Right ventricular-pulmonary arterial coupling in patients with first acute myocardial infarction: an emerging post-revascularization triage tool.

BACKGROUND: The tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio is a non-invasive surrogate for right ventricular-pulmonary arterial (RV-PA) coupling, studied in chronic RV pressure overload syndromes. However, its prognostic utility in patients with acute myocardial infarction (AMI), which may cause acute RV pressure overload, remains unexplored. OBJECTIVE: This study aimed to determine predictors of RV-PA uncoupling in patients with first AMI and examine whether it could improve risk stratification for cardiovascular in-hospital mortality after revascularization. METHODS: Three-hundred consecutive patients with first AMI were prospectively studied (age 61.2 ± 11.8, 24% females). Echocardiography was performed 24 h after successful revascularization, and TAPSE/PASP was evaluated. Cardiovascular in-hospital mortality was recorded. RESULTS: The optimal cutoff value of TAPSE/PASP to determine cardiovascular in-hospital mortality was 0.49 mm/mmHg. RV-PA uncoupling was considered for patients with TAPSE/PASP ≤0.49 mm/mmHg. Left ventricular ejection fraction (LVEF) was independently associated with RV-PA uncoupling. A total of 23 (7.7%) patients died in hospital despite successful revascularization. TAPSE/PASP was independently associated with in-hospital mortality after adjustment for Global Registry of Acute Coronary Events (GRACE) risk score and LVEF (odds ratio 0.14 [95% confidence interval 0.03-0.56], P = 0.007). The prognostic value of a baseline model including the GRACE risk score and NT-pro-BNP (χ2 26.55) was significantly improved by adding LVEF ≤40% (χ2 44.71, P < 0.001), TAPSE ≤ 17 mm (χ2 75.42, P < 0.001) and TAPSE/PASP ≤ 0.49 mm/mmHg (χ2 101.74, P < 0.001) for predicting cardiovascular in-hospital mortality. CONCLUSION: RV-PA uncoupling, assessed by echocardiographic TAPSE/PASP ≤ 0.49 mm/mmHg 24 h after revascularization, may improve risk stratification for cardiovascular in-hospital mortality after first AMI.

Current trends and latest developments in echocardiographic assessment of right ventricular function: load dependency perspective.

Right ventricle (RV) failure is a common complication of many cardiopulmonary diseases. Since it has a significant adverse impact on prognosis, precise determination of RV function is crucial to guide clinical management. However, accurate assessment of RV function remains challenging owing to the difficulties in acquiring its intricate pathophysiology and imaging its complex anatomical structure. In addition, there is historical attention focused exclusively on the left ventricle assessment, which has led to overshadowing and delayed development of RV evaluation. Echocardiography is the first-line and non-invasive bedside clinical tool for assessing RV function. Tricuspid annular plane systolic excursion (TAPSE), RV systolic tissue Doppler velocity of the tricuspid annulus (RV S'), and RV fractional area change (RV FAC) are conventional standard indices routinely used for RV function assessment, but accuracy has been subject to several limitations, such as load-dependency, angle-dependency, and localized regional assessment. Particularly, load dependency is a vexing issue, as the failing RV is always in a complex loading condition, which alters the values of echocardiographic parameters and confuses clinicians. Recently, novel echocardiographic methods for improved RV assessment have been developed. Specifically, "strain", "RV-pulmonary arterial (PA) coupling", and "RV myocardial work" are newly applied methods for RV function assessment, a few of which are designed to surmount the load dependency by taking into account the afterload on RV. In this narrative review, we summarize the latest data on these novel RV echocardiographic parameters and highlight their strengths and limitations. Since load independency is one of the primary advantages of these, we particularly emphasize this aspect.

Right ventricular to pulmonary artery coupling in patients with different types of aortic stenosis undergoing TAVI.

