CT imaging post-TAVI: Murphy's first law in action-preparing to recognize the unexpected

Transfemoral aortic valve implantation (TAVI) has been long considered the standard of therapy for high-risk patients with severe aortic-stenosis and is now effectively employed in place of surgical aortic valve replacement also in intermediate-risk patients. The potential lasting consequences of minor complications, which might have limited impact on elderly patients, could be more noteworthy in the longer term when occurring in younger individuals. That's why a greater focus on early diagnosis, correct management, and prevention of post-procedural complications is key to achieve satisfactory results. ECG-triggered multidetector computed tomography angiography (CTA) is the mainstay imaging modality for pre-procedural planning of TAVI and is also used for post-interventional early detection of both acute and long-term complications. CTA allows detailed morphological analysis of the valve and its movement throughout the entire cardiac cycle. Moreover, stent position, coronary artery branches, and integrity of the aortic root can be precisely evaluated. Imaging reliability implies the correct technical setting of the computed tomography scan, knowledge of valve type, normal post-interventional findings, and awareness of classic and life-threatening complications after a TAVI procedure. This educational review discusses the main post-procedural complications of TAVI with a specific imaging focus, trying to clearly describe the technical aspects of CTA Imaging in post-TAVI and its clinical applications and challenges, with a final focus on future perspectives and emerging technologies. CRITICAL RELEVANCE STATEMENT: This review undertakes an analysis of the role computed tomography angiography (CTA) plays in the assessment of post-TAVI complications. Highlighting the educational issues related to the topic, empowers radiologists to refine their clinical approach, contributing to enhanced patient care. KEY POINTS: Prompt recognition of TAVI complications, ranging from value issues to death, is crucial. Adherence to recommended scanning protocols, and the optimization of tailored protocols, is essential. CTA is central in the diagnosis of TAVI complications and functions as a gatekeeper to treatment.

Future Horizons: The Potential Role of Artificial Intelligence in Cardiology

Cardiovascular diseases (CVDs) are the leading cause of premature death and disability globally, leading to significant increases in healthcare costs and economic strains. Artificial intelligence (AI) is emerging as a crucial technology in this context, promising to have a significant impact on the management of CVDs. A wide range of methods can be used to develop effective models for medical applications, encompassing everything from predicting and diagnosing diseases to determining the most suitable treatment for individual patients. This literature review synthesizes findings from multiple studies that apply AI technologies such as machine learning algorithms and neural networks to electrocardiograms, echocardiography, coronary angiography, computed tomography, and cardiac magnetic resonance imaging. A narrative review of 127 articles identified 31 papers that were directly relevant to the research, encompassing a broad spectrum of AI applications in cardiology. These applications included AI models for ECG, echocardiography, coronary angiography, computed tomography, and cardiac MRI aimed at diagnosing various cardiovascular diseases such as coronary artery disease, hypertrophic cardiomyopathy, arrhythmias, pulmonary embolism, and valvulopathies. The papers also explored new methods for cardiovascular risk assessment, automated measurements, and optimizing treatment strategies, demonstrating the benefits of AI technologies in cardiology. In conclusion, the integration of artificial intelligence (AI) in cardiology promises substantial advancements in diagnosing and treating cardiovascular diseases.

Syncope due to recurrent ventricular tachycardias after transcatheter aortic valve implantation with unexpected diagnosis in cardiac computed tomography: a case report

Background

Delayed coronary obstruction (DCO) is a rare but potentially life-threatening complication after transcatheter aortic valve implantation (TAVI) mostly affecting the left main coronary artery (LMCA) and often caused by prosthesis endothelialization or thrombus formations. Herein, we report an unusual case of a delayed LMCA-obstruction caused by a calcium nodule, which was diagnosed 4 months after TAVI due to recurrent ventricular tachycardia (VT) episodes.

Case summary

A 73-year-old patient was readmitted to an external hospital with syncope three months after TAVI. Fast VT could be induced in electrophysiological examination, why the patient received a two-chamber implantable cardioverter defibrillator (ICD). However, after 1 month the patient was readmitted to our department with another syncope. Implantable cardioverter defibrillator records revealed multiple fast VT episodes (200-220 b.p.m.). In addition, the patient reported new-onset exertional dyspnoea (New York Class Association Stage III) and elevated high-sensitive cardiac troponin of 115 ng/L. Due to the symptoms and laboratory markers indicating potential myocardial ischaemia, a cardiac computed tomography angiography (CCTA) was performed. Cardiac computed tomography angiography revealed obstruction of the LMCA likely caused by calcium shift during TAVI. After CCTA-guided percutaneous coronary intervention, patient's course remained uneventful.

Discussion

The present case report highlights the role of CCTA as a powerful non-invasive diagnostic tool in complex settings after TAVI. Delayed coronary obstruction as a procedural complication can occur after TAVI and manifest with various symptoms, including new-onset or recurrent VTs, like in the present case. Cardiac computed tomography angiography provided accurate assessment of the implanted prosthesis and detection of DCO, thus guiding the subsequent PCI.

Updated 2022 ACC/AHA Guideline Improves Concordance Between TTE and CT in Monitoring Marfan Snydrome and Related Disorders, but Relevant Measurement Differences Remain Frequent

Background

Patients diagnosed with Marfan syndrome or a related syndrome require frequent aorta monitoring using imaging techniques like transthoracic echocardiography (TTE) and computed tomography (CT). Accurate aortic measurement is crucial, as even slight enlargement (>2 mm) often necessitates surgical intervention. The 2022 ACC/AHA guideline for Aortic Disease Diagnosis and Management includes updated imaging recommendations. We aimed to compare these with the 2010 guideline.

Methods

This retrospective study involved 137 patients with Marfan syndrome or a related disorder, undergoing TTE and ECG-triggered CT. Aortic diameter measurements were taken based on the old 2010 guideline (TTE: inner edge to inner edge, CT: external diameter) and the new 2022 guideline (TTE: leading edge to leading edge, CT: internal diameter). Bland-Altman plots compared measurement differences.

Results

Using the 2022 guideline significantly reduced differences outside the clinical agreement limit from 49% to 26% for the aortic sinus and from 41% to 29% for the ascending aorta. Mean differences were -0.30 mm for the aortic sinus and +1.12 mm for the ascending aorta using the 2022 guideline, compared to -2.66 mm and +1.21 mm using the 2010 guideline.

Conclusion

This study demonstrates for the first time that the 2022 ACC/AHA guideline improves concordance between ECG-triggered CT and TTE measurements in Marfan syndrome patients, crucial for preventing life-threatening aortic complications. However, the frequency of differences >2 mm remains high.

Clinical Relevance/Application

Accurate aortic diameter measurement is vital for patients at risk of fatal aortic complications. While the 2022 guideline enhances concordance between imaging modalities, frequent differences >2 mm persist, potentially impacting decisions on aortic repair. The risk of repeat radiation exposure from ECG-triggered CT, considered the 'gold standard', continues to be justified.

Temporal trends of frame expansion and paravalvular leak reduction after transcatheter aortic valve replacement with self-expandable prostheses

BACKGROUND

Paravalvular leakage (PVL) is a common finding after transcatheter aortic valve replacement (TAVR) and affects late clinical outcome. It is more frequent with self-expandable (SE) transcatheter-heart-valve (THV). Few is known about SE-THV expansion after implantation. The purpose is to assess SE-THV frame expansion and its possible influence on PVL.

METHODS

We designed a prospective pilot study to assess the time-course of SE-THV frame dimensions and PVL after TAVR. Consecutive patients undergoing TAVR with SE-THV were enrolled. Prosthesis fluoroscopy and echocardiography were prospectively performed immediately after TAVR (T0) and before discharge (T1) to grade PVL. Prosthesis diameters were assessed in 2 fluoroscopic orthogonal views. PVL reduction ≥1+ from T0 to T1 at echocardiography was the primary study endpoint.

RESULTS

Twenty-five patients were enrolled. Mean interval between T0 and T1 evaluations was 5 days. Grade 1 or 2 was present in 76% of patients at T0 and in 68% at T1 (P=0.034). A total of 7 patients (28%) improved PVL ≥1 grade from T0 to T1. Differences between T0 and T1 fluoroscopic diameters were not statistically significant. When comparing the diameter changes according to PVL evolution, patients with PVL improvement (as compared with those without) had significantly larger minimum diameter increase at both annulus/inflow (P=0.016) and outflow/distal edge (P=0.027).

CONCLUSIONS

PVL may improve in the early days after SE-THV and those patients with PVL improvement may have THV frame expansion. Further studies are needed to confirm such preliminary observations and to establish the clinical relevance of this phenomenon.

Association between three-year mortality after transcatheter aortic valve implantation and paravalvular regurgitation graded by videodensitometry in comparison with visual grading

BACKGROUND

Estimation of regurgitant fraction by videodensitometry (VD-AR) of aortic root angiograms is a new tool for objective grading of paravalvular regurgitation (PVR) after transcatheter aortic valve implantation (TAVI). Stratification with boundaries at 6% and 17% has been proposed to reflect "none/trace", "mild" and "moderate or higher" PVR.

