Increased right ventricular Septomarginal trabeculation mass is a novel marker for pulmonary hypertension: comparison with ventricular mass index and right ventricular mass

Prognostic value of right ventricular trabecular complexity in patients with arrhythmogenic cardiomyopathy

OBJECTIVES

The present study aimed to investigate the incremental prognostic value of the right ventricular fractal dimension (FD), a novel marker of myocardial trabecular complexity by cardiac magnetic resonance (CMR) in patients with arrhythmogenic cardiomyopathy (ACM).

METHODS

Consecutive patients with ACM undergoing CMR were followed up for major cardiac events, including sudden cardiac death, aborted cardiac arrest, and appropriate implantable cardioverter defibrillator intervention. Prognosis prediction was compared by Cox regression analysis. We established a multivariable model supplemented with RV FD and evaluated its discrimination by Harrell's C-statistic. We compared the category-free, continuous net reclassification improvement (cNRI) and integrated discrimination index (IDI) before and after the addition of FD.

RESULTS

A total of 105 patients were prospectively included from three centers and followed up for a median of 60 (48, 66) months; experienced 36 major cardiac events were recorded. Trabecular FD displayed a strong unadjusted association with major cardiac events (p < 0.05). In the multivariable Cox regression analysis, RV maximal apical FD maintained an independent association with major cardiac events (hazard ratio, 1.31 (1.11-1.55), p < 0.002). The Hosmer-Lemeshow goodness of fit test displayed good fit (X2 = 0.68, p = 0.99). Diagnostic performance was significantly improved after the addition of RV maximal apical FD to the multivariable baseline model, and the continuous net reclassification improvement increased 21% (p = 0.001), and the integrated discrimination index improved 16% (p = 0.045).

CONCLUSIONS

In patients with ACM, CMR-assessed myocardial trabecular complexity was independently correlated with adverse cardiovascular events and provided incremental prognostic value.

CLINICAL RELEVANCE STATEMENT

The application of FD values for assessing RV myocardial trabeculae may become an accessible and promising parameter in monitoring and early diagnosis of risk factors for adverse cardiovascular events in patients with ACM.

KEY POINTS

• Ventricular trabecular morphology, a novel quantitative marker by CMR, has been explored for the first time to determine the severity of ACM. • Patients with higher maximal apical fractal dimension of RV displayed significantly higher cumulative incidence of major cardiac events. • RV maximal apical FD was independently associated with major cardiac events and provided incremental prognostic value in patients with ACM.

Assessment of Right Ventricular Function-a State of the Art

PURPOSE OF REVIEW

The right ventricle (RV) has a complex geometry and physiology which is distinct from the left. RV dysfunction and failure can be the aftermath of volume- and/or pressure-loading conditions, as well as myocardial and pericardial diseases.

RECENT FINDINGS

Echocardiography, magnetic resonance imaging and right heart catheterisation can assess RV function by using several qualitative and quantitative parameters. In pulmonary hypertension (PH) in particular, RV function can be impaired and is related to survival. An accurate assessment of RV function is crucial for the early diagnosis and management of these patients. This review focuses on the different modalities and indices used for the evaluation of RV function with an emphasis on PH.

Semi-automatic thresholding of RV trabeculation improves repeatability and diagnostic value in suspected pulmonary hypertension

Objectives

Right ventricle (RV) mass is an imaging biomarker of mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance (PVR). Some methods of RV mass measurement on cardiac MRI (CMR) exclude RV trabeculation. This study assessed the reproducibility of measurement methods and evaluated whether the inclusion of trabeculation in RV mass affects diagnostic accuracy in suspected pulmonary hypertension (PH).

Materials and methods

Two populations were enrolled prospectively. (i) A total of 144 patients with suspected PH who underwent CMR followed by right heart catheterization (RHC). Total RV mass (including trabeculation) and compacted RV mass (excluding trabeculation) were measured on the end-diastolic CMR images using both semi-automated pixel-intensity-based thresholding and manual contouring techniques. (ii) A total of 15 healthy volunteers and 15 patients with known PH. Interobserver agreement and scan-scan reproducibility were evaluated for RV mass measurements using the semi-automated thresholding and manual contouring techniques.

