Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement

OBJECTIVES

To determine the safety and feasibility of over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement.

BACKGROUND

Transcatheter pulmonary valve placement is an alternative to surgical pulmonary valve replacement. Traditionally, it was thought to be unsafe to expand a conduit to >110% of its original size.

METHODS

This retrospective cohort study from two centers includes patients with right ventricle to pulmonary artery conduits with attempted transcatheter pulmonary valve placement from 2010 to 2017. Demographic, procedural, echocardiographic and follow-up data, and complications were evaluated in control and overdilation (to >110% original conduit size) groups.

RESULTS

One hundred and seventy-two patients (51 overdilation and 121 control) had attempted transcatheter pulmonary valve placement (98% successful). The overdilation group was younger (11.2 versus 16.7 years, p < 0.001) with smaller conduits (15 versus 22 mm, p < 0.001); however, the final valve size was not significantly different (19.7 versus 20.2 mm, p = 0.2). Baseline peak echocardiographic gradient was no different (51.8 versus 55.6 mmHg, p = 0.3). Procedural complications were more frequent in overdilation (18%) than control (7%) groups (most successfully addressed during the procedure). One patient from each group required urgent surgical intervention, with no procedural mortality. Follow-up echocardiographic peak gradients were similar (24.1 versus 26 mmHg, p = 0.5).

CONCLUSIONS

Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement can be performed successfully. Procedural complications are more frequent with conduit overdilation, but there was no difference in the rate of life-threatening complications. There was no difference in valve function at most recent follow-up, and no difference in rate of reintervention. The long-term outcomes of transcatheter pulmonary valve placement with conduit over-expansion requires further study.

Out of the blue: inflammatory myofibroblastic tumour identified during repair of tetralogy of Fallot with absent pulmonary valve

Inflammatory myofibroblastic tumour of the heart is an exceedingly rare benign neoplasm. While benign, without prompt management its impact can be devastating. Tetralogy of Fallot with absent pulmonary valve is a rare form of CHD. We present the first documented case of inflammatory myofibroblastic tumour of the heart in the presence of tetralogy of Fallot with absent pulmonary valve.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits, and Bioprosthetic Valves

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital heart disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons, and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multimodality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Unmet Clinical Needs for Transcatheter Pulmonary Valves

A common feature of congenital heart disease is the presence of right ventricular outflow tract (RVOT) obstruction that can range from mild to severe and can lead to atresia of the pulmonary valve, in extreme conditions. RVOT abnormalities can frequently be corrected surgically or via interventional means. However, most of these patients will ultimately develop pulmonary valve insufficiency and eventual right ventricular dilation, which will require a pulmonary valve replacement at some point in their life to mitigate the detrimental effects of pulmonary valve regurgitation (PVR) on the right ventricle (RV). The evolution from the studies done by Philip Bonhoeffer to implant a pulmonary valve via transcatheter means, have provided a bedrock for transcatheter pulmonary valve replacement (TPVR). Yet, several areas of unmet need for a demographic of patients still exist. Here, we discuss the clinical unmet needs in children under 20 Kg and expand the use of hybrid and other TPVR approaches along with the current indications and contraindications for pulmonary valve replacement. The constraints and limitations from commercially available pulmonary valves will be discussed from a clinical standpoint. Finally, we explore the use of hybrid and periventricular delivery of transcatheter pulmonary valves in younger patients.

