Effect of altering pathologic right ventricular loading conditions by percutaneous pulmonary valve implantation on exercise capacity

A decade's summary of transcatheter tricuspid valve repair

Tricuspid regurgitation (TR) is the most common pathology for the tricuspid valve. Moderate to severe TR is associated with morbidity and adverse outcomes. The concept that TR resolves on its own if the underlying disease is successfully treated has proven to be false. Only a few patients with significant TR are deemed suitable for surgery. Given the late presentation of patients with high perioperative risks and substantial perioperative mortality, the development of transcatheter therapies and the experience gained with transcatheter aortic valve implantation operations have turned attention towards treating this challenging group of patients. In this article, we review the treatment options and highlight the role of transcatheter valve therapies in patients with severe TR.

Rightward imbalanced pulmonary perfusion predicts better exercise stroke volume in children after Fallot repair

BACKGROUND

Residual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise tolerance, particularly because of a poor increase in left ventricular stroke volume. Pulmonary perfusion imbalance is also common, but its effect on cardiac adaptation to exercise is not known.

AIM

To assess the association between pulmonary perfusion asymmetry and peak indexed exercise stroke volume (pSVi) in young patients.

METHODS

We retrospectively studied 82 consecutive patients with Fallot repair (mean age 15.2±3.8 years) who underwent echocardiography, four-dimensional flow magnetic resonance imaging and cardiopulmonary testing with pSVi measurement by thoracic bioimpedance. Normal pulmonary flow distribution was defined as right pulmonary artery perfusion between 43 and 61%.

RESULTS

Normal, rightward and leftward flow distributions were found in 52 (63%), 26 (32%) and four (5%) patients, respectively. Independent predictors of pSVi were right pulmonary artery perfusion (β=0.368, 95% confidence interval [CI] 0.188 to 0.548; P=0.0003), right ventricular ejection fraction (β=0.205, 95% CI 0.026 to 0.383; P=0.049), pulmonary regurgitation fraction (β=-0.283, 95% CI -0.495 to -0.072; P=0.006) and Fallot variant with pulmonary atresia (β=-0.213, 95% CI -0.416 to -0.009; P=0.041). The pSVi prediction was similar when the categorical variable right pulmonary artery perfusion>61% was used (β=0.210, 95% CI 0.006 to 0.415; P=0.044).

CONCLUSION

In addition to right ventricular ejection fraction, pulmonary regurgitation fraction and Fallot variant with pulmonary atresia, right pulmonary artery perfusion is a predictor of pSVi, in that rightward imbalanced pulmonary perfusion favours greater pSVi.

Right ventricle remodeling after transcatheter tricuspid leaflet repair in patients with functional tricuspid regurgitation: Lessons from the surgical experience

Clinically significant tricuspid regurgitation (TR) is common and associated with excess mortality. At the same time right ventricular (RV) failure is a complex clinical syndrome that results from many causes, but is often associated with long-term prognosis. Whilst results of isolated tricuspid valve (TV) surgery are often unsatisfactory and limited by the prohibitive risk of most patients, the recent development of percutaneous recovery techniques has opened new scenarios. In consideration of the complexity of the mechanisms that lead to right heart failure and RV dysfunction it is important to understand the real advantages that percutaneous TV treatment can offer, more specifically the effect of TR reduction on RV remodeling in the setting of functional tricuspid regurgitation (fTR).

Single-Centre Case Series Assessment of Early Exercise Capacity Data Among Patients Who Received an Alterra Prestent and SAPIEN 3 Valve Placement

Previous studies have used cardiopulmonary exercise test (CPET) data to objectively assess physiological changes in patients undergoing percutaneous pulmonary valve implantation. A retrospective review was performed to assess pre- and post-CPET data among patients undergoing Alterra Adaptive Prestent and SAPIEN 3 transcatheter heart valve (Alterra) placement. Of the 7 patients eligible for the study, 5 (71%) were male. The mean age was 22 years (range: 12-49 years). CPET data showed significant (P = 0.03) improvement in ventilatory efficiency (VE/VCO2) while only 2 (29%) patients had an improvement of percent predicted peak oxygen consumption (VO2). These findings suggest favourable haemodynamic changes though further investigation is needed.

Is there a role for endovascular stent implantation in the management of postoperative right ventricular outflow tract obstruction in the era of transcatheter valve implantation?

BACKGROUND

The optimal management pathway for the dysfunctional right ventricular outflow tract (RVOT) is uncertain. We evaluated the long-term outcomes and clinical impact of stent implantation for obstructed RVOTs in an era of rapidly progressing transcatheter pulmonary valve technology.

METHODS

Retrospective review of 151 children with a biventricular repair who underwent stenting of obstructed RVOT between 1991 and 2017.

RESULTS

RVOT stenting resulted in significant changes in peak right ventricle (RV)-to-pulmonary artery (PA) gradient (39.4 ± 17.1-14.9 ± 8.3; p < 0.001) and RV-to-aortic pressure ratio (0.78 ± 0.22-0.49 ± 0.13; p < 0.001). Subsequent percutaneous reinterventions in 51 children to palliate recurrent stenosis were similarly effective. Ninety-nine (66%) children reached the primary outcome of subsequent pulmonary valve replacement (PVR). Freedom from PVR from the time of stent implantation was 91%, 51%, and 23% at 1, 5, and 10 years, respectively. Small balloon diameters for stent deployment were associated with shorter freedom from PVR. When additional children without stent palliation (with RV-to-PA conduits) were added to the stent cohort (total 506 children), the multistate analysis showed the longest freedom from PVR in those with stent palliation and subsequent catheter reintervention. Pulmonary regurgitation was well-tolerated clinically. Indexed RV dimensions and function estimated by echocardiography remained stable at last follow up or before primary outcome.

