Quantitative assessment of paravalvular regurgitation following transcatheter aortic valve replacement

Periprocedural Assessment of Paravalvular Regurgitation After Transcatheter Aortic Valve Replacement Using Diastolic Delta and Videodensitometry

BACKGROUND

Paravalvular regurgitation (PVR) is a common complication after transcatheter aortic valve replacement, posing an increased risk of heart failure and mortality. Accurate intraprocedural quantification of PVR is challenging. Both hemodynamic indices and videodensitometry can be used for intraprocedural assessment of PVR. We compared the predictive value of the isolated versus combined use of the hemodynamic index diastolic delta (DD) and videodensitometry for the incidence of relevant PVR 1 month after transcatheter aortic valve replacement.

METHODS AND RESULTS

In this prospective cohort study, patients underwent periprocedural PVR assessment by DD and videodensitometry (using left ventricular outflow tract-aortic regurgitation [LVOT-AR]). Cardiac magnetic resonance served as reference modality for PVR assessment. Relevant PVR was defined as cardiac magnetic resonance-regurgitant fraction >20%. Fifty-one patients were enrolled in this study. Mean age was 80.6±5.2 years and 45.1% of patients were men. Mean LVOT-AR and cardiac magnetic resonance-regurgitant fraction were 8.2%±7.8% and 11.7%±9.6%, respectively. The correlation between DD and LVOT-AR was weak (r=-0.36). DD and LVOT-AR showed a comparable accuracy to predict relevant PVR (area under the curve 0.82, 95% CI: 0.69-0.95 versus area area under the time-density curve 0.80, 95% CI: 0.62-0.99). The combination of DD and LVOT-AR improved the prediction of relevant PVR (area under the time-density curve, 0.90, 95% CI: 0.81-0.99), and resulted in an increased concordance (86.3%) and positive predictive value (75%) compared with DD alone (76.5% and 40%, respectively), or LVOT-AR alone (82.3% and 50%, respectively).

CONCLUSIONS

DD and videodensitometry are both accurate and feasible modalities for the assessment of PVR after transcatheter aortic valve replacement. The synergistic use of both techniques increases the predictive value for relevant PVR after transcatheter aortic valve replacement.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04281771.

Assessment of paravalvular regurgitation after transcatheter aortic valve replacement using 2D multi-velocity encoding and 4D flow cardiac magnetic resonance

AIMS

To compare the novel 2D multi-velocity encoding (venc) and 4D flow acquisitions with the standard 2D flow acquisition for the assessment of paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR) using cardiac magnetic resonance (CMR)-derived regurgitant fraction (RF).

METHODS AND RESULTS

In this prospective study, patients underwent CMR 1 month after TAVR for the assessment of PVR, for which 2D multi-venc and 4D flow were used, in addition to standard 2D flow. Scatterplots and Bland-Altman plots were used to assess correlation and visualize agreement between techniques. Reproducibility of measurements was assessed with intraclass correlation coefficients. The study included 21 patients (mean age ± SD 80 ± 5 years, 9 men). The mean RF was 11.7 ± 10.0% when standard 2D flow was used, 10.6 ± 7.0% when 2D multi-venc flow was used, and 9.6 ± 7.3% when 4D flow was used. There was a very strong correlation between the RFs assessed with 2D multi-venc and standard 2D flow (r = 0.88, P < 0.001), and a strong correlation between the RFs assessed with 4D flow and standard 2D flow (r = 0.74, P < 0.001). Bland-Altman plots revealed no substantial bias between the RFs (2D multi-venc: 1.3%; 4D flow: 0.3%). Intra-observer and inter-observer reproducibility for 2D multi-venc flow were 0.98 and 0.97, respectively, and 0.92 and 0.90 for 4D flow, respectively.

CONCLUSION

Two-dimensional multi-venc and 4D flow produce an accurate quantification of PVR after TAVR. The fast acquisition of the 2D multi-venc sequence and the free-breathing acquisition with retrospective plane selection of the 4D flow sequence provide useful advantages in clinical practice, especially in the frail TAVR population.

Complications of transcatheter paravalvular leak device closure of mitral valve: An updated review of the literature and a rare case presentation

Paravalvular leak (PVL) is an uncommon complication of prosthetic valve implantation, which can lead to infective endocarditis, heart failure, and hemolytic anemia. Surgical reintervention of PVLs is associated with high mortality rates. Transcatheter PVL closure (TPVLc) has emerged as an alternative to surgical reoperation. This method provides a high success rate with a low rate of complications. This article reviews the pathogenesis, clinical manifestation, diagnosis, and management of PVL and complications following TPVLc. Besides, we presented a case of a patient with severe PVL following mitral valve replacement, who experienced complete heart block (CHB) during TPVLc. The first TPVLc procedure failed in our patient due to possible AV-node insult during catheterization. After 1 week of persistent CHB, a permanent pacemaker was implanted. The defect was successfully passed using the previous attempt. Considering the advantages of TPVLc, procedure failure should be regarded as a concern. TPVLc should be performed by experienced medical teams in carefully selected patients.