Results

Total RV mass correlated more strongly with MPAP and PVR (r = 0.59 and 0.63) than compacted RV mass (r = 0.25 and 0.38). Using a diagnostic threshold of MPAP ≥ 25 mmHg, ROC analysis showed better performance for total RV mass (AUC 0.77 and 0.81) compared to compacted RV mass (AUC 0.61 and 0.66) when both parameters were indexed for LV mass. Semi-automated thresholding was twice as fast as manual contouring (p < 0.001).

Conclusion

Using a semi-automated thresholding technique, inclusion of trabecular mass and indexing RV mass for LV mass (ventricular mass index), improves the diagnostic accuracy of CMR measurements in suspected PH.

COL18A1 genotypic associations with endostatin levels and clinical features in pulmonary arterial hypertension: a quantitative trait association study

Endostatin (ES) is a circulating peptide derived from collagen XVIII alpha 1 (COL18A1) known to inhibit angiogenesis [1, 2]. Decreased angiogenesis is a feature of pulmonary arterial hypertension (PAH) in animal models [3] and human subjects [4]. Our group has reported strong associations between circulating ES levels and haemodynamics and survival in PAH [5–7]. We have also reported that a missense variant in COL18A1, which encodes ES, confers lower ES and longer survival, suggesting that variation within the gene contributes to circulating levels [5]. In the current study, we assessed COL18A1 variant associations with clinical phenotypes and outcomes, including COL18A1 associations with circulating ES levels, in a large, multicentre PAH cohort in which we previously investigated ES as a prognostic biomarker [6].

Variation around the COL18A1 gene, which encodes the angiostatic peptide endostatin, may influence disease heterogeneity in pulmonary arterial hypertensionhttps://bit.ly/3shXrNR

Clinical Effect of Pulmonary Artery Diameter/Ascending Aorta Diameter Ratio on Left Ventricular Reverse Remodeling in Patients With Dilated Cardiomyopathy

BACKGROUND

Many patients with dilated cardiomyopathy (DCM) progress to heart failure (HF), although some demonstrate left ventricular (LV) reverse remodeling (LVRR), which is associated with better outcomes. The pulmonary artery diameter (PAD) to ascending aortic diameter (AoD) ratio has been used as a prognostic predictor in patients with HF, although this tool's usefulness in predicting LVRR remains unknown.Methods and Results:Data from a prospective observational study of 211 patients diagnosed in 2000-2020 with DCM were retrospectively analyzed. Sixty-nine patients with New York Heart Association class I or II HF were included. LVRR was observed in 23 patients (33.3%). The mean LV ejection fraction (29%) and LV end-diastolic dimension (64.5 mm) were similar in patients with and without LVRR. The PAD/AoD ratio was significantly lower in patients with LVRR than those without (81.4% vs. 92.4%, respectively; P=0.003). The optimal PAD/AoD cut-off value for detecting LVRR was 0.9 according to the receiver operating characteristic curve analysis. Multivariate analysis identified a PAD/AoD ratio ≥0.9 as an independent predictor of presence/absence of LVRR. Cardiac events were significantly more common in patients with a PAD/AoD ratio ≥0.9 than those with a ratio <0.9, after a median follow up of 2.5 years (log-rank, P=0.007).

CONCLUSIONS

The PAD/AoD ratio can predict LVRR in patients with DCM.

The angiostatic peptide endostatin enhances mortality risk prediction in pulmonary arterial hypertension

Currently available noninvasive markers for assessing disease severity and mortality risk in pulmonary arterial hypertension (PAH) are unrelated to fundamental disease biology. Endostatin, an angiostatic peptide known to inhibit pulmonary artery endothelial cell migration, proliferation and survival in vitro, has been linked to adverse haemodynamics and shortened survival in small PAH cohorts. This observational cohort study sought to assess: 1) the prognostic performance of circulating endostatin levels in a large, multicentre PAH cohort; and 2) the added value gained by incorporating endostatin into existing PAH risk prediction models.

Endostatin ELISAs were performed on enrolment samples collected from 2017 PAH subjects with detailed clinical data, including survival times. Endostatin associations with clinical variables, including survival, were examined using multivariable regression and Cox proportional hazards models. Extended survival models including endostatin were compared to null models based on the REVEAL risk prediction tool and European Society of Cardiology/European Respiratory Society (ESC/ERS) low-risk criteria using likelihood ratio tests, Akaike and Bayesian information criteria and C-statistics.

