Right Ventricular Ejection Fraction Research Articles

Prognostic value of first pass perfusion transit time beyond the pulmonary circulation

Abstract Background Pulmonary transit time (PTT), defined as the time required for a bolus of contrast agent to pass from the right cavities to the left cavities, is an emerging parameter reflective of cardiopulmonary hemodynamics that can be measured in first-pass perfusion cardiovascular magnetic resonance (CMR). Transit times along the left heart (LHTT) and perfusion times of peripheral organs have not been explored so far. Purpose To assess the prognostic value of LHTT and peripheral organs perfusion time in a cohort of patients with left ventricular (LV) disfunction. Methods 50 consecutive patients with LV disfunction (ejection fraction ≤45%) and 56 normal controls who underwent a CMR at our institution were selected. Transit time was calculated as the peak-to-peak time interval between two different areas of the cardiovascular system. PTT was assessed between right ventricle (RV) and left ventricle. LHTT was assessed between left atrium and ascending aorta. Myocardial perfusion time (MyoPT) was measured between left ventricle and the peak of myocardial perfusion. Peripheral organ perfusion (kidney, KPT; spleen, SPT and liver, LPT) between abdominal aorta and the peak organ perfusion. The primary end point was a composite of cardiovascular death, hospitalization, ventricular arrhythmias and the need of any cardiac invasive intervention within the first year. Results Compared with controls, LV disfunction patients presented higher PTT (7.4 [5.9-8.4] vs 11.9 [9.5-13.9] s, p<0.001), LHTT (1.9 [1.05-2.3] vs 3.3 [1.9-4.8] s, p<0.01), MyoPT (9.9 [7.8-11.5] vs 13.1 [9.7-18.6] s, p<0.01), KPT (9.4[7.8-11.2] vs 11.5[8.3-15.5] s, p = 0.012). SPT showed a non-significant trend (9.4[8.1-11.9] vs 11.5[7.9-13.4]s , p = 0.058) . There were no differences in LPT (28.9[24.4-35] vs 33.3[23.3-41.1] s, p = 0.267). Among the patients with LV disfunction, 16 subjects reached the composite end-point; compared to those who did not, these patients had significant higher values of PTT (10.1 [8.7-13.7] vs 13.4[10-15.7] s, p = 0.04), LHTT (2.3[1.8-4] vs 4.3 [3.3-5.8] s, p = 0.008) and MyoPT (10.5[8.8-17.5] vs 13.3[11.9-20.5] s, p = 0.049). SPT showed a non-significant trend (10.3[6.9-12.6] vs 12.6[10.9-17.1] s, p = 0.078), KPT and LPT showed no significant differences. Patients with worse prognosis also presented lower LV ejection fraction (LV: 34.7± 9.5 vs 25.5±9 %, p<0.001) but no significant differences in RV ejection fraction: 52.9±14 vs 49.3±13.8 %, p = 0.473). Due to the small number of events we did not performed a multivariate analysis. KPT showed a weak but significant positive correlation with the creatinine measured at the time of the CMR study (r = 0.262, p = 0.024) and also at follow-up (r = 0.247, p = 0.042). Conclusions Transit time is a surrogate marker of the heamodynamic status that can be assessed beyond the pulmonary circulation. LHTT and organ perfusion times are markedly altered in patients with LV disfunction and are associated with poor prognosis.

Tricuspid regurgitation in pulmonary arterial hypertension: relations with right ventricular function and prognosis

Abstract Background Pulmonary arterial hypertension (PAH) is a devastating disease characterized by progressive pulmonary vascular remodeling and increased pulmonary vascular resistance (PVR), subsequent right ventricular (RV) failure and premature death (1). Progressive RV overload leads to RV dilatation, which in turn induces tethering of the tricuspid valve and functional valvular regurgitation (2,3). As such, severity and the progression of tricuspid regurgitation (TR), as evaluated by echocardiographic qualitative analysis, are reported to associate with a poor prognosis in PAH (4,5). However, it has remained unclear to what extent the severity of TR directly impacts RV hemodynamics and prognosis of PAH patients. Purpose This study aimed to explore the consequences of TR for RV function and prognosis in PAH using a volumetric analysis by cardiac magnetic resonance (CMR). Methods 92 PAH patients, mean pulmonary arterial pressure (mPAP) ≥25 mmHg and pulmonary artery wedge pressure ≤15 mmHg, with available CMR data from January 1st 2010 to August 31st 2021 were included in this study. TR volume was calculated as the difference between the stroke volume (SV) of RV and pulmonary artery (PA). TR severity was graded as no or mild (TR<30 mL), moderate (30≤TR<45 mL) and severe (TR≤45 mL). Hemodynamic assessment was performed by right heart catheterization. Event free survival was estimated from the time of the CMR scan to cardiopulmonary death or lung transplantation. Results In the studied cohort, 74% of PAH patients had no or mild TR, 16% had moderate TR, and 10% had severe TR (Table 1). A greater TR volume was characterized by increased NT-proBNP, increased mPAP, PVR and mean right atrial pressure (mRAP), and increased RV volume. Additionally, RVSV was higher while PASV was lower. There was no difference in RV ejection fraction (RVEF). Pearson correlation analysis showed a good correlation between TR volume and parameters of PAH severity, such as NT-proBNP, RV end-systolic volume (RVESV), mRAP and cardiac index (CI) (Figure 1). ROC curves analysis revealed that the optimal cut-off value of TR volume was 30 mL. Kaplan-Meier survival analysis demonstrated that TR volume ≥30 mL was strongly associated with a poor event free survival (Figure 2). Conclusion 26% of PAH patients had a TR volume 30 ≥mL. TR severity showed a good correlation with PAH disease severity. TR volume 30 ≥mL, i.e. moderate or severe TR, was strongly associated with a poor prognosis in PAH patients.TableFigure