CONCLUSION

Prolongation of conduit longevity with stent implant remains an important strategy to allow for somatic growth to optimize the risk-benefit profile for subsequent surgical or transcatheter pulmonary valve replacement performed at an older age.

Favorable Atrial Remodeling After Percutaneous Pulmonary Valve Implantation and Its Association With Changes in Exercise Capacity and Right Ventricular Function

Background

Right atrial (RA) dilatation and impaired right ventricular (RV) filling are common in patients with RV outflow tract dysfunction. We aimed to study potential correlations between atrial function with clinically relevant hemodynamic parameters and to assess the predictive impact of atrial performance on the recovery of exercise capacity and RV pump function after percutaneous pulmonary valve implantation (PPVI).

Methods and Results

Altogether, 105 patients with right ventricular outflow tract dysfunction (median age at PPVI, 19.2 years; range, 6.2–53.4 years) who underwent cardiac magnetic resonance imaging before and 6 months after PPVI were included. RA and left atrial maximal and minimal volumes as well as atrial passive and active emptying function were assessed from axial cine slices. RA emptying function was inversely related to invasive RV end‐diastolic pressure, and RA passive emptying correlated significantly with peak oxygen uptake. After PPVI, a significant decrease in RA minimum volume was observed, whereas RA passive emptying function improved, and RA active emptying function decreased significantly. Patients with predominant right ventricular outflow tract stenosis showed more favorable changes in RA active and left atrial passive emptying than those with primary volume overload. None of the RA and left atrial emptying parameters was predictive for recovery of peak oxygen uptake or RV ejection fraction.

Conclusions

In patients with right ventricular outflow tract dysfunction, impaired RA emptying assessed by cardiac magnetic resonance imaging was associated with increased RV filling pressures and lower exercise capacity. PPVI leads to a reduction in RA size and improved passive RA emptying function. However, RA function was not associated with improved exercise performance and RV pump function.

Sportmedizinische Aspekte bei EMAH-Patienten

Immer mehr Patienten mit angeborenem Herzfehler erreichen das Erwachsenenalter. Neben der allgemeinen medizinischen Untersuchung (Elektrokardiogramm, Echokardiografie, Laborparameter etc.) findet auch die Funktionsdiagnostik immer mehr an Bedeutung. Zu dieser zählen sowohl die Lungenfunktion (Spirometrie, Bodyplethysmografie) als auch die Bestimmung der Leistungsfähigkeit (6-Minuten-Gehtest, Spiroergometrie). Wann jedoch eine solche Untersuchung sinnvoll ist, scheint oftmals unklar. Dieser Artikel soll sowohl das standardisierte Vorgehen dieser Untersuchungen aufzeigen als auch die Vor- und Nachteile unterschiedlicher Untersuchungen je nach Fragestellung aufzeigen.

Wichtig hierbei ist, dass eine vollständige sportmedizinische Untersuchung bei Patienten mit angeborenem Herzfehler immer zusammen mit einer kardiologischen Untersuchung stattfinden muss. Nur dann kann eine sichere Untersuchung durch das geschulte Personal gewährleistet werden.

Physiologic effects and functional outcome after treatment of dysfunctional right ventricular outflow tract in congenital heart disease using a two-stage intervention

BACKGROUND

Pathophysiological differences in relief of pulmonary stenosis (PS) as opposed to pulmonary regurgitation (PR) by percutaneous pulmonary valve implantation (PPVI) remain elusive, but might impact current assessment of procedural success and ultimately indications.

METHODS

Invasive pressure measurements, cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed before pre-stenting (BMS), after BMS and after PPVI in patients with either PS or PR.

RESULTS

In PS (n = 14), BMS reduced the right ventricular (RV) to systemic pressure ratio (0.8 ± 0.2 vs. 0.4 ± 0.1%; p < .01), improved RF EF (53 ± 14 vs. 59 ± 12%; p = .01) but introduced free PR (PR fraction post 39 ± 12%; p < .01) with no changes in effective RV stroke volume (SV). PPVI eliminated PR (PR fraction 5 ± 3%; p < .01) and improved effective RV SV (p < .01) with no changes in RV EF (p = .47). Peak VO2 improved significantly after BMS, with no changes following PPVI (26 ± 9 vs. 30 ± 11 vs. 31 ± 10 ml/kg*min). In PR (n = 14), BMS exaggerated PR (PR fraction post 47 ± 10) with reduction in effective RV SV (pre 43 ± 9 vs. post 38 ± 8 ml/m²; p = .01), which improved after PPVI (post PPVI 49 ± 9 ml/m²; p < .01), secondary to elimination of PR (PR fraction 5 ± 4%; p < .01). RV EF (pre 53 ± 11 vs. post 53 ± 9 vs. post PPVI 50 ± 9%) and Peak VO2 (pre 22 ± 7 vs. post 21 ± 7 vs. post PPVI 23 ± 7 ml/kg*min) remained unchanged.

CONCLUSIONS

Exercise capacity in patients with right ventricular outflow tract dysfunction is primarily afterload-dependent.

Percutaneous pulmonary valve implantation as an alternative to repeat open-heart surgery for patients with pulmonary outflow obstruction: a reality in Singapore

Right ventricle to pulmonary artery (RV-PA) conduits have been used for the surgical repair of congenital heart defects. These conduits frequently become stenosed or develop insufficiency with time, necessitating reoperations. Percutanous pulmonary valve implantation (PPVI) can delay the need for repeated surgeries in patients with congenital heart defects and degenerated RV-PA conduits. We presented our first experience with PPVI and described in detail the procedural methods and the considerations that are needed for this intervention to be successful. Immediate and short-term clinical outcomes of our patients were reported. Good haemodynamic results were obtained, both angiographically and on echocardiography. PPVI provides an excellent alternative to repeat open-heart surgery for patients with congenital heart defects and degenerated RV-PA conduits. This represents a paradigm shift in the management of congenital heart disease, which is traditionally managed by open-heart surgery.