Paravalvular regurgitation after transcatheter aortic valve replacement: incidence, quantification, and prognostic impact

Transcatheter aortic valve replacement (TAVR) is the standard of care in aortic stenosis with results comparable to surgical aortic valve replacement. However, paravalvular regurgitation (PVR) is more common after TAVR. With the alteration of devices and implantation techniques, the incidence of moderate or more PVR has declined. Mild PVR is still common in around 30% of TAVR patients in low-risk trials. Progression of AS causes myocardial hypertrophy and varying degrees of diastolic dysfunction which may cause heart failure even in combination with small volumes of PVR. Any degree of PVR is associated with an increased risk of overall and cardiovascular mortality. Predictors of PVR are annular eccentricity, severe calcification of the aortic valve, bicuspid aortic valves, and type of prosthesis where balloon-expandable devices are associated with less PVR. PVR is diagnosed using echocardiography, aortic angiogram with or without videodensitometry, haemodynamic parameters, or cardiac magnetic resonance. PVR can be treated using post-dilation, interventional treatment using a vascular plug, or implantation of a second device. Successful post-dilation depends on balloon size which should at least be equal to or >95% of the mean annulus diameter. Implantation of a second device to reduce PVR is successful in ∼90% of cases, either through lengthening of the sealing skirt in case of inadequate position or through further expansion of the index device. Implantation of a vascular plug can successfully reduce PVR and reduce mortality.

Artificial Intelligence in Transcatheter Aortic Valve Replacement: Its Current Role and Ongoing Challenges

Transcatheter aortic valve replacement (TAVR) has emerged as a viable alternative to surgical aortic valve replacement, as accumulating clinical evidence has demonstrated its safety and efficacy. TAVR indications have expanded beyond high-risk or inoperable patients to include intermediate and low-risk patients with severe aortic stenosis. Artificial intelligence (AI) is revolutionizing the field of cardiology, aiding in the interpretation of medical imaging and developing risk models for at-risk individuals and those with cardiac disease. This article explores the growing role of AI in TAVR procedures and assesses its potential impact, with particular focus on its ability to improve patient selection, procedural planning, post-implantation monitoring and contribute to optimized patient outcomes. In addition, current challenges and future directions in AI implementation are highlighted.

Is there a role for cardiovascular magnetic resonance imaging in the assessment of biological aortic valves?

Patients with biological aortic valves (following either surgical aortic valve replacement [SAVR] or trans catheter aortic valve implantation [TAVI]) require lifelong follow-up with an imaging modality to assess prosthetic valve function and dysfunction. Echocardiography is currently the first-line imaging modality to assess biological aortic valves. In this review, we discuss the potential role of cardiac magnetic resonance imaging (CMR) as an additional imaging modality in situations of inconclusive or equivocal echocardiography. Planimetry of the prosthetic orifice can theoretically be measured, as well as the effective orifice area, with potential limitations, such as CMR valve-related artefacts and calcifications in degenerated prostheses. The true benefit of CMR is its ability to accurately quantify aortic regurgitation (paravalvular and intra-valvular) with a direct and reproducible method independent of regurgitant jet morphology to accurately assess reverse remodelling and non-invasively detect focal and interstitial diffuse myocardial fibrosis. Following SAVR or TAVI for aortic stenosis, interstitial diffuse fibrosis can regress, accompanied by structural and functional improvement that CMR can accurately assess.

Imaging of Bioprosthetic Valve Dysfunction after Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) has become the standard of care in elderly high-risk patients with symptomatic severe aortic stenosis. Recently, TAVI has been increasingly performed in younger-, intermediate- and lower-risk populations, which underlines the need to investigate the long-term durability of bioprosthetic aortic valves. However, diagnosing bioprosthetic valve dysfunction after TAVI is challenging and only limited evidence-based criteria exist to guide therapy. Bioprosthetic valve dysfunction encompasses structural valve deterioration (SVD) resulting from degenerative changes in the valve structure and function, non-SVD resulting from intrinsic paravalvular regurgitation or patient-prosthesis mismatch, valve thrombosis, and infective endocarditis. Overlapping phenotypes, confluent pathologies, and their shared end-stage bioprosthetic valve failure complicate the differentiation of these entities. In this review, we focus on the contemporary and future roles, advantages, and limitations of imaging modalities such as echocardiography, cardiac computed tomography angiography, cardiac magnetic resonance imaging, and positron emission tomography to monitor the integrity of transcatheter heart valves.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

BACKGROUND

 Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles.