OBJECTIVE

We sought to investigate the association of strata of VD-AR with 3-year mortality and to compare VD-AR with visual grading of angiograms.

METHODS

We interrogated our database for patients undergoing transfemoral TAVI from 2008 to 2018. Vital status of the patients was obtained from population registers. To test differences in survival and estimate adjusted hazard ratios (HRs) we fitted Cox models.

RESULTS

Our retrospective study included 699 patients with evaluable angiograms at completion of the TAVI procedure. Cumulative 3-year mortality was 35.0% in 261 (37.3%) patients with VD-AR < 6%, 33.9% in 325 (46.5%) patients with VD-AR between 6 and 17% (HR [95% confidence interval] 1.06 [0.80-1.42]; P = 0.684) and 47.2% in 113 (16.2%) patients with VD-AR > 17% (HR 1.57 [1.11-2.22]; P = 0.011). Visually, PVR was graded as "none/trace" in 470 (67.2%) patients, as "mild" in 219 (31.3%) and as "moderate" in 10 (1.4%). Both mild PVR and moderate PVR on visual grading were significantly associated with mortality (HRs 1.31 [1.12-1.54]; P = 0.001 and 1.92 [1.13-3.24]; P = 0.015; respectively).

CONCLUSIONS

VD-AR > 17%, but not VD-AR 6-17%, was independently associated with mortality. Compared with subjective visual evaluation, VD-AR resulted in a smaller proportion of patients with PVR classified as prognostically relevant.

The feasibility of relaxation-enhanced angiography without contrast and triggering for preprocedural planning of transcatheter aortic valve implantation

Background

Cardiovascular MRI is advantageous in transcatheter aortic valve implantation (TAVI) planning. This study aimed to evaluate the feasibility of comprehensive non-contrast MRI [relaxation-enhanced angiography without contrast and triggering (REACT)] combined with a three-dimensional whole-heart MRI protocol for preprocedural planning of TAVI vs. computed tomography angiography (CTA).

Methods

Thirty patients with severe aortic stenosis were prospectively enrolled. The anatomical properties of the aortic root anatomy, including the perimeter and area of the virtual aortic valve annulus and coronary heights, were determined from 3D whole-heart MRI and cardiac CTA (CCTA) images, respectively. The diameters of the aorta (thoracic and abdominal aorta) and iliofemoral arteries were measured from REACT and aortic CTA (ACTA) images, respectively. A paired t-test was used to compare these two modalities. Bland-Altman plots were used to assess cardiovascular MRI and CTA measurements. Transcatheter heart valve (THV) sizing was performed based on CCTA measurements and compared with 3D whole-heart MRI measurements. The extent of annular calcification on 3D whole-heart MRI images was evaluated by a four-point grading scale and compared with CCTA data.

Results

All 30 patients completed CTA and cardiovascular MRI examinations, with the TAVI procedure being administered in 25 patients. The mean acquisition time of the comprehensive MRI protocol was 18 ± 3.2 min. There were no significant differences between ACTA and REACT data in regard to the diameters of aortic and iliofemoral arteries, including the ascending thoracic aorta (37 ± 4.6 mm vs. 37.7 ± 5.2 mm, p = 0.085), descending thoracic aorta (24.3 ± 2.8 mm vs. 24.3 ± 2.8 mm, p = 0.832), abdominal aorta (20.9 ± 2.5 mm vs. 20.8 ± 2.5 mm, p = 0.602), bilateral common iliac arteries (right: 8.36 ± 1.44 mm vs. 8.42 ± 1.27 mm, p = 0.590; left: 8.61 ± 1.71 mm vs. 8.86 ± 1.46 mm, p = 0.050), and bilateral femoral arteries (right: 6.77 ± 1.06 mm vs. 6.87 ± 1.00 mm, p = 0.157; left: 6.75 ± 1.02 mm vs. 6.90 ± 0.80 mm, p = 0.142). Both modalities showed similar aortic valve morphology and semi-quantitative valve calcification (all, p's > 0.05). Overall agreement for implanted THV was found in all 25 (100%) patients assessed with both modalities.

Conclusion

REACT combined with 3D whole-heart MRI enables reliable measurements of aortic root anatomy, annular calcification, and aorta and iliofemoral access in patients under evaluation for TAVI.

Pre-Procedural Assessment of the Femoral Access Route for Transcatheter Aortic Valve Implantation: Comparison of a Non-Contrast Time-of-Flight Magnetic Resonance Angiography Protocol with Contrast-Enhanced Dual-Source Computed Tomography Angiography

Background: We aimed to evaluate the feasibility of a non-contrast time-of-flight magnetic resonance angiography (TOF-MRA) protocol for the pre-procedural access route assessment of transcatheter aortic valve implantation (TAVI) in comparison with contrast-enhanced cardiac dual-source computed tomography angiography (CTA). Methods and Results: In total, 51 consecutive patients (mean age: 82.69 ± 5.69 years) who had undergone a pre-TAVI cardiac CTA received TOF-MRA for a pre-procedural access route assessment. The MRA image quality was rated as very good (median of 5 [IQR 4-5] on a five-point Likert scale), with only four examinations rated as non-diagnostic. The TOF-MRA systematically underestimated the minimal effective vessel diameter in comparison with CTA (for the effective vessel diameter in mm, the right common iliac artery (CIA)/external iliac artery (EIA)/common femoral artery (CFA) MRA vs. CTA was 8.04 ± 1.46 vs. 8.37 ± 1.54 (p < 0.0001) and the left CIA/EIA/CFA MRA vs. CTA was 8.07 ± 1.32 vs. 8.28 ± 1.34 (p < 0.0001)). The absolute difference between the MRA and CTA was small (for the Bland-Altman analyses in mm, the right CIA/EIA/CFA was -0.36 ± 0.77 and the left CIA/EIA/CFA was -0.25 ± 0.61). The overall correlation between the MRA and CTA measurements was very good (with a Pearson correlation coefficient of 0.87 (p < 0.0001) for the right CIA/EIA/CFA and a Pearson correlation coefficient of 0.9 (p < 0.0001) for the left CIA/EIA/CFA). The feasibility agreement between the MRA and CTA for transfemoral access was good (the right CIA/EIA/CFA agreement was 97.9% and the left CIA/EIA/CFA agreement was 95.7%, Kohen's kappa: 0.477 (p = 0.001)). Conclusions: The TOF-MRA protocol was feasible for the assessment of the access route in an all-comer pre-TAVI population. This protocol might be a reliable technique for patients at an increased risk of contrast-induced nephropathy.

Advanced Cardiac Imaging in the Assessment of Aortic Stenosis

Aortic stenosis is the most common form of valve disease in the Western world and a major healthcare burden. Although echocardiography remains the central modality for the diagnosis and assessment of aortic stenosis, recently, advanced cardiac imaging with cardiovascular magnetic resonance, computed tomography, and positron emission tomography have provided invaluable pathological insights that may guide the personalized management of the disease. In this review, we discuss applications of these novel non-invasive imaging modalities for establishing the diagnosis, monitoring disease progression, and eventually planning the invasive treatment of aortic stenosis.

Identifying fragile calcifications of the aortic valve in transcatheter aortic valve replacement: iodine concentration of aortic valvular calcification by spectral CT

OBJECTIVE

To demonstrate the relationship between spectral computed tomography (CT) measured iodine concentration and strength of aortic valvular calcification (AVC) in patients with aortic valve stenosis (AVS).

METHODS

A retrospective study was performed on patients who underwent transcatheter aortic valve replacement (TAVR) for symptomatic AVS and underwent both pre and postprocedural electrocardiogram gated CT scans using a spectral CT system. Preprocedural CT was used to evaluate the volume and iodine concentration (IC) in the AVC. Postprocedural CT data were used to calculate the volume reduction percentage (VRP) of AVC. Multiple linear regression analysis was used to identify the independent variables related to the VRP in AVCs.

RESULTS

A total of 94 AVCs were selected from 22 patients. The mean volume and IC of the AVCs before TAVR were 0.37 mL ± 0.15 mL and 7 mg/mL ± 10.5 mg/mL, respectively. After TAVR, a median VRP of all 94 AVCs was 18.5%. Multiple linear regression analysis showed that the IC was independently associated with the VRP (coefficient = 1.64, p < 0.001). When an optimal IC cutoff point was set at 4 mg/mL in the assessment of a fragile AVC which showed the VRP was > 18.5%, the sensitivity was 63%; specificity, 91%; positive predictive value, 88%; and negative predictive value, 71%.

CONCLUSIONS

When using spectral CT to prepare the TAVR, measuring the IC of the AVC may be useful to assess the probability of AVC deformity after TAVR.