Survival and Freedom From Reinterventions in Patients With Repaired Tetralogy of Fallot: Up to 42-Year Follow-Up of 917 Patients

Background To evaluate long-term outcome of tetralogy of Fallot repair analyzing an unbiased country-wide surgically treated population with tetralogy of Fallot. Methods and Results Retrospective analysis of consecutive patients aged <18 years who underwent tetralogy of Fallot repair at a single nationwide pediatric cardiac center. Death from any cause and need for surgical or catheter reintervention were the study end points. Cox regression analysis was used to identify related risk factors. A total of 917 patients (male, 56.3%) were analyzed. Staged repair was performed in 16.9%. Early mortality (24/917, 2.62% patients) was confined to the early surgical eras. Late mortality was 4.5% (40/893 patients). Survival probability was 95.1%, 93.8% and 91.9% at 10, 20 and 30 years after repair, respectively. Early surgical era (P=0.013) and surgical/catheter reinterventions (P<0.001) were multivariable predictors of late death. A total of 487 reinterventions were performed after initial repair in 253/917 patients (27.6%), with pulmonary artery revalvulation (196/917 patients, 21.4%) being most frequent. Probability of freedom from first reintervention was 89.0%, 73.3%, and 55.1% at 10, 20, and 30 years after primary repair, respectively. Transannular repair was associated with the need for pulmonary artery revalvulation (P<0.001). Patients who underwent staged repair were more likely to need reinterventions on pulmonary arteries (P<0.001). Conclusions In an unbiased nationwide cohort, tetralogy of Fallot repair carried a favorable survival of >90% at 30 years. Each reintervention significantly incrementally increased the risk of mortality. Type of initial repair predicted the need for specific surgical or catheter reinterventions.

Outcomes of the Ross procedure in patients older versus younger than 50 years old

OBJECTIVES

The Ross procedure is traditionally considered for young adult patients with aortic valve disease. This study compares long-term outcomes of patients undergoing the Ross procedure who are ≥50 and <50-years old.

METHODS

Data were collected from 225 patients undergoing Ross procedure at a single centre from 1994 to 2019. Patients were categorized into younger (<50-years old; n = 156) and older (≥50-years old; n = 69) cohorts. Baseline demographics clinical outcomes were compared.

RESULTS

The mean age was 36 ± 8.1 and 55 ± 4.2 years in the younger and older cohort, respectively. Both groups were predominantly male (58.5% vs 69.6%; P = 0.59). The younger group had a higher rate of aortic insufficiency (51% vs 26.1%; P < 0.01), and bicuspid aortic valve (81.4% vs 58.0%; P < 0.01). Aortic stenosis was more prevalent in the older cohort (25.6% vs 58.0%; P < 0.01). Operative mortality was acceptable in both groups (1.3% vs 4.3%; P = 0.15). Survival up to 10 years was not statistically different between 2 groups (96.2% vs 91.3% P = 0.16), whereas survival up to 15 years for younger patients was significantly higher (94.9% vs 85.5%; P = 0.03). After non-cardiac related deaths were excluded, survival up to 15 years (98.7% vs 91.3%; P = 0.02) was significantly lower than younger patients. In both groups, survival after the Ross procedure was similar to the age- and sex-matched US population.

CONCLUSIONS

Survival up to 10 years after Ross procedure were similar, but up to 15 years was significantly higher in younger patients. The Ross procedure restored patients from both groups to expected survival. Our results suggest that at experienced centres, the Ross procedure is a safe and reasonable option for patients who are 50 years and older.

Early results of Pulsta® transcatheter heart valve in patients with enlarged right ventricular outflow tract and severe pulmonary regurgitation due to transannular patch

OBJECTIVE

The purpose of this study is to assess the feasibility, effectivity, and safety of a novel self-expandable valve system, Pulsta® transcatheter heart valve in patients with tetralogy of fallot and severe pulmonary regurgitation after transannular patch repair.

BACKGROUND

Severe pulmonary regurgitation after tetralogy of fallot repair is a life-threatening problem and should be treated by pulmonary valve implantation. Although percutaneous pulmonary valve implantation has been ever increasingly used for this purpose, available balloon-expandable valves have limitations and cannot be used by most patients. Pulsta® transcatheter heart valve is a new self-expandable valve system and offers a new solution to be used in patients with different types of native right ventricular outflow tract geometry.