METHOD

 The review is based on a PubMed literature search using the search terms "transcatheter heart valve", "TAVI", "TAVR", "CT", "imaging", "MR" over a period from 2010-2020, combined with personal comments based on the author's experience.

RESULTS AND CONCLUSION

 CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration.

KEY POINTS

  · CT plays a crucial role in evaluating transcatheter heart valve candidates. · Evaluation must include the dimensions of the aortic root and access paths. · The exact post-procedural role of CT and MRI has not yet been determined..

CITATION FORMAT

· Salgado R, El Addouli H, Budde RP. Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021. Fortschr Röntgenstr 2021; 193: 1411 - 1425.

Quantitative assessment of aortic regurgitation following transcatheter aortic valve replacement

Introduction: Transcatheter aortic valve replacement (TAVR) is expanding to lower risk and younger patients with severe symptomatic aortic valve disease. Despite clinical and technological improvements, post-procedural aortic regurgitation (AR) remains a limitation of TAVR, particularly when compared to surgical aortic valve replacement. Although several methods for AR quantification after TAVR are currently available, its exact graduation in everyday clinical practice remains challenging.Areas covered: This review describes the currently available evaluation methods of AR after TAVR, with a special emphasis on the quantitative assessment using videodensitometric angiography, echocardiography and cardiac magnetic resonance imaging.Expert opinion: In the majority of clinical scenarios, satisfactory evaluation of post-TAVR AR can be achieved with a combination of post-procedural angiography, hemodynamic indices and transthoracic echocardiography. Nevertheless, some TAVR patients show 'intermediate' forms of post-procedural AR, in which quantitative evaluation is mandatory for prognostic purposes and further decision-making. Notably, interpretation of quantitative measures early post-TAVR is challenging because of the lack of left ventricular enlargement. Video-densitometric angiography is an emerging method that appears to be clinically attractive for immediate post-TAVR assessment, but requires further validation in everyday clinical practice.

Clinical and Technical Challenges of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Implantation

Prosthesis-patient mismatch (PPM) is present when the effective area of a prosthetic valve inserted into a patient is inferior to that of a normal human valve; the hemodynamic consequence of a valve too small compared with the size of the patient's body is the generation of higher than expected transprosthetic gradients. Despite evidence of increased risk of short- and long-term mortality and of structural valve degeneration in patients with PPM after surgical aortic valve replacement, its clinical impact in patients subject to transcatheter aortic valve implantation (TAVI) is yet unclear. We aim to review and update on the definition and incidence of PPM after TAVI, and its prognostic implications in the overall population and in higher-risk subgroups, such as small aortic annuli or valve-in-valve procedures. Last, we will focus on the armamentarium available in order to reduce risk of PPM when planning a TAVI procedure.

Cardiovascular magnetic resonance and transesophageal echocardiography in patients with prosthetic valve paravalvular leaks: towards an accurate quantification and stratification

BACKGROUND

Objective assessment of prosthetic paravalvular leak (PVL) is complex and challenging even in transesophageal echocardiography (TEE). Our aim was to assess the value of cardiovascular magnetic resonance (CMR) in quantifying PVL in aortic (AVR) or mitral valve (MVR) replacement.

METHODS

Thirty-one patients (62 ± 15.1 years, 63% males) with a preliminary diagnosis of significant PVL (AVR, n-23; MVR, n = 8) were recruited. The TEE PVL grading was based on the semi-quantitative (SQ) TEE according to the VARC II PVL classification (%PVL: mild < 10%; moderate 10%-30%; severe > 30%). Non-contrast CMR studies were acquired at 1.5 T with a quantitative approach (phase-contrast velocity encoded imaging). The CMR PVL severity was classified according to regurgitant fraction (RF: (1) mild ≤ 20%, (2) moderate 21%-39%, or (3) severe ≥ 40%).

RESULTS

All patients revealed symptoms of heart failure (71%: New York Heart Association [NYHA] II; 91%: N-terminal pro-B-type natriuretic peptide [NT-proBNP] > 150 pg/ml) and typical cardiovascular disease risk factors. The SQ-TEE results revealed several categories: (1) mild (n = 5; 16%), (2) moderate (n = 21; 67%), and (3) severe (n = 5; 16%) PVL. However, CMR PVL RF reclassified the severity of PVL: (1) mild to moderate (in 80%), (2) moderate to severe (in 47%), and (3) severe to moderate (in 40%). The receiver operating characteristic analysis showed that SQ-TEE and CMR PVL-vol and -RF predicted the upper tertile of NT-proBNP (> 2000 pg/ml) with the best sensitivity for CMR parameters.

