularization on outcome in patients undergoing transcatheter aortic valve implantation (TAVI) has not been fully elucidated so far.

OBJECTIVES

To assess whether the degree of CAD influences the prognosis of patients undergoing TAVI.

METHODS

Before TAVI, all patients underwent revascularization of the proximal vessels or the left main stem if indicated (stenosis ≥70% or 50%, respectively). In 666 patients, we calculated the baseline (bSS) and residual SYNTAX Score (rSS) prior to TAVI. In patients with revascularization, we determined the SYNTAX Revascularization Index (SRI=(1-(rSS/bSS))∗100). We also assessed the SYNTAX Score II (SS-II), combining anatomical and clinical variables. The primary endpoint was 3-year all-cause mortality.

RESULTS

Higher baseline and residual SYNTAX Score were associated with increased 3-year mortality (no CAD 26.2%, low bSS 34.8%, high bSS 46.8%; p=0.001, respectively, no CAD 25.9%, low rSS 31.4%, high rSS 41.5%; p=0.01). The extent of revascularization represented by the SRI was not associated with outcome. The SYNTAX Score II was also associated with increased 3-year mortality. However, baseline and residual SYNTAX Score as well as SYNTAX Score II did not independently predict mortality.

CONCLUSION

The anatomic severity of CAD as assessed by the baseline and residual SYNTAX Score is associated with survival after TAVI. Coronary artery disease seems to reflect general comorbidity burden and is associated with a higher risk profile of the patient.

Aortic Valve Gradient and Clinical Outcome in Patients Undergoing Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

Objectives: To explore the relation between the baseline aortic valve gradient (AVG) as a continuous variable and clinical outcomes following transcatheter aortic valve implantation (TAVI) in general and specifically in patients with high-gradient aortic stenosis (AS). Methods: We reviewed 317 consecutive patients who underwent TAVI at our institution. We investigated the relation between AVG as a continuous/categorical variable and outcome among all patients and in patients without low-flow low-gradient AS, using the Cox proportional hazard model adjusting for multiple prognostic variables. Results: Patients had a peak AVG of 79.9 ± 22.8 mm Hg (mean 50.5 ±15.7). During a mean follow-up of 2.7 years, AVG was inversely associated with mortality and mortality or cardiac hospitalization. Every 10-mm-Hg increase in peak AVG was associated with 18% reduction in mortality (p = 0.003) and 19% reduction in mortality/cardiac hospitalization (p < 0.001). Every 10-mm-Hg increase in mean AVG was associated with a 24% reduction in both outcomes (p = 0.005 and p < 0.001). Subgroup analysis of patients with left-ventricular ejection fraction >40% or peak AVG >64 mm Hg yielded similar results. Conclusions: Mean and peak baseline AVGs are directly associated with improved outcomes after TAVI; AVG can be used to select the patients most likely to benefit from TAVI.

Vascular complications post-transcatheter aortic valve procedures

Transcatheter aortic valve replacement (TAVR) has rapidly emerged as the standard of care for severe symptomatic aortic stenosis in patients whose comorbidities put them at prohibitive risk for surgical aortic valve replacement (SAVR). Several trials have demonstrated superior outcomes with TAVR compared to medical management alone. TAVR has also shown favorable outcomes in patients at high risk for SAVR. TAVR can be associated with significant vascular complications, which adversely impact outcomes, and operators should be cognizant of their early recognition and appropriate management. In this article, we review the major vascular complications associated with TAVR, along with optimal prevention and management strategies.

Minimally invasive approach to calcified aortic valve replacement: Anaesthetic considerations

For symptomatic patients with severe calcified aortic valve stenosis, open heart surgery for aortic valve replacement remains the gold standard. However, elderly patients with an increased risk profile can be treated by using transcatheter approaches (transcatheter aortic valve implantation [TAVI]). The major considerations related to use of general and local anaesthesia for TAVI are discussed in this review.