BACKGROUND: Right ventricular (RV) dysfunction in patients undergoing transcatheter aortic valve implantation (TAVI) for aortic stenosis (AS) has long been disregarded. We aimed to assess the predictive value of RV to pulmonary artery coupling (RV/PAc), defined as tricuspid annular plane systolic excursion to systolic pulmonary artery pressure, on mortality in different flow types of AS after TAVI. METHODS: All patients undergoing TAVI for AS at our centre between 2018 and 2020 were assessed; 862 patients were analysed. The cohort was dichotomized using a ROC analysis (cut-off 0.512 mm/mmHg), into 429 patients with preserved and 433 patients with reduced RV/PAc. RESULTS: Reduced RV/PAc was associated with male sex and a higher rate of comorbidities. Short-term VARC-3 endpoints and NYHA classes at follow-up were comparable. Reduced RV/PAc was associated with higher 2-year all-cause mortality (35.0% [30.3-39.3%] vs. 15.4% [11.9-18.7%], hazard ratio 2.5 [1.9-3.4], p < 0.001). Cardiovascular mortality was almost tripled. Results were consistent after statistical adjustment and in a multivariate model. Sub-analyses of AS flow types revealed lower RV/PAc in classical and paradoxical low-flow low-gradient AS, with the majority having reduced RV/PAc (74% and 59%). RV/PAc retained its predictive value in these subgroups. CONCLUSIONS: RV dysfunction defined by low RV/PAc is a strong mortality predictor after TAVI independent of flow group. It should be incorporated in future TAVI risk assessment.

Optimal combination of right ventricular functional parameters using echocardiography in pulmonary arterial hypertension.

AIMS: Novel echocardiographic parameters of right ventricular (RV) function, including speckle-tracking-derived, three-dimensional, and RV-pulmonary artery coupling parameters, have emerged for the evaluation of pulmonary arterial hypertension (PAH). The relative role of these parameters in the risk stratification of PAH patients is unclear. We compared the performance of multiple RV parameters and sought to establish an optimal model for identifying the risk profile of patients with PAH. METHODS AND RESULTS: Comprehensive risk assessments were performed for 70 patients with PAH. The risk profile of every patient was determined based on the guideline recommendations. Conventional parameters, including fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE), novel speckle-tracking-derived RV longitudinal strain (RVLS), and three-dimensional RV ejection fraction (3D-RVEF), were used to evaluate RV function. Pressure-strain loops were measured for the assessment of RV myocardial work, including RV global wasted work (RVGWW). RV-pulmonary artery coupling was assessed by indexing RV parameters to the estimated pulmonary artery systolic pressure (PASP). The median age was 34 (30-43) years, and 62 (88.6%) patients were female. Forty-five patients were classified into the low-risk group, while 25 patients were classified into the intermediate-high-risk group. Most RV parameters could be used to determine the risk profile and exhibited significantly improved diagnostic performance after indexing to PASP (including FAC/PASP, TAPSE/PASP, and 3D-RVEF/PASP). RVLS/PASP showed the best performance, with an area under the curve of 0.895. In multivariate analysis (Model 1), only RVGWW (>90.5 mmHg%), RVLS (> -16.7%), and TAPSE (<17.5 mm) remained significant (all P < 0.05). Model 1 outperformed every single RV parameter, with a significantly larger area under the curve (all P < 0.05). With PASP indexing in Model 2, RVLS/PASP > -0.275 [odds ratio (OR) 20.63, 95% confidence interval (CI) 4.62-92.11, P < 0.001] and RVGWW > 90.5 mmHg% (OR 6.17, 95% CI 1.37-27.76, P = 0.018) independently identified a higher risk profile. The addition of RVGWW to two models determined incremental value in identification (continuous net reclassification improvement 1.058, 95% CI 0.639-1.477, P < 0.001). CONCLUSIONS: The combination models for RV function outperformed any single parameter in identifying the risk profile of patients with PAH. Comprehensive assessment of RV-pulmonary artery coupling using multiparametric methods is clinically meaningful in patients with PAH.

The prognostic impact of right ventricular-pulmonary arterial coupling in heart failure: a systematic review and meta-analysis.