KEY POINTS

• A dual-layer detector-based spectral CT enables quantifying iodine of contrast media in the aortic valve calcification (AVC) on contrast-enhanced CT images. • The AVC including iodine of contrast media on contrast-enhanced CT image may have loose compositions, associated with the deformity of AVC after TAVR. • Measuring the iodine concentration in AVC may have the potential to assess the probability of AVC deformity, which may be associated with the outcome and complications after TAVR.2.

Radiation-Induced Aortic Stenosis: An Update on Treatment Modalities

The adverse effects of radiation therapy for cancer are well described and can include a wide array of cardiac complications. Radiation-induced aortic stenosis (AS) is an increasingly recognized entity that poses particular therapeutic challenges. Several retrospective studies comparing the outcomes after transcatheter aortic valve replacement (TAVR) vs those after surgical aortic valve replacement patients with radiation-induced AS have found a trend toward decreased mortality and fewer major complications with TAVR. Surgical aortic valve replacement is associated with increased mortality in patients with radiation-induced AS compared with patients without a history of prior radiation. TAVR has been shown to be a safe and effective alternative in patients with radiation-induced AS, with safety similar to that for patients who have not received prior radiation. However, rare and unexpected complications may occur after TAVR from the deleterious effects of radiation on mediastinal structures. More studies are needed to identify the optimal way of managing patients with radiation-induced AS, and algorithms are needed for planning these complex interventions.

Cardiac gated multidetector computed tomography (MDCT) to determine valvular leaflet thrombosis and leaflet restriction

The evaluation of patients following aortic valve replacement has evolved, with multiple imaging modalities available that complement each other and permit better and prompt delineation of specific structural or functional valve complications. Multidetector computed tomography (MDCT) is one of the diagnostic modalities with significant technologic advancements that have made possible to evaluate high detail of the moving heart. The ability to deliver three-dimensional and multiplanar dynamic imaging with fine detail has demonstrated the technique is well suited to investigate valve complications. In this review article, we focus on some of the most contributing roles of MDCT in the diagnosis of complications associated with valvular pathology.

Impact of aortic annular size and valve type on haemodynamics and clinical outcomes after transcatheter aortic valve implantation

Introduction: Data on patients with small aortic annuli (SAA) undergoing transcatheter aortic valve implantation (TAVI) are limited. We aim to describe the impact of aortic annular size, particularly SAA and TAVI valve type on valve haemodynamics, durability and clinical outcomes. Method: All patients in National Heart Centre Singapore who underwent transfemoral TAVI for severe symptomatic native aortic stenosis from July 2012 to December 2019 were included. Outcome measures include valve haemodynamics, prosthesis-patient mismatch (PPM), structural valve degeneration (SVD) and mortality. Results: A total of 244 patients were included. The mean Society of Thoracic Surgeons score was 6.22±6.08, with 52.5% patients with small aortic annulus (<23mm), 33.2% patients with medium aortic annulus (23–26mm) and 14.3% patients with large aortic annulus (>26mm). There were more patients with self-expanding valve (SEV) (65.2%) versus balloon-expandable valve (BEV) (34.8%). There were no significant differences in indexed aortic valve area (iAVA), mean pressure gradient (MPG), PPM, SVD or mortality across all aortic annular sizes. However, specific to the SAA group, patients with SEV had larger iAVA (SEV 1.19±0.35cm2/m2 vs BEV 0.88±0.15cm2/m2, P<0.01) and lower MPG (SEV 9.25±4.88 mmHg vs BEV 14.17±4.75 mmHg, P<0.01) at 1 year, without differences in PPM or mortality. Aortic annular size, TAVI valve type and PPM did not predict overall mortality up to 7 years. There was no significant difference in SVD between aortic annular sizes up to 5 years. Conclusion: Valve haemodynamics and durability were similar across the different aortic annular sizes. In the SAA group, SEV had better haemodynamics than BEV at 1 year, but no differences in PPM or mortality. There were no significant differences in mortality between aortic annular sizes, TAVI valve types or PPM. Keywords: Aortic stenosis, small aortic annulus, transcatheter aortic valve implantation

Risk Stratification for Pacemaker Implantation after Transcatheter Aortic Valve Implantation in Patients with Right Bundle Branch Block

Background: Permanent pacemaker implantation (PPI) after transcatheter valve implantation (TAVI) is a common complication. Pre-existing right bundle branch block (RBBB) is a strong risk factor for PPI after TAVI. However, a patient-specific approach for risk stratification in this subgroup has not yet been established. Methods: We investigated TAVI patients with pre-existing RBBB to stratify risk factors for PPI and 1-year-mortality by detailed analysis of ECG data, RBBB morphology and degree of calcification in the implantation area assessed by computed tomography angiography. Results: Between 2010 and 2018, 2129 patients underwent TAVI at our institution. Among these, 98 pacemaker-naïve patients with pre-existing RBBB underwent a TAVI procedure. PPI, because of relevant conduction disturbances (CD), was necessary in 43 (43.9%) patients. PPI was more frequently indicated in women vs. men (62.1% vs. 32.8%, p = 0.004) and in men treated with a self-expandable vs. a balloon-expandable valve (58.3% vs. 26.5%, p = 0.035). ECG data (heart rhythm, PQ, QRS, QT) and RBBB morphology had no influence on PPI rate, whereas risk for PPI increased with the degree of calcification in the left septal His-/left bundle branch-area to a 9.375-fold odds for the 3rd tertile of calcification (1.639–53.621; p = 0.012). Overall, 1-year-mortality was comparable among patients with or without PPI (14.0% vs. 16.4%; p = 0.697). Conclusions: Patients with RBBB undergoing TAVI have a high risk of PPI. Among this subgroup, female patients, male patients treated with self-expandable valve types, patients with high load/degree of non-coronary LVOT calcification and patients with atrial fibrillation need enhanced surveillance for CD after procedure.

Discrepancy of echocardiography and computed tomography in initial assessment and 2-year follow-up for monitoring Marfan syndrome and related disorders

Patients with Marfan syndrome and related disorders are at risk for aortic dissection and aortic rupture and therefore require appropriate monitoring. Computed tomography (CT) and transthoracic echocardiography (TTE) are routinely used for initial diagnosis and follow-up. The purpose of this study is to compare whole-heart CT and TTE aortic measurement for initial work-up, 2-year follow-up, and detection of progressive aortic enlargement. This retrospective study included 95 patients diagnosed with Marfan syndrome or a related disorder. All patients underwent initial work-up including aortic diameter measurement using both electrocardiography-triggered whole-heart CT and TTE. Forty-two of these patients did not undergo aortic repair after initial work-up and were monitored by follow-up imaging within 2 years. Differences between the two methods for measuring aortic diameters were compared using Bland-Altman plots. The acceptable clinical limit of agreement (acLOA) for initial work-up, follow-up, and progression within 2 years was predefined as <  ± 2 mm. Bland-Altman analysis revealed a small bias of 0.2 mm with wide limits of agreement (LOA) from + 6.3 to - 5.9 mm for the aortic sinus and a relevant bias of - 1.6 mm with wide LOA from + 5.6 to - 8.9 mm for the ascending aorta. Follow-up imaging yielded a small bias of 0.5 mm with a wide LOA from + 6.7 to - 5.8 mm for the aortic sinus and a relevant bias of 1.1 mm with wide LOA from + 8.1 to - 10.2 mm for the ascending aorta. Progressive aortic enlargement at follow-up was detected in 57% of patients using CT and 40% of patients using TTE. Measurement differences outside the acLOA were most frequently observed for the ascending aorta. Whole-heart CT and TTE measurements show good correlation, but the frequency of measurement differences outside the acLOA is high. TTE systematically overestimates aortic diameters. Therefore, whole-heart CT may be preferred for aortic monitoring of patients with Marfan syndrome and related disorders. TTE remains an indispensable imaging tool that provides additional information not available with CT.

Comparison of outcomes after transcatheter aortic valve replacement between elderly (65-79 years) and super-elderly (≥80 years) patients

Transcatheter aortic valve replacement (TAVR) is an effective treatment option for patients with severe symptomatic aortic stenosis. Nonetheless, there is a paucity of data regarding the differences in the clinical outcomes of TAVR procedures between elderly and super-elderly patients. This study aimed to compare the clinical characteristics and outcomes of patients aged 65 to 79 years and ≥80 years who underwent TAVR for aortic stenosis. The clinical characteristics and outcomes of 134 patients with aortic stenosis who underwent TAVR were analyzed. Patients were categorized into 2 groups: an elderly group (EG; 65-79 years) and a super-elderly group (SEG) (≥80 years). The in-hospital and follow-up clinical outcomes were compared between the 2 groups. The EG tended to be more overweight, obese, and diabetic than the SEG, whereas the SEG had a higher surgical risk but lower creatinine clearance, hematocrit level, and effective orifice area than the EG. However, no difference was found in in-hospital clinical outcomes between the 2 groups, except for atrial fibrillation. In the propensity score matching and inverse probability of treatment weighting-adjusted analyses, these results were similar. All follow-up clinical outcomes were similar, except for rehospitalization, which was statistically attenuated after propensity score matching and inverse probability of treatment weighting-adjusted analyses. TAVR was associated with similar safety outcomes in the EG (65-79 years) and the SEG (≥80 years). Advanced age is not negatively associated with clinical outcomes after the TAVR procedure.

