RV-PA Coupling Research Articles

Right ventricular function in moderate-to-severe ventricular tricuspid regurgitation: Is there a pseudo-normalization of conventional echocardiographic parameters?

Abstract Background A reliable evaluation of right ventricular (RV) function in the presence of moderate-to-severe tricuspid regurgitation (m/s-TR) is of paramount importance for surgical or interventional risk stratification. Due to the significant systolic regurgitation of blood from the RV to the low-pressure right atrium, conventional echocardiographic parameters could appear normal and thus overestimate RV function (pseudo-normal). The aim of this study was to analyse and compare RV function in trace TR versus m/s-TR by the invasive pressure-volume-loop (PV-loop) technique, the gold standard of RV function analysis, with conventional echocardiographic indices in patients with the ventricular form of mild/no vs. m/s-TR. Methods The study was conducted in 134 patients with HFrEF in a post-hoc analysis (110 from the Magdeburg CRT Responder Trial, and 24 from a local CRT-optimization trial). Results The logistic regression analysis demonstrated that RV size (RV-end-diastolic volume, RVEDV) and RV function (measured as RV fractional area change, FAC), TAPSE, and lower fractional shortening (FS) of proximal the RV-outflow tract (RVOTprox) was closely associated with PV-loop-derived RV total afterload (pulmonary arterial elastance, Ea) and coupling of RV contractility (end-systolic RV elastance, Ees) to Ea (Ees/Ea) (all, p<0.001). Compared to trace TR (n=98, 73%), m/s-TR (n=36, 27%) was accompanied with significant higher total afterloads (Ea: 0.75 vs.0.41, p<0.001) and lower RV-PA coupling ratios (Ees/Ea, 0.4 vs. 0.79, p<0.001). This was associated with enlarged RVs (RVEDV: 210ml vs. 166ml), lower FAC (31% vs. 50%), TAPSE (13mm vs. 18mm), and RVOTprox (22% vs. 39%) (all p<0.001). For better comparability between trace TR and m/s-TR tertiles (T1-T3) of similar afterloads (Ea) were formed. The m/s-TR patients showed significant lower RV-PA coupling ratios than trace TR at the lower two Ea tertiles T1 (p=0.034) and T2 (p<0.001). At Ea T3 the difference was no longer significant (p=0.055). The hemodynamic data are mirrored by significant lower FACs, FS RVOTprox, and TAPSE at T1 and T2 (all p<0.05), and a nonsignificant difference at T3 in m/s-TR. In conclusion: In our cohort of HFrEF patients, echocardiographic RV function reflects very closely the hemodynamic coupling efficiency of RV contractility (Ees) to afterload (Ea) and seems independent from the extent of TR. We found no evidence for pseudo-normal or overestimated echocardiographic RV function in m/s-TR.

Abstract 14318: Right Ventriculo- Arterial Coupling Assessment by High-Fidelity Hemodynamic Measurements in Patients Undergoing Left Ventricular Assist Device Implantation

Background: The changes in RV function after LVAD placement are not fully understood. RV- PA coupling, defined as the ratio of RV end-systolic to arterial elastances (E ES /E A ), offers unique insight into the cardiopulmonary unit and opportunity to address these knowledge gaps. We present early results from our study investigating RV adaptive changes after LVAD implantation by intraoperative placement of RV conductance catheters. Methods: Conductance catheter, echocardiographic, and hemodynamic data were gathered starting on the day of surgery. We used a 7Fr high-fidelity RV conductance catheter delivered through a 9Fr central venous sheath. P-V loop parameters were obtained before skin incision and after chest closure. Single- beat methods were used for E ES /E A determination. Early RVF was defined according to INTERMACS criteria. Intraoperative pre- and post-implantation echocardiographic and hemodynamic parameters were compared. Results: We present data on the first 14 patients who underwent successful placement of the RV conductance catheter. Moderate or severe RVF occurred in 3 patients (21.4%). Data are presented in the table. While overall E Es (1.2 vs 1.3, p=0.785), E A (1.1 vs 1.3, p=0.154), and RV-PA coupling (E ES /E A ratio 1.1 vs 1.0, p=0.129 ) remained unchanged, several patients underwent dramatic changes, either increase or decrease, in E ES and E A (Figure). Measures of energetic expense, such as stroke work ( SW, correlate of myocardial energy transferred) and pressure-volume area (PVA, correlate of myocardial oxygen consumption) significantly decreased after LVAD implantation. Conclusions: We have shown that RV function assessment using conductance catheters and 3D echocardiography is feasible and able to identify individual responses in RV-PA coupling after LVAD implantation. Continued accrual of data will help identify different phenotypes of RV adaptation and establish a cut-off level of RV-PA uncoupling at which RVF occurs.