Percutaneous pulmonary valve implantation in patients with dysfunction of a "native" right ventricular outflow tract - Mid-term results

BACKGROUND

To investigate the feasibility and mid-term results of percutaneous pulmonary valve implantation (PPVI) in patients with conduit free or "native" right ventricular outflow tracts (RVOT).

METHODS AND RESULTS

We identified all 18 patients with conduit free or "native" right ventricular outflow tract, who were treated with percutaneous pulmonary valve implantation (PPVI) in our institution. They were divided into two groups - these in whom the central pulmonary artery was used as an anchoring point for the preparation of the landing zone (n=10) for PPVI and these, in whom a pulmonary artery branch was used for this purpose (n=8). PPVI was performed successfully in all patients with significant immediate RVOT gradient and pulmonary regurgitation grade reduction. Four patients had insignificant paravalvular regurgitation. In one patient the valve was explanted after 4months because of bacterial endocarditis. A follow-up of 19 (4-60) months showed sustained good function of the other implanted valves. The MRI indexed right ventricular end diastolic volume significantly decreased from 108(54-174) ml/m² before the procedure to 76(60-126) ml/m² six months after PPVI, p=0.01.

CONCLUSIONS

PPVI is feasible with good mid-term results in selected patients with a "native" RVOT without a previously implanted conduit. Creating a stable landing zone with a diameter less than the largest available valve (currently 29mm) is crucial for the technical success of the procedure. Further studies and the development of new devices could widen the indications for this novel treatment.

Percutaneous pulmonary valve implantation in small conduits: A multicenter experience

BACKGROUND

Guidelines allow percutaneous pulmonary valve implantation (PPVI) in conduits above 16mm diameter. Balloon dilatation of a conduit to a diameter>110% of the original implant size is also not recommended. We analyzed patients undergoing PPVI in such conditions.

METHODS AND RESULTS

Nine patients (May 2008-July 2016) from 8 institutions underwent PPVI in conduits <16mm diameter. Five patients with 16-18mm conduit diameter underwent PPVI after over-expansion of the conduit>110%. Mean age and weight of the 14 patients was 12.1 (7.7 to 16) years and 44.9 (19 to 83) kg. Median conduit diameter at PPVI was 12 (10 to 17) mm. Median systolic right ventricular pressure was 70 (40 to 94) mmHg. Procedure was successful in all cases. A confined conduit rupture occurred in 7 patients (50%) and was treated with covered stent in 6. One patient experienced dislocation of 2 pulmonary artery stents that were parked distally. The post-implantation median systolic right ventricular pressure was 36 (28 to 51) mmHg. A fistula between right-ventricle outflow and aorta was found in one patient, secondary to undiagnosed conduit rupture. This was closed surgically. After a median follow-up of 20.16 (6.95 to 103.61) months, all the patients are asymptomatic with no significant RVOT stenosis.

CONCLUSIONS

PPVI is feasible in small conduits but rate of ruptures is high. Although such ruptures remain contained and can be managed with covered stents in our experience, careful selection of patients and high level of expertise are necessary. More studies are needed to better assess the risk of PPVI in this population.

In-hospital cost comparison between percutaneous pulmonary valve implantation and surgery

OBJECTIVES: Today, both surgical and percutaneous techniques are available for pulmonary valve implantation in patients with right ventricle outflow tract obstruction or insufficiency. In this controlled, non-randomized study the hospital costs per patient of the two treatment options were identified and compared.

METHODS: During the period of June 2011 until October 2014 cost data in 20 patients treated with the percutaneous technique and 14 patients treated with open surgery were consecutively included. Two methods for cost analysis were used, a retrospective average cost estimate (overhead costs) and a direct prospective detailed cost acquisition related to each individual patient (patient-specific costs).

RESULTS: The equipment cost, particularly the stents and valve itself was by far the main cost-driving factor in the percutaneous pulmonary valve group, representing 96% of the direct costs, whereas in the open surgery group the main costs derived from the postoperative care and particularly the stay in the intensive care department. The device-related cost in this group represented 13.5% of the direct costs. Length-of-stay-related costs in the percutaneous group were mean $3885 (1618) and mean $17 848 (5060) in the open surgery group. The difference in postoperative stay between the groups was statistically significant (P≤ 0.001).

CONCLUSIONS: Given the high postoperative cost in open surgery, the percutaneous procedure could be cost saving even with a device cost of more than five times the cost of the surgical device.

Short-Term Change of Exercise Capacity in Patients with Pulmonary Valve Replacement after Tetralogy of Fallot Repair

BACKGROUND AND OBJECTIVES

The aim of this study was to investigate the effect of pulmonary valve replacement (PVR) on exercise capacity and determine cardiopulmonary exercise (CPEX) parameters associated with improvement in right ventricle (RV) function.

SUBJECTS AND METHODS

We retrospectively analyzed CPEX and magnetic resonance imaging parameters in a total of 245 patients who underwent PVR from January 1998 to October 2015. In addition, we analyzed the characteristics of the patients who showed improved exercise capacity after PVR.