A quality-improvement project to enhance systemic arterial contrast opacification in CT for trans-catheter aortic valve implantation

AIM

To assess improvement in arterial opacification by optimising the contrast medium dosing protocol for computed tomography (CT) prior to trans-catheter aortic valve implantation (TAVI).

MATERIALS AND METHODS

A wide variation in arterial opacification was observed in the initial CT TAVI protocol (standard protocol). The practice was optimised by considering the time required for the examination and optimising contrast medium flux. This became the optimised protocol with a 30-second contrast medium bolus of iodine flux 15-19 mg iodine/kg body weight/second (mg/kg/s). Attenuation (mean HU) in (a) the ascending aorta (gated systolic acquisition) and (b) the ascending, descending thoracic (at carina), infra-renal abdominal aorta, and right common iliac artery (non-gated acquisition) was measured. Thirty-one sequential optimised examinations were compared to 31 prior standard protocol examinations.

RESULTS

There was no difference between the standard and optimised groups regarding age, sex, weight, body mass index (BMI), or voltage. The mean bolus durations were 24.9±4.4 seconds for the standard and 30±0.3 seconds for the optimised protocols (p<0.001). Although there was no difference in the attenuation in the gated ascending aorta (p>0.99), there was improvement at all other anatomical points in the non-gated examinations of the optimised protocol (p<0.002).

CONCLUSION

Optimising contrast medium flux and matching bolus duration to the CT technology dramatically improves the vascular access component of TAVI planning and provides a reliable method to achieve objectively enhanced arterial opacification. This work highlights how to obtain good arterial contrast medium opacification in haemodynamically fragile patients without excessive contrast medium volumes.

CT in Transcatheter-delivered Treatment of Valvular Heart Disease

Minimally invasive strategies to treat valvular heart disease have emerged over the past 2 decades. The use of transcatheter aortic valve replacement in the treatment of severe aortic stenosis, for example, has recently expanded from high- to low-risk patients and became an alternative treatment for those with prohibitive surgical risk. With the increase in transcatheter strategies, multimodality imaging, including echocardiography, CT, fluoroscopy, and cardiac MRI, are used. Strategies for preprocedural imaging strategies vary depending on the targeted valve. Herein, an overview of preprocedural imaging strategies and their postprocessing approaches is provided, with a focus on CT. Transcatheter aortic valve replacement is reviewed, as well as less established minimally invasive treatments of the mitral and tricuspid valves. In addition, device-specific details and the goals of CT imaging are discussed. Future imaging developments, such as peri-procedural fusion imaging, machine learning for image processing, and mixed reality applications, are presented.

The Role of Cardiac Computed Tomography in Heart Failure

PURPOSE OF REVIEW

Cardiac computed tomography (CT) is becoming a more widely applied tool in the diagnosis and management of a variety of cardiovascular conditions, including heart failure. The aim of this narrative review is to examine the role of cardiac CT in patients with heart failure.

RECENT FINDINGS

Coronary computed tomographic angiography has robust diagnostic accuracy for ruling out coronary artery disease. These data are reflected in updated guidelines from major cardiology organizations. New roles for cardiac CT in myocardial imaging, perfusion scanning, and periprocedural planning, execution, and monitoring are being implemented. Cardiac CT is useful in ruling out coronary artery disease its diagnostic accuracy, accessibility, and safety. It is also intricately linked to invasive cardiac procedures that patients with heart failure routinely undergo.

TAVI-CT score to evaluate the anatomic risk in patients undergoing transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) requires thorough preprocedural planning with non-invasive imaging, including computed tomography (CT). The plethora of details obtained with thoraco-abdominal CT represents a challenge for accurate and synthetic decision-making. We devised and tested a comprehensive score suitable to summarize CT exams when planning TAVI. An original comprehensive scoring system (TAVI-CT score) was devised, including details on cardiac, aortic, iliac and femoral artery features. The score was applied to a prospectively collected series of patients undergoing TAVI at our institution, driving decision making on access and prosthesis choice. Different TAVI-CT score groups were compared in terms of procedural success, acute complications, and early clinical outcomes. We included a total of 200 undergoing TAVI between February 2020 and May 2021, with 74 (37.0%) having a low (0–2) TAVI-CT score, 50 (25.0%) having a moderate (3) TAVI-CT score, and 76 (38.0%) having a high (≥ 4) TAVI-CT score. Male gender was the only non-CT variable significantly associated with the TAVI-CT score (p = 0.001). As expected, access choice differed significantly across TAVI-CT scores (p = 0.009), as was device choice, with Portico more favored and Allegra less favored in the highest TAVI-CT score group (p = 0.036). Acute outcomes were similar in the 3 groups, including device and procedural success rates (respectively p = 0.717 and p = 1). One-month follow-up showed similar rates of death, myocardial infarction, stroke, and bleeding, as well as of a composite safety endpoint (all p > 0.05). However, vascular complications were significantly more common in the highest TAVI-CT score group (p = 0.041). The TAVI-CT score is a simple scoring system that could be routinely applied to CT imaging for TAVI planning, if the present hypothesis-generating findings are confirmed in larger prospective studies.

Recommendations in pre-procedural imaging assessment for TAVI intervention: SIC-SIRM position paper part 2 (CT and MR angiography, standard medical reporting, future perspectives)

Non-invasive cardiovascular imaging owns a pivotal role in the preoperative assessment of patient candidates for transcatheter aortic valve implantation (TAVI), providing a wide range of crucial information to select the patients who will benefit the most and have the procedure done safely. This document has been developed by a joined group of experts of the Italian Society of Cardiology and the Italian Society of Medical and Interventional Radiology and aims to produce an updated consensus statement about the pre-procedural imaging assessment in candidate patients for TAVI intervention. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac and vascular radiology. Part 2 of the document will cover CT and MR angiography, standard medical reporting, and future perspectives.

Dual-Layer Spectral CTA for TAVI Planning Using a Split-Phase Protocol and Low-keV Virtual Monoenergetic Images: Improved Image Quality in Comparison with Single-Phase Conventional CTA

PURPOSE

 Adaptation of computed tomography protocols for transcatheter aortic valve implantation (TAVI) planning is required when a first-generation dual-layer spectral CT scanner (DLCT) is used. The purpose of this study was to evaluate the objective image quality of aortic CT angiography (CTA) for TAVI planning using a split-phase technique with reconstruction of 40 keV virtual monoenergetic images (40 keV-VMI) obtained with a DLCT scanner. CT angiography obtained with a single-phase protocol of a conventional single-detector CT (SLCT) was used for comparison.

MATERIALS AND METHODS

 75 CTA scans from DLCT were retrospectively compared to 75 CTA scans from SLCT. For DLCT, spiral CTA without ECG-synchronization was performed immediately after a retrospectively ECG-gated acquisition covering the heart and aortic arch. For SLCT, spiral CTA with retrospective ECG-gating was performed to capture the heart and the access route simultaneously in one scan. Objective image quality was compared at different levels of the arterial access route.

RESULTS

 40 keV virtual monoenergetic images of DLCT showed a significantly higher mean vessel attenuation, SNR, and CNR at all levels of the arterial access route. With 40 keV-VMI of DLCT, the overall mean aortic attenuation of all six measured regions was 589.6 ± 243 HU compared to 492.7 ± 209 HU of SLCT (p < 0.01). A similar trend could be observed for SNR (23.6 ± 18 vs. 18.6 ± 9; p < 0.01) and CNR (21.1 ± 18 vs. 16.4 ± 8; p < 0.01). No deterioration was observed for vascular noise (27.8 ± 9 HU vs. 28.1 ± 8 HU; p = 0.599).

CONCLUSION

 Using a DLCT scanner with a split-phase protocol and 40 keV-VMI for TAVI planning, higher objective image quality can be obtained compared to a single-phase protocol of a conventional CT scanner.

KEY POINTS

  · Adaption of TAVI planning CT protocols may be required when using a first-generation dual-layer CT scanner.. · Reconstruction of virtual monoenergetic images at 40 keV improves image quality.. · With a split-phase protocol, the radiation dose is lower compared to a single-phase ECG-gated CT acquisition..

CITATION FORMAT

· Mangold D, Salatzki J, Riffel J et al. Dual-Layer Spectral CTA for TAVI Planning Using a Split-Phase Protocol and Low-keV Virtual Monoenergetic Images: Improved Image Quality in Comparison with Single-Phase Conventional CTA. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1717-2542.