CONCLUSION

The SQ-TEE showed moderate agreement with CMR and underestimated a considerable number of AVR or MVR-PVL.

Hemodynamic performance of the balloon-expandable SAPIEN 3 valve as assessed by cardiac magnetic resonance

BACKGROUND

Scarce data exist on transcatheter heart valve (THV) performance evaluated by cardiac magnetic resonance (CMR) in newer generation THV patients. Furthermore, it has been suggested that echocardiographic evaluation after TAVR may inaccurately assess residual AR in some patients. This study aimed to determine the incidence and severity of aortic regurgitation (AR) assessed by CMR in patients undergoing TAVR with the SAPIEN 3 valve, and evaluate the agreement between CMR and transthoracic echocardiography (TTE) on the assessment of AR severity in such patients.

METHODS

This multicentric observational study included 146 SAPIEN 3 patients with TTE and CMR within the month following their procedure. According to the CMR regurgitation fraction (RF), AR was considered mild and moderate-severe if the RF was 15-<30% and ≥ 30%, respectively. TTE exams followed VARC-2 recommendations.

RESULTS

By CMR, SAPIEN 3 recipients displayed a mean RF of 5.0 ± 6.1%, and mild and moderate-severe AR rates of 3.4% and 0.7%, respectively. The agreement between CMR-TTE was modest (weighted κ = 0.2640, p<0.001), due to an overestimation of AR severity by TTE. A historical cohort of 139 SAPIEN XT patients with a post-procedure CMR, displayed a mean RF of 9.6 ± 10.7% and mild and moderate-severe AR rates of 18.7% and 3.6%, respectively (p < .001 vs. SAPIEN 3 group).

CONCLUSIONS

SAPIEN 3 recipients exhibited very low rates of residual AR by CMR, suggesting a surgical-like performance regarding AR with this newer generation THV. TTE tended to overestimate the severity of AR, particularly among mild AR patients.

[Role of magnetic resonance imaging in patients with aortic stenosis before and after replacement of the valve]

Risk stratification among patients with aortic stenosis remains inadequate, and there is a clinical need for the correct identification of high-risk patients who would benefit from aortic valve intervention before developing left ventricular decompensation. Since the publication of the results of the PARTNER study, transcatheter aortic valve implantation (TAVI) has become the method of choice for aortic valve stenosis in inoperable patients and is a real alternative to conventional surgical replacement of the aortic valve in high-risk patients. In planning TAVI and postoperative monitoring of a patient from imaging methods, the leading role is played by echocardiography and multispiral computed tomography. However, in recent years, the interest of researchers in the use of magnetic resonance imaging in this category of patients has increased. The review article examines the potential role of magnetic resonance imaging in patients with aortic stenosis before and after TAVI.

Neoaortic Regurgitation in Patients with Transposition Long Term After an Arterial Switch Operation and Its Relation to the Root Diameters and Surgical Technique Used

Neoaortic regurgitation and root dilatation are common findings in patients with transposition after an arterial switch operation. The aim of this study was to describe the relation between neoaortic regurgitation long term after an arterial switch procedure, aortic root diameters, and surgical technique used. We also assessed the agreement of the neoaortic regurgitation grade and root diameters in different imaging modalities. For this retrospective study, we qualified 56 consecutive patients who, according to our institutional protocol, had a routine postoperative evaluation of more than 16 years with multimodality imaging studies. Neoaortic regurgitation was assessed by both transthoracic echocardiography and magnetic resonance imaging, and the root diameters obtained by echocardiography and tomography were compared to the reference values and associated with the presence of neoaortic insufficiency. Neoaortic insufficiency was present in 75% of examined patients; the vast majority of them had trace or mild regurgitation, and its qualitative evaluation was significantly different between echocardiography and magnetic resonance imaging. In our study group, the neoaortic valve and aortic sinus were larger in relation to the normal values, and they were significantly correlated with the presence of neoaortic insufficiency, but not with the surgical technique used. Values obtained by echocardiography and tomography correlated well but were significantly different. Transthoracic echocardiography has a tendency to overestimate the severity of regurgitation compared to magnetic resonance imaging. Neoaortic valve and sinus dilatation are significantly correlated with valve insufficiency, but in most cases of root dilatation, the valve remains competent.