RESULTS

Twenty-eight patients met the inclusion criteria for the study. CPEX parameters after PVR showed no significant changes in all patients. However, baseline predicted peak oxygen uptake (VO2_peak) (%) value was significantly lower in patients with significant improvement in exercise capacity after PVR, as compared to patients who showed decreased exercise capacity after PVR (60.83±10.28 vs. 75.81±13.83) (p=0.003). In addition, patients with improved exercise capacity showed a positive correlation between the change of right ventricular ejection fraction (RVEF) (%) and the change of anaerobic threshold (r=0.733, p=0.007); whereas, patients with decreased exercise capacity showed a negative correlation between the change of RVEF (%) and the change of predicted VO2_peak (%) (r=-0.575, p=0.020).

CONCLUSION

The importance of predicted VO2_peak (%) in evaluating exercise capacity differentiated from other CPEX variables. The change of anaerobic threshold and predicted VO2_peak (%) might be a useful predictor of the change in RV function after PVR.

Patient outcomes after transcatheter and surgical pulmonary valve replacement for pulmonary regurgitation in patients with repaired tetralogy of Fallot: A quasi-meta-analysis

BACKGROUND

Individuals with repaired tetralogy of Fallot develop pulmonary regurgitation that may cause symptoms (dyspnea, chest pain, palpitations, fatigue, presyncope, and syncope), impair functional capacity, and may affect health-related quality of life. Surgical pulmonary valve replacement is the gold standard of treatment although transcatheter pulmonary valve replacement is becoming more common. Patients want to know whether less invasive options are as good.

AIMS

This analysis aimed to examine the differences in surgical versus transcatheter pulmonary valve replacement effects in terms of physiological/biological variables, symptoms, functional status and health-related quality of life.

METHODS

This quasi-meta-analysis included 85 surgical and 47 transcatheter pulmonary valve replacement studies published between 1995-2016.

RESULTS

In terms of physiological/biological variables, both surgical and transcatheter pulmonary valve replacement improved pulmonary regurgitation and systolic and diastolic right ventricular volume indices but not heart function. In the left heart, only surgical pulmonary valve replacement improved heart function. Only transcatheter pulmonary valve replacement improved left ventricular end-diastolic indices and neither improved endsystolic indices. Only surgery has been demonstrated to decrease QRS duration but there is little evidence of arrhythmia reduction. Symptom change is poorly documented. Functional class improves but exercise capacity generally does not. Some aspects of health-related quality of life improve with surgery and in one small transcatheter pulmonary valve replacement study.

CONCLUSION

Transcatheter and surgical pulmonary valve replacement compare favorably for heart remodeling. Exercise capacity does not change with either technique. Health-related quality of life improves after surgical pulmonary valve replacement. There are numerous gaps in documentation of changes in arrhythmias and symptoms.

Usefulness of maximal oxygen pulse in timing of pulmonary valve replacement in patients with isolated pulmonary regurgitation

Patients with pulmonary regurgitation after tetralogy of Fallot repair have impaired aerobic capacity; one of the reasons is the decreasing global ventricular performance at exercise, reflected by decreasing peak oxygen pulse. The aims of our study were to evaluate the impact of pulmonary valve replacement on peak oxygen pulse in a population with pure pulmonary regurgitation and with different degrees of right ventricular dilatation and to determine the predictors of peak oxygen pulse after pulmonary valve replacement. The mean and median age at pulmonary valve replacement was 27 years. Mean pre-procedural right ventricular end-diastolic volume was 182 ml/m2. Out of 24 patients, 15 had abnormal peak oxygen pulse before pulmonary valve replacement. We did not observe a significant increase in peak oxygen pulse after pulmonary valve replacement (p=0.76). Among cardiopulmonary test/MRI/historical pre-procedural parameters, peak oxygen pulse appeared to be the best predictor of peak oxygen pulse after pulmonary valve replacement (positive and negative predictive values, respectively, 0.94 and 1). After pulmonary valve replacement, peak oxygen pulse was well correlated with left ventricular stroke and end-diastolic volumes (r=0.67 and 0.68, respectively). Our study confirms the absence of an effect of pulmonary valve replacement on peak oxygen pulse whatever the initial right ventricular volume, reflecting possible irreversible right and/or left ventricle lesions. Pre-procedural peak oxygen pulse seemed to well predict post-procedural peak oxygen pulse. These results encourage discussions on pulmonary valve replacement in patients showing any decrease in peak oxygen pulse during their follow-up.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Function Correlate With Improvement in Exercise Function After Percutaneous Pulmonary Valve Implantation

BACKGROUND

Speckle-tracking echocardiographic (STE) measures of right ventricular (RV) function appear to improve after transcatheter pulmonary valve implantation (TPVI). Measures of exercise function, such as ventilatory efficiency (the minute ventilation [VE]/carbon dioxide production [VCO2] slope), have been shown to be prognostic of mortality in patients who may require TPVI. The aim of this study was to evaluate the correlation between STE measures of RV function and changes in VE/VCO2 after TPVI.

METHODS

Speckle-tracking echocardiography and cardiopulmonary exercise testing were performed at baseline and 6 months after TPVI in 24 patients from four centers. Conventional echocardiographic measures of RV function were also assessed. Echocardiographic and exercise stress test results were interpreted by single blinded observers at separate core laboratories.

RESULTS

All patients demonstrated relief of pulmonary regurgitation and stenosis after TPVI. Improvements in RV longitudinal strain (-16.9 ± 3.5% vs -19.7 ± 4.3%, P < .01) and strain rate (-0.9 ± 0.4 vs. -1.2 ± 0.4 s(-1), P < .01) were noted. The VE/VCO2 slope improved (32.4 ± 5.7 vs 31.5 ± 8.8, P = .03). No other significant echocardiographic or exercise changes were found. On multivariate regression, the change in VE/VCO2 was independently associated with change in RV longitudinal early diastolic strain rate (P < .001) and tricuspid A velocity (P < .001). Preintervention RV longitudinal strain was found to be a predictor of change in VE/VCO2 after TPVI (r = -0.60, P < .001).