PATIENTS AND METHODS

Ten patients with severe regurgitation after tetralogy of fallot repair with a transannular patch have been enrolled in the study according to echocardiographic examination. MRI was used in asymptomatic patients to delineate the indication and the right ventricular outflow tract geometry. Pulsta® transcatheter heart valve implantation was performed in ten patients, and preprocedural, procedure, and 6 months follow-up findings of the patients were evaluated.

RESULTS

Pulsta® pulmonary valve implantation was performed in ten patients successfully without any severe complications. Valve functions were perfect in six of ten patients, while the others had insignificant regurgitation by echocardiographic examination at the end of 6 months follow-up.

CONCLUSIONS

This study showed that Pulsta® transcatheter heart valve is a feasible, effective, and safe method in the treatment of severe pulmonary regurgitation due to transannular patch repair in patients with tetralogy of fallot.

Right ventricular outflow tract landing zone perimeter / circularised diameter - new imaging standards in pulmonary valve replacement reporting

BACKGROUND

Right ventricular outflow tract intervention spans transcatheter, surgical, or hybrid pulmonary valve replacement methodologies. Standardised pre-procedure workup includes cardiac MRI to identify an intended valve site (landing zone). Our institutional practice includes measurement of the right ventricular outflow tract perimeter (circumference) of this site in end-systole. Our primary aim was to compare patients by their perimeter values to the palliative interventions performed (transcatheter versus surgical/hybrid methodologies).

METHODS

Retrospective review of patients undergoing pulmonary valve replacement from January 2017 to 2021. We performed perimeter measurements at the intended valve site on advanced imaging; the outcomes of interventions were outlined via descriptive and statistical analyses.

RESULTS

A total of 37 patients underwent pulmonary valve replacement that met study criteria - 21 transcatheter, 7 surgical, and 9 hybrid. Median age at intervention was 26 years (range 8-70). The mean end-systolic perimeter of the transcatheter cohort was 88.9 ± 8.7 mm and in the surgical/hybrid cohort measured 106.6 ± 7.5 mm. For the transcatheter cohort, the median "circularised" diameter derived from the perimeter measurement (divided by π) was 27.7 mm (range 24.3-32.4). Notably, this correlated (r = 0.93, p < 0.01) with the median diameter of the narrowest region during actual transcatheter right ventricular outflow tract balloon sizing (lateral imaging) of 27.1 mm (range 23.2-30.1).

CONCLUSIONS

Right ventricular outflow tract perimeter measurement to determine circularised diameter is useful in planning pulmonary valve replacement in terms of candidacy of transcatheter versus the need for a surgical/hybrid approach. The circularised diameter correlates with transcatheter right ventricular outflow tract balloon sizing.

4D flow magnetic resonance imaging to assess right ventricular outflow tract in patients undergoing transcatheter pulmonary valve replacement

INTRODUCTION AND OBJECTIVES

Magnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiography to balloon sizing of RVOT.

METHODS

Single-center prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiography. Balloon sizing was considered as the reference.

RESULTS

A total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3 mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<.001) than by diastolic 4D flow MRI (r=0.71, P <.001), 3D contrast magnetic resonance angiography (r=0.73; P <.001) and 3D SSFP/GRE (r=0.50; P=.04) and was not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2 mm (95%CI, -3.5 to 3.9 mm), whereas it was wider with other techniques.

CONCLUSIONS

Beyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.

Rationale and Design of the Multicenter Catheter Ablation of Ventricular Tachycardia Before Transcatheter Pulmonary Valve Replacement in Repaired Tetralogy of Fallot Study

Patients with repaired tetralogy of Fallot are at elevated risk for ventricular arrhythmia and sudden cardiac death. Over the past decade, the pathogenesis and natural history of ventricular tachycardia has become increasingly understood, and catheter ablation has emerged as an effective treatment modality. Concurrently, there has been great progress in the development of a versatile array of transcatheter valves that can be placed in the native right ventricular outflow tract for the treatment of long-standing pulmonary regurgitation. Although such valve platforms may eliminate the need for repeat cardiac operations, they may also impede catheter access to the myocardial substrates responsible for sustained macro-reentrant ventricular tachycardia. This manuscript provides the rationale and design of a recently devised multicenter study that will examine the clinical outcomes of a uniform, preemptive strategy to eliminate ventricular tachycardia substrates before transcatheter pulmonary valve implantation in patients with tetralogy of Fallot.