Abstract 14561: Utility of TAPSE/RVSP Ratio in Predicting Severity of Pulmonary Hypertension and Survival in the PVDOMICS Cohort

Introduction: The right ventricle [RV] adapts to pulmonary hypertension [PH] by increasing contractility to maintain RV-PA coupling. With increased afterload, RV contractility cannot compensate, resulting in RV failure. TAPSE/RVSP ratio is a non-invasive measure of RV-PA coupling. We aim to assess TAPSE/RVSP ratio for predicting PH severity and survival across a spectrum of PH in the PVDOMICS cohort. Methods: PVDOMICS subjects from the 5 World Symposium PH groups and comparators were evaluated. TAPSE/RVSP ratio, in mm/mmHg, was derived for each group. PH subjects were stratified by TAPSE/RVSP ratio into low < 0.19, intermediate ≥ 0.19 to < 0.32, and high ratio > 0.32. The relationship between the ratio and RHC parameters (mean PA pressure [mPAP] and pulmonary vascular resistance [PVR]), and between-group differences were evaluated by one-way ANOVA. Kaplan-Meier curves and log-rank tests were used to characterize and compare survival between groups. Results: Data were available for 514 PH subjects (58 ± 15 yrs, 64% female) and 179 comparators (61 ± 13 yrs, 59% female). Mean TAPSE/RVSP ratio was 0.35 ± 0.18 in PH vs 0.63 ± 0.26 in comparators (p < 0.001). Mean TAPSE/RVSP across the PH groups 1-5 were similar, 0.33 ± 0.19, 0.33 ± 0.16, 0.37 ± 0.15, 0.41 ± 0.21 and 0.43 ± 0.29 (p=NS). Within PH subjects, 99 (19.2%) had low, 173 (33.7%) had intermediate and 242 (47.1%) had high ratio. Those with low ratio had higher mPAP (53.6 ± 11.8 mmHg), compared to intermediate (44.6 ± 11.7 mmHg) and high ratio (34.1 ± 10.2 mmHg) [p < 0.001]. Those with low ratio had higher PVR (10.1 ± 5.1 WU), compared to intermediate (6.8 ± 4.1 WU) and high ratio (4.1 ± 2.1 WU) [p < 0.001]. Survival was significantly higher for those with high TAPSE/RVSP ratio compared to those with low ratio (p < 0.001) [Figure]. Discussion: TAPSE/RVSP ratio correlates well with invasive markers to predict PH severity. This useful measure of RV-PA coupling also enables stratification for outcome, with ratio > 0.32 having the best survival rates.

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 15158: Prognostic Impact of Right Ventricular-Pulmonary Arterial Coupling Ratio in Patients Undergoing Transcatheter Aortic Valve Replacement

Introduction: Right ventricular (RV) dysfunction is known as an important prognostic factor in heart failure. As reduced RV systolic reserve, RV contractility no longer increases against afterload, resulting in lower ratios of RV function to pulmonary artery (PA) pressure, known as RV-PA coupling ratios. Hypothesis: The assessment of RV-PA coupling ratios provides prognostic information for patients undergoing transcatheter aortic valve replacement (TAVR). Methods and Results: A total of 540 patients with TAVR (age, 84 ± 6 years; 186 men, 354 women) were included in this study. The RV-PA coupling ratio was calculated by dividing the tricuspid annular plane systolic excursion (TAPSE) by the PA systolic pressure (PASP) using transthoracic echocardiography before TAVR. Based on the median TAPSE/PASP (0.584 mm/mmHg), the patients were divided into two groups. Kaplan-Meier analysis demonstrated a higher incidence of adverse cardiac events (cardiac death and heart failure hospitalization) in the group with a low TAPSE/PASP ratio (log-rank test, P <0.001). In multivariate Cox regression analysis, TAPSE/PASP was identified as an independent prognostic parameter (adjusted hazard ratio, 0.259; P = 0.028), whereas neither TAPSE alone nor PASP alone demonstrated any significant prognostic value. Conclusion: The RV-PA coupling ratio serves as a prognostic predictor for adverse cardiac events in patients undergoing TAVR.