Impact of high-sensitivity cardiac troponin T on survival and rehospitalization after transcatheter aortic valve replacement

BACKGROUND

Constant elevations of the serum concentration of cardiac troponin T (TnT) indicate a myocardial injury that may affect the long-term outcome of transcatheter aortic valve replacement (TAVR).

OBJECTIVES

We sought to investigate the impact of pre-TAVR TnT on outcomes after TAVR during long-term follow-up.

METHODS

In a retrospective, observational study we compared long term outcomes after TAVR between tertiles of preinterventional high-sensitivity TnT. Systematic follow-up was performed annually for 5 years. The primary endpoint was a composite of all-cause death and any rehospitalization.

RESULTS

Between 2010 and 2018, 2,129 patients with severe aortic valve stenosis underwent TAVR at our institution (mean age 82.6 years, 57.2% female, logistic EuroSCORE 20.5 ± 15.8). Boundaries for TnT tertiles were <21 ng/L and >42 ng/L. The median follow-up was 895 days. Three-year incidences for the primary endpoint were 70.9%, 76.6%, and 81.7% in the low, middle, and high tertile (log rank p < .001). Compared with the first tertile, the corresponding adjusted hazard ratios were 1.23 (95%-CI 1.08-1.40, p < .001) and 1.50 (95%-CI 1.32-1.70, p < .001) for the second and third tertile. We found consistent differences between TnT strata for all-cause death (3-year incidences 23.3%, 33.3%, and 47.1%; adjusted p < .001) and rehospitalization (3-year incidences 64.7%, 68.7% and 72.0%; adjusted p < .001), including significant differences in deaths (p < .001). The association between TnT and outcome was independent of coronary artery disease or low aortic valve gradient.

CONCLUSIONS

TnT before TAVR is strongly associated with all-cause death and rehospitalization during 3-year follow-up.

Diagnostic Work-Up of the Aortic Patient: An Integrated Approach toward the Best Therapeutic Option

Aortic stenosis (AS) is the most common valvular heart disease. In the last decade, transcatheter aortic valve implantation (TAVI) has become the standard of care for symptomatic patients at high surgical risk. Recently, indications to TAVI have also been extended to the low surgical risk and intermediate surgical risk populations. Consequently, in this setting, some aspects acquire greater relevance: surgical risk evaluation, clinical assessment, multimodality imaging of the valve, and management of coronary artery disease. Moreover, future issues such as coronary artery re-access and valve-in-valve interventions should be considered in the valve selection process. This review aims to summarize the principal aspects of a multidimensional (multidisciplinary) and comprehensive preprocedural work-up. The Heart Team is at the center of the decision-making process of the management of aortic valve disease and bears responsibility for offering each patient a tailored approach based on an individual evaluation of technical aspects together with the risks and benefits of each modality. Considering the progressive expansion in TAVI indication and technological progress, the role of a work-up and multidisciplinary Heart Team will be even more relevant.

Three-year outcome after transcatheter aortic valve implantation: Comparison of a restrictive versus a liberal strategy for pacemaker implantation

BACKGROUND

Conduction disturbances after transcatheter aortic valve implantation (TAVI) are common, heterogeneous, and frequently result in permanent pacemaker implantation (PPI). Pacemaker therapy with a high rate of right ventricular pacing is associated with heart failure, hospitalizations, and reduced quality of life.

OBJECTIVE

The purpose of this study was to compare medium-term outcomes between PPI implantation strategies, as choosing the right indication for PPI is still an area of uncertainty and information on outcomes of PPI regimens beyond 1 year is rare.

METHODS

We compared outcomes after 3 years between a restrictive PPI strategy, in which the lowest threshold for PPI was left bundle branch block (LBBB) (QRS >120 ms) with the presence of new atrioventricular block (PQ >200 ms), and a liberal PPI regimen, in which PPI already was performed in patients with new-onset LBBB.

RESULTS

Between January 2014 and December 2016, TAVI was performed in 884 patients at our center. Of these, 383 consecutive, pacemaker-naive patients underwent TAVI with the liberal PPI strategy and subsequently 384 with the restrictive strategy. The restrictive strategy significantly reduced the percentage of patients undergoing PPI before discharge (17.2% vs 38.1%; P <.001). The incidence of the primary endpoint (all-cause-mortality and hospitalization for heart failure) after 3 years was similar in both groups (30.7% vs 35.2%; P = .242), as was all-cause-mortality (26.6% vs 29.2%; P = .718). Overall, patients who required PPI post-TAVI had significantly more hospitalizations due to heart failure (14.8% vs 7.8%; P = .004).

CONCLUSION

A restrictive PPI strategy after TAVI reduces PPI significantly and is safe in medium-term follow-up over 3 years.

Impact of left ventricular outflow tract calcification on outcomes following transcatheter aortic valve replacement

BACKGROUND

We aimed to determine left ventricular outflow tract (LVOT) calcification impact following transcatheter aortic valve replacement (TAVR) with contemporary transcatheter heart valves. Recent studies reported a higher rate of 2-year mortality with greater than moderate LVOT calcium, but they have not established a reliable and validated method to assess the degree of valve calcification and utilized first-generation valves for their analyses.

MATERIALS/METHODS

We conducted a retrospective analysis of patients who underwent TAVR at our institution from 2013 through 2017 with available valves. LVOT calcification quantification was assessed as a continuous variable.

RESULTS

We included 273 patients: 179 had a non-calcified LVOT (NOLVOTCA) and 96 had a calcified LVOT (LVOTCA). Balloon post-dilatation (BPD) was utilized in 31.3% of LVOTCA vs. 19% of NOLVOTCA (p = 0.029). The Evolut R valve was used in 40.6% vs. 23.4% (p = 0.002), while the Sapien 3 was used in 59.4% vs. 76.6% (p = 0.004), for the LVOTCA and NOLVOTCA, respectively. Paravalvular leak (PVL) at hospital discharge was higher in LVOTCA (47.5%) versus NOLVOTCA (29.1%; p = 0.004). All-cause mortality (11.5% vs. 10.1%; p = 0.5) and need for permanent pacemaker implantation were similar between the groups. There was a positive trend between LVOT calcification volume and the probability of any PVL (OR 1.012; 95% CI, 0.99-1.02).

CONCLUSIONS

TAVR performed in patients with calcified LVOT is safe, but LVOT calcification adversely impacts TAVR outcomes, with a higher PVL rate despite greater usage of BPD. Calcium quantification did not predict any PVL degree post-TAVR.

Manta versus Perclose ProGlide vascular closure device after transcatheter aortic valve implantation: Initial experience from a large European center

BACKGROUND

Vascular and bleeding complications are common after transcatheter aortic valve implantation (TAVI) and are associated with worse outcomes. The plug-based Manta (M) vascular closure device (VCD) is a novel option to achieve haemostasis for large-bore arterial access sites.

OBJECTIVE

We aimed to compare vascular and bleeding complications between the M-VCD and the established suture-based Perclose ProGlide (P)-VCD.

METHODS

From February to September 2019 a total of 578 patients underwent transfemoral TAVI at a single high-volume centre. Access site closure was performed using M-VCD in 195 patients (33.7%) and P-VCD in 383 patients (66.3%). We assessed vascular and access site-related complications as well as bleeding events according to the Valve Academic Research Consortium-2 definition.

RESULTS

Overall vascular complications occurred less frequently in the M-VCD group (10.7% vs. 19.0%, p = 0.011) driven by a significantly lower rate of major vascular events (2.0% vs. 6.5%, p = 0.025). Access site-related complications were significantly less frequent in the M-VCD cohort (10.7% vs. 16.6%, p = 0.048). The M-VCD was associated with significantly lower rates of major (0.5% vs. 4.4%, p = 0.009) and life-threatening bleeding (0% vs. 2.3%, p = 0.032). In multivariable analysis, the use of M-VCD was the only independent predictor of vascular complications (odds ratio 0.54, 95% confidence interval 0.32-0.91, p = 0.022).

CONCLUSIONS

The M-VCD was associated with a reduction of vascular and access-site complications as well as severe bleeding after transfemoral TAVI compared to the P-VCD in this observational study.

Improving CT assessment for pulmonary hypertension in patients with severe aortic stenosis, correlation with right heart catheterization

PURPOSE

To identify CT parameters useful for assessment of pulmonary hypertension (PH) in patients with severe aortic stenosis (AS).

MATERIALS AND METHODS

Retrospective study of 165 patients who had undergone right heart catheterization (RHC), and CTA of the thorax for preoperative aortic valve replacement (TAVR) planning. These were divided into groups based on mean pulmonary artery (PA) pressure (mPAP) of 25 mm Hg on RHC (85 cases and 80 controls). Diameters of main pulmonary artery diameter (MPAD), left pulmonary artery (LPA), right pulmonary artery (RPA), and maximal long axis and short axis diameters of the right atrium (RA) and ventricle (RV) were measured on the axial plane. Univariate and multivariate statistical analysis was utilized to identify metrics predictive of PH.