Effect of Balloon Pulmonary Valvuloplasty on Growth of Pulmonary Annulus in Infants with Tetralogy of Fallot

Percutaneous balloon pulmonary valvuloplasty (PBPV) is an alternative intervention in infants with Tetralogy of Fallot (TOF). It can not only improve hypoxia but also promote pulmonary annulus (PA) growth. In this study, we evaluated the effect of PBPV on PA growth in infants with TOF. To eliminate the effect of the systemic to pulmonary shunt (SPS) that may promote PA growth, we divided TOF infants into 2 groups: group A, patients who underwent PBPV with or without other SPS, and group B, patients who attempted SPS but without PBPV. Sixty patients were included, 28 patients in group A and 32 patients in group B. Age at the time of intervention in group A (range, 0.4-5.4; median 1.4 months) was lower than that in group B (range, 2.3-7.7; median 4.8 months), p-value 0.02. The body weight in group A (range, 3-5.5; median 3.7 kg) was also lower than that in group B (range 4.1-6.4; median 5.9 kg), p-value 0.02. Echocardiographic data at the mean follow-up period of 37.2 months (3-88 months) in group A and 39.6 months (6-95 months) in group B demonstrated an increase in mean PA diameter from 5.0 ± 1.3 mm to 10.2 ± 2.9 mm, p-value < 0.001 in group A; and from 6.2 ± 2 mm to 9.5 ± 2.9 mm, p-value < 0.001 in group B. The median PA z-score increased from - 3.4SD (- 3.9 to - 2.6SD) to - 1.8SD (- 2.5 to - 0.8SD), with the p-value of 0.002 in group A; and increased from - 2.9SD (- 4.5 to - 1.3SD) to - 2.7SD (- 3.6 to - 1.4SD), with the p-value of 0.73 in group B. By using the PA z-score as the absolute value, there was a statistically significant increase in the PA z-score during follow-up in group A, but not in group B. Balloon pulmonary valvuloplasty in infants with TOF can facilitate the growth of the pulmonic annulus even after eliminating the effect of the systemic to pulmonary shunt.

Use of the Inspiris valve in the native right ventricular outflow tract is associated with early prosthetic regurgitation

OBJECTIVE

The Inspiris Resilia prosthesis (Edwards Lifesciences) has been increasingly used in the pulmonic position with limited performance data. We sought to investigate its durability as a surgical pulmonary valve replacement (PVR).

METHODS

We retrospectively reviewed patients who underwent PVR or conduit replacement with an Inspiris or non-Inspiris valve/conduit from 2018 to 2022. The primary end point was freedom from a composite of at least moderate pulmonary regurgitation, pulmonary stenosis, or valve/conduit reintervention. Secondary end points were individual components of the composite outcome. To account for baseline differences, propensity matching identified 70 patient pairs.

RESULTS

A total of 227 patients (median age: 19.3 years [interquartile range, 11.8-34.4]) underwent PVR or conduit replacement (Inspiris: n = 120 [52.9%], non-Inspiris: n = 107 [47.1%]). Median follow-up was 26.6 months [interquartile range, 12.4-41.1]. Among matched patients, 2-year freedom from valve failure was lower in the Inspiris group (53.5 ± 9.3% vs 78.5 ± 5.9%, P = .03), as was freedom from at least moderate pulmonary regurgitation (54.2 ± 9.6% vs 86.4 ± 4.9%, P < .01). There was no difference in 2-year freedom from at least moderate pulmonary stenosis (P = .61) or reintervention (P = .92). Inspiris durability was poorer when implanted in the native right ventricular outflow tract compared with as a conduit, with 18-month freedom from valve failure of 59.0 ± 9.5% versus 85.9 ± 9.5% (P = .03).