The echocardiographic tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio is a non-invasive surrogate of right ventricular-pulmonary arterial (RV-PA) coupling which corresponds well with the respective invasively derived index. Recently, a wealth of observational data has arisen, outlining its prognostic value in heart failure (HF) patients. To systematically appraise and quantitatively synthesize the evidence of the prognostic value of TAPSE/PASP ratio in left-sided HF regardless of etiology or left ventricular ejection fraction. A systematic literature review was conducted in electronic databases to identify studies reporting the association of TAPSE/PASP ratio with outcomes in patients with HF and, when appropriate, a random-effects meta-analysis was conducted to quantify the unadjusted and adjusted hazard ratios [(a)HRs] for all-cause death and the composite outcome of all-cause death or HF hospitalization. Eighteen studies were deemed eligible encompassing 8,699 HF patients. The applied cut-off value for RV-PA uncoupling varied substantially from 0.27 to 0.58 mm/mmHg, and in most studies values lower than the applied cutoff conveyed dismal prognosis. Eleven studies reported appropriate data for meta-analysis. TAPSE/PASP reduction by 1 mm/mmHg was independently associated with all-cause death (pooled aHR=1.32 [1.06-1.65]; p=0.01; I2=56%) and the composite outcome (pooled aHR=3.48 [1.67-7.25]; p<0.001; I2=0%). When a TAPSE/PASP cutoff value of 0.36 mm/mmHg was applied it yielded independent association with all-cause death (pooled aHR=2.84 [2.22-3.64]; p<0.001; I2=82%). RV-PA coupling assessed by echocardiographic TAPSE/PASP ratio appears to be an independent outcome predictor for HF patients.

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.

Comprehensive echocardiographic assessment of right ventricular function, pulmonary arterial elastic properties and ventricular-vascular coupling in adult patients with repaired tetralogy of fallot: clinical significance of 3D derived indices.

We aimed to comprehensively analyze by three-dimensional speckle-tracking echocardiography (3DSTE) and Doppler echocardiography right ventricular (RV) performance, pulmonary arterial (PA) elastic properties and right ventricular-pulmonary artery coupling (RVPAC) in patients with repaired tetralogy of Fallot (rTOF) and assess the feasibility and clinical utility of related echocardiographic indices. Twenty-four adult patients with rTOF and twenty-four controls were studied. RV end-diastolic volume(3D-RVEDV), RV end-systolic volume(3D-RVESV), RV ejection fraction(3D-RVEF), RV longitudinal strain(3D-RVLS) and RV area strain(3D-RVAS) were calculated by 3DSTE. RV end-systolic area (RVESA) was obtained by planimetry. Pulmonary regurgitation (PR) was assessed as trivial/mild or significant by cardiac magnetic resonance (CMR) and color-Doppler. Pulmonary artery (PA) elastic properties were determined using two-dimensional/Doppler echocardiography. RV systolic pressure (RVSP) was measured using standard Doppler methods. RVPAC was assessed using various 3DSTE-derived parameters (3DRVAS/RVSP, 3DRVLS/RVESA, 3DRVAS/RVESV). Overall, 3DRVEF and 3DRVAS were impaired in rTOF patients compared with controls. PA pulsatility and capacitance were reduced (p = 0.003) and PA elastance was higher (p = 0.0007) compared to controls. PA elastance had a positive correlation with 3DRVEDV (r = 0.64, p = 0.002) and 3DRVAS (r = 0.51, p = 0.02). By ROC (receiver operating characteristics) analysis, 3DRVAS/RVESV, 3DRVAS/RVSP and 3DRVLS/RVESA cutoff values of 0.31%/mmHg, 0.57%/mmHg and 0.86%/mmHg, respectively, had 91%, 88% and 88% sensitivity and 81%, 81% and 79% specificity in identifying exercise capacity impairment. In rTOF patients increased 3DSTE-derived RV volumes and impaired RV ejection fraction and strain are associated with reduced PA pulsatility and capacitance and increased PA elastance. 3DSTE-derived RVPAC parameters using different afterload-markers are accurate indices of exercise capacity.

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.

Clinical significance of right ventricular-pulmonary arterial coupling in patients with tricuspid regurgitation before closure of atrial septal defect.