The emerging applications of cardiovascular magnetic resonance imaging in transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement in selected patients with severe symptomatic aortic stenosis (AS) and high surgical risk. The planning and follow-up of TAVI requires an array of imaging techniques, each has advantages and limitations. Echocardiography and multidetector computer tomography (MDCT) have established applications in patient selection and procedure guidance, but are limited in some patients. TAVI applications of cardiovascular magnetic resonance imaging (CMRI) are emerging. CMRI can provide the structural and functional imaging details required for TAVI procedure in away comparable or superior to that obtained by echocardiography and MDCT combined. In this review, we look at the continuously evolving role of CMRI as a complimentary or an alternative to more established imaging techniques and address the advantages and disadvantages of CMRI in this setting. We discuss the role of CMRI in selecting anatomically suitable patients for the TAVI procedure and in the post-TAVI follow-up with particular emphasis on its applications for assessing AS severity and haemodynamic impact, vascular imaging for TAVI access route, quantification of paravalvular leaks and LV remodelling in the post TAVI setting as well as providing imaging biomarkers tool for AS risk-stratification.

Early detection of transcatheter heart valve dysfunction

Introduction: Transcatheter aortic valve implantation therapy is spreading rapidly, representing the standard of care in inoperable and high-risk patients, and a valid alternative in intermediate- and low-risk patients with severe symptomatic aortic stenosis. In this subset, the development and validation of noninvasive, quantitative, in vivo imaging modality, to monitor possible valve dysfunction is mandatory, in order to plan timely therapeutic interventions before the onset of symptoms.Areas covered: The implantation of transcatheter heart valves (THV) is increasing rapidly. As a consequence, THV dysfunction will become a major cause of cardiovascular morbidity after TAVI. Emergency repeat aortic valve replacement surgery is associated with a high rate of mortality compared with elective repeat surgery. In this context, early detection of THV dysfunction is therefore highly desirable. The review aims to examine the different diagnostic method to early detect THV dysfunction.Expert opinion: Most promising innovations in the diagnosis of early detection of THV dysfunction are evaluated, and the future outlook is explored. Waiting for upcoming evidence about the utility of CT, CMR, and PET on early detection of THV dysfunction, tailoring echocardiogram follow-up based on patients' characteristics is the desirable approach.

Meta-Analysis of Transthoracic Echocardiography Versus Cardiac Magnetic Resonance for the Assessment of Aortic Regurgitation After Transcatheter Aortic Valve Implantation

Residual aortic regurgitation (AR) is a major complication after transcatheter aortic valve implantation (TAVI). Although the echocardiographic assessment of post-TAVI AR remains challenging, cardiac magnetic resonance (CMR) allows direct quantification of AR. The aim of this study was to review the level of agreement between 2-dimensional transthoracic echocardiography (2D TTE) and CMR on grading the severity of AR after TAVI, and determine the accuracy of TTE in detecting moderate or severe AR. Electronic databases were searched in order to identify studies comparing 2D TTE to CMR for post-TAVI AR assessment. Kappa coefficient was used to determine the level of agreement between the 2 imaging modalities. CMR was used as the reference standard in order to assess the diagnostic accuracy of 2D TTE. Seven studies were included in this systematic review. Six studies reported a low correlation between 2D TTE and CMR (kappa coefficient ranging from -0.02 to 0.41), whereas one study showed good agreement with a kappa coefficient of 0.72. Given the heterogeneity in the included studies the diagnostic accuracy of TTE was evaluated by estimating the hierarchical summary receiver operator characteristic curve. The area under the curve for detection of moderate or severe AR with TTE was 0.83 (95% confidence interval 0.79 to 0.86). In conclusion, despite the reported significant disconcordance between TTE and CMR grading of AR, TTE has sufficient ability to discriminate moderate or severe AR from mild or none AR after TAVI in the clinical setting. CMR should be considered when TTE results are equivocal.

Effect of Aortic Regurgitation by Cardiovascular Magnetic Resonance After Transcatheter Aortic Valve Implantation