CONCLUSIONS

Early durability of the Inspiris valve is poor when implanted in the native right ventricular outflow tract; its unique design may be incompatible with the compliant pulmonary root. Modified implantation techniques or alternative prostheses should be considered.

Impact of Right Ventricular Surface Area-to-Volume Ratio on Ventricular Remodeling After Pulmonary Valve Replacement

Optimal reverse remodeling of the right ventricle (RV), a sentinel goal of pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot, is not fully predicted by volume-based pre-PVR parameters. Our objectives were to characterize novel geometric RV parameters in patients receiving PVR and in controls, and to identify associations between these parameters and chamber remodeling post-PVR. Secondary analysis was performed on cardiac magnetic resonance (CMR) data from 60 patients enrolled in a randomized trial of PVR with and without surgical RV remodeling. 20 healthy age-matched subjects served as controls. The primary outcome was optimal post-PVR RV remodeling (end-diastolic volume index (EDVi) ≤ 114 ml/m2 and ejection fraction (EF) ≥ 48%) vs. suboptimal remodeling (EDVi ≥ 120 ml/m2 and EF ≤ 45%). RV geometry was markedly different at baseline in PVR patients compared with controls, with lower systolic surface area-to-volume ratio (SAVR) (1.16 ± 0.26 vs.1.44 ± 0.21 cm2/mL, p < 0.001) and lower systolic circumferential curvature (0.87 ± 0.27 vs. 1.07 ± 0.30 cm- 1, p = 0.007) but similar longitudinal curvature. In the PVR cohort, higher systolic SAVR was associated with higher RVEF both pre- and post-PVR (p < 0.001). Among PVR patients, 15 had optimal and 19 had suboptimal remodeling post-PVR. Multivariable modeling showed that among the geometric parameters, higher systolic SAVR (OR 1.68 per 0.1 cm2/mL increase; p = 0.049) and shorter systolic RV long-axis length (OR 0.92 per 0.1 cm increase; p = 0.035) were independently associated with optimal remodeling. Compared with controls, PVR patients have lower SAVR and lower circumferential but not longitudinal curvature. Higher pre-PVR systolic SAVR is associated with optimal remodeling post-PVR.

Physician-Modified Endograft-Facilitated Transcatheter Pulmonary Valve Replacement in Large Right Ventricular Outflow Tract

BACKGROUND

Transcatheter pulmonary valve replacement (TPVR) in patients with a congenital or acquired abnormality resulting in enlarged right ventricular outflow tract (RVOT) is challenging and may preclude treatment with dedicated devices. We describe a technique using a physician-modified endograft to facilitate TPVR.

METHODS

Six patients underwent physician-modified endograft-facilitated TPVR for severe symptomatic pulmonary insufficiency with enlarged RVOT. The fenestration was created in a commercially available endograft before implantation, which was then deployed from the dominant branch pulmonary artery into the RVOT, with the fenestration aligned with the ostium of the nondominant pulmonary artery. A covered stent was placed through the fenestration into the nondominant branch pulmonary artery, and a transcatheter heart valve was deployed within the endograft at the level of the original pulmonary valve.

RESULTS

Four patients had tetralogy of Fallot, 1 had pulmonary atresia, and 1 had rheumatic valve disease. The RVOT/main pulmonary artery was severely enlarged (diameter, 44.2 [43.5-50.6] mm). All patients had reduced right ventricular (RV) function and dilated RVs (RV end-diastolic volume, 314 [235-316] mL). Successful endograft, covered stent, and transcatheter heart valve deployment were achieved in all cases without stent/valve embolization, vascular complications, or bleeding complications. At 30 days, 1 patient had mild pulmonary insufficiency, while others had none. The RV size measured by echocardiography was significantly reduced after TPVR (RV area, 34.4 [baseline] versus 29.0 [pre-discharge] versus 25.3 [30 days] cm2; P=0.03). During median follow-up of 221.5 (range, 29-652) days, there were no deaths or need for pulmonary valve reintervention. One patient developed severe tricuspid regurgitation due to entrapment of the anterior tricuspid leaflet by the endograft. The patient underwent successful tricuspid replacement and resection of the offending endograft with preservation of the pulmonary valve prosthesis.