Background: Functional tricuspid regurgitation (TR) usually decreases after atrial septal defect (ASD) closure; however, it may persist and cause heart failure that requires treatment. We aimed to investigate clinical and echocardiographic factors predicting persistent TR after ASD closure. Methods: Among 348 adults who underwent isolated ASD closure between January 2010 and September 2020, 91 (26.1%) patients with significant TR (at least moderate degree) before ASD closure were included. Persistent TR was defined as significant TR on echocardiography at 6 months to 1 year after ASD correction. We comprehensively analyzed the echocardiogram before ASD closure, including speckle-tracking imaging. Right ventricular (RV)-pulmonary arterial (PA) (RV-PA) coupling was assessed by the ratio of RV global longitudinal strain (RV GLS) and tricuspid annular S' velocity to PA systolic pressure (PASP). Results: Persistent TR was observed in 22 (24.2%) patients. Patients with persistent TR were significantly older and had larger TR jet areas and lower RV-PA coupling parameters than those without persistent TR. On multivariable regression, persistent TR was independently associated with age [odds ratio (OR) 1.07, 95% confidence interval (CI) 1.01-1.14, p = 0.030) and |RV GLS|/PASP (OR 0.001, 95% CI 0.00-0.017, p = 0.012). ROC curves analysis showed that |RV GLS|/PASP's best cut-off for persistent TR was 0.46 (cut-off 0.46, the area under the curve 0.789, p < 0.001). Conclusion: Persistent TR after ASD closure is not rare. Old age and RV-PA uncoupling could be associated with persistent TR after ASD closure. In older patients with abnormal RV-PA coupling, careful evaluation and concomitant or subsequent TR intervention may be considered.

Right ventricular-pulmonary artery coupling in cardiac resynchronization therapy: evolution and prognosis.

AIMS: Chronic pressure overload and right ventricular (RV) dysfunction can lead to RV-pulmonary artery (PA) uncoupling in patients with heart failure. The evolution and prognostic values of RV-PA coupling assessed by echocardiography in patients undergoing cardiac resynchronization therapy (CRT) have not been thoroughly investigated. The aim of this study was to evaluate the evolution and prognostic value of tricuspid annular plane systolic excursion (TAPSE)/pulmonary artery systolic pressure (PASP) ratio in CRT recipients. METHODS AND RESULTS: The RV-PA coupling was measured non-invasively with echocardiography using the TAPSE/PASP ratio at baseline and 6 month follow-up in CRT recipients. The cut-off value for TAPSE/PASP uncoupling was derived from spline curve analysis (i.e. <0.45 mm/mmHg). The primary endpoint was all-cause mortality. A total of 807 patients (age 66 ± 11 years, 76% men) were analysed. During a median follow-up of 97 (54-143) months, 483 (60%) patients died. Survival rates at 3 and 5 year follow-up were significantly lower for patients with a TAPSE/PASP ratio <0.45 mm/mmHg (76% and 58%, respectively), compared with those with a TAPSE/PASP ratio ≥0.45 mm/mmHg (91% and 82%, respectively) (P < 0.001). On multivariable analysis, TAPSE/PASP ratio <0.45 mm/mmHg (hazard ratio 1.437; 95% confidence interval: 1.145-1.805; P = 0.002) was independently associated with all-cause mortality, whereas TAPSE <17 mm (hazard ratio 1.237; 95% confidence interval: 0.990-1.546; P = 0.061) was not. In addition, no improvement of the TAPSE/PASP ratio after CRT implantation was independently associated with worse survival. CONCLUSIONS: The TAPSE/PASP ratio at baseline is independently associated with long-term outcomes in CRT recipients. The baseline TAPSE/PASP ratio has incremental value over TAPSE, which does not take account of RV afterload. A lack of improvement in the TAPSE/PASP ratio after CRT implantation is associated with worse survival.

Three-dimensional right ventriculo-arterial coupling as an independent determinant of severe heart failure symptoms in patients with dilated cardiomyopathy.

BACKGROUND: Right ventricular-pulmonary artery coupling (RVPAC) is a predictor of outcome in pulmonary hypertension. However, the role of this parameter in dilated cardiomyopathy (DCM) remains to be established. The aim of this study was to assess the contribution of RVPAC to the occurrence of severe heart failure (HF) symptoms in patients with DCM using three-dimensional (3D) echocardiography. METHODS: We prospectively screened 139 outpatients with DCM, 105 of whom were enrolled and underwent 3D echocardiographic assessment. RVPAC was estimated non-invasively as the 3D right ventricular stroke volume (SV) to end-systolic volume (ESV) ratio. Severe HF symptoms were defined by New York Heart Association (NYHA) class III or IV. We evaluated differences in RVPAC across NYHA classes and the ability of RVPAC to predict severe symptoms. RESULTS: Mean left ventricular (LV) ejection fraction was 28±7%. Mean RVPAC was 0.77±0.30 and it was significantly more impaired with increasing symptom severity (p = 0.001). RVPAC was the only independent determinant of severe HF symptoms, after adjusting for age, diuretic use, LV systolic function, LV diastolic function, and pulmonary artery systolic pressure (OR 0.035 [95% CI, 0.004-0.312], p = 0.003). By receiver-operating characteristic analysis, the RVPAC cut-off value for predicting severely symptomatic status was 0.54 (area under the curve = 0.712, p < 0.001). CONCLUSION: 3D echocardiographic SV/ESV ratio is an independent correlate of severe HF symptoms in patients with DCM. 3D RVPAC might prove to be a useful risk stratification tool for these patients, should it be further validated in larger studies.

