Evaluation of thyroid congestion in patients with heart failure using shear wave elastography: An observational study

Shear wave elastography (SWE) is a noninvasive method for measuring organ stiffness. Liver stiffness measured using SWE reflects hepatic congestion in patients with heart failure (HF). However, little is known about the use of SWE to assess other organ congestions. This study aimed to evaluate the utility of SWE for assessing not only the liver but also thyroid congestion in patients with HF. This prospective study included 21 patients with HF who have normal thyroid lobes (age: 77.0 ± 11.0, men: 14). Thyroid and liver stiffness were measured by SWE using the ARIETTA 850 ultrasonography system (Fujifilm Ltd., Tokyo, Japan). SWE of the thyroid was performed on B-mode ultrasonography; a target region was identified within a region of interest. SWE was performed in each lobe of the thyroid gland. Five measurements were taken at the same location and the averages were recorded for comparison. We investigated the relationship between SWE for evaluating thyroid stiffness and the clinical characteristics of patients with HF. SWE of the thyroid was significantly correlated with SWE of the liver (R = 0.768, P < .001), thyroid stimulation hormone (R = 0.570, P = .011), free thyroxine (R = 0.493, P = .032), estimated right atrial pressure (RAP; R = 0.468, P = .033), and composite congestion score (R = 0.441, P = .045). SWE may be useful for evaluating thyroid stiffness and assessing the degree of thyroid congestion. Thyroid congestion may reflect the elevation of RAP and cause thyroid dysfunction through organ congestion.

Positive correlation between echocardiographic tricuspid E peak velocity and central venous pressure in dogs: A preliminary study

In the absence of vascular obstruction, central venous pressure (CVP) is a hydrostatic pressure in the cranial and caudal vena cava, providing valuable information about cardiac function and intravascular volume status. It is also a component in evaluating volume resuscitation in patients with septic shock and monitoring patients with right heart disease, pericardial disease, or volume depletion. Central venous pressure is calculated in dogs by invasive central venous catheterization, which is considered high-risk and impractical in critically ill patients. This study aimed to investigate the feasibility of using echocardiographic tricuspid E/E' as a noninvasive method to estimate CVP in anesthetized healthy dogs under controlled hypovolemic conditions. Ten male mixed-breed dogs were included in the study after a thorough health assessment. For hypovolemia induction, blood withdrawal was performed, and echocardiographic factors of the tricuspid valve, including peak E and E' velocities, were measured during CVP reduction. Repeated measures analysis of variance and Bonferroni post hoc tests were employed to compare the average difference between measured echocardiographic indices and CVP values derived from catheterization and intermittent measurement methods. Spearman's ρ correlation coefficient was used to evaluate the correlation between echocardiographic indices and CVP. E peak velocity had a significant negative correlation with venous blood pressure phases (r = -0.44, P = .001), indicating a decrease in peak E velocity with progressive CVP reduction. However, tricuspid valve E' peak velocity and E/E' did not correlate with CVP, suggesting that these parameters are not reliable for CVP estimation in dogs.

Prognostic Implication of Right Ventricular Free Wall Longitudinal Strain and Right Atrial Pressure Estimated By Echocardiography in Patients With Severe Functional Tricuspid Regurgitation

BACKGROUND

The interaction between right ventricular (RV) function and pulmonary hypertension is crucial for prognosis of patients with severe functional tricuspid regurgitation. RV free wall longitudinal strain (RVFWLS) has been reported to detect RV systolic dysfunction earlier than other conventional parameters. Although pulmonary artery systolic pressure measured by Doppler echocardiography is often underestimated in severe functional tricuspid regurgitation, right atrial pressure (RAP) estimated by echocardiography may be viewed as a prognostic factor. Impact of RAP and RVFWLS on outcome in patients with severe functional tricuspid regurgitation remains unclear. The aim of the present study was to investigate prognostic implication of RAP, RVFWLS, and their combination in this population.

METHODS AND RESULTS

We retrospectively examined 377 patients with severe functional tricuspid regurgitation. RAP, pulmonary artery systolic pressure, RV fractional area change, and RVFWLS were analyzed. RAP of 15 mm Hg was classified as elevated RAP. All-cause death at 2-year follow-up was defined as the primary end point. RVFWLS provided better prognostic information than RV fractional area change by receiver operating characteristic curve analysis. In the multivariable Cox regression analysis, elevated RAP and RVFWLS of ≤18% were independent predictors of clinical outcome. Patients with RVFWLS of ≤18% had higher risk of all-cause death than those without by Kaplan-Meier curve analysis. Furthermore, when patients were stratified into 4 groups by RAP and RVFWLS, the group with elevated RAP and RVFWLS of ≤18% had the worst outcome.

CONCLUSIONS

Elevated RAP and RVFWLS of ≤18% were independent predictors of all-cause death. The combination of elevated RAP and RVFWLS effectively stratified the all-cause death.

Right Heart Adaptation to Exercise in Pulmonary Hypertension: An Invasive Hemodynamic Study

BACKGROUND

Right heart failure (RHF) is associated with a dismal prognosis in patients with pulmonary hypertension (PH). Exercise right heart catheterization may unmask right heart maladaptation as a sign of RHF. We sought to (1) define the normal limits of right atrial pressure (RAP) increase during exercise; (2) describe the right heart adaptation to exercise in PH owing to heart failure with preserved ejection fraction (PH-HFpEF) and in pulmonary arterial hypertension (PAH); and (3) identify the factors associated with right heart maladaptation during exercise.