Higher endostatin was associated with higher right atrial pressure, mean pulmonary arterial pressure and pulmonary vascular resistance, and with shorter 6-min walk distance (p<0.01). Mortality risk doubled for each log higher endostatin (hazard ratio 2.3, 95% CI 1.6–3.4, p<0.001). Endostatin remained an independent predictor of survival when incorporated into existing risk prediction models. Adding endostatin to REVEAL-based and ESC/ERS criteria-based risk assessment strategies improved mortality risk prediction.

Endostatin is a robust, independent predictor of mortality in PAH. Adding endostatin to existing PAH risk prediction strategies improves PAH risk assessment.

Endostatin is a robust, easily accessible biomarker of PAH severity and mortality that is mechanistically related to PAH pathogenesis. Incorporating endostatin into commonly used risk prediction strategies for PAH improves prediction of mortality.https://bit.ly/3kzGT0w

What is the mid-wall linear high intensity "lesion" on cardiovascular magnetic resonance late gadolinium enhancement?

BACKGROUND

Cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) is a valuable technique for detecting myocardial disorders and fibrosis. However, we sometimes observe a linear, mid-wall high intensity signal in the basal septum in the short axis view, which often presents diagnostic difficulties in the clinical setting. The purpose of this study was to compare the linear, mid-wall high intensity in the basal septum identified by LGE with the anterior septal perforator arteries identified by coronary computed tomography angiography (CorCTA).

METHODS

We retrospectively selected 148 patients who underwent both CorCTA and CMR LGE within 1 year. In the interpretation of LGE, we defined a positive linear high intensity (LHI+) as follows: ① LHI in the basal septum and ② observable for 1.5 cm or more. All other patients were defined as a negative LHI (LHI-). In LHI+ patients, we assessed the correlation between the LHI length and the septal perforator artery length on CorCTA. We also compared the length of the septal perforator artery on CorCTA between LHI+ patients and LHI- patients.

RESULTS

A population of 111 patients were used for further analysis. Among these , there were 55 LHI+ patients and 56 LHI- patients. In LHI+ patients, linear regression analysis revealed that there was a good agreement between LGE LHI and septal perforator arteries by CorCTA in terms of length measurements. The measured length of the anterior septal perforator arteries was significantly shorter in LHI- patients than in LHI+ patients (10 ± 8 mm vs. 21 ± 8 mm; P < 0.05).

CONCLUSIONS

The LHI observed in the basal septum on short axis LGE may reflect contrast enhancement of the anterior septal perforator arteries. It is important to interpret this septal LHI against knowledge of anatomic structure, to avoid misinterpretations of LGE and prevent misdiagnosis.

Comparative accuracy of non-invasive imaging versus right heart catheterization for the diagnosis of pulmonary hypertension: A systematic review and meta-analysis

BACKGROUND

Right heart catheterization (RHC) is the gold-standard in the diagnosis of pulmonary hypertension (PH) but at the cost of procedure-related complications. We sought to determine the comparative accuracy of RHC versus non-invasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and transthoracic echocardiography (TTE).

METHODS

Pulmonary hypertension was defined as a mean pulmonary artery pressure (mPAP) of>20 mmHg. Multiple databases were queried for relevant articles. Raw data were pooled using a bivariate model to calculate the measures of diagnostic accuracy and to estimate Hierarchical Summary Receiver Operating Characteristic (HSROC) on Stata 13.

RESULTS

A total of 51 studies with a total patient population of 3947 were selected. The pooled sensitivity and specificity of MRI for diagnosing PH was 0.92(95% confidence interval (CI) 0.88-0.96) and 0.86 (95% CI, 0.77-0.95), respectively. The net sensitivities for CT scan and TTE were 0.79 (95% CI 0.72-0.89) and 0.85 (95% CI 0.83-0.91), respectively. The overall specificity was 0.82 (0.76-0.92) for the CT scan and 0.71 (95% CI 0.61-0.84) for TTE. The diagnostic odds ratio (DOR) for MRI was 124 (95% CI 36-433) compared to 30 (95% CI 11-78) and 24 (95% 11-38) for CT scan and TTE, respectively. Chi-squared (x2) test showed moderate heterogeneity on the test for equality of sensitivities and specificities.

CONCLUSIONS

MRI has the highest sensitivity and specificity compared to CT and TTE. MRI can potentially serve as a surrogate technique to RHC for the diagnosis of PH.

Feature-Tracking MRI Fractal Analysis of Right Ventricular Remodeling in Adults with Congenitally Corrected Transposition of the Great Arteries

Purpose

To assess a recently available technique for quantification of right ventricular (RV) trabeculae that is based on fractal analysis performed by using cardiac MRI feature tracking, in patients with congenitally corrected transposition of the great arteries (cc-TGA).

