Analyses of longitudinal and of transverse right ventricular function provide different clinical information in patients with pulmonary hypertension

Clinical and functional relevance of right ventricular contraction patterns in pulmonary hypertension

BACKGROUND

The right ventricle has a complex contraction pattern of uncertain clinical relevance. We aimed to assess the relationship between right ventricular (RV) contraction pattern and RV-pulmonary arterial (PA) coupling defined by the gold-standard pressure-volume loop-derived ratio of end-systolic/arterial elastance (Ees/Ea).

METHODS

Prospectively enrolled patients with suspected or confirmed pulmonary hypertension underwent three-dimensional echocardiography, standard right heart catheterization, and RV conductance catheterization. RV-PA uncoupling was categorized as severe (Ees/Ea < 0.8), moderate (Ees/Ea 0.8-1.29), and none/mild (Ees/Ea ≥ 1.3). Clinical severity was determined from hemodynamics using a truncated version of the 2022 European Society of Cardiology/European Respiratory Society risk stratification scheme.

RESULTS

Fifty-three patients were included, 23 with no/mild, 24 with moderate, and 6 with severe uncoupling. Longitudinal shortening was decreased in patients with moderate vs no/mild uncoupling (p <0.001) and intermediate vs low hemodynamic risk (p < 0.001), discriminating low risk from intermediate/high risk with an optimal threshold of 18% (sensitivity 80%, specificity 87%). Anteroposterior shortening was impaired in patients with severe vs moderate uncoupling (p = 0.033), low vs intermediate risk (p = 0.018), and high vs intermediate risk (p = 0.010), discriminating high risk from intermediate/low risk with an optimal threshold of 15% (sensitivity 100%, specificity 83%). Left ventricular (LV) end-diastolic volume was decreased in patients with severe uncoupling (p = 0.035 vs no/mild uncoupling).

CONCLUSIONS

Early RV-PA uncoupling is associated with reduced longitudinal function, whereas advanced RV-PA uncoupling is associated with reduced anteroposterior movement and LV preload, all in a risk-related fashion.

CLINICALTRIALS

GOV: NCT04663217.

IMproving PULmonary hypertension Screening by Echocardiography: IMPULSE

BACKGROUND

The world symposium on pulmonary hypertension (PH) has proposed that PH be defined as a mean pulmonary artery pressure (mPAP) > 20 mmHg as assessed by right heart catheterisation (RHC). Transthoracic echocardiography (TTE) is an established screening tool used for suspected PH. International guidelines recommend a multi-parameter assessment of the TTE PH probability although effectiveness has not been established using real world data.

STUDY AIMS

To determine accuracy of the European Society of Cardiology (ESC) and British Society of Echocardiography (BSE) TTE probability algorithm in detecting PH in patients attending a UK PH centre. To identify echocardiographic markers and revised algorithms to improve the detection of PH in those with low/intermediate BSE/ESC TTE PH probability.

METHODS

TTE followed by RHC (within 4 months after) was undertaken in patients for suspected but previously unconfirmed PH. BSE/ESC PH TTE probabilities were calculated alongside additional markers of right ventricular (RV) longitudinal and radial function, and RV diastolic function. A refined IMPULSE algorithm was devised and evaluated in patients with low and/or intermediate ESC/BSE TTE PH probability.

RESULTS

Of 310 patients assessed, 236 (76%) had RHC-confirmed PH (average mPAP 42.8 ± 11.7). Sensitivity and specificity for detecting PH using the BSE/ESC recommendations was 89% and 68%, respectively. 36% of those with low BSE/ESC TTE probability had RHC-confirmed PH and BSE/ESC PH probability parameters did not differ amongst those with and without PH in the low probability group. Conversely, RV free wall longitudinal strain (RVFWLS) was lower in patients with vs. without PH in low BSE/ESC probability group (- 20.6 ± 4.1% vs - 23.8 ± 3.9%) (P < 0.02). Incorporating RVFWLS and TTE features of RV radial and diastolic function (RVFAC and IVRT) within the IMPULSE algorithm reduced false negatives in patients with low BSE/ESC PH probability by 29%. The IMPULSE algorithm had excellent specificity and positive predictive value in those with low (93%/80%, respectively) or intermediate (82%/86%, respectively) PH probability.

CONCLUSION

Existing TTE PH probability guidelines lack sensitivity to detect patients with milder haemodynamic forms of PH. Combining additional TTE makers assessing RV radial, longitudinal and diastolic function enhance identification of milder forms of PH, particularly in those who have a low BSE/ESC TTE PH probability.