METHODS AND RESULTS

We analyzed rest and exercise right heart catheterization from patients with PH-HFpEF and PAH. Right heart adaptation was described by absolute or cardiac output (CO)-normalized changes of RAP during exercise. Individuals with noncardiac dyspnea (NCD) served to define abnormal RAP responses (>97.5th percentile). Thirty patients with PH-HFpEF, 30 patients with PAH, and 21 patients with NCD were included. PH-HFpEF were older than PAH, with more cardiovascular comorbidities, and a higher prevalence of severe tricuspid regurgitation (P < .05). The upper limit of normal for peak RAP and RAP/CO slope in NCD were >12 mm Hg and ≥1.30 mm Hg/L/min, respectively. PH-HFpEF had higher peak RAP and RAP/CO slope than PAH (20 mm Hg [16-24 mm Hg] vs 12 mm Hg [9-19 mm Hg] and 3.47 mm Hg/L/min [2.02-6.19 mm Hg/L/min] vs 1.90 mm Hg/L/min [1.01-4.29 mm Hg/L/min], P < .05). A higher proportion of PH-HFpEF had RAP/CO slope and peak RAP above normal (P < .001). Estimated stressed blood volume at peak exercise was higher in PH-HFpEF than PAH (P < .05). In the whole PH cohort, the RAP/CO slope was associated with age, the rate of increase in estimated stressed blood volume during exercise, severe tricuspid regurgitation, and right atrial dilation.

CONCLUSIONS

Patients with PH-HFpEF display a steeper increase of RAP during exercise than those with PAH. Preload-mediated mechanisms may play a role in the development of exercise-induced RHF.

Prognostic Value of Respiratory Variation in Right Atrial Pressure in Patients With Precapillary Pulmonary Hypertension

BACKGROUND

Precapillary pulmonary hypertension is characterized by elevated mean pulmonary artery pressure from increased pulmonary vascular resistance. Lack of respiratory variation in right atrial pressure can be viewed as a surrogate for severe pulmonary hypertension and inability of the right ventricle to tolerate preload augmentation during inspiration.

RESEARCH QUESTION

Is the lack of respiratory variation in right atrial pressure predictive of right ventricular dysfunction and worse clinical outcomes in precapillary pulmonary hypertension?

STUDY DESIGN AND METHODS

We retrospectively reviewed right atrial pressure tracings of patients with precapillary pulmonary hypertension who underwent right heart catheterization. Patients with respiratory variation in right atrial pressure (end expiratory-end inspiratory) ≤ 2 mm Hg were considered to have effectively no meaningful variation in right atrial pressure.

RESULTS

Lack of respiratory variation in right atrial pressure was associated with lower cardiac index by indirect Fick (2.34 ± 0.09 vs 2.76 ± 0.1 L/min/m2; P = .001), lower pulmonary artery saturation (60% ± 1.02% vs 64% ± 1.15%; P = .007), higher pulmonary vascular resistance (8.9 ± 0.44 vs 6.1 ± 0.49 Wood units, P < .0001), right ventricular dysfunction on echocardiography (87.3% vs 38.8%; P < .0001), higher pro brain natriuretic peptide (2,163 ± 2,997 vs 633 ± 402 ng/mL; P < .0001), and more hospitalizations within 1 year for right ventricular failure (65.4% vs 29.6%; P < .0001). There was also a trend toward higher mortality at 1 year in patients with no respiratory variation in right atrial pressure (25.4% vs 11.1%; P = .06).

INTERPRETATION

Lack of respiratory variation in right atrial pressure is associated with poor clinical outcomes, adverse hemodynamic parameters, and right ventricular dysfunction in patients with precapillary pulmonary hypertension. Larger studies are needed to further evaluate its utility in prognosis and potential risk stratification in patients with precapillary pulmonary hypertension.

Effectiveness of 2-dimensional shear wave elastography for noninvasive and reliable estimation of right atrial pressure in dogs with induced volume overload

BACKGROUND

Two-dimensional shear wave elastography (2D-SWE) provides information on hepatic elastic modulus as shear wave velocity (SWV).

HYPOTHESIS/OBJECTIVES

To assess SWV using 2D-SWE in dogs with induced volume overload, investigate the relationship between this information and right atrial pressure (RAP) measured by invasive right heart catheterization, and also evaluate the difference in SWV before and after diuretic administration.

ANIMALS

Six healthy beagles.

METHODS

Prospective experimental study. Right heart catheterization and 2D-SWE were performed in 6 anesthetized beagles at baseline and after the induction of volume overload. Volume overload was induced by IV hydroxyethyl starch 70/0.5 infusion (100 mL/kg/h). Furosemide (4-6 mg/kg, IV) was administered, and the SWVs were measured.

RESULTS

Shear wave velocity showed a significant gradual increase during acute volume overload compared to baseline. SWV was significantly positively correlated with RAP (P < .0001, ρ = 0.9729). The area under the curve of SWV to predict RAP at >10, >15, and >20 mm Hg was 0.9896 (95% confidence interval [95% CI], 0.9690-1.000), 0.9907 (95% CI, 0.9701-1.000), and 0.9722 (95% CI, 0.9280-1.000), respectively. The SWV after diuretic use decreased significantly.

CONCLUSIONS AND CLINICAL IMPORTANCE

Two-dimensional shear wave elastography might be useful for noninvasive and reliable estimation of RAP in dogs with acute volume overload and has potential as a quantitative biomarker for evaluating therapeutic response in dogs with right sided congestive heart failure.

Estimated glomerular filtration rate, haemodynamics, and mortality in patients with aortic stenosis

BACKGROUND

In aortic stenosis (AS), estimated glomerular filtration rate (eGFR) is an important prognostic marker but its haemodynamic determinants are unknown. We investigated the correlation between eGFR and invasive haemodynamics and long-term mortality in AS patients undergoing aortic valve replacement (AVR).