CONCLUSIONS

Simple fenestration of an off-the-shelf endograft and associated covered stent placement through the fenestration allows TPVR for patients with dysfunctional native or patch-repaired pulmonary valves and RVOT enlargement.

[Preliminary experience of transcatheter pulmonary valve replacement using domestic balloon-expandable valve]

Objectives: To evaluate the feasibility and preliminary clinical results of transcatheter pulmonary valve replacement (TPVR) with the domestically-produced balloon-expandable Prizvalve system. Methods: This is a prospective single-center observational study. Patients with postoperative right ventricular outflow tract (RVOT) dysfunction, who were admitted to West China Hospital of Sichuan University from September 2021 to March 2023 and deemed anatomically suitable for TPVR with balloon-expandable valve, were included. Clinical, imaging, procedural and follow-up data were analyzed. The immediate procedural results were evaluated by clinical implant success rate, which is defined as successful valve implantation with echocardiography-assessed pulmonary regurgitation Collapse

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MESH Headings

• Male
• Humans
• Pulmonary Valve/surgery
• Heart Valve Prosthesis/adverse effects
• Heart Valve Prosthesis Implantation
• Constriction, Pathologic/complications
• Constriction, Pathologic/surgery
• Prospective Studies
• Ventricular Outflow Obstruction/etiology
• Ventricular Outflow Obstruction/surgery
• Treatment Outcome
• Cardiac Catheterization/methods
• Transcatheter Aortic Valve Replacement

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Grants

• 2022ZDZX0030 Sichuan Science and Technology Program

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1-Year Outcomes in a Pooled Cohort of Harmony Transcatheter Pulmonary Valve Clinical Trial Participants

BACKGROUND

The Harmony transcatheter pulmonary valve (TPV) is the first U.S. Food and Drug Administration-approved device for severe pulmonary regurgitation (PR) in the native or surgically repaired right ventricular outflow tract (RVOT).

OBJECTIVES

One-year safety and effectiveness of the Harmony TPV were evaluated in patients from the Harmony Native Outflow Tract Early Feasibility Study, Harmony TPV Pivotal Study, and Continued Access Study, representing the largest cohort to date of Harmony TPV recipients.

METHODS

Eligible patients had severe PR by echocardiography or PR fraction ≥ 30% by cardiac magnetic resonance imaging and clinical indications for pulmonary valve replacement. The primary analysis included 87 patients who received a commercially available TPV22 (n = 42) or TPV25 (n = 45) device; 19 patients who received an early device iteration prior to its discontinuation were evaluated separately.

RESULTS

In the primary analysis, median patient age at treatment was 26 years (IQR: 18-37 years) in the TPV22 group and 29 years (IQR: 19-42 years) in the TPV25 group. At 1 year, there were no deaths; 98% of TPV22 and 91% of TPV25 patients were free from the composite of PR, stenosis, and reintervention (moderate or worse PR, mean RVOT gradient >40 mmHg, device-related RVOT reoperation, and catheter reintervention). Nonsustained ventricular tachycardia occurred in 16% of patients. Most patients had none/trace or mild PR (98% of TPV22 patients, 97% of TPV25 patients). Outcomes with the discontinued device are reported separately.

CONCLUSIONS

The Harmony TPV device demonstrated favorable clinical and hemodynamic outcomes across studies and valve types through 1 year. Further follow-up will continue to assess long-term valve performance and durability.