External validation of survival predicting score in repaired tetralogy of Fallot: an opportunity to improve

Abstract Introduction In recent years, integrating both better diagnosis and treatment allowed most adults with repaired tetralogy of Fallot (rTOF) to expect a longer life expectancy. However, a minority is at higher risk for premature cardiovascular death. Recently, 2 scores identified the subgroup of rTOF patients (pts) who are at high annual risk of death and ventricular arrhytmias (VA). We aimed to implement both in our population. Methods Retrospective single center review was done on rTOF pts who undergone cardiovascular magnetic resonance with gadolinium, blood sampling for B-type natriuretic peptide (BNP), echocardiography and cardiopulmonary exercise testing. The risk scores were calculated with weighted independent predictors, namely presence of late gadolinium enhancement in left ventricle (LV) and right ventricle (RV), akinetic RV outflow length, LV and RV ejection fraction (EF), RV systolic pressure, peak oxygen uptake (pVO2), BNP, atrial arrythmias and age. Low mortality risk was defined as 0-20 points, intermediate as 21-50 and high ≥51. In terms of VA prediction, low risk was defined as 0-20 points, intermediate as 21-39 and high as ≥51. Results From a total of 240 rTOF pts, 61 (56% male, mean age 34±9 years) had all the necessary data. RV dysfunction was present in 52.5%, RV systolic pressure was high in 12 and LVEF≤35% in 18% pts. BNP level was elevated in 27 and pVO2≤17mL/kg/m2 in 14.8% pts. The mean mortality risk score was 15.1±11.2, being that 68.9% had a lower and 31.1% an intermediate risk. Regarding VA score, the mean was 14.7±10.8, where the majority (80.3%) were in lower risk. 29.5% had a sustain atrial arrhythmia (mainly atrial fibrillation) and 14.8% a VA. There were 3 cardiac related deaths (4.9%). Analysis of time to event data showed that mortality and VA scores were not predictors of overall mortality (M) or VA events, respectively. However, considering 1-year M, LVEF≤35% (p= 0.002), RVEF≤35% (p=0.002), pVO2≤17mL/kg/m2 (p<0.001), and both scores: M (p=0.013) and VA (p<0.001) were predictors of that endpoint. In multivariate analysis, VA risk score (p=0.035) and low pVO2 (p= 0.006) were independent 1-year M predictors. Conclusion In our population, ventricular arrhythmia score and low peak oxygen uptake were independent predictors of 1-year mortality. However, there is probably a selection bias. Since the scores were recently proposed, patients were not recruited prospectively, many ended up not having all the needed or recent data, thus were not included. There is the need to validate and improve available scores to truly assess the risk of mortality and arrhythmias, as well as defined protocols and longer follow-up for this purpose.

Ventricular volume ratio as a novel imaging biomarker for disease prediction in 26,516 UK Biobank participants

Abstract Background/Introduction Right and left ventricular volumes are established imaging biomarkers for disease discrimination and outcome prediction. Limited research in select disease cohorts suggests additional clinical value from consideration of disproportionate (or imbalanced) dilatation of one ventricle over the other. The prognostic utility of this "ventricular volume ratio" (VVR) has not been tested in large, unselected cohorts. Purpose To examine associations of right-to-left and left-to-right VVR with cardiovascular phenotypes, prevalent disease, and incident cardiac outcomes in the UK Biobank. Methods The analysis includes 26,516 participants with cardiac magnetic resonance (CMR) available. We calculated right-to-left ventricular volume ratio (RV/LV), and the reciprocal left-to-right ventricular ratio (LV/RV), and identified participants with asymmetry above the 95th percentile of healthy cases. Multivariable linear and logistic regression models were used to calculate associations between ventricular volume asymmetry and sample characteristics, other cardiac imaging features, existing disease and incident disease. Incident disease associations were measured using Cox proportional hazards models adjusted by age, sex, systolic blood pressure, body mass index, smoking, Townsend deprivation score, hypertension, diabetes, hyperlipidaemia and other key imaging metrics (LV mass indexed to body surface area, LV ejection fraction and RV ejection fraction). The average follow-up time was 4.6 years (SD 1.3 years). Results Ventricular volume asymmetry in either direction was associated with increased age, lower RVEF, poorer LV global function index, poorer global longitudinal strain and greater maximum wall thickness. While RV-dominant volume asymmetry was associated with increased risk of all-cause mortality (HR= 1.56, 95% CI= [1.08, 2.26], p=0.019), LV-dominant volume asymmetry was found to associate with a much wider array of factors in the UK Biobank population. LV dominance was significantly associated with smoking, hypertension, diabetes, hyperlipidaemia, existing respiratory disease and existing heart disease. In fully-adjusted models, LV dominance was associated with increased risk for ischaemic heart disease (1.46 [1.12, 1.91], p=0.005), non-ischaemic cardiomyopathies (3.62, [1.93, 6.79], p < 0.001) and a two-fold increased risk for heart failure (2.30, [1.63, 3.26], p < 0.001). Conclusion(s) LV/RV is easily calculated from existing imaging metrics, and could potentially have important added value as a biomarker in predicting heart disease, incremental to well-established risk factors and imaging metrics.