METHODS

We studied 503 patients [median (interquartile range) age 76 (69-81) years] with AS [indexed aortic valve area .42 (.33-.49) cm² /m² ] undergoing cardiac catheterization prior to surgical (72%) or transcatheter (28%) AVR. Serum creatinine was measured on the day before cardiac catheterization for eGFR calculation (CKD-EPI formula).

RESULTS

The median eGFR was 67 (53-82) mL/min/1.73 m² . There were statistically significant correlations between eGFR and mean right atrial pressure (r = -.13; p = .004), mean pulmonary artery pressure (mPAP; r = -.25; p < .001), mean pulmonary artery wedge pressure (r = -.19; p < .001), pulmonary vascular resistance (r = -.21; p < .001), stroke volume index (r = .16; p < .001), extent of coronary artery disease, and mean transvalvular gradient but not indexed aortic valve area. In multivariate linear regression, higher age, lower haemoglobin, lower mean transvalvular gradient (i.e. lower flow), lower diastolic blood pressure, and higher mPAP were independent predictors of lower eGFR. After a median post-AVR follow-up of 1348 (948-1885) days mortality was more than two-fold higher in patients in the first eGFR quartile compared to those in the other three quartiles [hazard ratio 2.18 (95% confidence interval 1.21-3.94); p = .01].

CONCLUSION

In patients with AS, low eGFR is a marker of an unfavourable haemodynamic constellation as well as important co-morbidities. This may in part explain the association between low eGFR and increased post-AVR mortality.

The Frog Sign Revisited

The frog sign is a classic physical examination finding of typical atrioventricular nodal re-entrant tachycardia. We present the case of a 78-year-old man with recurrent, symptomatic supraventricular tachycardia referred for ablation in whom the frog sign was observed during physical examination.

Vascular function curve: confusion, clarification and new insights

The vascular function curve (VFC) in cardiovascular physiology describes the relationship between the steady state venous return (VR in L/min, in the Y-axis) and the steady state right atrial pressure (RAP in mmHg, in the X-axis). However, in some literature, the RAP is considered the independent variable (IV) and the VR the dependent variable (DV), whereas in other literature, the VR is the IV and the RAP the DV. Because of this confusion, when the VFC is combined with the cardiac function curve (CFC), which describes the relationship between the steady state cardiac output and the RAP, it is not strange that the interpretations of the combination are problematic. Hence, in this article, we will trace the origin of the inconsistency, differentiate the VFC into two types based on who created them, and differentiate the RAP into RAP as the IV and DV respectively. Through these in-depth analyses, the confusion will be clarified and new insights into the combination of a VFC with the CFC will develop.

Non-Invasive Estimation of Right Atrial Pressure Using a Semi-Automated Echocardiographic Tool for Inferior Vena Cava Edge-Tracking

The non-invasive estimation of right atrial pressure (RAP) would be a key advancement in several clinical scenarios, in which the knowledge of central venous filling pressure is vital for patients’ management. The echocardiographic estimation of RAP proposed by Guidelines, based on inferior vena cava (IVC) size and respirophasic collapsibility, is exposed to operator and patient dependent variability. We propose novel methods, based on semi-automated edge-tracking of IVC size and cardiac collapsibility (cardiac caval index—CCI), tested in a monocentric retrospective cohort of patients undergoing echocardiography and right heart catheterization (RHC) within 24 h in condition of clinical and therapeutic stability (170 patients, age 64 ± 14, male 45%, with pulmonary arterial hypertension, heart failure, valvular heart disease, dyspnea, or other pathologies). IVC size and CCI were integrated with other standard echocardiographic features, selected by backward feature selection and included in a linear model (LM) and a support vector machine (SVM), which were cross-validated. Three RAP classes (low < 5 mmHg, intermediate 5−10 mmHg and high > 10 mmHg) were generated and RHC values used as comparator. LM and SVM showed a higher accuracy than Guidelines (63%, 71%, and 61% for LM, SVM, and Guidelines, respectively), promoting the integration of IVC and echocardiographic features for an improved non-invasive estimation of RAP.

Accuracy of echocardiographic estimations of right heart pressures in adult heart transplant recipients

BACKGROUND

Accurate assessment of right atrial pressure (RAP) and pulmonary artery systolic pressure (PASP) is critical in the management of heart transplant recipients. The accuracy of echocardiography in estimating these pressures has been debated.

OBJECTIVE

To assess the correlation and agreement between echocardiographic estimations of right heart pressures with those of respective invasive hemodynamic measurements by right heart catheterization (RHC) in adult heart transplant recipients.

METHODS

This is a prospective evaluation of 84 unique measurements from heart transplant recipients who underwent RHC followed by standard echocardiographic evaluation within 159 ± 64 min with no intervening medication changes. The relationship between noninvasive pressure estimations and invasive hemodynamic measurements was examined.

RESULTS

Mean RAP was 7 ± 5 mmHg and mean PASP was 33 ± 8 mmHg by RHC. There was no significant correlation between echocardiographic estimation of RAP and invasive RAP (Spearman's rho = -0.05, p = .7), and no significant agreement between these two variables (weighted kappa = -0.1). There was a modest correlation between echocardiographic estimation of PASP and invasive PASP (r = .39, p = .002). Bland-Altman analysis showed a mean bias of 2.1 ± 9 mmHg (limits of agreement = -15 to 20 mmHg).

CONCLUSION

In heart transplant recipients, there is no significant correlation or agreement between echocardiographic RAP estimation and invasively determined RAP. Noninvasive PASP estimation correlates significantly but modestly with invasively measured PASP. Further refinement of echocardiographic methods for assessment of RAP is warranted in this unique patient population.