Evaluation of pulmonary artery stiffness in patients with systemic sclerosis

Objective: The study aims to investigate the use of pulmonary artery stiffness (PAS) parameter in early diagnosis of systemic sclerosis
 (SSc) and pulmonary hypertension in SSc patients.
 Patients and Methods: The study involved 102 SSc patients and 45 control group patients, who underwent transthoracic
 echocardiographic evaluations.
 Results: Pulmonary artery stiffness was measured as 25.7±7.6 (Hz/msn) in the SSc cases and 13.7 ±1.6 (Hz/msn) in the healthy
 subjects (P< 0.001). TAPSE/sPAP ratio, which we used as an indicator of RV-PA coupling, was calculated as 0.65+0.28 in SSc cases and
 1.12+0.33 in the control group (P

Pressure Overload and Right Ventricular Failure: From Pathophysiology to Treatment.

Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a phase of adaptive hypertrophy, pressure-overloaded RVs evolve towards maladaptive hypertrophy and finally ventricular dilatation, with reduced stroke volume and systemic congestion. In this article, we review the concept of RV-PA coupling, which depicts the interaction between RV contractility and afterload, as well as the invasive and non-invasive techniques for its assessment. The current principles of RVF management based on pathophysiology and underlying etiology are subsequently discussed. Treatment strategies remain a challenge and range from fluid management and afterload reduction in moderate RVF to vasopressor therapy, inotropic support and, occasionally, mechanical circulatory support in severe RVF.

Left atrial remodeling and right ventricular-pulmonary arterial coupling after MitraClip implantation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter edge-to-edge mitral valve repair (TEER) with the MitraClip system has emerged as a therapeutic alternative to surgical solutions in high risk patients with severe mitral regurgitation (MR). MR is characterized by left ventricular volume overload, which leads to left ventricular dilatation. Furthermore, MR is a common cause of pulmonary hypertension. Right ventricular (RV) intrinsic contractility and its response to afterload is referred to as RV-pulmonary arterial (PA) coupling. Effect of TEER in patients with MR on left atrial (LA) function and RV-PA coupling is less investigated. Purpose The aim of our study was to assess clinical characteristics of patients undergoing MitraClip implantation including LA function and RV-PA coupling. Methods Eighty-eight consecutive patients with chronic severe MR were enrolled in the single-center observational study (mean age 71.5±7.9 years, male 54.5%, ischemic cardiomyopathy 54.5%). Primary MR (PMR) was present in 22.7%, secondary MR (SMR) in 73.9 % and mixed (MxMR) etiology in 3.4%. Conventional and advanced echocardiography examination was performed using speckle tracking echocardiography before TEER and at 6 month post-TEER follow-up. Left atrial maximal (LAV max) and minimal (LAV min) volumes were measured indexed for body surface area. Furthermore, we analysed left atrial functional parameters, such as reservoir strain, conduit strain and contraction strain. Results The technical success of MitraClip implantation was 95,5%. Mortality rate at 6 month follow-up time was 10.8% (1/88 PMR, 7/88 SMR, 1/88 MxMR). Severe residual MR developed during follow-up in 4.2% and New York Heart Association class III-IV functional status was concluded in 6.8% at 6 month post-TEER. Significant decrease in left ventricular end-diastolic median diameter (mm) was observed at follow-up compared to pre-TEER: 57.5 (IQR: 51.25 – 63.75) vs 60.5 (IQR: 52.5 – 66.75), respectively, p = 0.01. Similarly, the median value of pulmonary artery systolic pressure (PASP) substantially decreased (mmHg) after TEER: 42 (IQR: 32 – 52) vs 49.5 (IQR: 41 – 57), respectively, p = 0.003. Tricuspid annulus systolic excursion/PASP median value, representing RV-PA coupling, improved remarkably: 0.45 (IQR: 0.31 – 0.69) vs 0.38 (IQR: 0.29 – 0.52), respectively, p = 0.02. Compared to pre-TEER, median LA volumes and strain parameters did not change significantly at 6 month post-TEER: reservoir strain (%) 12.88 (IQR: 8.18–18.78) vs 11.74 (IQR: 7.48–20.36), p = 0.41; LAV max (ml) 48.70 (IQR: 39.81–62.29) vs 48.17 (IQR: 42.08–58.7), p = 0.31; LAV min (ml) 34.33 (IQR: 24.5–46.32) vs 33.89 (IQR: 26.02–44.53), p = 0.69. Conclusions The function of the enlarged LA was severely reduced, which did not change after MitraClip implantation in our population. However, positive left ventricular remodeling and improvement in RV-PA coupling was observed 6 month after MitraClip procedure.