Right ventricular global longitudinal strain on cardiovascular magnetic resonance imaging predicts outcome in patients undergoing transcatheter edge-to-edge mitral valve repair

Abstract Background Right ventricular dysfunction (RVD) on echocardiography was shown to predict outcomes in patients undergoing transcatheter edge-to-edge mitral valve repair (M-TEER). However, the prognostic value of left and RV global longitudinal strain (LV- and RV-GLS) on cardiovascular magnetic resonance feature tracking (CMR-FT) is unknown. Methods Consecutive M-TEER patients underwent pre-procedural and follow-up CMR-FT analysis. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed, using a composite endpoint of heart failure hospitalization (HFH) and death. Results 62 patients (78.3±7.0y/o, 45% female, EuroSCORE-II: 9.6±7.1%) underwent CMR-FT prior to M-TEER, 24% had concomitant tricuspid edge-to-edge repair (T-TEER). On presentation, 23 (37%) patients suffered RVD, defined as RV-GLS >-20% on CMR-FT. RVD was associated with reduced LV and RV ejection fraction (LVEF: 39 vs. 49%, p=0.01, RVEF: 35 vs. 47%, p<0.01), as well as impaired LV-GLS (-14.0 vs. -19.5%, p=0.01). Eighteen events (12 deaths, 6 HFH) occurred during follow-up (11.4±9.1months). On multivariable Cox-regression adjusted for baseline, procedural, imaging, and biomarker data, RV but not LV-GLS was significantly associated with outcome (adj.HR 2.50, 95% CI: 1.29-4.86, p=0.01 and 1.46, 95% CI: 0.50-4.28, p=0.49, respectively). Among various definitions of RVD on echocardiography and CMR, only RV-GLS on CMR-FT was significantly associated with outcome (RV-GLS >-20%: adj.HR 7.53, 95% CI: 2.07-27.42, p<0.01), but not RVEF on CMR or echo-indices of RV function. Follow-up CMR-FT was performed in 21 (34%) patients and RV-GLS significantly improved after TMVR (-20.6 to -25.2%, p=0.02), irrespective of additional T-TEER. Conclusions RV-GLS, as determined on CMR-FT, rather than LV-GLS or RVEF, is an independent predictor of outcome in patients undergoing M-TEER.Central Illustration

Sport-specific cardiac adaptation in 104 female elite athletes: MRI findings from the ELITE cohort

Abstract Background The overlap between exercise-induced cardiac remodelling (EICR) and cardiac pathology is a key challenge in sports cardiology. Mainly based on findings in male athletes, EICR is thought to be sport-specific, and varyingly characterised by increased ventricular volumes, cardiac mass and/or wall thickness. However, no large cardiac magnetic resonance imaging (CMR) study in female elite athletes has extensively examined sport-specific cardiac adaptations. Purpose To investigate sport-specific EICR on CMR in a large cohort of female elite athletes. Methods We performed a cross-sectional CMR analysis in female elite athletes (Para-/Olympic or professional athletes competing ≥10 hours per week at a national/international level) aged ≥16 years, included in the ELITE cohort (1). We excluded athletes with known cardiovascular disease, and classified athletes according to the ESC sports disciplines classification. Our outcomes of interest were sport-specific EICR, defined as BSA-indexed LV and RV end-diastolic volume (EDVi), LV wall mass (LVMi), and maximal LV wall thickness (LVWdmax), LV remodelling index (LVMi/LVEDVi), and LV/RV ratio (LVEDi/RVEDVi). CMR was performed according to a uniform protocol, preferentially on 1.5T. A dedicated core-lab analysed all CMRs in Circle Cardiovascular Imaging. Results We included 104 female elite athletes, 96% Caucasian, mean age of 26.1 ±5 years, BSA 1.8 ±0.1 m2, and mean professional (≥10 hours/week) athlete years of 11.6 ±5. The athletes were classified as skill (n=8), power (n=9), mixed (n=39) and endurance (n=48) sports. Endurance athletes had markedly increased left- and right ventricular volumes compared to power (LVEDVi 111.2 ±15 vs 98.7 ±11 ml/m2, p=0.009; RVEDVi 114.8 ±18 vs 101.7 ±10 ml/m2, p=0.006) and mixed athletes (LVEDVi 111.2 ±15 vs 107.3 ±13 ml/m2, p=0.058; RVEDVi 114.8 ±18 vs 107.8 ±12 ml/m2, p=0.031) (Figure 1). No differences were found between endurance, mixed, power and skill athletes in LVEDVi/RVEDVi ratios (0.97 vs 0.99 vs 0.97 vs 0.99), LVMi (52.6 ±12 vs 46.9 ±10 vs 48.7 ±10 vs 50.4 ±11 g/m2) (Figure 2), LVWdmax (8.1 ±1 vs 7.9 ±1 vs 7.9 ±1 vs 8.9 ±1 mm), LV remodelling index (LVMi/LVEDVi 0.47 vs 0.44 vs 0.49 vs 0.48), LV ejection fraction (56.3 ±4 vs 56.7 ±5 vs 58.2 ±3 vs 57.7 ±3 %), and RV ejection fraction (54.6 ±4 vs 55.7 ±4 vs 55.4 ±3 vs 56.7 ±4). Conclusion In female elite athletes, EICR according to sport categories is mainly characterised by balanced increases in ventricular volumes in endurance athletes, but not in increases in left ventricular wall-mass and thickness, even in sport categories with high static demands. Our findings constitute a first step towards the understanding of sport-specific EICR in female elite athletes.Figure 1.Figure 2.