Clinical utility of superior vena cava flow velocity waveform measured from the subcostal window for estimating right atrial pressure1

BACKGROUND

Superior vena cava (SVC) flow velocity waveform from the supraclavicular window reflects the right atrial pressure (RAP) status. Recent guidelines have stated that the subcostal window is an alternative view for recording SVC flow, but the validity of this approach remains unclear. This study aimed to determine the usefulness of SVC flow evaluation from the subcostal window for estimating RAP.

METHODS

Differences in SVC flow characteristics between opposite approaches were examined in 38 healthy adults. In 115 patients with cardiovascular diseases who underwent cardiac catheterization and echocardiography within 48 h, the ratio of peak systolic to diastolic forward SVC flows was measured (SVC-S/D), and the diagnostic ability of SVC-S/D for elevated RAP was tested. A validation cohort was conducted to confirm the diagnostic ability of SVC-S/D in 48 patients who underwent both cardiac catheterization and echocardiography within 24 h. In 59 patients of derivation and validation cohorts, the relationship between SVC flow and RAP was compared between the opposite windows.

RESULTS

Both systolic and diastolic SVC flow velocities were higher in the subcostal than in the supraclavicular approach, and effect of position change on the subcostal SVC-S/D was smaller than that on the supraclavicular SVC-S/D in healthy adults. Measurement of SVC-S/D from the subcostal window was feasible in 98 patients (85%). RAP was inversely correlated with SVC-S/D (r=-0.50, P<.001), and was an independent determinant of SVC-S/D after the adjustment for right ventricular systolic function (β=-0.48, P<.001). A cutoff value of 1.9 for SVC-S/D showed 85% sensitivity and 74% specificity in identifying elevated RAP. Additionally, SVC-S/D showed an incremental diagnostic value combined with inferior vena cava size and collapsibility (P=.006). When the cutoff value, SVC-S/D<1.9, was applied to the validation cohort, it showed an acceptable accuracy of 72%, and an incremental diagnostic value combined with inferior vena cava parameters (P=.033). SVC-S/D from the subcostal window correlated better with RAP than that from the supraclavicular window (P<.001, Meng's test).

CONCLUSIONS

Measurement of SVC flow velocity from the subcostal window was feasible, and SVC-S/D from the subcostal window could be an additive parameter for estimating RAP.

Inferior Vena Cava Edge Tracking Echocardiography: A Promising Tool with Applications in Multiple Clinical Settings

Ultrasound (US)-based measurements of the inferior vena cava (IVC) diameter are widely used to estimate right atrial pressure (RAP) in a variety of clinical settings. However, the correlation with invasively measured RAP along with the reproducibility of US-based IVC measurements is modest at best. In the present manuscript, we discuss the limitations of the current technique to estimate RAP through IVC US assessment and present a new promising tool developed by our research group, the automated IVC edge-to-edge tracking system, which has the potential to improve RAP assessment by transforming the current categorical classification (low, normal, high RAP) in a continuous and precise RAP estimation technique. Finally, we critically evaluate all the clinical settings in which this new tool could improve current practice.

Continuous atrial pressure monitoring via steerable guide catheter in transcatheter mitral and tricuspid edge-to-edge repair

Transcatheter edge-to-edge repair (TEER) has emerged to address severe mitral and tricuspid valve regurgitation in patients who are at high perioperative risk for open-heart surgery. No clinical data is available for continuous left and right atrial pressure monitoring using the steerable guiding catheter (SGC) during TEER. In a prospective single-center study, 40 patients with severe mitral (n = 20) or tricuspid (n = 20) regurgitation underwent TEER with the registration of atrial pressure via the SGC. All patients had successful TEER using the PASCAL Ace repair system, while atrial pressure was monitored continuously via the SGC. Simultaneous right or left atrial pressure monitoring via the SGC and a pigtail catheter during mitral and tricuspid TEER showed excellent reliability for SGC pressure registration. While for mitral TEER the beneficial effects of continuous atrial pressure monitoring are well known, we further evaluated the outcome of patients with tricuspid TEER. Echocardiographic and clinical results after tricuspid TEER showed a reduction of quantitative echocardiographic tricuspid regurgitation parameters and improved New York Heart Association classification after 3-month follow-up. Also, qualitative tricuspid valve assessment showed improved tricuspid regurgitation classification postimplantation and at 3-month follow-up. Furthermore, right atrial pressure was reduced by 37.6% and mean right atrial pressure by 30.6% after successful tricuspid TEER using the PASCAL Ace device. Continuous atrial pressure monitoring using the SGC of the PASCAL Ace repair system is reliable during mitral and tricuspid TEER. Furthermore, successful tricuspid TEER leads to reduced right atrial pressure.

Coronary sinus collapsibility index and inferior vena cava collapsibility index can predict right atrial pressure in patients undergoing right heart catheterization

BACKGROUND

The aim of the study is to investigate the relationship between the diameters and collapsibility indices of coronary sinus (CS) and inferior vena cava (IVC) and invasively measured right atrial pressure (RAP), and to determine whether these parameters have predictive value on RAP.

METHODS

A total of 136 patients undergoing right heart catheterization due to pulmonary arterial hypertension were included in the study prospectively. CS diameters, IVC diameters, CS collapsibility index (CSCI), and IVC collapsibility index (IVCCI) were measured by echocardiography before catheterization. Pearson correlation analysis was used to compare the parameters. Receiver operating characteristics (ROC) curve analysis was used to determine the predictive value of the CS and IVC collapsibility indices in predicting RAP.