Early Aortic Transcatheter Heart Valve Thrombosis

Background—

Early stent valve thrombosis after transcatheter aortic valve implantation (TAVI) is a rare complication, which is diagnosed based on the appearance of clinical symptoms of heart failure and echocardiographic findings. After TAVI, transthoracic echocardiography is performed to assess transcatheter heart valve (THV) function. However, preliminary reports indicate the potential additive clinical value of multidetector computed tomography (MDCT) for the diagnosis of THV thrombosis. We sought to determine the value of MDCT for the diagnosis of THV thrombosis and the frequency of this complication after balloon-expandable TAVI.

Methods and Results—

MDCT was performed in 140 patients within 1 to 3 months after TAVI with the Edwards Sapien XT THV to assess the presence of THV thrombosis and THV stent geometry. Post-TAVI MDCT identified THV thrombosis in 5 patients (4%). Of note, 4 of these patients were asymptomatic and had a normal transthoracic echocardiographic examination without signs of thrombus formation or flow obstruction. In patients with THV thrombosis, a left ventricular ejection fraction of <35% was present in 3 (60%), whereas 2 (40%) did not receive standard post-TAVI dual-antiplatelet therapy. Neither THV underexpansion nor THV noncircularity was detected in patients with THV thrombosis.

Conclusions—

Post-TAVI MDCT is a valuable tool for the diagnosis of THV thrombosis, and this complication seems to be more common than previously anticipated. Larger studies are required to identify specific risk factors of THV thrombosis.

Coronary artery disease severity and aortic stenosis: clinical outcomes according to SYNTAX score in patients undergoing transcatheter aortic valve implantation

AIM

The aim of this study was to evaluate whether coronary artery disease (CAD) severity exerts a gradient of risk in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

A total of 445 patients with severe AS undergoing TAVI were included into a prospective registry between 2007 and 2012. The preoperative SYNTAX score (SS) was determined from baseline coronary angiograms. In case of revascularization prior to TAVI, residual SS (rSS) was also determined. Clinical outcomes were compared between patients without CAD (n = 158), patients with low SS (0-22, n = 207), and patients with high SS (SS > 22, n = 80). The pre-specified primary endpoint was the composite of cardiovascular death, stroke, or myocardial infarction (MI). At 1 year, CAD severity was associated with higher rates of the primary endpoint (no CAD: 12.5%, low SS: 16.1%, high SS: 29.6%; P = 0.016). This was driven by differences in cardiovascular mortality (no CAD: 8.6%, low SS: 13.6%, high SS: 20.4%; P = 0.029), whereas the risk of stroke (no CAD: 5.1%, low SS: 3.3%, high SS: 6.7%; P = 0.79) and MI (no CAD: 1.5%, low SS: 1.1%, high SS: 4.0%; P = 0.54) was similar across the three groups. Patients with high SS received less complete revascularization as indicated by a higher rSS (21.2 ± 12.0 vs. 4.0 ± 4.4, P < 0.001) compared with patients with low SS. High rSS tertile (> 14) was associated with higher rates of the primary endpoint at 1 year (no CAD:12.5%, low rSS: 16.5%, high rSS: 26.3%, P = 0.043).

CONCLUSIONS

Severity of CAD appears to be associated with impaired clinical outcomes at 1 year after TAVI. Patients with SS > 22 receive less complete revascularization and have a higher risk of cardiovascular death, stroke, or MI than patients without CAD or low SS.

Preinterventional screening of the TAVI patient: how to choose the suitable patient and the best procedure