Fragmented QRS complexes in veteran athletes

Abstract Background QRS fragmentation (fQRS), characterized by multiple peaks within the QRS, is considered an adverse risk marker that may indicate underlying myocardial fibrosis and has been implicated in cardiomyopathies. The presence of fQRS is often noted in pre-participation screening of athletes. In this study, we aimed to investigate the prevalence and clinical significance of fQRS in a cohort of ostensibly fit veteran athletes (VA). Methods We recruited 314 predominantly Caucasian VA's with a history of endurance exercise and no traditional risk factors for coronary artery disease. Participants underwent a 12-lead electrocardiogram, cardiopulmonary exercise testing (CPET), 24-hour Holter monitoring, and cardiac magnetic resonance imaging (CMR). fQRS was categorized as >2 consecutive leads using established criteria (1). Results fQRS in 2 or more contiguous leads was identified in 12% of VA's. The presence of fQRS was more prevalent in males and increased with age (p < 0.05). There were no significant differences in ECG conduction indices. When CMR parameters were considered, the presence of fQRS was associated with increased left ventricular (LV) mass index and increased right ventricular (RV) function. There was no relationship with the presence of late gadolinium enhancement. Athletes with fQRS achieved a significantly lower predicted peak VO2 and trended towards lower peak resistance on CPET. No relationship was observed with total ventricular premature beat count or the presence of complex ectopy on 24-hour Holter monitoring. Conclusions fQRS in 2 or more contiguous leads is commonly present amongst male Caucasian VA’s, and its prevalance increases with age. It is associated with greater LV mass and increased RV ejection fraction. Athletes with fQRS may achieve a lower percentage predicted VO2 max compared to those without. Furthermore, FQRS did not predict late gadolinium enhancement, increased VPB count or complex ectopy.Comparing VAs with FQRSQRS-fragmentation patterns (Das et al)

Cardiac damage extent in patient with isolated severe aortic stenosis referred to surgical aortic valve replacement: is it reversible after surgery?

Abstract Background Aortic stenosis (AS) may lead to progressive and adverse cardiac remodeling. A recently-proposed staging classification regarding extravalvular cardiac damage in AS patients undergoing aortic valve intervention was shown to have significant prognosis implications. However, cardiac damage evolution and reversibility after intervention remain unknown. Aims to assess extravalvular cardiac damage evolution after surgical aortic valve replacement (SAVR) in patients with isolated severe AS. Methodology we performed a single-center, prospective cohort study enrolling consecutive patients with severe aortic stenosis undergoing SAVR. Those with previous cardiomyopathy or concomitant severe valve dysfunction beyond AS were excluded. All patients performed transthoracic echocardiogram (TTE) and cardiac magnetic resonance (CMR) within 3 months before SAVR as well as at the 3rd to 6th post-operative month. Patients were classified according to the extent of cardiac damage into 4 groups: stage 0: no damage; stage 1: left ventricle (LV) hypertrophy (indexed LV mass >95 g/m2 [women] or >115 g/m2 [men]), LV diastolic (E/e′ > 14) or systolic (ejection fraction <50%) dysfunction; stage 2: dilated left atrium (>34mL/m2) or atrial fibrillation; stage 3: pulmonary hypertension (systolic pulmonary artery pressure ≥60mmHg); stage 4: significant right ventricle (RV) dysfunction. Global longitudinal strain (GLS) was also assessed to further characterize the extent of LV damage – a GLS > -14.7% was considered abnormal. Due to the impact of on-pump cardiac surgery on RV systolic longitudinal function, RV ejection fraction assessed by CMR (<45%) was used to define significant post-operative RV dysfunction. Results A total of 67 patients were included (mean age 71 ± 8 years; 50% male; mean valvular transaortic gradient 60 ± 19 mmHg; mean indexed aortic valve area 0.4 ± 0.01 cm2/m2; mean LV ejection fraction by TTE 58 ± 9%). Overall, a significant number of patients still showed sign of structural cardiac damage after surgery – 14 vs. 10 on stage 1, 44 vs. 39 on stage 2, 1 vs. 1 on stage 3 and 4 vs. 4 on stage 4 after AVR- figure 1. However, a statistically significant improvement in the number of patients at stage 0 after surgery (4 vs. 11, paired McNemar test p=0.016) was observed, as well as a significant improvement in GLS (mean GLS pre and post AVR -14.8 ± 3.6% vs. -16.6 ± 3.3%, respectively; 45 vs. 21% patients with abnormal GLS before and after AVR, p=0.001). Conclusion Extravalvular cardiac damage is common in a selected cohort of severe AS and potentially reversible after SAVR. A significant improvement in GLS, although not a part of the previously established staging system, was observed after AVR. Whether or not these findings may correlate with long-term patient prognosis or if additional favorable cardiac remodeling is seen on a longer-term follow-up remains to be determined.