RESULTS

Patients were divided into two groups as invasively measured RAP≥10 mm Hg (n:57) and RAP < 10 mm Hg (n:79). In the group with RAP≥10 mm Hg, IVC and CS diameters were higher than in the group with RAP < 10 mm Hg, while the IVCCI and CSCI were lower (p < 0.001). A negative correlation was observed between CSCI and IVCCI and RAP. Also, a positive correlation was observed between CSCI and IVCCI. Optimal cut-off value for IVCCI was 46.1 with a sensitivity of 75%, and specificity of 79.7%. Optimal cut-off value for CSCI was 39.2 with a sensitivity of 75.4%, and specificity of 88.6%.

CONCLUSION

CS and IVC diameters and collapsibility indices measured by echocardiography were found to be associated with invasively measured RAP, and may be used together for estimating RAP.

MicroRNA-17 as a potential diagnostic biomarker in pulmonary arterial hypertension

Objective

This study aimed to detect circulating microRNA (miR)-17 and miR-20a levels in patients with pulmonary arterial hypertension (PAH), and to investigate whether circulating miR-17 levels are associated with PAH.

Methods

Thirty-five PAH patients and 20 healthy controls were enrolled in the study. Circulating miR-17 and miR-20a levels were measured using real-time PCR analysis.

Results

miR-17 levels were significantly increased in PAH patients compared with healthy controls. They were also higher in PAH patients at World Health Organization functional class (WHO FC) III–IV than WHO FC I–II PAH patients. There was no significant difference in miR-20a levels between PAH patients and controls. miR-17 had a high area under the corresponding receiver operating characteristic curve. Further, we found that circulating miR-17 levels correlated with the 6-minute walk distance, mean pulmonary artery pressure, and mean right atrial pressure in PAH patients.

Conclusion

Circulating miR-17 levels may be associated with human PAH. Therefore, miR-17 could be used as a diagnostic index and prognostic factor for PAH patients.

Multiparametric vs. Inferior Vena Cava-Based Estimation of Right Atrial Pressure

Background: Right atrial pressure (RAP) can be estimated by echocardiography from inferior vena cava diameter and collapsibility (eRAP_IVC), tricuspid E/e' ratio ( eRAP E / e ' ), or hepatic vein flow (eRAP_HV). The mean of these estimates (eRAP_mean) might be more accurate than single assessments. Methods and Results: eRAP_IVC, eRAP E / e ' , eRAP_HV (categorized in 5, 10, 15, or 20 mmHg), eRAP_mean (continuous values) and invasive RAP (iRAP) were obtained in 43 consecutive patients undergoing right heart catheterization [median age 69 (58-75) years, 49% males]. There was a positive correlation between eRAP_mean and iRAP (Spearman test r = 0.66, P < 0.001), with Bland-Altman test showing the best agreement for values <10 mmHg. There was also a trend for decreased concordance between eRAP_IVC, eRAP E / e ' , eRAP_HV, and iRAP across the 5- to 20-mmHg categories, and iRAP was significantly different from eRAP E / e ' and eRAP_HV for the 20-mmHg category (Wilcoxon signed-rank test P = 0.02 and P < 0.001, respectively). The areas under the curve in predicting iRAP were nonsignificantly better for eRAP_mean than for eRAP_IVC at both 5-mmHg [0.64, 95% confidence interval (CI) 0.49-0.80 vs. 0.70, 95% CI 0.53-0.87; Wald test P = 0.41] and 10-mmHg (0.76, 95% CI 0.60-0.92 vs. 0.81, 95% CI 0.67-0.96; P = 0.43) thresholds. Conclusions: Our data suggest that multiparametric eRAP_mean does not provide advantage over eRAP_IVC, despite being more complex and time-consuming.

Right Atrial Pressure Is Associated With Outcomes in Patient With Cardiogenic Shock Receiving Acute Mechanical Circulatory Support

Background: We describe the association between longitudinal hemodynamic changes and clinical outcomes in patients with cardiogenic shock (CS) receiving acute mechanical circulatory support devices (AMCS) at a single center. We hypothesized that improved right atrial pressure is associated with better survival in CS.

Methods: Retrospective analysis of patients from Tufts Medical Center that received AMCS for CS. Baseline characteristics and invasive hemodynamics were collected, analyzed, and correlated against outcomes. Hemodynamics were recorded at different time intervals during index admission [pre-AMCS, 24 h after AMCS (post AMCS), and last available set of hemodynamics (final-AMCS)]. Logistic regression was performed to determine variables associated with in-hospital mortality.

Results: A total of 76 patients had longitudinal hemodynamics available. In hospital mortality occurred in 46% of the cohort. Mean baseline right atrial pressure (RAP) was significantly higher among non-survivors vs. survivors (19.5+6.6 vs. 16.4+5.3 mmHg). Change in right atrial pressure from baseline to before device removal (ΔRA:final AMCS—pre AMCS) was significantly different between survivors and non survivors (−6.5 ± 6.9 mmHg vs. −2.5 ± 6.2 mmHg p = 0.03). Unadjusted logistic regression revealed baseline RAP (OR: 1.1 95% CI: 1.0–1.2), 24 h post device implant RAP (OR: 1.3 95% CI: 1.1–1.4), and final RAP (OR: 1.3 95% CI: 1.1–1.5) to be significant predictors of in-hospital mortality. In a multivariate logistic regression baseline RAP was no longer significantly associated with mortality in the overall cohort, while 24 h (OR: 1.26 95% CI: 1.1–1.5) and final RAP (OR: 1.3 95% CI: 1.1–1.6) remained statistically significant.