Right atrial strain: what does it tell us about cardiac function and prognosis?

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): New Zealand National Heart Foundation Background The role of speckle tracking echocardiography has been expanding thanks to its utility in detecting subtle changes in cardiac function, and has prognostic value(1). Right atrial (RA) strain has shown promise in prognostication amongst patients with pulmonary hypertension and heart failure. It is associated with RA size, RV function and IVC size. However, its clinical utility and application remain under investigation (2–5). We sought to evaluate the associations of right atrial strain with both invasive and non-invasive measure of RV function and the association of RA strain with heart failure hospitalisations and death across a heterogeneous cohort. Methods A single-centre retrospective analysis of data from 225 consecutive patients (age 72 ±11.6 years old; male 56%) with both right heart catheterization (RHC) and TTE. Data regarding unplanned heart failure hospitalisations and date of death were recorded. Statistical analysis was performed using SAS 15.1 to assess the association between right atrial strain and prespecified echo and haemodynamic measures of right and left heart function and prognosis defined by heart failure hospitalisations and death. Results Over a median follow up of 28±16 months, there were 59 events. RA strain was associated with the following non-invasive and invasive measures of right heart function and left heart systolic function : TAPSE; RA size, RA pressure, RV strain, PAPi, RVSWI, RV FAC, LAVi, RV PA coupling (TAPSE/systolic PAP), LVEF, cardiac index, diastolic function (E/e’) with a p value of <0.05. Increasing atrial size was associated with lower values of R strain. Despite the association of impaired RV strain with prognosis, HR 2.94 (1.14 – 7.60), RA strain did not appear to be associated independently with prognosis HR 0.98 (0.95–1.0) P value = 0.0676. Conclusions Right atrial strain is independently associated with both invasive and non-invasive measures of RV function and may be a useful tool to help us assess right heart function. It did not appear to be associated with prognosis despite being independently linked with RV strain, which was strongly associated with prognosis in our cohort.

Right ventricular to pulmonary artery coupling change after catheter ablation of atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Right ventricular (RV) to pulmonary artery (PA) coupling can be assessed using the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary arterial systolic pressure (PASP). Although its use has been widely adopted in clinical practice, less is known about its role in patients with atrial fibrillation (AF) and its change after catheter ablation. Purpose The aim of this study is to assess the changes and the clinical impact of RV-PA coupling in patients with AF who underwent catheter ablation. Methods This is a prospective study that enrolled patients undergoing catheter ablation for AF between March 2021 and September 2022 in three tertiary centers in Italy. We evaluated the changes in RV structure and function and TAPSE/PASP between baseline and the 3-month follow-up and their relation with AF relapse after procedure. Results A total of 135 patients were included (mean age 65.2 ± 9.1 years; 68% males, mean left ventricular ejection fraction [LVEF] 56.9 ± 7.9%). Patients in the lowest tertile (TAPSE/PASP < 0.67 mm/mmHg) were older, with and LVEF and LV global longitudinal strain (LVGLS). They also showed lower TAPSE, S’ wave at Tissue Doppler and RV global strain and higher PASP. In the overall population, after 3 months from the ablation procedure, we observed a significant increase of TAPSE (from 22.4 ± 4.1 to 24.0 ± 3.8, p < 0.001), a reduction of PASP (from 29.5 ± 6.6 to 27.9 ± 7.7, p = 0.030) and an increase in TAPSE/PASP from 0.81 ± 0.27 to 0.93 ± 0.29 (p < 0.001). The latter improved both in the patients who were in sinus rhythm (p = 0.031) and with AF (p = 0.003) at baseline. Compared to patients in the highest TAPSE/PASP tertile, those in the lowest one (TAPSE/PASP < 0.67 mm/mmHg) showed an increased risk of AF relapse after catheter ablation (OR 4.33, 95% confidence interval 1.25 – 14.96, p = 0.020). Moreover, the increase of TAPSE/PASP ratio during the follow-up period was associated with a reduced probability of AF relapse, after adjustment for covariates (OR 0.70, 95% confidence interval 0.49 – 0.99, p = 0.046). Conclusion In a multicenter cohort of patients with AF undergoing catheter ablation, a significant improvement of RV-PA coupling, assessed by the TAPSE/PASP ratio, has been observed, regardless of rhythm at admission. Moreover, TAPSE/PASP at baseline, and its change, may represent a useful parameter to predict AF relapse after the procedure.