Dobutamine stress echocardiography in pulmonary arterial hypertension

BACKGROUND

There is a growing interest in exploring the concept of right ventricular functional reserve in patients with pulmonary arterial hypertension. However, it is still unclear how it should be assessed. Aim of the study was to investigate the determinants of the changes in cardiac output and in pulmonary pressure during dobutamine stress echocardiography in pulmonary arterial hypertension.

METHODS

Low-dose dobutamine stress echocardiography was performed in 55 patients and 28 controls. Tricuspid annular plane systolic excursion, its ratio to systolic pulmonary artery pressure, right ventricular area change, degree of tricuspid regurgitation, right ventricular end-systolic pressure-area ratio, cardiac output were assessed at rest and at peak stress.

RESULTS

According to the stress induced increase in cardiac output, patients were classified into 2 groups: above/equal to the median of 2.8 L/min (high cardiac output) or below the median (low cardiac output). High cardiac output patients were characterized by a greater increase in heart rate (+45.1 ± 17.5 vs +21.3 ± 17.7 bpm), a greater improvement in tricuspid annular plane systolic excursion (+4.2 ± 3.3 vs +1.9 ± 2.6 mm, P = 0.005) and a decrease in tricuspid regurgitation (P = 0.010) as compared to low cardiac output patients. Changes in pulmonary pressure were not associated with changes in indicators of right ventricular function but only with changes in heart rate.

CONCLUSIONS

The increase in cardiac output during dobutamine is associated with an improvement in longitudinal right ventricular function, a decrease in tricuspid regurgitation and an increase in heart rate. Changes in pulmonary pressure only reflect the changes in heart rate.

Right heart dysfunction and failure in heart failure with preserved ejection fraction: mechanisms and management. Position statement on behalf of the Heart Failure Association of the European Society of Cardiology

There is an unmet need for effective treatment strategies to reduce morbidity and mortality in patients with heart failure with preserved ejection fraction (HFpEF). Until recently, attention in patients with HFpEF was almost exclusively focused on the left side. However, it is now increasingly recognized that right heart dysfunction is common and contributes importantly to poor prognosis in HFpEF. More insights into the development of right heart dysfunction in HFpEF may aid to our knowledge about this complex disease and may eventually lead to better treatments to improve outcomes in these patients. In this position paper from the Heart Failure Association of the European Society of Cardiology, the Committee on Heart Failure with Preserved Ejection Fraction reviews the prevalence, diagnosis, and pathophysiology of right heart dysfunction and failure in patients with HFpEF. Finally, potential treatment strategies, important knowledge gaps and future directions regarding the right side in HFpEF are discussed.

Pulmonary hypertension attenuates the dynamic preload indicators increase during experimental hypovolemia

Background

Pulse pressure (PPV) and stroke volume (SVV) variations may not be reliable in the setting of pulmonary hypertension and/or right ventricular (RV) failure. We hypothesized that RV afterload increase attenuates SVV and PPV during hypovolemia in a rabbit model of pulmonary embolism (PE) secondary to RV dysfunction.

Methods

Seven anesthetized and mechanically ventilated rabbits were studied during four experimental conditions: normovolemia, blood withdrawal, pulmonary embolism and fluid loading of a colloidal solution. Central venous, RV and left ventricular (LV) pressures, and infra-diaphragmatic aortic blood flow (AoF) and pressure were measured. SV was estimated by the integral of systolic AoF. We analyzed RV and LV function through stroke work output curves. PPV and SVV were obtained by the variation of beat-to-beat PP and SV, respectively. We assessed RV and LV diastolic and systolic function by the time rate of relaxation (tau) and the ratio of the first derivative of ventricular pressure and the highest isovolumic developed pressure (dP/dt/DP), respectively. The vasomotor tone was estimated by the dynamic arterial elastance (Ea_dyn = PPV/SVV).

Results

PPV and SVV increased significantly during hemorrhage and returned to baseline values after PE which was associated to biventricular right-downward of the stroke work curves and a decrease of AoF and SV (P < 0.05). RV systo-diastolic function and LV systolic function were impaired. All the animals were nonresponders after volume expansion. Ea_dyn did not show any significant change during the different experimental conditions.

Conclusions

The dynamic preload indicators (SVV and PPV) were significantly reduced after a normotensive PE in hypovolemic animals, mainly by the systo-diastolic dysfunction of the RV associated with LV systolic impairment, which makes the animals nonresponsive to volume loading. This normalization of dynamic preload indices may prevent the detrimental consequence of fluid loading.