Conclusion: We report a novel retrospective analysis of hemodynamic changes in patients with CS receiving AMCS. Our findings identify the potential importance of venous congestion as a prognostic marker of mortality. Furthermore, early decongestion or reduced RA pressure is associated with better survival in these critically ill CS patients. These observations suggest the need for further study in larger retrospective and prospective cohorts of patients with varying degrees of CS severity.

Echocardiographic RV-E/e' for predicting right atrial pressure: a review

Right atrial pressure (RAP) is a key cardiac parameter of diagnostic and prognostic significance, yet current two-dimensional echocardiographic methods are inadequate for the accurate estimation of this haemodynamic marker. Right-heart trans-tricuspid Doppler and tissue Doppler echocardiographic techniques can be combined to calculate the right ventricular (RV) E/e′ ratio – a reflection of RV filling pressure which is a surrogate of RAP. A systematic search was undertaken which found seventeen articles that compared invasively measured RAP with RV-E/e′ estimated RAP. Results commonly concerned pulmonary hypertension or advanced heart failure/transplantation populations. Reported receiver operating characteristic analyses showed reasonable diagnostic ability of RV-E/e′ for estimating RAP in patients with coronary artery disease and RV systolic dysfunction. The diagnostic ability of RV-E/e′ was generally poor in studies of paediatrics, heart failure and mitral stenosis, whilst results were equivocal in other diseases. Bland–Altman analyses showed good accuracy but poor precision of RV-E/e′ for estimating RAP, but were limited by only being reported in seven out of seventeen articles. This suggests that RV-E/e′ may be useful at a population level but not at an individual level for clinical decision making. Very little evidence was found about how atrial fibrillation may affect the estimation of RAP from RV-E/e′, nor about the independent prognostic ability of RV-E/e′ . Recommended areas for future research concerning RV-E/e′ include; non-sinus rhythm, valvular heart disease, short and long term prognostic ability, and validation over a wide range of RAP.

Hypochloremia Is a Noninvasive Predictor of Mortality in Pulmonary Arterial Hypertension

Background

Pulmonary arterial hypertension (PAH) is a lethal disease. In resource‐limited countries PAH outcomes are worse because therapy costs are prohibitive. To improve global outcomes, noninvasive and widely available biomarkers that identify high‐risk patients should be defined. Serum chloride is widely available and predicts mortality in left heart failure, but its prognostic utility in PAH requires further investigation.

Methods and Results

In this study 475 consecutive PAH patients evaluated at the University of Minnesota and Vanderbilt University PAH clinics were examined. Clinical characteristics were compared by tertiles of serum chloride. Both the Kaplan‐Meier method and Cox regression analysis were used to assess survival and predictors of mortality, respectively. Categorical net reclassification improvement and relative integrated discrimination improvement compared prediction models. PAH patients in the lowest serum chloride tertile (≤101 mmol/L: hypochloremia) had the lowest 6‐minute walk distance and highest right atrial pressure despite exhibiting no differences in pulmonary vascular disease severity. The 1‐, 3‐, and 5‐year survival was reduced in hypochloremic patients when compared with the middle‐ and highest‐tertile patients (86%/64%/44%, 95%/78%/59%, and, 91%/79%/66%). After adjustment for age, sex, diuretic use, serum sodium, bicarbonate, and creatinine, the hypochloremic patients had increased mortality when compared with the middle‐tertile and highest‐tertile patients. The Minnesota noninvasive model (functional class, 6‐minute walk distance, and hypochloremia) was as effective as the French noninvasive model (functional class, 6‐minute walk distance, and elevated brain natriuretic peptide or N‐terminal pro–brain natriuretic peptide) for predicting mortality.

Conclusions

Hypochloremia (≤101 mmol/L) identifies high‐risk PAH patients independent of serum sodium, renal function, and diuretic use.

Pathophysiologic and Prognostic Implications of Right Atrial Hypertension in Adults With Tetralogy of Fallot

Background

Right atrial pressure (RAP), a composite metric of right ventricular diastolic function, volume status, and right heart compliance, is a predictor of mortality in patients with heart failure due to acquired heart disease. Because patients with tetralogy of Fallot (TOF) might have abnormal right atrial and ventricular mechanics caused by myocardial injury and remodeling, we hypothesized that RAP would be associated with disease severity and cardiovascular adverse events in this population.

Methods and Results

We performed a cohort study of adults with TOF who underwent right heart catheterization at the Mayo Clinic Rochester between 1990 and 2017. The objective was to determine the association between RAP and multiple domains of disease severity in TOF (percentage of predicted peak oxygen consumption, atrial or ventricular arrhythmia, and heart failure hospitalization), as well as cardiovascular adverse events, defined as sustained ventricular tachycardia, resuscitated or aborted sudden death, heart transplantation, or death. Among 225 patients (113 male; mean age: 39±14 years), mean RAP was 10.7±5.2 mm Hg and median was 10 mm Hg (interquartile range: 7–13 mm Hg). Increasing RAP was associated with atrial or ventricular arrhythmias (odds ratio: 5.01; 95% CI, 1.22–23.49; P<0.001), heart failure hospitalization (odds ratio: 1.47; 95% CI, 1.10–2.39; P=0.033) per 5 mm Hg, and worsening exercise capacity (peak oxygen consumption; R²=0.74, r=−0.86, P<0.001). RAP was a predictor of cardiovascular adverse events (hazard ratio: 1.28; 95% CI, 1.10–1.47; P=0.028) per 5 mm Hg.

Conclusions

In symptomatic patients with TOF, increasing RAP correlates with multiple domains of disease severity (risk stratification) and predicts future cardiovascular events (prognostication). These data have potential clinical implications in the target population of symptomatic TOF patients.