Right ventricular dysfunction after coronary artery bypass grafting

Abstract Background Impaired right ventricular (RV) function is a frequent echocardiographic finding following coronary artery bypass grafting (CABG). It is subject of debate whether this finding reflects actual RV dysfunction with clinical impact, or rather limitations of the applied echocardiographic measurements. Purpose We aimed to investigate prevalence of RV dysfunction using currently available echocardiographic measurements, and self-reported physical capacity more than two years after CABG. Materials and methods This pre-specified cross-sectional substudy of the SWEDEGRAFT trial included patients scheduled for follow-up more than two years after elective CABG at our institution. The SWEDEGRAFT trial is an ongoing multicenter, randomized clinical trial comparing patency of saphenous vein grafts harvested with "no-touch" and open skeletonized technique. We prospectively assessed RV function with multivariable transthoracic echocardiography. Self-reported physical capacity was assessed using the three items for physical limitation of the Seattle Angina Questionnaire (SAQ-7) (3 denotes the worst and 15 the best possible physical capacity), as well as NYHA-class. Baseline and procedural data were retrieved from the SWEDEGRAFT trial. Preoperative echocardiographies were systematically reexamined. Results We enrolled 207 patients into our substudy at a median follow-up after CABG of 31.0 (range 24.2-39.9) months. RV function assessed by tricuspid annular plane systolic excursion (TAPSE) was significantly reduced compared to the preoperative assessment. In contrast, postoperative RV function as assessed by RV fractional area change (FAC) was preserved. Similarly, assessment of three-dimensional RV ejection fraction (3D-RVEF) indicated preserved RV function (mean 49.4 ± 6.3 %). Mean RV global longitudinal strain was -19.7 (±3.6), and mean RV free wall strain was -22.7 (±4.9). At follow-up, assessments of 3D-RVEF and strain modalities were obtainable in 51.7% and 72.4% of patients, respectively. Patient-reported functional capacity was excellent (median score 15, interquartile range 1.5). NYHA-class improved significantly (NYHA-class I preoperative 49.4% vs. postoperative 61.4%, p=0.032). Postoperative median pro-Brain Natiuretic Peptide levels were 163 (interquartile range 195) ng/L. Conclusion RV systolic function was preserved more than two years after CABG when assessed by RV FAC and 3D-RVEF despite significant reduction in TAPSE. These findings likely reflect the increased sphericity of the RV following opening the pericardium during surgery. Our study supports that measurements of longitudinal systolic parameters likely underestimate RV systolic function after CABG.

Abstract 15106: Echocardiography versus Cardiac Magnetic Resonance-Quantification of Right Ventricular Function to Stratify the Risk of Appropriate Defibrillator Therapy

Background: Right ventricular dysfunction is recently referred as an independent predictor of sudden cardiac death. The purpose of this study was to evaluate the efficiency of risk stratification methods for appropriate implantable cardiac defibrillator (ICD) therapy using two different modalities to quantify the right ventricular function. Methods: Consecutive patients undergoing ICD implantations who completed both preprocedural echocardiography and cardiac magnetic resonance (CMR) were retrospectively enrolled. Any channelopathy or arrhythmogenic right ventricular disease were excluded. The right ventricular fractional area change (RVFAC) and estimated pulmonary artery pressure (EPAP) were calculated from echocardiography. The contraction-pressure index (CPI) was defined as the quotient of the RVFAC divided by EPAP. The right ventricular ejection fraction (RVEF) was automatically provided by CMR. Both were evaluated to predict the initial appropriate ICD therapy. Results: In total, 111 patients (59.5±14.9 years, 79 males) including 20 with ischemic cardiomyopathy were retrospectively enrolled. Fifty-six patients received an ICD as secondary prophylaxis. The mean RVFAC, CPI, and RVEF were 36.7±8.9%, 1.4±0.7%, and 39.9±13.8%, respectively. Regarding appropriate ICD therapy events, the best cut-off value of the RVFAC was 34.8 (specificity 0.63, sensitivity 0.65, ROC-AUC 0.64), CPI 1.59 (specificity 0.42, sensitivity 0.94, ROC-AUC 0.61) and RVEF 43.0 (specificity 0.48, sensitivity 0.87, ROC-AUC 0.64). The hazard ratio of a low RVFAC was 3.13 (95%CI: 1.32-7.44, P<0.01, concordance=0.62), that of low CPI was 9.60 (95%CI: 1.27-72.4, P=0.03, c=0.65), and that of reduced RVEF was 5.55 (95%CI: 1.64-18.7, P<0.01, c=0.67). Conclusion: CPI and RVEF were similarly associated with an increased appropriate ICD therapy. The CPI seemed to provide an equivalent stratification for the risk of appropriate ICD therapy as compared to a CMR indicator.

Abstract 15449: Cardiopulmonary Best Abstract Award : Pausing Reveals Exercise-Induced Uncoupling: Exploring the Dynamics of RV-PA Coupling in the Six-Minute Walking Test