RESULTS

MPAD, LPA, and RPA were higher in subjects with mPAP >25 mm Hg (p < 0.0001 for all). Thresholds of 30.5 mm for MPAD (68.4% sensitivity, 82.7% specificity), and 27.5 mm for LPA and RPA (LPA: 51.9% sensitivity, 78.8% specificity; RPA: 62.0% sensitivity, 78.8% specificity) provided the best discrimination of elevated mPAP. Compared to literature values for MPAD (28.9 mm in men and 26.9 mm in women), these thresholds provide lower sensitivity but greatly increased specificity. Inclusion of RA enlargement to MPAD increased specificity to 98.5%, while inclusion of RV enlargement increased specificity to 100%.

CONCLUSION

Threshold to identify PH in patients with AS using PA enlargement is higher than previously reported range for normal. Inclusion of RA and RV enlargement improves the ability of CT to more accurately identify PH in patients with AS.

Transcatheter aortic valve implantation for tricuspid aortic valve with a calcium bridge between the cusps: a case report

Background

Indications for transcatheter aortic valve (AV) implantation (TAVI) have been extended to patients with challenging anatomical features such as a bicuspid AV. However, no case reports of TAVI for tricuspid AV with a 'calcium bridge' have been published.

Case summary

We report the case of an 87-year-old woman with severe symptomatic aortic stenosis (AS). Pre-procedural multidetector computed tomography (MDCT) showed a calcium bridge between the non-coronary and left cusps. Although these cusps appeared to be fused together in the centre by the calcium bridge, the commissure area between the fused cusps appeared to normally open. We cracked apart the calcium bridge from the commissure area using balloon aortic valvuloplasty, which was guided by transoesophageal echocardiography. Subsequently, we successfully implanted a balloon-expandable transcatheter heart valve (THV).

Discussion

To our knowledge, this is the first report of TAVI for a tricuspid AV with a 'calcium bridge' between the non-coronary and left cusps. In our patient, the unique structure of cusp fusing in the centre seemed to be caused by an acquired atherosclerotic process, as documented using a contemporary technique, i.e. MDCT. Cracking the calcium bridge with a balloon aortic valvuloplasty ensured that the THV adequately expanded. Severe AS caused by a calcium bridge may be treated with detailed evaluation of the AV morphology together with a procedural strategy planning.

Assessment of aortic annulus dimensions for transcatheter aortic valve replacement (TAVR) with high-pitch dual-source CT: Comparison of systolic high-pitch vs. multiphasic data acquisition

OBJECTIVES

To evaluate a systolic ECG-gated high-pitch aortoiliac computed tomography (CT) angiography for planning transcatheter aortic valve implantation (TAVI).

METHODS

Patients referred for TAVI underwent a combined CT imaging with retrospective, multiphasic ECG-gating of the heart and systolic ECG-gated high-pitch aortoiliac CT angiography. Consecutive patients were retrospectively included in this study group. Heart rate (HR) and heart rate variability (HRV) were assessed during the high-pitch ECG prediction phase. Aortic annulus area (AAA) was planimetrically quantified on both datasets. While only one moment of cardiac cycle was available for measurements in the high-pitch CT, the point of time in the multiphasic CT was chosen, where AAA yielded maximum size. Hypothetical prosthesis sizing was compared between multiphasic vs. high-pitch CT.

RESULTS

Among 61 patients (44.2 % men, mean age: 83.3 ± 5.5 years) average heart rate and HRV were 71.0 ± 13.4 bpm and 7.3 ± 8.5 bpm. 20 patients (32.7 %) had atrial fibrillation at the time of image acquisition. There was a strong correlation of AAA as derived from multiphasic vs. the high-pitch CT (r = 0.98). The difference in AAA was 10.5 ± 17.1mm² (455.1 ± 83.0 mm² for multiphasic vs. 444.5 ± 87.2 mm² for high-pitch CT) and did not reach statistical significance (p = 0.08). Hypothetical prosthesis sizing showed an agreement in 55 of 61 patients (90.2 %). A sizing based on the high-pitch CT resulted in smaller prosthesis choice in 6 patients, all of them suffering from atrial fibrillation. Mean effective radiation dose was 10.9 ± 6.1 mSv for cardiac CTA and 4.1 ± 1.0 mSv for high-pitch CTA.

CONCLUSION

For patients with sinus rhythm, systolic high-pitch aortoiliac CTA provides adequate prosthesis size selection as compared with multiphasic ECG-gated cardiac CTA and may result in significantly reduced radiation exposition.

Prognostic Value of Computed Tomography-Derived Extracellular Volume in TAVR Patients With Low-Flow Low-Gradient Aortic Stenosis

OBJECTIVES

The association between extracellular volume (ECV) measured by computed tomography angiography (CTA) and clinical outcomes was evaluated in low-flow low-gradient (LFLG) aortic stenosis (AS) patients undergoing transcatheter aortic valve replacement (TAVR).

BACKGROUND

Patients with LFLG AS comprise a high-risk group with respect to clinical outcomes. Although ECV, a marker of myocardial fibrosis, is traditionally measured with cardiac magnetic resonance, it can also be measured using cardiac CTA. The authors hypothesized that in LFLG AS, increased ECV may be associated with adverse clinical outcomes.

METHODS

In 150 LFLG patients with AS who underwent TAVR, ECV was quantified using pre-TAVR CTA. Echocardiographic and clinical information including all-cause death and heart failure rehospitalization (HFH) was obtained from electronic medical records. A Cox proportional hazards model was used to evaluate the association between ECV and death+HFH.

RESULTS

During a median follow-up of 13.9 months (range 0.07 to 28.9 months), there were 31 death+HFH events (21%). Patients who experienced death+HFH had a greater median Society of Thoracic Surgery score (9.9 vs. 4.7; p < 0.01), lower left ventricular ejection fraction (42.3 ± 20.2% vs. 52.7 ± 17.2%; p < 0.01), lower mean transvalvular gradient (24.9 ± 8.9 mm Hg vs. 28.1 ± 7.3 mm Hg; p = 0.04) and increased mean ECV (35.5 ± 9.6% vs. 29.9 ± 8.2%; p < 0.01) compared with patients who did not experience death+HFH. In a multivariable Cox proportional hazards model, increase in ECV was associated with increase in death+HFH, (hazard ratio per 1% increase: 1.04, 95% confidence interval: 1.01 to 1.09; p < 0.01).

CONCLUSIONS

In patients with LFLG AS, CTA measured increase in ECV is associated with increased risk of adverse clinical outcomes post-TAVR and may thus serve as a useful noninvasive marker for prognostication.

Fusion imaging of pre- and post-procedural computed tomography angiography in transcatheter aortic valve implantation patients: evaluation of prosthesis position and its influence on new conduction disturbances

AIMS

The purpose of this study was to evaluate prosthesis position by fusion of pre- and post-transcatheter aortic valve implantation (TAVI) computed tomography angiography (CTA) images and to investigate its influence on the occurrence of new conduction disturbances (CD).

METHODS AND RESULTS

We performed CTA fusion imaging in 120 TAVI patients (Edwards Sapien 3) on a standard image post-processing workstation to obtain a 3D reconstruction of the transcatheter heart valve (THV) position within the native annulus region. Optimal implantation depth of the THV was defined according to the manufacturers recommendations as 70-80% of the prosthesis above (aortic) and 20-30% below (ventricular) the native annulus plane. Pre- and post-interventional electrocardiograms (ECGs) were assessed for the development of new CD. THV position was found to be within, above, or below the prespecified margins in 32 patients (27%), 71 patients (59%), and 17 patients (14%), respectively. Interobserver reliability was high for fusion measurements [e.g. median THV position 0.983, 95% confidence interval (CI): 0.935-0.996]. Patients with low stent position were significantly more likely to develop new CD compared with patients with optimal or high stent position (P = 0.039). Independent predictors of CD in multivariate analysis were low THV position [odds ratio (CI): 1.362 (1.093-1.698), P = 0.006] and calcification of the device landing zone [odds ratio (CI): 1.149 (1.024-1.289), P = 0.018].

CONCLUSION

Fusion imaging of pre- and post-TAVI-CTA allows for the exact evaluation of THV position in relation to the native annulus plane. A low THV position as assessed by fusion imaging is associated with the development of new CD post-TAVI.

Subclinical leaflet thrombosis is associated with impaired reverse remodelling after transcatheter aortic valve implantation

AIMS

Cardiac CT is increasingly applied for planning and follow-up of transcatheter aortic valve implantation (TAVI). However, there are no data available on reverse remodelling after TAVI assessed by CT. Therefore, we aimed to evaluate the predictors and the prognostic value of left ventricular (LV) reverse remodelling following TAVI using CT angiography.