Understanding basic vein physiology and venous blood pressure through simple physical assessments

An understanding of the complexity of the cardiovascular system is incomplete without a knowledge of the venous system. It is important for students to understand that, in a closed system, like the circulatory system, changes to the venous side of the circulation have a knock-on effect on heart function and the arterial system and vice versa. Veins are capacitance vessels feeding blood to the right side of the heart. Changes in venous compliance have large effects on the volume of blood entering the heart and hence cardiac output by the Frank-Starling Law. In healthy steady-state conditions, venous return has to equal cardiac output, i.e., the heart cannot pump more blood than is delivered to it. A sound understanding of the venous system is essential in understanding how changes in cardiac output occur with changes in right atrial pressure or central venous pressure, and the effect these changes have on arterial blood pressure regulation. The aim of this paper is to detail simple hands-on physiological assessments that can be easily undertaken in the practical laboratory setting and that illustrate some key functions of veins. Specifically, we illustrate that venous valves prevent the backflow of blood, that venous blood pressure increases from the heart to the feet, that the skeletal muscle pump facilitates venous return, and we investigate the physiological and clinical significance of central venous pressure and how it may be assessed.

Liver Stiffness Reflecting Right-Sided Filling Pressure Can Predict Adverse Outcomes in Patients With Heart Failure

OBJECTIVES

This study sought to investigate whether elevated liver stiffness (LS) values at discharge reflect residual liver congestion and are associated with worse outcomes in patients with heart failure (HF).

BACKGROUND

Transient elastography is a newly developed, noninvasive method for assessing LS, which can be highly reflective of right-sided filling pressure associated with passive liver congestion in patients with HF.

METHODS

LS values were determined for 171 hospitalized patients with HF before discharge using a Fibroscan device.

RESULTS

The median LS value was 5.6 kPa (interquartile range: 4.4 to 8.1 kPa; range 2.4 to 39.7 kPa) and that of right-sided filling pressure, which was estimated based on LS, was 5.7 mm Hg (interquartile range: 4.1 to 8.2 mm Hg; range 0.1 to 18.9 mm Hg). The patients in the highest LS tertile (>6.9 kPa, corresponding to an estimated right-sided filling pressure of >7.1 mm Hg) had advanced New York Heart Association functional class, high prevalence of jugular venous distention and moderate/severe tricuspid regurgitation, large inferior vena cava (IVC) diameter, low hemoglobin and hematocrit levels, high serum direct bilirubin level, and a similar left ventricular ejection fraction compared with the lower tertiles. During follow-up periods (median: 203 days), 8 (5%) deaths and 33 (19%) hospitalizations for HF were observed. The patients in the highest LS group had a significantly higher mortality rate and HF rehospitalization (hazard ratio: 3.57; 95% confidence interval: 1.93 to 6.83; p < 0.001) compared with the other tertiles. Although LS correlated with IVC diameter and serum direct bilirubin and brain natriuretic peptide levels, LS values were predictive of worse outcomes, even after adjustment for these indices.

CONCLUSIONS

These data suggest that LS is a useful index for assessing systemic volume status and predicting the severity of HF, and that the presence of liver congestion at discharge is associated with worse outcomes in patients with HF.

Discriminatory ability of right atrial volumes with two- and three-dimensional echocardiography to detect elevated right atrial pressure in pulmonary hypertension

AIMS

Pulmonary hypertension (PH) patients have high mortality due to right ventricular failure. Predictors of poor prognostic outcome are increased right atrial volume (RAV) and elevated mean right atrial pressure (mRAP). Our aim was to determine whether RAV measured with 2D echocardiography (2DE) and 3D echocardiography (3DE) can detect elevated mRAP in patients evaluated for PH.

METHODS

Of 85 patients prospectively evaluated for PH, 44 patients (63 ± 15 years, 57% female) had 2DE, 3DE and right heart catheterization within 48 h and were in sinus rhythm. Maximum (RAV_max ) and minimum (RAV_min ) volumes were measured with 3DE. 2D maximum RAV and RA area, inferior vena cava diameter and collapsibility were measured. Invasive mRAP > 8 mmHg was predefined as elevated.

RESULTS

RAV_max and RAV_min correlated with mRAP (r = 0·40 and r = 0·35, P<0·05, for both), and so did 2DE maximum RAV (r = 0·42, P = 0·005) and RA area (r = 0·40, P = 0·008). Area under the curve (AUC) from receiver-operating characteristics curves was for 3DE 0·77 for RAV_max , 0·74 for RAV_min , from 2DE, 0·76 for maximum RAV and 0·75 for RA area to discriminate elevated mRAP (P<0·01 for all). PH patients had larger 3D RAV compared with controls (P<0·01). IVC diameter correlated with mRAP (r = 0·41, P = 0·007), but collapsibility did not (P = 0·078). AUC was neither significant for IVC diameter nor for collapsibility for predicting mRAP>8 mmHg. The optimal threshold was 57 ml m^-2 for RAV_max , 31 ml m^-2 for RAV_min and 36 ml m^-2 for 2DE RAV.

CONCLUSIONS

Enlarged RA measures with 2DE and 3DE have better discriminatory ability compared with IVC measures, to detect elevated mRAP in patients evaluated for PH.