Background: The six-minute walking test (6MWT) is a commonly used test for assessing the functional capacity of patients with pulmonary hypertension (PH), providing functional and prognostic information. Functional capacity depends on RV-PA coupling, the matching of right ventricular contractility to afterload. However, the dynamics of RV-PA coupling during the 6MWT have never been studied. Methods: We used a wireless hemodynamic monitoring system (CorLog, emka-medical, Germany) to continuously measure right ventricular pressure in 10 patients with PH (8 = group I, 1 = III, 1 = IV) during a 6MWT. We calculated right ventricular ejection fraction (RVEF) and Ees/Ea based on the pressure signal as shown in the figure (panel a). Dyspnea was evaluated using the Borg scale. Results: By analyzing the hemodynamic response during the 6MWT, we identified two patterns: 1) Improved/preserved coupling: Five patients exhibited an initial improvement in Ees/Ea and maintained coupling at least at the baseline level throughout the test, without requiring pauses. 2) Uncoupling associated with pauses: Five patients experienced a slight increase in Ees/Ea at the beginning, followed by a progressive loss of coupling and ejection fraction, necessitating pauses. During pauses, Ees/Ea values restored, enabling patients to resume walking. Patients of the second phenotype reported higher levels of dyspnea. The highest reported Borg score was 8 ± 0.9 vs. 4.6 ± 1.2 in the first group. Also, the covered distance was shorter in the second group (159 ± 64m vs. 288 ± 88m, p=0.03). Both groups showed differences in Ees/Ea (0.47 [0.46 - 0.57] vs. 0.34 [0.30 - 0.43], P=0.05) and RVEF (34 ± 4.1% vs. 28.5 ± 2.6%, P=0.03) at baseline, with Group One exhibiting superior values. Conclusion: This is the first investigation into the significance of RV-PA coupling in real-life exercise limitation and dyspnea during the 6MWT. Pauses observed during the 6MWT can serve as indicators of exercise-induced uncoupling.

Abstract 14833: Association of RV Hemodynamics From 4D Flow CMR With RV Restrictive Physiology From Pediatric to Adult Repaired Tetralogy of Fallot

Introduction: Right ventricular restrictive physiology (RVRP) is common after repair of Tetralogy of Fallot (rTOF), especially with residual pulmonary regurgitation. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) quantitates biventricular blood flow components and kinetic energy (KE) parameters, but their association with RVRP is unclear. We aimed to study 4D flow CMR parameters in adult and pediatric rTOF patients vs healthy controls and associations of 4D flow parameters with RVRP in rTOF. Methods: 103 rTOF patients (40 pediatric, 63 adult; age 24±17 years; 53M:50F) and 171 healthy controls (14 pediatric, 157 adult; age 40±15 years; 97M:74F) were prospectively recruited from centers in Singapore (2) and China (1) to undergo 4D flow CMR on multi-vendor scanners. LV and RV flow components—direct flow, retained inflow, delayed ejection flow and residual volume—and KE parameters (normalized to end-diastolic volume, KEi EDV )—global, peak systolic, average systolic, average diastolic, peak E-wave and peak A-wave—were analyzed. KE discordance was calculated as the ratio of RV and LV average systolic KEi EDV . Results: See Table. RVRP was identified in 70 patients (68%). rTOF with RVRP exhibited higher median RV stroke volume index, RV ejection fraction, RV direct flow, RV peak E-wave and E-wave/A-wave, and lower RV residual volume compared to rTOF without RVRP (all P<0.05). Using binary multivariable logistic regression analysis—and after adjustment for age, pulmonary regurtitation, LV and RV ejection fraction, RV direct flow was found to be independently associated with RVRP in rTOF (P<0.001). Conclusion: Patients with RVRP had higher RV direct flow, RVEF and RV peak E-wave energy, indicating the potential compensatory adaptations in patients with RVRP.

Abstract 11685: Effects of Pectus Excavatum Surgical Repair on Cardiac Volumes and Systolic Function as Assessed by 3D Transesophageal Echocardiography

Introduction: The consequences of external cardiovascular compression and cardiac displacement from pectus excavatum (PEx) are debated. The complex geometry of the right (RV) and left ventricle (LV) along with distortion from the extrinsic chest deformity pose significant limitations to reliable assessment of LV and RV volumes and function using transthoracic 2D-echocardiography in this population. Hypothesis: A 3D-echocardiography approach can reliably assess the effects of external cardiac compression and the benefits of surgical correction on RV and LV function in PEx patients. Methods: Adult patients undergoing minimally invasive repair of PEx between Oct-2021 and Feb-2023 were included in this prospective study. Intraoperative transesophageal (TEE) 6 beat full volume video loops incorporating LV and RV were captured and compared before and after surgical correction of the PEx. TomTec Software® was used for offline 3D/4D reconstruction ( Figure 1 shows changes in 3D RV and LV shape pre- and post-surgery). Result: The study included 102 patients (mean age of 32.1 ±11.8 years; Haller index 4.9 ±2.5; 60.8% males). Post PEx repair, there was a significant (p<0.001) increase in the 3D RV volumes, RV ejection fraction (EF), RV stroke volume and RV strain ( Figure 1 ). Additionally, there was a significant improvement in 3D LVEF, 3D LV strain (longitudinal and circumferential), LV twist, and torsion ( Figure 1 ). Conclusion: In this PEx cohort, 3D/4D TEE imaging demonstrated significant increases in RV volumes and in RV and LV systolic function after surgical repair. These findings support the negative cardiovascular consequences of PEx compression and benefits of surgical repair.

Abstract 16277: Glycoprotein 130 Antagonism Improves Right Ventricle Function in Pulmonary Artery Banded Piglets