Right ventricular–pulmonary arterial coupling in patients with implanted left ventricular assist devices

ObjectiveBoth the right ventricular (RV) contractile function and pulmonary arterial (PA) pressure influence clinical outcomes in patients supported with left ventricular assist devices (LVADs), but the impact of RV-PA coupling is unknown. This study aimed to determine the prognostic impact of RV-PA coupling in patients with implanted LVADs. MethodsPatients with implanted third-generation LVADs were retrospectively enrolled. The RV-PA coupling was assessed preoperatively by the ratio of RV free wall strain (RVFWS) derived from speckle-tracking echocardiography and noninvasively measured peak RV systolic pressure (RVSP). The primary end point was a composite of all-cause mortality or right heart failure (RHF) hospitalization. Secondary end points consisted of all-cause mortality at a 12-month follow-up and RHF hospitalization. ResultsA total of 103 patients were screened, and 72 with good RV myocardial imaging were included. The median age was 57 years; 67 patients (93.1%) were men, and 41 (56,9%) had dilated cardiomyopathy. A receiver-operating characteristic analysis (AUC 0.703, 51.5% sensitivity, 94.9% specificity) was used to identify the optimal cutoff point (0.28%/mmHg) for the RVFWS/TAPSE threshold. Nineteen subjects (26.4%) had advanced RV-PA uncoupling. Event rates were estimated using the Kaplan-Meier method showing a strong association with an increased risk for the primary end point of death or RHF hospitalization (89.47% vs. 30.19%, p < 0.001). A similar observation applied to all-cause mortality (47.37% vs. 13.21%, p = 0.003) and RHF hospitalization (80.43% vs. 20%, p < 0.001). ConclusionsAn advanced RV dysfunction assessed by RV-PA coupling may serve as a predictor of adverse outcomes in patients with implanted LVADs.

C63 PREVALENCE AND CLINICAL SIGNIFICANCE OF RIGHT VENTRICULAR PULMONARY ARTERIAL UNCOUPLING IN CARDIAC AMYLOIDOSIS

Abstract Background This study aims to evaluate the prevalence and clinical significance of the right ventricular pulmonary arterial (RV–PA) uncoupling in patients with cardiac amyloidosis (CA). Methods The study population consisted in 92 consecutive patients with CA (age 71.1±12.2 years, 71% males; 47% with immunoglobulin light chain (AL), 53% with transthyretin [ATTR]). All patients underwent a comprehensive evaluation. A pre–specified tricuspid annulus plane systolic excursion on pulmonary arterial systolic pressure (TAPSE/PASP) value &amp;lt;0.31 mm/mmHg was used to define RV–PA uncoupling and to dichotomize the study population. Results Thirty–two patients (35%) showed RV–PA uncoupling at baseline evaluation (15/44 [34%] AL and 17/48 [35%] ATTR). Patients with RV–PA uncoupling in both AL and ATTR showed worse NYHA functional class, lower systemic blood pressure, and more pronounced left and right ventricular systolic dysfunction than those with RV–PA coupling. During a median follow–up of 8 months (IQR 4–13), 26 patients (28%) experienced cardiovascular death. Patients with RV–PA uncoupling showed lower survival at 12 months follow–up than those with RV–PA coupling (42.7% [95%CI 21.7–63.7%] vs. 87.3% [95%CI 78.3–96.3%], p–value&amp;lt;0.001). Multivariate analysis identified high–sensitivity troponin I values (HR 1.01 [95%CI 1.00–1.02] per 1 pg/mL increase; p–value 0.013) and TAPSE/PASP (HR 1.07 [95%CI 1.03–1.11] per 0.01 mm/mmHg decrease; p–value 0.002) as independent predictors of cardiovascular death. Conclusions RV–PA uncoupling is common among patients with CA, and it is a marker of advanced disease and worse outcomes. This study suggest that TAPSE/PASP ratio has the potential to improve risk stratification and guide management strategies in patients with CA.