Treatment goals of pulmonary hypertension

With significant therapeutic advances in the field of pulmonary arterial hypertension, the need to identify clinically relevant treatment goals that correlate with long-term outcome has emerged as 1 of the most critical tasks. Current goals include achieving modified New York Heart Association functional class I or II, 6-min walk distance >380 m, normalization of right ventricular size and function on echocardiograph, a decreasing or normalization of B-type natriuretic peptide (BNP), and hemodynamics with right atrial pressure <8 mm Hg and cardiac index >2.5 mg/kg/min(2). However, to more effectively prognosticate in the current era of complex treatments, it is becoming clear that the "bar" needs to be set higher, with more robust and clearer delineations aimed at parameters that correlate with long-term outcome; namely, exercise capacity and right heart function. Specifically, tests that accurately and noninvasively determine right ventricular function, such as cardiac magnetic resonance imaging and BNP/N-terminal pro-B-type natriuretic peptide, are emerging as promising indicators to serve as baseline predictors and treatment targets. Furthermore, studies focusing on outcomes have shown that no single test can reliably serve as a long-term prognostic marker and that composite treatment goals are more predictive of long-term outcome. It has been proposed that treatment goals be revised to include the following: modified New York Heart Association functional class I or II, 6-min walk distance ≥ 380 to 440 m, cardiopulmonary exercise test-measured peak oxygen consumption >15 ml/min/kg and ventilatory equivalent for carbon dioxide <45 l/min/l/min, BNP level toward "normal," echocardiograph and/or cardiac magnetic resonance imaging demonstrating normal/near-normal right ventricular size and function, and hemodynamics showing normalization of right ventricular function with right atrial pressure <8 mm Hg and cardiac index >2.5 to 3.0 l/min/m(2).

Role of echocardiography in patients with intravascular hemolysis due to suspected continuous-flow LVAD thrombosis

OBJECTIVES

This study sought to characterize the echocardiographic findings of patients presenting with intravascular hemolysis (IVH) due to suspected continuous-flow left ventricular assist device (LVAD) pump thrombosis.

BACKGROUND

LVAD patients who develop pump thrombosis often present with IVH. Echocardiography may be able to detect device dysfunction in this setting.

METHODS

Continuous-flow LVAD patients presenting with IVH due to suspected pump thrombosis were identified. Patients underwent echocardiography with cannula Doppler flow velocity interrogation. Findings were compared with baseline and follow-up studies, and with 49 stable LVAD control patients.

RESULTS

Of 145 patients, 14 (10%) had IVH due to suspected pump thrombosis. The mean age was 55 ± 15 years, 93% were men, and 50% received LVAD as destination therapy. Mean duration between implantation and IVH was 231 ± 218 days. Eleven (79%) patients presented with hemoglobinuria, 9 (64%) with jaundice, and 5 (36%) with acute heart failure. Reduced cannula diastolic flow velocity and increased systolic/diastolic (S/D) flow velocity ratio were the only echocardiographic parameters significantly different from controls (outflow cannula 0.3 ± 0.2 m/s vs. 0.8 ± 0.3 m/s, p = 0.03, and 5.9 ± 2.8 vs. 1.7 ± 0.7, p < 0.01, respectively), and were worse for IVH patients with acute heart failure compared with those without (outflow cannula 0.2 ± 0.1 m/s vs. 0.5 ± 0.2 m/s, p = 0.04, and 7.2 ± 3.3 vs. 5.3 ± 2.0, p = 0.02, respectively). Outflow cannula diastolic flow velocity and S/D flow velocity ratio changed significantly from baseline (p = 0.01 and p < 0.01, respectively) in IVH patients, whereas systolic flow velocity did not change (p = 0.59). Odds ratios for outflow cannula diastolic flow velocity and S/D flow velocity ratio for predicting IVH were 0.60 (95% confidence interval [CI]: 0.51 to 0.73), p = 0.02, and 2.45 (95% CI: 2.37 to 2.52) p < 0.01, respectively. Corresponding inflow cannula values were similarly significant. Pump thrombosis was confirmed in 7 (50%) patients after LVAD retrieval.

CONCLUSIONS

Reduced cannula diastolic flow velocity and increased S/D flow velocity ratio identified continuous-flow LVAD dysfunction in patients with IVH due to suspected pump thrombosis better than other echocardiographic parameters.

Pulmonary edema predictive scoring index (PEPSI), a new index to predict risk of reperfusion pulmonary edema and improvement of hemodynamics in percutaneous transluminal pulmonary angioplasty

OBJECTIVES

This study sought to identify useful predictors for hemodynamic improvement and risk of reperfusion pulmonary edema (RPE), a major complication of this procedure.

BACKGROUND

Percutaneous transluminal pulmonary angioplasty (PTPA) has been reported to be effective for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH). PTPA has not been widespread because RPE has not been well predicted.

METHODS

We included 140 consecutive procedures in 54 patients with CTEPH. The flow appearance of the target vessels was graded into 4 groups (Pulmonary Flow Grade), and we proposed PEPSI (Pulmonary Edema Predictive Scoring Index) = (sum total change of Pulmonary Flow Grade scores) × (baseline pulmonary vascular resistance). Correlations between occurrence of RPE and 11 variables, including hemodynamic parameters, number of target vessels, and PEPSI, were analyzed.

RESULTS

Hemodynamic parameters significantly improved after median observation period of 6.4 months, and the sum total changes in Pulmonary Flow Grade scores were significantly correlated with the improvement in hemodynamics. Multivariate analysis revealed that PEPSI was the strongest factor correlated with the occurrence of RPE (p < 0.0001). Receiver-operating characteristic curve analysis demonstrated PEPSI to be a useful marker of the risk of RPE (cutoff value 35.4, negative predictive value 92.3%).

CONCLUSIONS

Pulmonary Flow Grade score is useful in determining therapeutic efficacy, and PEPSI is highly supportive to reduce the risk of RPE after PTPA. Using these 2 indexes, PTPA could become a safe and common therapeutic strategy for CTEPH.