CONCLUSIONS

STE measures of RV function appear to hold the potential for use as predictors of improved outcomes in patients requiring TPVI. Future studies should directly assess the prognostic significance of STE measures of RV function in this population.

Percutaneous pulmonary and tricuspid valve implantations: An update

The field of percutaneous valvular interventions is one of the most exciting and rapidly developing within interventional cardiology. Percutaneous procedures focusing on aortic and mitral valve replacement or interventional treatment as well as techniques of percutaneous pulmonary valve implantation have already reached worldwide clinical acceptance and routine interventional procedure status. Although techniques of percutaneous pulmonary valve implantation have been described just a decade ago, two stent-mounted complementary devices were successfully introduced and more than 3000 of these procedures have been performed worldwide. In contrast, percutaneous treatment of tricuspid valve dysfunction is still evolving on a much earlier level and has so far not reached routine interventional procedure status. Taking into account that an “interdisciplinary challenging”, heterogeneous population of patients previously treated by corrective, semi-corrective or palliative surgical procedures is growing inexorably, there is a rapidly increasing need of treatment options besides redo-surgery. Therefore, the review intends to reflect on clinical expansion of percutaneous pulmonary and tricuspid valve procedures, to update on current devices, to discuss indications and patient selection criteria, to report on clinical results and finally to consider future directions.

Impact of percutaneous pulmonary valve implantation for right ventricular outflow tract dysfunction on exercise recovery kinetics

The recovery of cardiopulmonary variables from peak exercise in patients with pulmonary stenosis (PS) or regurgitation (PR) is delayed, but the impact of treating PS or PR on exercise recovery kinetics is unknown. 43 patients (median age 14 years) with PS (n = 23) or PR (n = 20) after repair of congenital heart disease underwent successful percutaneous pulmonary valve implantation (PPVI). Cardiopulmonary exercise tests (CPET) were performed both before and within 1 month after PPVI. Apart from peak oxygen uptake (VO2), the constant decay of VO2, CO2 output (VCO2), minute ventilation (VE), and heart rate (HR) and oxygen pulse were calculated for the first minute of recovery as the first-degree slope of a single linear relation. PPVI led to a significant improvement in NYHA functional class in the PS and PR groups (p<0.001 and p=0.0015, respectively). On CPET, peak VO2 improved post-PPVI only in the PS (25.6 ± 6.2 vs. 27.8 ± 7.9 ml/kg/min; p = 0.01) but not PR group (29.0 ± 9.8 vs. 28.6 ± 8.9 ml/kg/min; p = 0.6). However, VO2 slope improved in the PS (0.40 ± 0.23 vs. 0.65 ± 0.27, p < 0.001) as well as in the PR group (0.56 ± 0.37 vs. 0.67 ± 0.37, p = 0.003) as did VCO2 slope (0.39 ± 0.2 vs. 0.55 ± 0.24, p = 0.002 and 0.42 ± 0.33 vs. 0.53 ± 0.35, p = 0.02: for the PS and PR groups, respectively). The VE and HR slopes did not change after PPVI. Despite the lack of improvement in exercise capacity in the PR group, treatment of PS and PR by PPVI induces significant and similar improvements in the ability of recovering from maximal exercise in the 2 groups.

Clinical Outcomes of Surgical Pulmonary Valve Replacement After Repair of Tetralogy of Fallot and Potential Prognostic Value of Preoperative Cardiopulmonary Exercise Testing

Background—

Indications for surgical pulmonary valve replacement (PVR) after repair of tetralogy of Fallot have recently been broadened to include asymptomatic patients.

Methods and Results—

The outcomes of PVR in adults after repair of tetralogy of Fallot at a single tertiary center were retrospectively studied. Preoperative cardiopulmonary exercise testing was included. Mortality was the primary outcome measure. In total, 221 PVRs were performed in 220 patients (130 male patients; median age, 32 years; range, 16–64 years). Homografts were used in 117 patients, xenografts in 103 patients, and a mechanical valve in 1 patient. Early (30-day) mortality was 2%. Overall survival was 97% at 1 year, 96% at 3 years, and 92% at 10 years. Survival after PVR in the later era (2005–2010; n=156) was significantly better compared with survival in the earlier era (1993–2004; n=65; 99% versus 94% at 1 year and 98% versus 92% at 3 years, respectively; P =0.019). Earlier era patients were more symptomatic preoperatively ( P =0.036) with a lower preoperative peak oxygen consumption (peak o 2 ; P <0.001). Freedom from redo surgical or transcatheter PVR was 98% at 5 years and 96% at 10 years for the whole cohort. Peak o 2 , E/CO2 slope (ratio of minute ventilation to carbon dioxide production), and heart rate reserve during cardiopulmonary exercise testing predicted risk of early mortality when analyzed with logistic regression analysis; peak o 2 emerged as the strongest predictor on multivariable analysis (odds ratio, 0.65 per 1 mL·kg −1 ·min −1 ; P =0.041).

Conclusions—

PVR after repair of tetralogy of Fallot has a low and improving mortality, with a low need for reintervention. Preoperative cardiopulmonary exercise testing predicts surgical outcome and should therefore be included in the routine assessment of these patients.

Impact of transcatheter pulmonary valve replacement on biventricular strain and synchrony assessed by cardiac magnetic resonance feature tracking

BACKGROUND

Transcatheter pulmonary valve (TPV) replacement is an emerging therapy intended to restore pulmonary valve function in patients with right ventricular outflow tract conduit dysfunction; the impact of this technique on ventricular strain and synchrony is not known.