Impact of right ventricular-pulmonary arterial coupling on clinical outcomes in patients undergoing transcatheter aortic valve implantation

AimsThe interplay between pulmonary hypertension (PH) and right ventricular (RV) function is reflected in an index of RV function to pulmonary artery (PA) systolic pressure (PASP). The present study aimed to assess the importance of RV-PA coupling on clinical outcomes after transcatheter aortic valve implantation (TAVI). Methods and resultsIn a prospective TAVI registry, clinical outcomes of TAVI patients with RV dysfunction or PH were stratified according to coupling or uncoupling of tricuspid annular plane systolic excursion (TAPSE) to PASP, and compared to those of patients with normal RV function and absence of PH. The median TAPSE/PASP ratio was used to differentiate uncoupling (>0.39) from coupling (<0.39). Among 404 TAVI patients, 201 patients (49.8 %) had RVD or PH at baseline: 174 patients had RV-PA uncoupling, and 27 had coupling at baseline. RV-PA hemodynamics normalized in 55.6 % of patients with RV-PA coupling and in 28.2 % of patients with RV-PA uncoupling, and deteriorated in 33.3 % of patients with RV-PA coupling and in 17.8 % of patients with no RVD, respectively, at discharge. Patients with RV-PA uncoupling after TAVI showed a trend towards an increased risk of cardiovascular death at 1 year as compared to patients with normal RV-function (HRadjusted 2.06, 95 % CI 0.97–4.37). ConclusionAfter TAVI, RV-PA coupling changed in a significant proportion of patients and is a potentially important metric for risk stratification of TAVI patients with RVD or PH. Tweet“Patients with right ventricular dysfunction and pulmonary hypertension are at increased risk of death after TAVI. Integrated right ventricular to pulmonary artery hemodynamics change after TAVI in a significant proportion of patients and is instrumental to refine risk stratification.” Clinical trial registrationhttps://www.clinicaltrials.gov: NCT01368250.

Right ventricle to pulmonary artery coupling after transcatheter aortic valve implantation-Determinant factors and prognostic impact.

Right ventricular (RV) dysfunction and pulmonary hypertension (PH) have been previously associated with unfavorable outcomes in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI), but little is known about the effect of right ventricle (RV) to pulmonary artery (PA) coupling. Our study aimed to evaluate the determinant factors and the prognostic value of RV-PA coupling in patients undergoing TAVI. One hundred sixty consecutive patients with severe AS were prospectively enrolled, between September 2018 and May 2020. They underwent a comprehensive echocardiogram before and 30 days after TAVI, including speckle tracking echocardiography (STE) for myocardial deformation analysis of the left ventricle (LV), left atrium (LA), and RV function. Complete data on myocardial deformation was available in 132 patients (76.6 ± 7.5 years, 52.5% men) who formed the final study population. The ratio of RV free wall longitudinal strain (RV-FWLS) to PA systolic pressure (PASP) was used as an estimate of RV-PA coupling. Patients were analyzed according to baseline RV-FWLS/PASP cut-off point, determined through time-dependent ROC curve analysis, as follows: normal RV-PA coupling group (RV-FWLS/PASP ≥0.63, n = 65) and impaired RV-PA coupling group (RV-FWLS/PASP < 0.63, n = 67). A significant improvement of RV-PA coupling was observed early after TAVI (0.75 ± 0.3 vs. 0.64 ± 0.3 before TAVI, p < 0.001), mainly due to PASP decrease (p < 0.001). LA global longitudinal strain (LA-GLS) is an independent predictor of RV-PA coupling impairment before and after TAVI (OR = 0.837, p < 0.001, OR = 0.848, p < 0.001, respectively), while RV diameter is an independent predictor of persistent RV-PA coupling impairment after TAVI (OR = 1.174, p = 0.002). Impaired RV-PA coupling was associated with a worse survival rate (66.3% vs. 94.9%, p-value < 0.001) and emerged as an independent predictor of mortality (HR = 5.97, CI = 1.44-24.8, p = 0.014) and of the composite endpoint of death and rehospitalization (HR = 4.14, CI = 1.37-12.5, p = 0.012). Our results confirm that relief of aortic valve obstruction has beneficial effects on the baseline RV-PA coupling, and they occur early after TAVI. Despite significant improvement in LV, LA, and RV function after TAVI, RV-PA coupling remains impaired in some patients, it is mainly related to persistent pulmonary hypertension and is associated with adverse outcomes.