Cardiovascular magnetic resonance (CMR) has demonstrated a high accuracy for evaluating the severity of aortic regurgitation (AR). However, scarce data exist on the impact of AR as evaluated by CMR on clinical outcomes following transcatheter aortic valve implantation (TAVI). The objective of this study was to evaluate the impact of AR as determined by CMR on clinical outcomes (mortality, heart failure [HF] hospitalization) post-TAVI. A total of 448 TAVI recipients from 2 centers (mean age: 80 ± 7 years, mean STS: 5.8 ± 5.4%) who survived the periprocedural period with no pacemaker implantation were included. A newer generation transcatheter valve system was used in 213 patients (48%). The CMR examination was performed at a median of 12 (IQR: 7 to 21) days post-TAVI. After a mean follow-up of 24 ± 19 months, a total of 94 patients (21%) had died and 72 patients (16%) had at least 1 hospitalization because of decompensated HF. The aortic regurgitation fraction (RF) as determined by CMR was an independent predictor of mortality (hazard ratio[HR]:1.06 for each increase of 10%, 95% confidence interval [CI]: 1.01 to 1.12, p = 0.03) and HF hospitalization (HR:1.15 for each increase of 10%, 95% CI:1.02 to 1.30, p = 0.02). The rate of moderate-severe CMR-AR defined as a RF ≥30% was 3%, and this was associated with an increased risk of mortality (HR: 2.63, 95% CI: 2.30 to 2.99, p <0.001) and HF hospitalization (HR: 2.96, 95% CI: 1.62 to 5.42, p ˂0.001). A stepwise increase in the risk of mortality and HF hospitalization was observed with an increase in AR severity, with a peak increase among patients with RF ≥30%. In conclusion, our results showed the clinical usefulness of evaluating AR severity by CMR post-TAVI. CMR would be particularly helpful in doubtful cases or those with discordances between echocardiography and clinical data.

Ex Vivo Pilot Study of Cardiac Magnetic Resonance Velocity Mapping for Quantification of Aortic Regurgitation in a Porcine Model in the Presence of a Transcatheter Heart Valve

Accuracy of aortic regurgitation (AR) quantification by magnetic resonance (MR) imaging in the presence of a transcatheter heart valve (THV) remains to be established. We evaluated the accuracy of cardiac MR velocity mapping for quantification of antegrade flow (AF) and retrograde flow (RF) across a THV and the optimal slice position to use in cardiac MR imaging. In a systematic and fully controlled laboratory ex vivo setting, two THVs (Edwards SAPIEN XT, Medtronic CoreValve) were tested in a porcine model (n = 1) under steady flow conditions. Results showed a high level of accuracy and precision. For both THVs, AF was best measured at left ventricular outflow tract level, and RF at ascending aorta level. At these levels, MR had an excellent repeatability (ICC > 0.99), with a tendency to overestimate (4.6 ± 2.4% to 9.4 ± 7.0%). Quantification of AR by MR velocity mapping in the presence of a THV was accurate, precise, and repeatable in this pilot study, when corrected for the systematic error and when the best MR slice position was used. Confirmation of these results in future clinical studies would be a step forward in increasing the accuracy of the assessment of paravalvular AR severity.

Cardiovascular magnetic resonance assessment of 1st generation CoreValve and 2nd generation Lotus valves

OBJECTIVES

We sought to compare using serial CMR, the quantity of AR and associated valve hemodynamics, following the first-generation CoreValve (Medtronic, Minneapolis, MN) and the second-generation Lotus valve (Boston Scientific, Natick, MA).

BACKGROUND

Aortic regurgitation (AR) following Transcatheter Aortic Valve Replacement (TAVR) confers a worse prognosis and can be accurately quantified using cardiovascular magnetic resonance (CMR). Second generation valves have been specifically designed to reduce paravalvular AR and improve clinical outcomes.

METHODS

Fifty-one patients (79.0 ± 7.7 years, 57% male) were recruited and imaged at three time points: immediately pre- and post-TAVR, and at 6 months.

RESULTS

CMR-derived AR fraction immediately post-TAVR was greater in the CoreValve compared to Lotus group (11.7 ± 8.4 vs. 4.3 ± 3.4%, P = 0.001), as was the frequency of ≥moderate AR (9/24 (37.5%) versus 0/27, P < 0.001). However, at 6 months AR fraction had improved significantly in the CoreValve group such that the two valve designs were comparable (6.4 ± 5.0 vs 5.6 ± 5.3%, P = 0.623), with no patient in either group having ≥moderate AR. The residual peak pressure gradient immediately following TAVR was significantly lower with CoreValve compared to Lotus (14.1 ± 5.6 vs 25.4 ± 11.6 mmHg, P = 0.001), but again by 6 months the two valve designs were comparable (16.5 ± 9.4 vs 19.7 ± 10.5 mmHg, P = 0.332). There was no difference in the degree of LV reverse remodeling between the two valves at 6 months.

CONCLUSION

Immediately post-TAVR, there was significantly less AR but a higher residual peak pressure gradient with the Lotus valve compared to CoreValve. However, at 6 months both devices had comparable valve hemodynamics and LV reverse remodeling.

