Impact of Transcatheter Pulmonary Valve Replacement on Biventricular Strain and Synchrony Assessed by Cardiac Magnetic Resonance Feature Tracking

Abstract

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 Harrild et al Impact of TPV Replacement 681are no reports of any kind of its impact on synchrony of the left ventricle (LV) or RV. The goal of the present study was to quantify the impact of TPV replacement on indices of RV and LV strain and synchrony in patients with dysfunctional RVOT conduits using high-quality CMR images. Methods Study DesignThis was a retrospective cohort study of patients undergoing placement of a Melody TPV in the setting of a dysfunctional RVOT conduit designed to investigate changes in ventricular mechanics based on CMR images before and after pulmonary valve implantation. This study was performed according to a protocol approved by the Committee for Clinical Investigations at Boston Children's Hospital, Boston, MA. PatientsPatients included in this study comprised a subset of the cohort enrolled at our center as part of the multicenter US Melody TPV investigational device exemption (IDE) trial. Briefly, the IDE trial was designed to investigate the safety, procedural success, and short-term effectiveness of Melody valve placement in patients with a biventricular circulation and a dysfunctional RVOT conduit. Study protocols and short-term outcomes have been previously reported. 4,5 As part of their participation in the trial, patients had clinical, ECG, and CMR data collected before and 6±2 months after TPV replacement. Patients were included in the present study if they had high-quality CMR images for analysis both pre-and post-TPV replacement performed between 2007 and 2010.Patients were first analyzed as an entire cohort, and then dichotomized into 2 groups: predominant pulmonary stenosis (PS; RVOT peak systolic e...

Clinical and Hemodynamic Outcomes up to 7 Years After Transcatheter Pulmonary Valve Replacement in the US Melody Valve Investigational Device Exemption Trial

“…Procedural results were described previously, but, given the reported relationships between residual obstruction and adverse outcomes, 4,18,21,22 a new analysis was conducted of factors associated with a higher early postimplantation gradient, which included all patients in whom TPVR was attempted. Follow-up analyses included only patients discharged with a Melody valve in place.…”

“…[2][3][4][5][6][7][8][9] At a functional level, TPVR is followed by improved circulatory efficiency and ventricular strain, enhanced cardiopulmonary exercise function in some patients, and better quality of life. [10][11][12][13][14][15][16][17][18] Although these and other reports helped substantiate TPVR as a valuable tool in the management of patients with postoperative RVOT dysfunction, the lack of longer-term follow-up data remains an important limitation in the Melody valve literature. To date, the studies with the longest follow-up were a 2008 report of 155 patients from the Bonhoeffer group and a 63-patient series collected through an Italian registry that was published in 2013, which reported outcomes at a median of 2.3 and 2.5 years after TPVR, respectively.…”

Relation of Biventricular Strain and Dyssynchrony in Repaired Tetralogy of Fallot Measured by Cardiac Magnetic Resonance to Death and Sustained Ventricular Tachycardia

“…Cardiac magnetic resonance (CMR) imaging overcomes most of these limitations to allow accurate and reproducible evaluation of the RV. 10 Speckle trackingebased techniques have been applied to CMR data, 11,12 and these CMR-based techniques have been termed "feature tracking." The goals of this investigation were to use these new tools to (1) determine whether LV and RV strain measurements in patients with repaired TOF are associated with poor clinical outcomes such as death and sustained ventricular tachycardia (VT) and (2) evaluate whether indexes of dyssynchrony are related to the same clinical outcomes.…”

Feature tracking cardiac magnetic resonance imaging: A review of a novel non-invasive cardiac imaging technique

“…Feature tracking was also useful in identifying higher indexes of left ventricular dyssynchrony which were associated with ventricular tachycardia and death in patients with repaired tetralogy of Fallot[29]. This technique was also used to study the impact of transcatheter pulmonary valve placement on biventricular strain and synchrony in patients with right ventricular outflow tract conduit dysfunction which showed improved right and left ventricular global strain and left ventricular synchrony, showing the value of feature tracking in this patient population[30]. Role of feature tracking in the diagnosis of muscular dystrophy associated cardiomyopathy has been evaluated in some studies.…”

“…Other diseases: A small study identified the role of feature tracking in diagnosing myocardial abnormalities in patients with Churg-Strauss syndrome and Wegener’s Granulomatosis and in clinical remission with normal EKG and transthoracic echocardiogram[30]. Feature tracking could also be useful in the diagnostic workup of left ventricular hypertrophy and the detection of early cardiac involvement in Anderson Fabry’s disease which is an X-linked lipid storage disorder (characterized by multi organ involvement and premature death due to cardiac failure, renal failure, stroke and arrhythmias), with potential for therapy monitoring[42].…”