Non-invasive right ventriculo-arterial coupling as a rehospitalization predictor in dilated cardiomyopathy: A comparison of five different methods.

BACKGROUND: Right ventricular (RV) pulmonary artery coupling (RVPAC) is a predictor of outcome in left-sided heart failure (HF). Several echocardiographic estimates for RVPAC have been proposed. AIMS: This study aimed to compare multiple non-invasive methods to calculate RVPAC and to assess its prognostic role in patients with dilated cardiomyopathy (DCM). METHODS: We prospectively enrolled 60 stable patients with DCM. RVPAC was estimated using five methods: as the tricuspid annular plane excursion/pulmonary artery systolic pressure (PASP) ratio; as the RV global longitudinal strain/PASP ratio; as the RV free wall strain (RVFW-LS)/PASP ratio; as the three-dimensional (3D) RV ejection fraction (RVEF)/PASP ratio; and as the 3D RV stroke volume (SV)/end-systolic volume (ESV) ratio. Patients were followed for a mean period of 18 (9) months for the endpoint of HF rehospitalizations. RESULTS: Twenty-nine patients (48%) reached the endpoint. All RVPAC estimates were more impaired in those patients reaching the endpoint (P <0.001 for all) and all predicted rehospitalizations in un-adjusted analysis. RVFW-LS/PASP and RVEF/PASP remained independent predictors of events, after adjustment for clinical and echocardiographic confounders. Using cut-offs obtained from receiver operating characteristic (ROC) analysis, we found that patients with RVFW-LS/PASP >-0.40 and patients with RVEF/PASP <1.30 had a higher risk of HF rehospitalization (log-rank P = 0.001 and P = 0.002, respectively). CONCLUSION: RVFW-LS/PASP and RVEF/PASP as non-invasive estimates of RVPAC are independent predictors of HF rehospitalization in patients with DCM.

Pulmonary pulse wave transit time is associated with right ventricular-pulmonary artery coupling in pulmonary arterial hypertension.

Pulmonary pulse wave transit time (pPTT), defined as the time for the systolic pressure pulse wave to travel from the pulmonary valve to the pulmonary veins, has been reported to be reduced in pulmonary arterial hypertension (PAH); however, the underlying mechanism of reduced pPTT is unknown. Here, we investigate the hypothesis that abbreviated pPTT in PAH results from impaired right ventricular-pulmonary artery (RV-PA) coupling. We quantified pPTT using pulsed-wave Doppler ultrasound from 10 healthy age- and sex-matched controls and 36 patients with PAH. pPTT was reduced in patients with PAH compared with controls. Univariate analysis revealed the following significant predictors of reduced pPTT: age, right ventricular fractional area change (RV FAC), tricuspid annular plane excursion (TAPSE), pulmonary arterial pressures (PAP), diastolic pulmonary gradient, transpulmonary gradient, pulmonary vascular resistance, and RV-PA coupling (defined as RV FAC/mean PAP or TAPSE/mean PAP). Although the correlations between pPTT and invasive markers of pulmonary vascular disease were modest, RV FAC (r = 0.64, P < 0.0001), TAPSE (r = 0.67, P < 0.0001), and RV-PA coupling (RV FAC/mean PAP: r = 0.72, P < 0.0001; TAPSE/mean PAP: r = 0.74, P < 0.0001) had the strongest relationships with pPTT. On multivariable analysis, only RV FAC, TAPSE, and RV-PA coupling were independent predictors of pPTT. We conclude that shortening of pPTT in patients with PAH results from altered RV-PA coupling, probably occurring as a result of reduced pulmonary arterial compliance. Thus, pPTT allows noninvasive determination of the status of both the pulmonary vasculature and the response of the RV in patients with PAH, thereby allowing monitoring of disease progression and regression.