Review of Journal of Cardiovascular Magnetic Resonance (JCMR) 2015-2016 and transition of the JCMR office to Boston

The Journal of Cardiovascular Magnetic Resonance (JCMR) is the official publication of the Society for Cardiovascular Magnetic Resonance (SCMR). In 2016, the JCMR published 93 manuscripts, including 80 research papers, 6 reviews, 5 technical notes, 1 protocol, and 1 case report. The number of manuscripts published was similar to 2015 though with a 12% increase in manuscript submissions to an all-time high of 369. This reflects a decrease in the overall acceptance rate to <25% (excluding solicited reviews). The quality of submissions to JCMR continues to be high. The 2016 JCMR Impact Factor (which is published in June 2016 by Thomson Reuters) was steady at 5.601 (vs. 5.71 for 2015; as published in June 2016), which is the second highest impact factor ever recorded for JCMR. The 2016 impact factor means that the JCMR papers that were published in 2014 and 2015 were on-average cited 5.71 times in 2016.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in the order that they are accepted with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes with previously published JCMR papers to guide continuity of thought in the journal. In addition, I have elected to open this publication with information for the readership regarding the transition of the JCMR editorial office to the Beth Israel Deaconess Medical Center, Boston and the editorial process.Though there is an author publication charge (APC) associated with open-access to cover the publisher's expenses, this format provides a much wider distribution/availability of the author's work and greater manuscript citation. For SCMR members, there is a substantial discount in the APC. I hope that you will continue to send your high quality manuscripts to JCMR for consideration. Importantly, I also ask that you consider referencing recent JCMR publications in your submissions to the JCMR and elsewhere as these contribute to our impact factor. I also thank our dedicated Associate Editors, Guest Editors, and reviewers for their many efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the leading publication in our field.

Role of CMR in TAVR

Multimodality imaging plays a critical role in planning, performing, and evaluating transcatheter aortic valve replacement (TAVR). Cardiovascular magnetic resonance (CMR) has been underutilized in this patient population to date, but there is increasing evidence that it can offer equivalent or even superior information to more commonly used imaging modalities, such as echocardiography or computed tomography for specific applications. In addition, CMR can provide incremental information, including advanced tissue characterization with late gadolinium enhancement and T1 mapping. In this paper, we review the evidence for CMR in TAVR and explore whether CMR should still be considered a research tool, or whether it is now ready for implementation into clinical practice.

Update on the significance of postprocedural aortic regurgitation after transcatheter aortic valve replacement on postprocedural prognosis

Transcatheter aortic valve replacement (TAVR) is an established therapy for patients with aortic stenosis and a high surgical risk. Recent data on intermediate-risk patients will probably enlarge the indication for TAVR. In the beginning of the TAVR era, relevant (>mild) aortic regurgitation (AR) was a common finding after TAVR; it was associated with worse outcome compared with patients without significant AR. To date, several improvements in imaging, grading of severity and treatment have been done and will be discussed in this article. AR after TAVR still is a strong and independent predictor of 1-year mortality and every effort should be made to prohibit its development.

Evaluation of aortic regurgitation with cardiac magnetic resonance imaging: a systematic review

This review summaries the utility, application and data supporting use of cardiac magnetic resonance imaging (CMR) to evaluate and quantitate aortic regurgitation. We systematically searched Medline and PubMed for original research articles published since 2000 that provided data on the quantitation of aortic regurgitation by CMR and identified 11 articles for review. Direct aortic measurements using phase contrast allow quantitation of volumetric flow across the aortic valve and are highly reproducible and accurate compared with echocardiography. However, this technique requires diligence in prescribing the correct imaging planes in the aorta. Volumetric analytic techniques using differences in ventricular volumes are also highly accurate but less than phase contrast techniques and only accurate when concomitant valvular disease is absent. Comparison of both aortic and ventricular data for internal data verification ensures fidelity of aortic regurgitant data. CMR data can be applied to many types of aortic valve regurgitation including combined aortic stenosis with regurgitation, congenital valve diseases and post-transcatheter valve placement. CMR also predicts those patients who progress to surgery with high overall sensitivity and specificity. Future studies of CMR in patients with aortic regurgitation to quantify the incremental benefit over echocardiography as well as prediction of cardiovascular events are warranted.

Echocardiographic follow-up after transcatheter aortic valve replacement

The use of transcatheter aortic valve replacement (TAVR) for high-risk patients with aortic stenosis has rapidly increased during the past years. Accordingly, more and more patients are referred for a follow-up echocardiographic study after TAVR. However, the echocardiographic evaluation of patients who underwent TAVR places specific demands on echocardiographers. Furthermore, TAVR may be associated with new types of complications, which are frequently unrecognized or underestimated due to lack of familiarity with the normal and pathological appearance of TAVR. Therefore, this review summarizes the echocardiographic parameters describing the structural and functional status of bioprostheses used in TAVR, procedures taking into account their peculiar hemodynamics. We also describe the strengths and the limitations of echocardiography and of other imaging modalities in detecting long-term complications of TAVR (eg, infective endocarditis, thrombosis). The aim of this review was to serve as a guide for a structured echocardiographic follow-up of TAVR patients, as well as for the echocardiographic diagnosis of the procedure-associated complications.