METHODS AND RESULTS

Cardiac magnetic resonance and ECG data acquired at 1 center as part of the US Melody TPV trial were analyzed. Biventricular strain and mechanical synchrony measurements were made based on short-axis and 4-chamber steady-state free precession images using feature tracking software. Post- versus pre-TPV replacement findings were compared for all patients (n=31) and subgroups with predominant pulmonary regurgitation (n=13) or stenosis (n=18). Most patients had tetralogy of Fallot (18/31). After TPV replacement, left ventricular (LV) circumferential strain increased for the whole cohort (P<0.001) and both subgroups (pulmonary regurgitation P=0.01; pulmonary stenosis P=0.02). LV longitudinal strain increased for the whole cohort (P=0.02) and pulmonary regurgitation subgroup (P=0.05); circumferential right ventricular strain increased for the pulmonary stenosis group only (P=0.05). LV longitudinal synchrony improved significantly in the pulmonary regurgitation group (maximum wall delay P=0.03; cross-correlation delay P=0.01). Electric measures of synchrony did not improve.

CONCLUSIONS

In patients with right ventricular outflow tract conduit dysfunction, TPV replacement is associated with improved global LV strain, as well as improved right ventricular strain and LV synchrony in subgroups. Given the associations between strain and synchrony and clinical outcomes, these findings support potential long-term benefits of TPV replacement.

Percutaneous options for heart failure in adults with congenital heart disease

In the context of congenital heart disease (CHD), the complex biochemical and physiologic response to the pressure- or volume-loaded ventricle can be induced by stenotic and shunt/regurgitant lesions, respectively. A range of transcatheter therapies have recently emerged to expand the therapeutic potential of the more traditional surgical and medical interventions for heart failure in patients with CHD. Together, these complementary interventions aim to treat the growing patient population with adult CHD (ACHD). In this article, the most commonly used transcatheter interventions for heart failure in patients with ACHD are reviewed.

Early echocardiographic changes after percutaneous implantation of the Edwards SAPIEN transcatheter heart valve in the pulmonary position

OBJECTIVES

To evaluate echocardiographic changes after SAPIEN valve implantation in the pulmonary position.

BACKGROUND

The feasibility of the SAPIEN transcatheter pulmonary valve (TPV) has recently been demonstrated. We evaluated changes in pulmonary valve function and the right ventricle after SAPIEN TPV placement.

METHODS

We evaluated echocardiograms at baseline, discharge, 1 and 6 months after TPV placement in 33 patients from 4 centers. Pulmonary insufficiency severity was graded 0-4. TPV peak and mean gradients were measured. Right ventricular (RV) size and function were quantified using routine measures derived from color, spectral, and tissue Doppler indices and two-dimensional echocardiography.

RESULTS

At baseline, 94% patients demonstrated pulmonary insufficiency grade 2-4. This decreased to 12% patients at 6 months (P < 0.01). TPV peak (P < 0.01) and mean gradient (P < 0.01) decreased. RV end-diastolic area indexed to body surface area (BSA) (P < 0.01), Tricuspid regurgitation (TR) gradient (P < 0.01), and the ratio of TR jet area to BSA (P < 0.01) decreased. Tricuspid inflow peak E:A, tissue Doppler imaging (TDI): septal E' and A', TDI: tricuspid A' improved between baseline and discharge, but trended back to baseline by 6-month follow-up. Tricuspid valve annulus z-score, RV area change, tricuspid annular plane systolic excursion (TAPSE), RV dP/dt, tricuspid E:E', and TDI: tricuspid annulus E' showed no change.

CONCLUSION

Improvements in pulmonary insufficiency and stenosis, RV size, and TR gradient and severity are seen after SAPIEN TPV placement. Selected indices of RV diastolic function improve immediately after TPV implantation, but return to baseline by 6 months. RV systolic function is unchanged.

Transcatheter Pulmonary Valve Replacement: Current Status and Future Potentials

Although established, transcatheter pulmonary valve replacement is in its infancy compared with surgical pulmonary valve replacement. Extended clinical experience and follow-up have identified new challenges; however, careful evaluation of data through clinical trials has facilitated effective evolution of responses to these challenges. The limited patient population has resulted in less interest in new valve design, but having been the older sibling to transcatheter aortic valve replacement, transcatheter pulmonary valve replacement is likely to benefit in the future from design modifications to the more popular and commercially viable transcatheter aortic valve revolution. Improving valve longevity and applying the technology to native outflow tracts remain the short-to-medium term goals.

A teenager with tetralogy of fallot becomes a soccer player

Patient: Male, 0

Final Diagnosis: Tetralogy of Fallot

Symptoms: —

Medication: —

Clinical Procedure: —

Specialty: Cardiology

Effect of ventricular size and function on exercise performance and the electrocardiogram in repaired tetralogy of Fallot with pure pulmonary regurgitation

Background:

In repaired tetralogy of Fallot (TOF), exercise test parameters like peak oxygen uptake and ventilatory efficiency predict mortality. Studies have also suggested cardiac magnetic resonance (CMR)-derived right ventricular (RV) size threshold values for pulmonary valve replacement in repaired TOF. However, effects of proposed RV size on exercise capacity and morbidity are not known.

Methods:

The relationship between CMR-derived ventricular size, function, and pulmonary regurgitation (PR) and NYHA class, exercise performance, and electrocardiogram (ECG) was studied in patients of repaired TOF with pure PR in a retrospective review of records.