Surgical and transcatheter pulmonary valve replacement in patients with repaired tetralogy of Fallot: cardiac magnetic resonance imaging characteristics and morphology of right ventricular outflow tract

BACKGROUND

Pulmonary valve replacement is recommended in patients with repaired tetralogy of Fallot based on cardiac magnetic resonance imaging (MRI) criteria. This procedure is performed by surgical or transcatheter approaches.

OBJECTIVE

We aimed to investigate the differences in preprocedural MRI characteristics (volume, function, strain) and morphology of the right ventricular outflow tract and branch pulmonary arteries in patients for whom surgical or transcatheter pulmonary valve replacement was planned.

MATERIALS AND METHODS

Cardiac MRI of 166 patients with tetralogy of Fallot were analyzed. Of these, 36 patients for whom pulmonary valve replacement was planned were included. Magnetic resonance imaging characteristics, right ventricular outflow tract morphology, branch pulmonary artery flow distribution and diameter were compared between surgical and transcatheter groups. Spearman correlation and Kruskal-Wallis tests were performed.

RESULTS

Circumferential and radial MRI strain for the right ventricle were lower in the surgical group (P=0.045 and P=0.046, respectively). The diameter of the left pulmonary artery was significantly lower (P=0.021) and branch pulmonary artery flow and diameter ratio were higher (P=0.044 and P = 0.002, respectively) in the transcatheter group. There was a significant correlation between right ventricular outflow tract morphology and right ventricular end-diastolic volume index and global circumferential and radial MRI strain (P=0.046, P=0.046 and P= 0.049, respectively).

CONCLUSION

Preprocedural MRI strain, right-to-left pulmonary artery flow, diameter ratio and morphological features of the right ventricular outflow tract were significantly different between the two groups. A transcatheter approach may be recommended for patients with branch pulmonary artery stenosis, since both pulmonary valve replacement and branch pulmonary artery stenting can be performed in the same session.

Discordance between 2D and 4D flow in the assessment of pulmonary regurgitation severity: a right ventricular remodeling follow-up study

OBJECTIVES

Pulmonary regurgitation (PR) is common in adult congenital heart disease (ACHD). 2D phase contrast MRI is the reference method for the quantification of PR and helps in the decision of pulmonary valve replacement (PVR). 4D flow MRI can be an alternative method to estimate PR but more validation is still needed. Our purpose was to compare 2D and 4D flow in PR quantification using the degree of right ventricular remodeling after PVR as the reference standard.

METHODS

In 30 adult patients with a pulmonary valve disease recruited between 2015 and 2018, PR was assessed using both 2D and 4D flow. Based on the clinical standard of care, 22 underwent PVR. The pre PVR estimate of PR was compared using the post-operative decrease in right ventricle end-diastolic volume on follow-up exam as reference.

RESULTS

In the overall cohort, regurgitant volume (Rvol) and regurgitant fraction (RF) of PR measured by 2D and 4D flow were well correlated but with moderate agreement in the overall cohort (r = 0.90, mean diff.  -14 ± 12.5 mL; and r = 0.72, mean diff.  -15 ± 13%; all p < 0.0001). Correlations between Rvol estimates and right ventricle end-diastolic volume decrease after PVR was higher with 4D flow (r = 0.80, p < 0.0001) than with 2D flow (r = 0.72, p < 0.0001).

CONCLUSIONS

In ACHD, PR quantification from 4D flow better predicts post-PVR right ventricle remodeling than that from 2D flow. Further studies are needed to evaluate the added value of this 4D flow quantification for guiding replacement decision.

KEY POINTS

• Using 4D flow MRI allows a better quantification of pulmonary regurgitation in adult congenital heart disease than 2D flow when taking right ventricle remodeling after pulmonary valve replacement as a reference. • A plane positioned perpendicular to the ejected flow volume as allowed by 4D flow provides better results to estimate pulmonary regurgitation.