Introduction: Right ventricular dysfunction (RVD) is a risk factor for death in multiple cardiovascular diseases, but RV-specific therapies are lacking. We recently showed inhibition of glycoprotein 130 (GP130) signaling with the small molecule SC144 improved RV function via modulation of microtubules and mitochondria metabolism in rodent RVD. However, SC144’s efficacy in a translational large animal model of RVD is untested. Methods: Ten 4-week-old castrated male piglets underwent pulmonary artery banding (PAB). After 3 weeks, PAB pigs were randomized into 2 groups (daily injections of SC144 [2 mg/kg, PAB-SC144, n =5] or vehicle control [PAB-Veh, n =5] for 3 weeks). Five pigs of a similar age served as controls. Cardiac MRI evaluated RV function, mass, and volume. Immunoblots of RV extracts quantified microtubule and GP130 pathway protein levels. Quantitative proteomics evaluated RV mitochondrial enrichments. KEGG pathway analysis delineated the biochemical pathways associated with RV ejection fraction. Results: SC144 significantly improved RV ejection fraction ( A , Control: 59.5±4.2, PAB-Veh: 22.6±10.8, PAB-SC144: 37.6±6.4) without changing RV afterload ( B-C ). Molecularly, GP130 antagonism normalized abundances of microtubule proteins and increased levels of suppressor of cytokine signaling 3 (SOCS3), an endogenous GP130 antagonist. Mitochondrial proteomics analysis revealed amino acid metabolism and oxidative phosphorylation suppression was mitigated by SC144 ( D ). Conclusions: SC144 improves RV function in porcine RV failure, potentially by maintaining oxidative phosphorylation, amino acid metabolism, and microtubule regulation.

Abstract 12375: Performance of Echocardiographic Measures of Right Ventricular Assessment Against Cardiac MRI in Pulmonary Hypertension - Results From the PVDOMICS Cohort

Introduction: Assessment of right ventricular (RV) size and function by echo is challenging due to complex RV anatomy and requires integration of multiple measurements. We sought to compare accuracy of echo measures of RV size and function with cardiac MRI (CMR) in pulmonary hypertension (PH). Methods: We included patients with PH from the PVDOMICS Study who underwent both echo and CMR. Echo measures of RV size (basal dimension, area, 3D volume) and function (fractional area change [FAC], 3D RV ejection fraction [EF], RV global longitudinal strain [GLS], S’, TAPSE, Tei index) were compared to CMR derived RV volumes and RVEF. Agreement was assessed using Bland-Altman (BA) plots and Lin’s concordance correlation coefficients (ρ c ). Predictive trends were evaluated using linear regression. Results: The cohort included 446 subjects (58 ± 15 yrs, 36% male). Echo measures of RV size showed poor agreement with CMR, but substantial linear associations, when comparing CMR end diastolic volume (EDV) with: echo basal dimension (ρ c = 0.002; β = 60, R 2 = 0.47), end-diastolic area (ρ c = 0.04, β = 6.4, R 2 = 0.64), and 3D EDV (bias = 106, limits of agreement [LOA]: -14.1 to 225); and also when comparing CMR end-systolic volume (ESV) with: end-systolic area (ρ c = 0.08; β = 6.8, R 2 = 0.74) and 3D ESV (bias = 67.3, LOA: -31.8 to 166). Select echo measures of RV function demonstrated better agreement with CMR RVEF including: 3D RVEF (bias -0.23, LOA -17.9 to 17.5) and FAC (ρ c = 0.55; β = 0.89, R 2 = 0.50). Others exhibited modest or poor agreement including: RV GLS (ρ c = 0.11; β = -1.5, R 2 = 0.40), along with S’, TAPSE, and Tei index (ρ c ≤ 0.02; R 2 ≤ 0.19 for all). [Figure] Discussion: In this largest comparison of echo vs CMR measures of RV assessment in PH, echo measures of RV size agreed poorly with CMR, especially at larger RV volumes. RV functional assessment was best with echo 3D RVEF and FAC, which should be preferentially used for echo RV functional assessment. Consider CMR for more accurate volume assessment of RV size.

Right Heart Remodeling After Pulmonary Valve Replacement in Patients With Pulmonary Atresia or Critical Stenosis With Intact Ventricular Septum.

Background Patients with pulmonary atresia or critical pulmonary stenosis with intact ventricular septum (PA/IVS) and biventricular circulation may require pulmonary valve replacement (PVR). Right ventricular (RV) remodeling after PVR is well described in tetralogy of Fallot (TOF); we sought to investigate RV changes in PA/IVS using cardiac magnetic resonance imaging. Methods and Results A retrospective cohort of patients with PA/IVS who underwent PVR at Boston Children's Hospital from 1995 to 2021 with cardiac magnetic resonance imaging before and after PVR was matched 1:3 with patients with TOF by age at PVR. Median regression modeling was performed with post-PVR indexed RV end-diastolic volume as the primary outcome. A total of 20 patients with PA/IVS (cases) were matched with 60 patients with TOF (controls), with median age at PVR of 14 years. Pre-PVR indexed RV end-diastolic volume was similar between groups; cases had higher RV ejection fraction (51.4% versus 48.6%; P=0.03). Pre-PVR RV free wall and left ventricular (LV) longitudinal strain were similar, although LV midcavity circumferential strain was decreased in cases (-15.6 versus -17.1; P=0.001). At a median of 2 years after PVR, indexed RV end-diastolic volume was similarly reduced; cases continued to have higher RV ejection fraction (52.3% versus 46.9%; P=0.007) with less reduction in RV mass (Δ4.5 versus 9.6 g/m2; P=0.004). Post-PVR, RV and LV longitudinal strain remained unchanged, and LV circumferential strain was similar, although lower in cases. Conclusions Compared with patients with TOF, patients with PA/IVS demonstrate similar RV remodeling after PVR, with lower reduction in RV mass and comparatively higher RV ejection fraction. Although no differences were detected in peak systolic RV or LV strain values, further investigation of diastolic parameters is needed.