Review of Journal of Cardiovascular Magnetic Resonance 2015

There were 116 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2015, which is a 14 % increase on the 102 articles published in 2014. The quality of the submissions continues to increase. The 2015 JCMR Impact Factor (which is published in June 2016) rose to 5.75 from 4.72 for 2014 (as published in June 2015), which is the highest impact factor ever recorded for JCMR. The 2015 impact factor means that the JCMR papers that were published in 2013 and 2014 were cited on average 5.75 times in 2015. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is <25 % and has been falling because the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality papers to JCMR for publication.

Prevalence and Prognostic Significance of Right Ventricular Systolic Dysfunction in Patients Undergoing Transcatheter Aortic Valve Implantation

Background—

Cardiovascular magnetic resonance (CMR) can provide important structural information in patients undergoing transcatheter aortic valve implantation. Although CMR is considered the standard of reference for measuring ventricular volumes and mass, the relationship between CMR findings of right ventricular (RV) function and outcomes after transcatheter aortic valve implantation has not previously been reported.

Methods and Results—

A total of 190 patients underwent 1.5 Tesla CMR before transcatheter aortic valve implantation. Steady-state free precession sequences were used for aortic valve planimetry and to assess ventricular volumes and mass. Semiautomated image analysis was performed by 2 specialist reviewers blinded to patient treatment. Patient follow-up was obtained from the Office of National Statistics mortality database. The median age was 81.0 (interquartile range, 74.9–85.5) years; 50.0% were women. Impaired RV function (RV ejection fraction ≤50%) was present in 45 (23.7%) patients. Patients with RV dysfunction had poorer left ventricular ejection fractions (42% versus 69%), higher indexed left ventricular end-systolic volumes (96 versus 40 mL), and greater indexed left ventricular mass (101 versus 85 g/m 2 ; P <0.01 for all) than those with normal RV function. Median follow-up was 850 days; 21 of 45 (46.7%) patients with RV dysfunction died, compared with 43 of 145 (29.7%) patients with normal RV function ( P =0.035). After adjustment for significant baseline variables, both RV ejection fraction ≤50% (hazard ratio, 2.12; P =0.017) and indexed aortic valve area (hazard ratio, 4.16; P =0.025) were independently associated with survival.

Conclusions—

RV function, measured on preprocedural CMR, is an independent predictor of mortality after transcatheter aortic valve implantation. CMR assessment of RV function may be important in the risk stratification of patients undergoing transcatheter aortic valve implantation.

The role of cardiovascular magnetic resonance in the assessment of severe aortic stenosis and in post-procedural evaluation following transcatheter aortic valve implantation and surgical aortic valve replacement

Degenerative aortic stenosis (AS) is the most common valvular disease in the western world with a prevalence expected to double within the next 50 years. International guidelines advocate the use of cardiovascular magnetic resonance (CMR) as an investigative tool, both to guide diagnosis and to direct optimal treatment. CMR is the reference standard for quantifying both left and right ventricular volumes and mass, which is essential to assess the impact of AS upon global cardiac function. Given the ability to image any structure in any plane, CMR offers many other diagnostic strengths including full visualisation of valvular morphology, direct planimetry of orifice area, the quantification of stenotic jets and in particular, accurate quantification of valvular regurgitation. In addition, CMR permits reliable and accurate measurements of the aortic root and arch which can be fundamental to appropriate patient management. There is a growing evidence base to indicate tissue characterisation using CMR provides prognostic information, both in asymptomatic AS patients and those undergoing intervention. Furthermore, a number of current clinical trials will likely raise the importance of CMR in routine patient management. This article will focus on the incremental value of CMR in the assessment of severe AS and the insights it offers following valve replacement.

Transcatheter Aortic Valve Implantation in Lower-Risk Patients With Aortic Stenosis

Transcatheter aortic valve implantation underwent progressive improvements until it became the default therapy for inoperable patients, and a recommended therapy in high-risk operable patients with symptomatic severe aortic stenosis. In the lower-risk patient strata, a currently costly therapy that still has important complications with questionable durability is competing with the established effective and still-improving surgical replacement. This report tries to weigh the clinical evidence, the recent technical improvements, the durability, and the cost-effectiveness claims supporting the adoption of transcatheter aortic valve implantation in intermediate-low risk patients. The importance of appropriate patients’ risk stratification and a more comprehensive approach to estimate that risk are also emphasized in the present report.