Clinical Correlates and Prognostic Value of Elevated Right Atrial Pressure in Patients With Hypertrophic Cardiomyopathy

Head-to-Head Comparison of Hepatic Vein and Superior Vena Cava Flow Velocity Waveform Analyses for Predicting Elevated Right Atrial Pressure

OBJECTIVE

Blood flow in the hepatic veins and superior vena cava (SVC) reflects right heart filling; however, their Doppler profiles are often not identical, and no studies have compared their diagnostic efficacies. We aimed to determine which venous Doppler profile is reliable for detecting elevated right atrial pressure (RAP).

METHODS

In 193 patients with cardiovascular diseases who underwent cardiac catheterization within 2 d of echocardiography, the hepatic vein systolic filling fraction (HV-SFF) and the ratio of the peak systolic to diastolic forward velocities of the SVC (SVC-S/D) were measured. HV-SFF < 55% and SVC-S/D < 1.9 were regarded as elevated RAP. We also calculated the fibrosis 4 index (FIB-4) as a serum liver fibrosis marker.

RESULTS

HV-SFF and SVC-S/D were feasible in 177 (92%) and 173 (90%) patients, respectively. In the 161 patients in whom both venous Doppler waveforms could be measured, HV-SFF and SVC-S/D were inversely correlated with RAP (r = -0.350, p < 0.001; r = -0.430, p < 0.001, respectively). SVC-S/D > 1.9 showed a significantly higher diagnostic accuracy of RAP elevation compared with HV-SFF < 55% (area under the curve, 0.842 vs. 0.614, p < 0.001). Multivariate analyses showed that both FIB-4 (β = -0.211, p = 0.013) and mean RAP (β = -0.319, p < 0.001) were independent determinants of HV-SFF. In contrast, not FIB-4 but mean RAP (β = -0.471, p < 0.001) was an independent determinant of SVC-S/D. The diagnostic accuracy remained unchanged when HV-SFF < 55% was considered in conjunction with the estimated RAP based on the inferior vena cava morphology. Conversely, SVC-S/D showed an incremental diagnostic value over the estimated RAP.

CONCLUSIONS

SVC-S/D enabled a more accurate diagnosis of RAP elevation than HV-SFF.

Application of the ALBI Scoring System for Mortality Outcome Prediction in Patients with Hypertrophic Cardiomyopathy

Background:

There is no information about the clinical significance of the albumin-bilirubin (ALBI) score in patients with hypertrophic cardiomyopathy (HCM).

Objective:

We retrospectively performed clinical evaluations in 462 patients with HCM to estimate whether the ALBI score could be a new tool to predict mortality in HCM.

Methods and Results:

During a median follow-up of 4.7 years, HCM-related death occurred in 52 (11.3%) patients. Overall, there was a significant positive association between ALBI score and HCM-related death (adjusted hazard ratio [HR]: 1.79 per one standard deviation [SD] increment, 95% confidence interval [CI]: 1.36–2.35). When the score was assessed as tertiles, the adjusted HRs of HCM-related death were 1.30 (95% CI: 0.42–3.99) for the tertile 2 and 4.43 (95% CI: 1.65–11.89) for the tertile 3, compared with the tertile 1. Stratified analysis and E-value analysis suggested the robustness of the above-mentioned results. Meanwhile, time-dependent ROC analysis showed ALBI score could discriminate HCM-related death at various time points (AUC ranges: 0.725–0.850). Furthermore, exploratory analysis indicated the dynamic changes of ALBI score also could predict HCM-related death. Finally, multiple linear regression analysis suggested some pathogenetic pathways associated with HCM-related adverse outcomes significantly correlated with ALBI score, and the pathways included inflammation, myocardial injury, nutritional status and some clinical characteristics, but not abnormal cardiac structure and function itself.

Conclusions:

Higher ALBI score is a strong independent predictor of HCM-related death in patients with HCM.

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.

Comprehensive Proteomics Profiling Reveals Circulating Biomarkers of Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is caused by mutations in the genes coding for proteins essential in normal myocardial contraction. However, it remains unclear through which molecular pathways gene mutations mediate the development of HCM. The objectives were to determine plasma protein biomarkers of HCM and to reveal molecular pathways differentially regulated in HCM.

METHODS

We conducted a multicenter case-control study of cases with HCM and controls with hypertensive left ventricular hypertrophy. We performed plasma proteomics profiling of 1681 proteins. We performed a sparse partial least squares discriminant analysis to develop a proteomics-based discrimination model with data from 1 institution (ie, the training set). We tested the discriminative ability in independent samples from the other institution (ie, the test set). As an exploratory analysis, we executed pathway analysis of significantly dysregulated proteins. Pathways with false discovery rate <0.05 were declared positive.

RESULTS

The study included 266 cases and 167 controls (n=308 in the training set; n=125 in the test set). Using the proteomics-based model derived from the training set, the area under the receiver operating characteristic curve was 0.89 (95% CI, 0.83-0.94) in the test set. Pathway analysis revealed that the Ras-MAPK (mitogen-activated protein kinase) pathway, along with its upstream and downstream pathways, was upregulated in HCM. Pathways involved in inflammation and fibrosis-for example, the TGF (transforming growth factor)-β pathway-were also upregulated.

CONCLUSIONS

This study serves as the largest-scale investigation with the most comprehensive proteomics profiling in HCM, revealing circulating biomarkers and exhibiting both novel (eg, Ras-MAPK) and known (eg, TGF-β) pathways differentially regulated in HCM.

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.

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.

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.

Right atrial function assessed by volume-derived values and speckle tracking echocardiography in patients with hypertrophic cardiomyopathy

Background

To detect the right atrial (RA) functions in hypertrophic cardiomyopathy (HCM) patients by using volume-derived values and two-dimensional strain.

Methods

Thirty-two HCM patients and 34 age and gender matched normal controls were enrolled for this study. RA volume-derived values were measured by using 2D ultrasonic images. RA strain (S-reservoir, S-conduit, S-booster pump) and strain rate (SR-reservoir, SR-conduit, SR-booster pump), representing the reservoir, conduit and booster pump functions, respectively, were measured by EchoPAC.

Results

Total RA emptying fraction (RAEF) and RA expansion index in HCM patients were significantly lower than normal controls (p < 0.05). The values of S-reservoir, S-conduit, Sr-reservoir and Sr-conduit in HCM patients were significantly lower than normal controls (p < 0.001). Although there were no significant differences in S-booster pump and Sr-booster pump between HCM patients and normal controls, the absolute values in HCM patients were lower than normal controls.

Conclusions

In this study, we concluded that RA dysfunctions, including the reservoir and conduit functions were impaired in HCM patients.

Application of Proteomics Profiling for Biomarker Discovery in Hypertrophic Cardiomyopathy

High-throughput proteomics profiling has never been applied to discover biomarkers in patients with hypertrophic cardiomyopathy (HCM). The objective was to identify plasma protein biomarkers that can distinguish HCM from controls. We performed a case-control study of patients with HCM (n = 15) and controls (n = 22). We carried out plasma proteomics profiling of 1129 proteins using the SOMAscan assay. We used the sparse partial least squares discriminant analysis to identify 50 most discriminant proteins. We also determined the area under the curve (AUC) of the receiver operating characteristic curve using the Monte Carlo cross validation with balanced subsampling. The average AUC was 0.94 (95% confidence interval, 0.82-1.00) and the discriminative accuracy was 89%. In HCM, 13 out of the 50 proteins correlated with troponin I and 12 with New York Heart Association class. Proteomics profiling can be used to elucidate protein biomarkers that distinguish HCM from controls.