Pulmonary Hypertension and Indicators of Right Ventricular Function

Pulmonary hypertension (PH) is a rare disease, whose underlying mechanisms are not fully understood. It is characterized by pulmonary arterial vasoconstriction and vessels wall thickening, mainly intimal and medial layers. Several molecular pathways have been studied, but their respective roles remain unknown. Cardiac repercussions of PH are hypertrophy, dilation, and progressive right ventricular dysfunction. Multiple echocardiographic parameters are being used, in order to assess anatomy and cardiac function, but there are no guidelines edited about their usefulness. Thus, it is now recommended to associate the best-known parameters, such as atrial and ventricular diameters or tricuspid annular plane systolic excursion. Cardiac catheterization remains necessary to establish the diagnosis of PH and to assess pulmonary hemodynamic state. Concerning energetic metabolism, free fatty acids, normally used to provide energy for myocardial contraction, are replaced by glucose uptake. These abnormalities are illustrated by increased (18)F-fluorodeoxyglucose ((18)F-FDG) uptake on positron emission tomography/computed tomography, which seems to be correlated with echocardiographic and hemodynamic parameters.

Longitudinal and transverse right ventricular function in pulmonary hypertension: cardiovascular magnetic resonance imaging study from the ASPIRE registry

Right ventricular (RV) function is a strong predictor of outcome in cardiovascular diseases. Two components of RV function, longitudinal and transverse motion, have been investigated in pulmonary hypertension (PH). However, their individual clinical significance remains uncertain. The aim of this study was to determine the factors associated with transverse and longitudinal RV motion in patients with PH. In 149 treatment-naive patients with PH and 16 patients with suspected PH found to have mean pulmonary arterial pressure of <20 mmHg, cardiovascular magnetic resonance imaging was performed within 24 hours of right heart catheterization. In patients with PH, fractional longitudinal motion (fractional tricuspid annulus to apex distance [f-TAAD]) was significantly greater than fractional transverse motion (fractional septum to free wall distance [f-SFD]; P = 0.002). In patients without PH, no significant difference between f-SFD and f-TAAD was identified (P = 0.442). Longitudinal RV motion was singularly associated with RV ejection fraction independent of age, invasive hemodynamics, and cardiac magnetic resonance measurements (P = 0.024). In contrast, transverse RV motion was independently associated with left ventricular eccentricity (P = 0.036) in addition to RV ejection fraction (P = 0.014). In conclusion, RV motion is significantly greater in the longitudinal direction in patients with PH, whereas patients without PH have equal contributions of transverse and longitudinal motion. Longitudinal RV motion is primarily associated with global RV pump function in PH. Transverse RV motion not only reflects global pump function but is independently influenced by ventricular interaction in patients with PH.

Low cardiac index is associated with incident dementia and Alzheimer disease: the Framingham Heart Study

BACKGROUND

Cross-sectional epidemiological and clinical research suggests that lower cardiac index is associated with abnormal brain aging, including smaller brain volumes, increased white matter hyperintensities, and worse cognitive performances. Lower systemic blood flow may have implications for dementia among older adults.

METHODS AND RESULTS

A total of 1039 Framingham Offspring Cohort participants free of clinical stroke, transient ischemic attack, and dementia formed our sample (age, 69±6 years; 53% women). Multivariable-adjusted proportional hazard models adjusting for Framingham Stroke Risk Profile score (age, sex, systolic blood pressure, antihypertensive medication, diabetes mellitus, cigarette smoking, cardiovascular disease history, atrial fibrillation), education, and apolipoprotein E4 status related cardiac magnetic resonance imaging-assessed cardiac index (cardiac output divided by body surface area) to incident all-cause dementia and Alzheimer disease (AD). Over the median 7.7-year follow-up period, 32 participants developed dementia, including 26 cases of AD. Each 1-SD unit decrease in cardiac index increased the relative risk of both dementia (hazard ratio [HR]=1.66; 95% confidence interval [CI], 1.11-2.47; P=0.013) and AD (HR=1.65; 95% CI, 1.07-2.54; P=0.022). Compared with individuals with normal cardiac index, individuals with clinically low cardiac index had a higher relative risk of dementia (HR=2.07; 95% CI, 1.02-4.19; P=0.044). If participants with clinically prevalent cardiovascular disease and atrial fibrillation were excluded (n=184), individuals with clinically low cardiac index had a higher relative risk of both dementia (HR=2.92; 95% CI, 1.34-6.36; P=0.007) and AD (HR=2.87; 95% CI, 1.21-6.80; P=0.016) compared with individuals with normal cardiac index.

CONCLUSION

Lower cardiac index is associated with an increased risk for the development of dementia and AD.