Reverse Remodeling Effects of Sacubitril-Valsartan: Structural and Functional Optimization in Stage C Heart Failure

BackgroundSacubitril-valsartan, an angiotensin receptor-neprilysin inhibitor, reduces all-cause mortality as well as the rate of heart failure hospitalizations in patients with heart failure with reduced ejection fraction (HFrEF). This study aimed to elucidate the benefits of initiating sacubitril-valsartan on ventricular remodeling in patients previously optimized on guideline directed medical therapy. MethodsIn this prospective, single-arm longitudinal study, 40 patients with HFrEF who were optimized on guideline-directed medical therapy were transitioned to sacubitril-valsartan. The primary end-point was the change in left ventricular (LV) volume at 1 year as assessed by three dimensional transthoracic echocardiography. Other echocardiographic endpoints included change in LV function and change in right ventricular (RV) size and function. ResultsThe mean age was 55 ± 12 years and 63% were male. At 1 year, LV end-diastolic volume decreased from 242 ± 71 to 157 ± 57 ml (p <0.001) with a corresponding increase in LV ejection fraction from 32 ± 7 to 44 ± 9 % (p <0.001). RV end-diastolic volume decreased from 151 ± 51 to 105 ± 45 ml (p <0.001). While RV ejection fraction did not change (51 ± 8 vs 51 ± 10; p = 0.35), RV GLS improved from -14.9 ± 3.4 % to -19.3 ± 4.3 % (p <0.001) ConclusionWhen added to standard medical therapy for heart failure, sacubitril-valsartan induces significant remodeling of both the right and left ventricles as assessed by 3D echocardiography.

Echocardiographic Characteristics of Left and Right Ventricular Longitudinal Function in Patients With a History of Cardiac Surgery

Previous studies have indicated a reduction in right ventricular (RV) longitudinal motion following cardiac surgery. However, the long-term effect of cardiac surgery on longitudinal motion and the involvement of left ventricular (LV) motion remain unclear. Therefore, this study aimed to comprehensively investigate the longitudinal function of the right ventricle and left ventricle in patients who had undergone cardiac surgery. The study included patients who underwent comprehensive transthoracic echocardiography (TTE) with three-dimensional RV data sets. By propensity score matching of clinical and echocardiographic variables, including LV and RV ejection fraction, the echocardiographic parameters were compared between patients with and without a history of cardiac surgery (the surgery and nonsurgery groups, respectively). In this study, the surgery group had significantly lower LV global longitudinal strain values than the nonsurgery group, despite having similar LV ejection fraction. Tricuspid annular plane systolic excursion (TAPSE), tricuspid annular velocity, and RV free wall longitudinal strain were also significantly smaller in the surgery group, whereas the RV ejection fraction was comparable between the 2 groups. Additionally, a subgroup analysis based on the time from previous surgery to TTE (≤1 and >1 year) revealed that TAPSE was reduced in both postoperative phases. In conclusion, LV and RV longitudinal parameters were reduced after cardiac surgery, despite preserved LV and RV global functions. Moreover, TAPSE was reduced even a long time following cardiac surgery. These findings emphasize the need for careful interpretation of biventricular longitudinal motion in patients with a history of cardiac surgery.

Biventricular Dysfunction and Ventricular Interdependence in Patients With Pulmonary Hypertension: A 3.0-T Cardiac MRI Feature Tracking Study.

Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated. To explore the biventricular dysfunction and the ventricular interdependence in PH patients. Retrospective. One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age- and sex-matched controls with cardiac magnetic resonance imaging (MRI) studies. 3.0 T/balanced steady-state free precession sequence. LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59). Chi-squared tests or Fisher's exact test, t tests or Mann-Whitney U test, one-way ANOVA with Bonferroni's post hoc correction or Kruskal-Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two-tailed P < 0.05 was deemed statistically significant. RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: β = 0.416; LVGCS: β = -0.371; LVGLS: β = 0.283). Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease. 3 TECHNICAL EFFICACY: Stage 3.

Spatial-temporal V-Net for automatic segmentation and quantification of right ventricle on gated myocardial perfusion SPECT images.

Functional assessment of right ventricle (RV) using gated myocardial perfusion single-photon emission computed tomography (MPS) heavily relies on the precise extraction of right ventricular contours. In this paper, we present a new deep-learning-based model integrating both the spatial and temporal features in gated MPS images to perform the segmentation of the RV epicardium and endocardium. By integrating the spatial features from each cardiac frame of the gated MPS and the temporal features from the sequential cardiac frames of the gated MPS, we developed a Spatial-Temporal V-Net (ST-VNet) for automatic extraction of RV endocardial and epicardial contours. In the ST-VNet, a V-Net is employed to hierarchically extract spatial features, and convolutional long-term short-term memory (ConvLSTM) units are added to the skip-connection pathway to extract the temporal features. The input of the ST-VNet is ECG-gated sequential frames of the MPS images and the output is the probability map of the epicardial or endocardial masks. A Dice similarity coefficient (DSC) loss which penalizes the discrepancy between the model prediction and the manual annotation was adopted to optimize the segmentation model. Our segmentation model was trained and validated on a retrospective dataset with 45 subjects, and the cardiac cycle of each subject was divided into eight gates. The proposed ST-VNet achieved a DSC of 0.8914 and 0.8157 for the RV epicardium and endocardium segmentation, respectively. The mean absolute error, the mean squared error, and the Pearson correlation coefficient of the RV ejection fraction (RVEF) between the manual annotation and the model prediction were 0.0609, 0.0830, and 0.6985. Our proposed ST-VNet is an effective model for RV segmentation. It has great promise for clinical use in RV functional assessment.