Results:

46 patients (22 females), mean age 14 years (8–30.8), were studied. There was no relationship between CMR-derived ventricular size, function, or PR and exercise test parameters, or NYHA class. RV end systolic and end diastolic volume correlated positively with the degree of PR. QRS duration on ECG correlated positively with RV end-diastolic volume (P < 0.01, r² = 0.34) and PR (P < 0.01, r² = 0.52).

Conclusions:

In repaired TOF and pure PR, there is no correlation between ventricular size or function and exercise performance. RV size increases with increasing PR. Timing of pulmonary valve replacement in TOF with pure PR needs further prospective evaluation for its effect on morbidity and mortality.

State-of-the-art percutaneous pulmonary valve therapy

Transcatheter pulmonary valve replacement is one of the most exciting recent developments in the treatment of patients with congenital heart disease and is being used to treat both stenotic and regurgitant valves within previously placed surgical conduits. Although limited somewhat by both patients and available valve sizes, ongoing attempts are being made to extend this technology to native right ventricular outflow tracts. If achieved, this will represent a significant advancement in attempts to prevent morbidity and mortality secondary to the chronic effects of right ventricular volume loading. This review deals with the development, current status and future endeavors of this approach.

Impact of reduction in right ventricular pressure and/or volume overload by percutaneous pulmonary valve implantation on biventricular response to exercise: an exercise stress real-time CMR study

AIMS

To assess the impact of relief of pulmonary stenosis (PS) and pulmonary regurgitation (PR) by percutaneous pulmonary valve implantation (PPVI) on biventricular function during exercise stress.

METHODS AND RESULTS

Seventeen patients, who underwent PPVI for PS or PR, were included. Magnetic resonance imaging was performed at rest and during supine exercise stress pre- and within 1-month post-PPVI, using a radial k - t SENSE real-time sequence. In patients with PS (n = 9), there was no reserve in right ventricular (RV) ejection fraction (EF) in response to exercise prior to PPVI (48.2 ± 12.1% at rest vs. 48.4 ± 14.8% during exercise, P = 0.87). Post-PPVI, reserve in RVEF in response to exercise was re-established (53.4 ± 15.0% at rest vs. 59.6 ± 17.3% during exercise, P = 0.003) with improvement in left ventricular stroke volume (LVSV) (45.4 ± 6.2 mL/m(2) at rest vs. 52.8 ± 8.8 mL/m(2) during exercise, P = 0.001). In patients with PR prior to PPVI (n = 8), LVSV during exercise increased (43.0 ± 8.5 vs. 54.3 ± 6.6 mL/m(2), P < 0.001) due to reduction in PR fraction during exercise (29.2 ± 5.2 vs. 13.6 ± 6.1%, P < 0.001). After PPVI, LVSV increased from rest to exercise (48.4 ± 8.8 vs. 57.2 ± 8.1 mL/m(2), P < 0.001) due to improved RVEF (45.5 ± 8.3 vs. 50.4 ± 6.9%, P = 0.001). There was a significantly higher increase in LVSV at exercise from pre- to post-PPVI in PS patients than in PR patients (ΔLVSV 8.2 ± 4.1 vs. Δ2.9 ± 4.1 mL/m(2), P = 0.01). The reduction in the RV outflow tract gradient correlated significantly with the improvement in LVSV during exercise (r = -0.73, P < 0.001).

CONCLUSION

Percutaneous pulmonary valve implantation in patients with PS leads to restoration of reserve in RVEF during exercise stress. In patients with PR, SV augmentation improves only mildly post-PPVI. Improvement in SV augmentation during exercise stress after PPVI is dependent mainly on afterload reduction.

Cardiopulmonary exercise function among patients undergoing transcatheter pulmonary valve implantation in the US Melody valve investigational trial

OBJECTIVES

We assessed the hypothesis that there is an improvement in clinical and physiologic parameters of cardiopulmonary exercise testing (CPET) after implantation of a transcatheter pulmonary valve (TPV).

BACKGROUND

Transcatheter pulmonary valve provides a new tool for treating conduit stenosis and regurgitation in patients with right ventricle (RV) to pulmonary artery conduit dysfunction.

METHODS

Patients who underwent a TPV placement between January 2007 and January 2010 (N = 150) were investigated with a standardized CPET protocol before and at 6 months after TPV placement. Cardiopulmonary exercise testing was performed on a mechanically braked cycle ergometer with respiratory gas exchange analysis.

RESULTS

Six months post TPV, small but statistically significant improvements were observed in the maximum workload (65.0% ± 18.8% to 68.3% ± 20.3% predicted, P < .001) and the ratio of minute ventilation to CO(2) production at the anaerobic threshold (30.8 ± 4.7 to 29.1 ± 4.1, P < .001). There was no significant change in peak oxygen consumption (VO(2)). Patients with pre-TPV hemodynamics consistent with RV dysfunction and patients with a lower pre-TPV peak VO(2) tended to have the greatest improvement in peak VO(2). The correlation between TPV-related improvements in peak VO(2) and baseline clinical variables were weak, however, and these variables could not be used to reliably identify patients likely to have improved peak VO(2) after TPV.

CONCLUSION

In patients with RV to pulmonary artery conduit dysfunction, TPV is associated with modest improvement in exercise capacity and gas exchange efficiency during exercise.

Percutaneous implantation of the Edwards SAPIEN transcatheter heart valve for conduit failure in the pulmonary position: early phase 1 results from an international multicenter clinical trial

OBJECTIVES

The purpose of this study was to evaluate the safety and effectiveness of the Edwards SAPIEN transcatheter heart valve (Edwards Lifesciences LLC, Irvine, California) in the pulmonary position in patients with moderate to severe pulmonary regurgitation with or without stenosis.

BACKGROUND

Transcatheter pulmonary valve replacement is evolving, but to date, experience has been limited to the Melody valve (Medtronic Inc., Minneapolis, Minnesota).