METHODS AND RESULTS

We investigated 117 patients with severe, symptomatic aortic stenosis (AS) who underwent CT scanning before and after TAVI procedure with a mean follow-up time of 2.6 years after TAVI. We found a significant reduction in LV mass (LVM) and LVM indexed to body surface area comparing pre- vs. post-TAVI images: 180.5 ± 53.0 vs. 137.1 ± 44.8 g and 99.7 ± 25.4 vs. 75.4 ± 19.9 g/m2, respectively, both P < 0.001. Subclinical leaflet thrombosis (SLT) was detected in 25.6% (30/117) patients. More than 20% reduction in LVM was defined as reverse remodelling and was detected in 62.4% (73/117) of the patients. SLT, change in mean pressure gradient on echocardiography and prior myocardial infarction was independently associated with LV reverse remodelling after adjusting for age, gender, and traditional risk factors (hypertension, body mass index, diabetes mellitus, and hyperlipidaemia): OR = 0.27, P = 0.022 for SLT and OR = 0.22, P = 0.006 for prior myocardial infarction, OR = 1.51, P = 0.004 for 10 mmHg change in mean pressure gradient. Reverse remodelling was independently associated with favourable outcomes (HR = 0.23; P = 0.019).

CONCLUSION

TAVI resulted in a significant LVM regression on CT. The presence of SLT showed an inverse association with LV reverse remodelling and thus it may hinder the beneficial LV structural changes. Reverse remodelling was associated with improved long-term prognosis.

Evaluating the severity of aortic coarctation in infants using anatomic features measured on CTA

OBJECTIVES

A machine learning model was developed to evaluate the severity of aortic coarctation (CoA) in infants based on anatomical features measured on CTA.

METHODS

In total, 239 infant patients undergoing both thorax CTA and echocardiography were retrospectively reviewed. The patients were assigned to either mild or severe CoA group based on their pressure gradient on echocardiography. They were further divided into patent ductus arteriosus (PDA) and non-PDA groups. The anatomical features were measured on double-oblique multiplanar reconstructed CTA images. Then, the optimal features were identified by using the Boruta algorithm. Subsequently, the coarctation severity was classified using linear discriminant analysis (LDA). We further investigated the relationship between the anatomical features and re-coarctation using Cox regression.

RESULTS

Four anatomical features showed significant differences between the mild and severe CoA groups, including the smallest aortic cross-sectional area indexed to body surface area (p < 0.001), the narrowest aortic diameter (CoA diameter) indexed to height (p < 0.001), the diameter of the descending aorta at the diaphragmatic level (p < 0.001) and weight (p = 0.005). With these features, accuracy of 88.6% and 90.2%, sensitivity of 65.0% and 72.1%, and specificity of 92.9% and 100% were obtained for classifying the CoA severity in the non-PDA and PDA groups, respectively. Moreover, CoA diameter indexed to weight was associated with the risk of re-coarctation.

CONCLUSIONS

CoA severity can be evaluated by using LDA with anatomical features. When quantifying the severity of CoA and risk of re-coarctation, both anatomical alternations at the CoA site and the growth of the patients need to be considered.

KEY POINTS

• CTA is routinely ordered for infants with coarctation of the aorta; however, whether anatomical variations observed with CTA could be used to assess the severity of CoA remains unknown. • Using the diameter and area of the coarctation site adjusted to body growth as features, the LDA model achieved an accuracy of 88.6% and 90.2% in differentiating between the mild and severe CoA patients in the non-PDA group and PDA group, respectively. • The narrowest aortic diameter (CoA diameter) indexed to weight has a hazard ratio of 10.29 for re-coarctation.

Predictors for low TAVI-prosthesis position assessed by fusion imaging of pre- and post-procedural CT angiography

Background

Low prosthesis position after transcatheter aortic valve implantation (TAVI) is associated with higher rates of new onset conduction disturbances and permanent pacemaker implantations. Purpose of this study was to investigate possible predictors of a low prosthesis position of the SAPIEN 3 (Edwards Lifesciences, Irvine, California, USA) valve type using fusion imaging of pre- and post-procedural computed tomography angiography (CTA).

Methods

CTA fusion imaging was performed in 120 TAVI-patients with 3D-reconstruction of the transcatheter heart valve (THV) position within the device landing zone. A low implantation position was defined according to the manufacturer’s recommendations as > 30% of the prosthesis below the native annulus plane.

Results

A low THV position was found in 17 patients (14%). Patients with low THV position had less calcification of the annulus region and a smaller annulus size compared to patients with a normal or high THV position (P = 0.003 and 0.041, respectively). The only independent predictor of a low THV position in multivariate logistic regression analysis was the extent of calcification of the cusp region (odds ratio [CI] 0.842 [0.727–0.976], P = 0.022).

Conclusions

Fusion imaging of pre-and post-procedural CTA identified reduced calcification of the cusp region as an independent predictor of a low THV position of the SAPIEN 3. This should be considered when planning the TAVI procedure.

Graphic abstract

Correlation of cusp region calcification and prosthesis position after TAVI

Iodine accumulation of the liver in patients treated with amiodarone can be unmasked using material decomposition from multiphase spectral-detector CT

Amiodarone accumulates in the liver, where it increases x-ray attenuation due to its iodine content. We evaluated liver attenuation in patients treated and not treated with amiodarone using true-non-contrast (TNC) and virtual-non-contrast (VNC) images acquired with spectral-detector-CT (SDCT). 142 patients, of which 21 have been treated with amiodarone, receiving SDCT-examinations (unenhanced-chest CT [TNC], CT-angiography of chest and abdomen [CTA-Chest, CTA-Abdomen]) were included. TNC, CTA-Chest, CTA-Abdomen, and corresponding VNC-images (VNC-Chest, VNC-Abdomen) were reconstructed. Liver-attenuation-index (LAI) was calculated as difference between liver- and spleen-attenuation. Liver-attenuation and LAI derived from TNC-images of patients receiving amiodarone were higher. Contrary to TNC, liver-attenuation and LAI were not higher in amiodarone patients in VNC-Chest and in VNC-Abdomen. To verify these initial results, a phantom scan was performed and an additional patient cohort included, both confirming that VNC is viable of accurately subtracting iodine of hepatic amiodarone-deposits. This might help to monitor liver-attenuation more accurately and thereby detect liver steatosis as a sign of liver damage earlier as well as to verify amiodarone accumulation in the liver.

Imaging of transcatheter aortic valve replacement complications

Aortic stenosis is increasing in incidence and is now commonly managed with transcatheter aortic valve replacement (TAVR) in intermediate and high-risk patients. Radiologists are likely to encounter patients undergoing this procedure both pre- and postoperatively, and therefore, an understanding of procedural complications is essential. Complications may relate to the access site or approach, or the valve itself. This article will review the most common complications described in literature and focuses on the role of multidetector computed tomography (CT) in their evaluation either exclusively, or complementary to other imaging methods.

Evaluation of the liver with virtual non-contrast: single institution study in 149 patients undergoing TAVR planning

OBJECTIVE

To evaluate accuracy of virtual-non-contrast images (VNC) compared to true-unenhanced-images (TNC) for evaluation of liver attenuation acquired using spectral-detector CT (SDCT).

METHODS

149 patients who underwent multiphase transcatheter-aortic-valve-replacement (TAVR) SDCT-examinations [unenhanced-chest (TNC), CT-angiography chest (CTA-chest, early arterial-phase) and abdomen (CTA-abdomen, additional early arterial-phase after a second injection of contrast media)] were retrospectively included. VNC of CTA-chest (VNC-chest) and CTA-abdomen (VNC-abdomen) were reconstructed and compared to TNC. Region of interest-based measurement of mean attenuation (Hounsfield unit, HU) was applied in the following regions: liver, spleen, abdominal aorta and paraspinal muscle.

RESULTS

VNC accuracy was high in the liver, spleen, abdominal aorta and muscle for abdomen-scanning. For the liver, average attenuation was 59.0 ± 9.1 HU for TNC and 72.6 ± 9.5 HU for CTA-abdomen. Liver attenuation in VNC-abdomen (59.1 ± 6.4 HU) was not significantly different from attenuation in TNC (p > 0.05). In contrast, VNC was less accurate for chest-scanning: Due to the protocol, in CTA-chest no contrast media was present in the liver parenchyma as indicated by the same attenuation in TNC (59.0 ± 9.1 HU) and CTA-chest (58.8 ± 8.9 HU, p > 0.05). Liver attenuation in VNC-chest (56.2 ± 6.4 HU, p < 0.05) was, however, significantly lower than in TNC and CTA-chest implying an artificial reduction of attenuation.

CONCLUSION

VNC performed well in a large cohort of TAVR-examinations yielding equivalent mean attenuations to TNC; however, application of this technique might be limited when no or very little contrast media is present in parenchyma, more precisely in an early arterial-phase of the liver.