Transcatheter aortic valve implantation (TAVI) is a novel therapy, which has transformed the management of inoperable patients presenting with symptomatic severe aortic stenosis (AS). It is also a proven and less invasive alternative therapeutic option for high-risk symptomatic patients presenting with severe AS who are otherwise eligible for surgical aortic valve replacement. Patient age is not strictly a limitation for TAVI but since this procedure is currently restricted to high-risk and inoperable patients, it follows that most patients selected for TAVI are at an advanced age. Patient frailty and co-morbidities need to be assessed and a clinical judgment made on whether the patient will gain a measureable improvement in their quality of life. Risk stratification has assumed a central role in selecting suitable patients and surgical risk algorithms have proven helpful in this regard. However, limitations exist with these risk models, which must be understood in the context of TAVI. When making final treatment decisions, it is essential that a collaborative multidisciplinary "heart team" be involved and this is stressed in the most recent guidelines of the European Society of Cardiology. Choosing the best procedure is contingent upon anatomical feasibility, and multimodality imaging has emerged as an integral component of the pre-interventional screening process in this regard. The transfemoral route is now considered the default approach although vascular complications remain a concern. A minimal vessel diameter of 6 mm is required for currently commercial available vascular introducer sheaths. Several alternative access routes are available to choose from when confronted with difficult iliofemoral anatomy such as severe peripheral vascular disease or diffuse circumferential vessel calcification. The degree of aortic valve leaflet and annular calcification also needs to be assessed as the latter is a risk factor for post-procedural paravalvular aortic regurgitation. The ultimate goal of patient selection is to achieve the highest procedural success rate while minimizing complications and to choose patients most likely to derive tangible benefit from this procedure.

Imaging in Transcatheter Aortic Valve Replacement (TAVR): role of the radiologist

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a novel technique developed in the last decade to treat severe aortic stenosis in patients who are non-surgical candidates because of multiple comorbidities.

METHODS

Since the technique is performed using a transvascular approach, pre-procedural assessment of the aortic valve apparatus, ascending aorta and vascular access is of paramount importance for both appropriate patient selection and correct device selection. This assessment is performed by a multi-disciplinary team with radiology being an integral and important part.

RESULTS

Among imaging modalities, there is growing scientific evidence supporting the crucial role of MDCT in the assessment of the aortic valve apparatus, suitability of the iliofemoral or alternative pathway, and determination of appropriate coaxial angles. MDCT also plays an important role in post-procedure imaging in the assessment of valve integrity and position.

CONCLUSION

This review outlines the principal aspects of TAVR, the multidisciplinary approach and utilisation of different imaging modalities, as well as a step-by-step approach to MDCT acquisition protocols, reconstruction techniques, pre-procedure measurements and post-procedure assessment.

TEACHING POINTS

• TAVR is a new technique to treat severe aortic stenosis in high-risk and nonsurgical candidates. • MDCT assessment of the aortic annulus is important for appropriate patient and device selection. • Multidisciplinary approach is required for patient selection, procedure planning and performance. • MDCT is required for assessment of the aortic root, iliofemoral or alternative vascular pathway.

Almanac 2013: novel non-coronary cardiac interventions

Recent innovations in interventional cardiology have dramatically expanded the therapeutic options for patients with cardiac conditions. Interventional cardiology is no longer limited to the treatment of coronary artery disease but allows also treatment of valvular disease, stroke prevention, hypertension, etc. One of the most important new treatment options is the percutaneous treatment for aortic valve stenosis (transcatheter aortic valve implantation), since aortic valve disease is a rather common problem in elderly patients, with many of them at high risk for surgery. Similarly, mitral regurgitation is often associated with comorbidities which make surgery high risk. The MitraClip is a promising percutaneous alternative to surgical valve repair or replacement. Other procedures discussed in this review are the percutaneous left atrial appendage closure as a non-pharmacologic therapy to prevent strokes, and renal denervation for resistant hypertension. This review explains the basic principles of these procedures, the most important clinical evidence, and also provides additional recent clinical data on each of these them.

Almanac 2013: novel non-coronary cardiac interventions

Recent innovations in interventional cardiology have dramatically expanded the therapeutic options for patients with cardiac conditions. Interventional cardiology is no longer limited to the treatment of coronary artery disease but allows also treatment of valvular disease, stroke prevention, hypertension, etc. One of the most important new treatment options is the percutaneous treatment for aortic valve stenosis (transcatheter aortic valve implantation), since aortic valve disease is a rather common problem in elderly patients, with many of them at high risk for surgery. Similarly, mitral regurgitation is often associated with comorbidities which make surgery high risk. The MitraClip is a promising percutaneous alternative to surgical valve repair or replacement. Other procedures discussed in this review are the percutaneous left atrial appendage closure as a non-pharmacologic therapy to prevent strokes, and renal denervation for resistant hypertension. This review explains the basic principles of these procedures, the most important clinical evidence, and also provides additional recent clinical data on each of these them.