(854) Effect of Dobutamine on Rv Contractility and Rv-Pa Coupling in the Normal Rv

(854) Effect of Dobutamine on Rv Contractility and Rv-Pa Coupling in the Normal Rv

Clinical Usefulness of Right Ventricle-Pulmonary Artery Coupling in Cardiovascular Disease.

Right ventricular-pulmonary artery coupling (RV-PA coupling) refers to the relationship between RV contractility and RV afterload. Normal RV-PA coupling is maintained only when RV function and pulmonary vascular resistance are appropriately matched. RV-PA uncoupling occurs when RV contractility cannot increase to match RV afterload, resulting in RV dysfunction and right heart failure. RV-PA coupling plays an important role in the pathophysiology and progression of cardiovascular diseases. Therefore, early and accurate evaluation of RV-PA coupling is of great significance for a patient's condition assessment, clinical decision making, risk stratification, and prognosis judgment. RV-PA coupling can be assessed by using invasive or noninvasive approaches. The aim of this review was to summarize the pathological mechanism and evaluation methods of RV-PA coupling, the advantages and disadvantages of each method, and the application value of RV-PA coupling in various cardiovascular diseases.

Impact of Pulmonary Arterial Elastance on Right Ventricular Mechanics and Exercise Capacity in Repaired Tetralogy of Fallot.

Pathophysiological changes of right ventricle (RV) after repair of tetralogy of Fallot (TOF) are coupled with a highly compliant low-pressure pulmonary artery (PA) system. This study aimed to determine whether pulmonary vascular function was associated with RV parameters and exercise capacity, and its impact on RV remodeling after pulmonary valve replacement. In a total of 48 patients over 18 years of age with repaired TOF, pulmonary arterial elastance (Ea), RV volume data, and RV-PA coupling ratio were calculated and analyzed in relation to exercise capacity. Patients with a low Ea showed a more severe pulmonary regurgitation volume index, greater RV end-diastolic volume index, and greater effective RV stroke volume (p=0.039, p=0.013, and p=0.011, respectively). Patients with a high Ea had lower exercise capacity than those with a low Ea (peak oxygen consumption [peak VO2] rate: 25.8±7.7 vs. 34.3±5.5 mL/kg/min, respectively, p=0.003), while peak VO2 was inversely correlated with Ea and mean PA pressure (p=0.004 and p=0.004, respectively). In the univariate analysis, a higher preoperative RV end-diastolic volume index and RV end-systolic volume index, left ventricular end-systolic volume index, and higher RV-PA coupling ratio were risk factors for suboptimal outcomes. Preoperative RV volume and RV-PA coupling ratio reflecting the adaptive PA system response are important factors in optimal postoperative results. We found that PA vascular dysfunction, presenting as elevated Ea in TOF, may contribute to exercise intolerance. However, Ea was inversely correlated with pulmonary regurgitation (PR) severity, which may prevent PR, RV dilatation, and left ventricular dilatation in the absence of significant pulmonary stenosis.

Right Ventricle Response to Major Lung Resection (the RIVER Study).

Major lung resection is associated with high postoperative morbidity and mortality, especially due to cardiorespiratory complications. Right ventricle (RV) ejection, pulmonary artery (PA) pressure, and tone are tightly coupled. Since the RV is exquisitely sensitive to changes in afterload, an acute increase in RV outflow resistance (i.e., acute pulmonary embolism [PE]) will cause acute RV dilatation and, a reduction of left ventricle compliance too, rapidly spiraling to acute cardiogenic shock and death. We investigated the changing in RV performance after major lung resection. We carried out transthoracic echocardiography (TTE) aiming at searching for the incidence of early RV systolic dysfunction (defined as tricuspid annulus plane systolic excursion [TAPSE] <17 cm, S'-tissue Doppler imaging <10 cm/s) and estimate the RV-PA coupling by the TAPSE/pulmonary artery pressures (PAPs) ratio after major lung resection. The TTE has been performed before and immediately after surgery. After the end of the operation the echocardiographic parameters of the RV function worsened. TAPSE decreased from 24 (21 ÷ 28) to 18 (16 ÷ 22) mm (P = 0.015) and PAPs increased from 26 (25 ÷ 30) to 30 (25 ÷ 39) mmHg (P = 0.013). TAPSE/PAPs ratio decreased from 0.85 (0.80 ÷ 0.90) to 0.64 (0.54 ÷ 0.79) mm/mmHg (P = 0.002). In line with previous reports, after major lung resection the increase in afterload reduces the RV function, but the impairment remains clinically not relevant. The different clinical picture of an acute cor pulmonale due to PE implies that the pathogenesis of cardiac failure involves more pathways than the mere mechanic occlusion of the blood flow.