ADVANCES IN KNOWLEDGE

This study showed that VNC can be reliably applied in cardiac protocols when certain limitations are considered.

CT in planning transcatheter aortic valve implantation procedures and risk assessment

For surgical aortic valve replacement, the Society of Thoracic Surgeons score (STSS) is the reference standard for the prediction of operative risk. In transcatheter aortic valve implantation (TAVI) though, where the procedure itself is minimally invasive, the traditional risk assessment is supplemented by CTA. Through a consistent approach to the acquisition of high-quality images and the standardised reporting of annular measurements and adverse root and vascular features, patients at risk of complications can be identified. In turn, this may allow for a personalised procedural approach and treatment strategies devised to potentially reduce or mitigate this risk. This article provides a systematic and standardised approach to pre-procedural work-up with computed tomography angiography (CTA) and explores the current state of evidence and future areas of development in this rapidly developing field.

Cardiac CT: why, when, and how : Update 2019

PURPOSE

The aim of this study was to review established and emerging techniques of cardiac computed tomography (CT) and their clinical applications with a special emphasis on new techniques, recent trials, and guidelines.

TECHNOLOGICAL INNOVATIONS

Cardiac CT has made great strides in recent years to become an ever more robust and safe imaging technique. The improvements in spatial and temporal resolution are equally important as the substantial reduction in radiation exposure, which has been achieved through prospective ECG-triggering, low tube voltage scanning, tube current modulation, and iterative reconstruction techniques. CT-derived fractional flow reserve and CT myocardial perfusion imaging are novel, investigational techniques to assess the hemodynamic significance of coronary stenosis.

ESTABLISHED AND EMERGING INDICATIONS

In asymptomatic patients at risk for coronary artery disease, CT coronary artery calcium scoring is useful to assess cardiovascular risk and guide the intensity of risk factor modification. Coronary CT angiography is an excellent noninvasive test to rule out obstructive coronary artery disease in patients with stable chest pain. In acute chest pain with normal ECG and normal cardiac enzymes, cardiac CT can safely rule out acute coronary syndrome although its benefit and role in this indication remains controversial. Cardiac CT is the established standard for planning transcatheter aortic valve implantation and-increasingly-minimally invasive mitral valve procedures.

PRACTICAL RECOMMENDATIONS

Our review makes practical recommendations on when and how to perform cardiac CT and provides templates for structured reporting of cardiac CT examinations.

Need for pacemaker implantation in patients with normal QRS duration immediately after transcatheter aortic valve implantation

Aims

We sought to assess the need for permanent pacemaker implantation (PPI) in patients with QRS <120 ms in electrocardiogram (ECG) after transcatheter aortic valve implantation (TAVI).

Methods and results

We retrospectively analysed 1139 consecutive patients who underwent transfemoral TAVI between 2008 and 2016, receiving different valve types. All patients were surveyed by continuous ECG monitoring for 48 h, 12-lead ECGs starting immediately after procedure, as well as 24-h Holter recording the day before discharge. Indication for PPI was at the discretion of the attending physician. Among 760 patients with QRS <120 ms prior to the TAVI procedure, 400 patients showed QRS <120 ms immediately after procedure, whereas 360 patients had QRS ≥120 ms. In the group with QRS <120 ms, PPI was performed in 34 patients [8.5%; 95% confidence interval (CI) 5.6–11.2%] during the first week. Eight of the PPIs in the group with QRS <120 ms (2%; CI 0.8–3.5%) fulfilled Class I indications for PPI after TAVI, whereas 26 PPIs had different indications [left bundle branch block, sick sinus, low-grade atrioventricular (AV) block]. Complete AV block developed in three patients of the group of QRS <120 ms (0.75%; CI 0.0–1.7%), which in all cases occurred after the 48 h-surveillance period. During 1-year follow-up, 11 PPIs were performed (2.8%; CI 1.2–4.5%), thereof three PPI for Class I indications including one complete AV block.

Conclusion

In patients with QRS duration <120 ms immediately after TAVI, the risk for complete AV block was low during the first week after TAVI and 1-year follow-up.

Accuracy of Non-Electrocardiographically Gated Thoracic CT Angiography for Right Atrial and Right Ventricular Enlargement

PURPOSE

To assess the role of long-axis (LA) and short-axis (SA) measurements of the right atrium (RA) and right ventricle (RV) at non-electrocardiographically (ECG) gated thoracic CT angiography for identification of RA enlargement and RV enlargement.

MATERIALS AND METHODS

This study was a retrospective case review of 138 patients who underwent both non-ECG-gated CT angiography and ECG-gated CT angiography concurrently from November 2016 through November 2018. The SA and LA of the RA and RV were measured by two observers blinded to the ECG-gated CT angiography data. ECG-gated CT angiography-derived RA end-systolic and RV end-diastolic volumes were used as standard of reference to derive cutoff values for diagnosis of RA and RV enlargement.

RESULTS

In this study, 138 patients were evaluated (70 men, 68 women; mean age, 70.0 years ± 18.4 [standard deviation]; mean body mass index, 29.3 kg/m² ± 8.1). Of these patients, ECG-gated CT angiography revealed 36.2% had RA enhancement and 19.0% had RV enhancement. The best predictor of RA enhancement was the product of atrial LA and SA measurements, for which a threshold value of 3210 mm² yielded a 94% sensitivity and 81.8% specificity (area under the curve [AUC], 0.92). A threshold of 55.5 mm for LA diameter had 86% sensitivity and 78.4% specificity in identifying RA enlargement. RV enlargement could be predicted if the SA diameter was greater than 48.5 mm (76.9% sensitivity and 64.9% specificity) and with a body surface area indexed value of 27.0 mm/m² (92.3% sensitivity and 74.8% specificity [AUC, 0.87]).

CONCLUSION

RA and RV enlargement can be accurately diagnosed by using non-ECG-gated CT angiography.© RSNA, 2019Supplemental material is available for this article.

Utility of computed tomography in cases of aortic valve stenosis before and after transcatheter aortic valve implantation

Trans-catheter aortic valve implantation (TAVI) has been recognized as a useful treatment for patients with severe aortic valve stenosis, particularly those with moderate to high risks of open heart surgery. A thorough evaluation of the aortic valve complex, including the size or presence of calcifications of the leaflets and annulus, is important for the selection of appropriate candidates, artificial valve types and approach. Echocardiography is useful for the precise evaluation of aortic valve stenosis severity and aortic valve complex morphology, but it is not useful to evaluate three-dimensional aortic valve anatomy and pathway for the catheter of aortic valve implantation. Electrocardiography (ECG)-gating computed tomography (CT) has recently been recognized as a useful modality for evaluating significant coronary artery stenosis because of its higher spatial and temporal resolution and diagnostic accuracy based on recent studies. ECG-gating CT is also useful for evaluating aortic valve complex morphology, including calcifications and whole aorta and iliac arteries, as the access route of catheter in TAVI. TAVI candidates, who are at high risk of open surgery, tend to be old and require anti-platelet after TAVI; therefore CT, is also useful for screening for non-cardiac diseases including malignant tumors just before TAVI. Therefore, here we introduce the utility of cardiac and whole body CT in cases of severe aortic valve stenosis before and after TAVI.

CT and MR imaging prior to transcatheter aortic valve implantation: standardisation of scanning protocols, measurements and reporting-a consensus document by the European Society of Cardiovascular Radiology (ESCR)

Abstract

Transcatheter aortic valve replacement (TAVR) is a minimally invasive alternative to conventional aortic valve replacement in symptomatic patients with severe aortic stenosis and contraindications to surgery. The procedure has shown to improve patient’s quality of life and prolong short- and mid-term survival in high-risk individuals, becoming a widely accepted therapeutic option which has been integrated into current clinical guidelines for the management of valvular heart disease. Nevertheless, not every patient at high-risk for surgery is a good candidate for TAVR. Besides clinical selection, which is usually established by the Heart Team, certain technical and anatomic criteria must be met as, unlike in surgical valve replacement, annular sizing is not performed under direct surgical evaluation but on the basis of non-invasive imaging findings. Present consensus document was outlined by a working group of researchers from the European Society of Cardiovascular Radiology (ESCR) and aims to provide guidance on the utilisation of CT and MR imaging prior to TAVR. Particular relevance is given to the technical requirements and standardisation of the scanning protocols which have to be tailored to the remarkable variability of the scanners currently utilised in clinical practice; recommendations regarding all required pre-procedural measurements and medical reporting standardisation have been also outlined, in order to ensure quality and consistency of reported data and terminology.

Key Points

• To provide a reference document for CT and MR acquisition techniques, taking into account the significant technological variation of available scanners.

• To review all relevant measurements that are required and define a step-by-step guided approach for the measurements of different structures implicated in the procedure.

• To propose a CT/MR reporting template to assist in consistent communication between various sites and specialists involved in the procedural planning.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06357-8) contains supplementary material, which is available to authorized users.