Materials and Methods

A total of 19 patients (eight men, 11 women; mean age, 35 years ± 10 [standard deviation]) with consecutive cc-TGA who underwent cardiac MRI were enrolled in the study. For analysis, patients were divided into two groups: six patients (four men, two women; mean age, 34 years ± 14) with an end-systolic RV volume index higher than 72 mL/m² (indicative of adverse RV remodeling) and 13 patients (four men, nine women; mean age, 36 years ± 9) in whom this index was lower than or equal to 72 mL/m² (indicative of adapted RV). The following outcomes were quantified in the midsection of the RV: fractional fractal dimension (FD) and diastolic FD, circumferential strain, and radial strain. Receiver operating characteristic (ROC) analysis was performed to determine the cutoff FD values for the detection of adverse RV remodeling. Correlations among fractional FD, diastolic FD, circumferential strain, and radial strain were calculated by using Pearson correlation coefficient (r) analysis.

Results

The following ROC values were identified for fractional and diastolic FD: cutoff, 0.09 and 1.39, respectively; area under the ROC curve, 0.95 and 0.68, respectively; sensitivity, 1.00 and 0.33, respectively; and specificity, 0.92 and 1.00, respectively. Fractional FD correlated with circumferential strain and radial strain (r = -0.70 and 0.69, respectively; P < .01), as did diastolic FD (r = 0.37 and -0.38, respectively; P < .05).

Conclusion

The fractional FD derived from cardiac MRI feature-tracking analysis correlates with adverse RV remodeling, including a changed strain pattern and trabeculae, in patients with cc-TGA.© RSNA, 2019.

MRI-derived Regional Biventricular Function in Patients with Chronic Thromboembolic Pulmonary Hypertension Before and After Pulmonary Endarterectomy

RATIONALE AND OBJECTIVES

The aim of this study was to assess regional myocardial function in patients with chronic thromboembolic hypertension (CTEPH) before and after successful pulmonary endarterectomy (PEA) using magnetic resonance imaging.

METHODS

Twenty-two patients with CTEPH underwent cardiac magnetic resonance imaging before and 12 (11, 17) days after PEA. Mean pulmonary artery pressure was evaluated preoperatively by right heart catheterization and during post-PEA intensive care unit-stay using a Swan-Ganz catheter. Biventricular peak systolic longitudinal, radial, circumferential strain and time-to-peak strain were obtained by tissue-tracking analysis.

RESULTS

Mean pulmonary artery pressure decreased (46 mm Hg (34.5, 55) to 24 mm Hg (16, 27); P < .0001) and stroke volume increased (P < .0001) after PEA. In the right ventricle (RV) peak radial strain increased in the anterior (P = .04) and in the inferior wall (P = .0012) and slightly missed statistical significance in the lateral wall (P = .051) and septum (P = .07). Circumferential strain increased in the lateral (P = .0002) and inferior wall of the RV (P = .03) and in the lateral as well as in the inferior wall of the left ventricle (P = .01; P = .03). Radial, longitudinal, and circumferential time-to-peak strain shortened (P < .0001) with resynchronization of the ventricles 12 days after PEA.

CONCLUSION

While biventricular resynchronization and recovery of global predominantly RV function was observed, regional circumferential function mainly improved in the lateral and inferior walls of both ventricles and regional radial function in the RV wall and septum 12 days after PEA, suggesting fibers primarily affected by myocardial stress in patients with CTEPH possibly need a relatively longer recovery time.

Cardio-pulmonary MRI for detection of treatment response after a single BPA treatment session in CTEPH patients

OBJECTIVES

Chronic thromboembolic pulmonary hypertension (CTEPH) can be treated with balloon pulmonary angioplasty (BPA) in inoperable patients. Sensitive non-invasive imaging methods are missing to detect treatment response after a single BPA treatment session. Therefore, the aim of this study was to measure treatment response after a single BPA session using cardio-pulmonary MRI.

MATERIALS AND METHODS

Overall, 29 patients with CTEPH were examined with cardio-pulmonary MRI before and 62 days after their initial BPA session. Pulmonary blood flow (PBF), first-pass bolus kinetic parameters, and biventricular mass and function were determined. Multiple linear regression analysis was implemented to estimate the relationship of PBF change in the treated lobe with treatment change of full width at half maximum (FWHM), cardiac output (CO), ventricular mass index (VMI), pulmonary transit time (PTT) and PBF change in the non-treated lobes. Paired Wilcoxon rank sum test and Spearman rho correlation were used.