β3 adrenergic agonism: A novel pathway which improves right ventricular-pulmonary arterial hemodynamics in pulmonary arterial hypertension.

Efficacy of therapies that target the downstream nitric oxide (NO) pathway in pulmonary arterial hypertension (PAH) depends on the bioavailability of NO. Reduced NO level in PAH is secondary to "uncoupling" of endothelial nitric oxide synthase (eNOS). Stimulation of β3 adrenergic receptors (β3 ARs) may lead to the recoupling of NOS and therefore be beneficial in PAH. We aimed to examine the efficacy of β3 AR agonism as a novel pathway in experimental PAH. In hypoxia (5 weeks) and Sugen hypoxia (hypoxia for 5 weeks + SU5416 injection) models of PAH, we examined the effects of the selective β3 AR agonist CL316243. We measured echocardiographic indices and invasive right ventricular (RV)-pulmonary arterial (PA) hemodynamics and compared CL316243 with riociguat and sildenafil. We assessed treatment effects on RV-PA remodeling, oxidative stress, and eNOS glutathionylation, an oxidative modification that uncouples eNOS. Compared with normoxic mice, RV systolic pressure was increased in the control hypoxic mice (p < 0.0001) and Sugen hypoxic mice (p < 0.0001). CL316243 reduced RV systolic pressure, to a similar degree to riociguat and sildenafil, in both hypoxia (p < 0.0001) and Sugen hypoxia models (p < 0.03). CL316243 reversed pulmonary vascular remodeling, decreased RV afterload, improved RV-PA coupling efficiency and reduced RV stiffness, hypertrophy, and fibrosis. Although all treatments decreased oxidative stress, CL316243 significantly reduced eNOS glutathionylation. β3 AR stimulation improved RV hemodynamics and led to beneficial RV-PA remodeling in experimental models of PAH. β3 AR agonists may be effective therapies in PAH.

394 PROGNOSTIC POWER OF A NEW INDEX OF RIGHT VENTRICLE-PULMONARY ARTERY COUPLING BASED ON RIGHT VENTRICULAR VOLUMES IN PATIENTS WITH SECONDARY TRICUSPID REGURGITATION

Abstract Background Echocardiographic surrogates of right ventricle (RV) to pulmonary artery (PA) coupling have been reported to be associated with outcomes in secondary tricuspid regurgitation (STR). However, pulmonary artery systolic pressure (PASP) is difficult to be estimated using echocardiography in patients with severe STR and 3D-derived indexes are loading dependent. Objectives To evaluate the predictive power of a new surrogate of RV-PA coupling obtained using RV volumes measured by three-dimensional echocardiography (3DE), accounting for regurgitant volume of STR. Methods Patients with moderate or severe STR were enrolled. The primary outcome was the composite endpoint of death from any cause and heart failure hospitalization. Results 180 patients were included with a median follow up of 24 months (IQR: 2-48); 72 patients (40%) reached the primary endpoint. Among the tested RV-PA coupling indexes, the ratio between (RV stroke volume [SV]-regurgitant volume)/ RV End-systolic volume (ESV) (i.e. RV forward SV/ESV) showed the highest predictive power of the combined endpoint (AUC 0.85 [IC 95% 0.78-0.93]), with a threshold value of 0.40. It was followed by RV ejection fraction/PASP (AUC 0.75 [IC 95% 0.67-0.84]), and TAPSE/PASP (AUC 0.76 [IC 95% 0.68-0.85]). Severe TR (HR 2.04 [CI 95%: 1.10-3.78], p=0.02), TAPSE/PASP &amp;lt;0.36 mm/mmHg (HR 2.39 [CI 95%: 1.26-4.54], p=0.01), and RV forward SV/ESV &amp;lt;0.40 (HR 5.45 [CI 95% 2.47-12.00], p&amp;lt;0.001) were independently associated with the combined endpoint. Conclusions RV forward SV/ESV is able to stratify the risk of death and HF hospitalization in patients with STR when added to TR severity, RV ejection fraction and TAPSE/PASP