METHODS

Eligible patients with dysfunctional right ventricle-to-pulmonary artery conduits were screened if body weight was ≥35 kg and the in situ conduit diameter was ≥16 mm and ≤24 mm. Standardized implantation and follow-up protocols were used.

RESULTS

Thirty-six patients from 4 centers were recruited between April 2008 and May 2010. Mean body weight was 73.4 ± 22.9 kg. Successful valve deployment was achieved in 33 of 34 attempts (97.1%). Valve migration occurred in 3 patients, with 2 requiring surgical retrieval; however, 1 patient underwent successful perventricular valve implantation. Further intraprocedure complications included pulmonary hemorrhage (n = 2), ventricular fibrillation (n = 1), and stent migration (n = 1). Pullback gradient across the conduit decreased from 26.8 ± 18.4 mm Hg to 11.7 ± 8.0 mm Hg (p < 0.001). The right ventricular/aortic pressure ratio decreased from 0.6 ± 0.2 to 0.4 ± 0.1 (p < 0.001). Peak Doppler gradient across the right ventricular outflow tract decreased from 41.9 ± 27.9 mm Hg to 19.1 ± 13.3 mm Hg (p < 0.001). At 6-month follow-up, all patients were alive. The number of patients with New York Heart Association functional class I increased from 5 at baseline to 27 at follow-up. Pulmonary regurgitation was ≤2+ in 97% of patients. Freedom from reintervention was 97% with 1 patient undergoing elective placement of a second valve due to conduit-induced distortion of the initial implant.

CONCLUSIONS

Transcatheter pulmonary valve replacement using the Edwards SAPIEN transcatheter heart valve is safe and effective in patients with dysfunctional right ventricle-to-pulmonary artery conduits.

Early versus late functional outcome after successful percutaneous pulmonary valve implantation: are the acute effects of altered right ventricular loading all we can expect?

OBJECTIVES

The purpose of this study was to assess the potential of late positive functional remodeling after percutaneous pulmonary valve implantation (PPVI) in right ventricular outflow tract dysfunction.

BACKGROUND

PPVI has been shown to impact acutely on biventricular function and exercise performance, but the potential for further late functional remodeling remains unknown.

METHODS

Sixty-five patients with sustained hemodynamic effects of PPVI at 1 year were included. Patients were divided into 2 subgroups based on pre-procedural predominant pulmonary stenosis (PS) (n = 35) or predominant pulmonary regurgitation (PR) (n = 30). Data from magnetic resonance imaging and cardiopulmonary exercise testing were compared at 3 time points: before PPVI, within 1 month (early) and at 12 months (late) after PPVI.

RESULTS

There was a significant decrease in right ventricle end-diastolic volume early after PPVI in both subgroups of patients. Right ventricle ejection fraction improved early only in the PS group (51 ± 11% vs. 58 ± 11% and 51 ± 12% vs. 50 ± 11%, p < 0.001 for PS, p = 0.13 for PR). Late after intervention, there were no further changes in magnetic resonance parameters in either group (right ventricle ejection fraction, 58 ± 11% in the PS group and 52 ± 11% in the PR group, p = 1.00 and p = 0.13, respectively). In the PS group at cardiopulmonary exercise testing, there was a significant improvement in peak oxygen uptake early (24 ± 8 ml/kg/min vs. 27 ± 9 ml/kg/min, p = 0.008), with no further significant change late (27 ± 9 ml/kg/min, p = 1.00). In the PR group, no significant changes in peak oxygen uptake from early to late could be demonstrated (25 ± 8 ml/kg/min vs. 25 ± 8 ml/kg/min vs. 26 ± 9 ml/kg/min, p = 0.48).

CONCLUSIONS

In patients with a sustained hemodynamic result 1 year after PPVI, a prolonged phase of maintained cardiac function is observed. However, there is no evidence for further positive functional remodeling beyond the acute effects of PPVI.

Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support

Surgical management of tetralogy of Fallot (TOF) results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for many years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced by pulmonary valve replacement the dysfunction might be irreversible. Cardiovascular magnetic resonance (CMR) has evolved during the last 2 decades as the reference standard imaging modality to assess the anatomic and functional sequelae in patients with repaired TOF. This article reviews the pathophysiology of chronic right ventricular volume load after TOF repair and the risks and benefits of pulmonary valve replacement. The CMR techniques used to comprehensively evaluate the patient with repaired TOF are reviewed and the role of CMR in supporting clinical decisions regarding pulmonary valve replacement is discussed.

[Transcatheter valve interventions for heart valve diseases]

Severe aortic stenosis is a significant source of morbidity and mortality among the aging population. Due to prohibitive surgical risk, many patients are not candidates for surgery. Therefore, transcatheter aortic valve implantation has emerged as a promising technology for treating this group of high risk patients. With increasing experience, this procedure can be performed successfully and safely in selected high risk patients. Nevertheless, before widespread use and application to lower risk patients the results of randomized studies are mandatory. Primary (degenerative) and secondary (functional) mitral regurgitation (MR) is an important cause of heart failure. The double orifice technique of mitral valve repair using the MitraClip® system is one of many transcatheter approaches to treat significant MR in patients at high risk for conventional surgery. This technique is effective in reducing MR severity in patients suffering from both degenerative and functional MR. Percutaneous pulmonary valve implantation (PPVI) is an interventional treatment for adolescents and young adults with congenital heart disease. After corrective or palliative operation in infancy or early childhood, some patients regularly need reoperations for right ventricular outflow tract reconstruction. In the last decade, PPVI has evolved as an alternative treatment option with much less morbidity compared to repeated surgery.