RESULTS

After BPA regional PBF increased in the treated lobe (p < 0.0001) as well as in non-treated lobes (p = 0.015). PBF treatment changes in the treated lobe were significantly larger compared with the non-treated lobes (p = 0.0049). Change in NT proBNP, MRI-derived mean pulmonary artery pressure (mPAP), PTT, FWHM, right ventricular (RV) ejection fraction, RV stroke volume, CO, VMI and PBF in the non-treated lobes correlated with PBF change in the treated lobe (p < 0.05). PBF changes in the treated lobe were independently predicted by PTT as well as PBF change in the non-treated lobes.

CONCLUSION

Cardio-pulmonary MRI detects and quantifies treatment response after a single BPA treatment session.

KEY POINTS

• Two months after BPA regional parenchymal pulmonary perfusion (PBF) increased in the total lung parenchyma (p = 0.005), the treated lobes (p < 0.0001) and non-treated lobes (p = 0.015). • The PBF treatment changes in the treated lobe were significantly larger than in the non-treated lobes (p = 0.0049). • Change in NT proBNP, MRI-derived mean pulmonary artery pressure, pulmonary transit time, full width at half maximum, right ventricular (RV) ejection fraction, RV stroke volume, cardiac output, ventricular mass index and PBF in the non-treated lobes correlated with PBF change in the treated lobe (p < 0.05).

Non-invasive algorithms for the diagnosis of pulmonary hypertension

Precapillary pulmonary hypertension (PH) is diagnosed when mean pulmonary arterial pressure (mPAP) equals or exceeds 25 mmHg and the pulmonary capillary wedge pressure (PCWP) is equal or lower than 15 mmHg. Because both parameters can only be derived from invasive hemodynamic assessment, right heart catheter (RHC) is still a gold standard for the diagnosis of PH. Severe precapillary PH corresponds to pulmonary vascular disease and carries a poor prognosis. Unfortunately, due to a generally low specificity of non-invasive estimates of systolic pulmonary pressure, at least 50% of patients with suspicion of PH need to undergo invasive RHC for exclusion of precapillary PH. Therefore, and also in order to manage the growing number of postcapillary PH due to heart and lung disease in the general population, pulmonary and cardiologic diagnostic algorithms combining multiple parameters have been developed. Recent disease scores are reviewed, and an outlook is given on emerging evidence from the DETECT clinical study holding the promise to non-invasively predict precapillary PH in vulnerable patients. These diagnostic trees help limit unnecessary procedures and help differentiate the current categories of PH. However, one has to keep in mind that the diagnosis of PH is still made by hemodynamic assessment.

MR and CT Imaging for the Evaluation of Pulmonary Hypertension

Imaging plays a central role in the diagnosis and management of all forms of pulmonary hypertension (PH). Although Doppler echocardiography is essential for the evaluation of PH, its ability to optimally evaluate the right ventricle and pulmonary vasculature is limited by its 2-dimensional planar capabilities. Magnetic resonance and computed tomography are capable of determining the etiology and pathophysiology of PH, and can be very useful in the management of these patients. Exciting new techniques such as right ventricle tissue characterization with T1 mapping, 4-dimensional flow of the right ventricle and pulmonary arteries, and computed tomography lung perfusion imaging are paving the way for a new era of imaging in PH. These imaging modalities complement echocardiography and invasive hemodynamic testing and may be useful as surrogate endpoints for early phase PH clinical trials. Here we discuss the role of magnetic resonance imaging and computed tomography in the diagnosis and management of PH, including current uses and novel research applications, and we discuss the role of value-based imaging in PH.

Ambrisentan and Tadalafil Up-front Combination Therapy in Scleroderma-associated Pulmonary Arterial Hypertension

BACKGROUND

Scleroderma-associated pulmonary arterial hypertension (SSc-PAH) is a rare disease characterized by a very dismal response to therapy and poor survival. We assessed the effects of up-front combination PAH therapy in patients with SSc-PAH.

METHODS

In this prospective, multicenter, open-label trial, 24 treatment-naive patients with SSc-PAH received ambrisentan 10 mg and tadalafil 40 mg daily for 36 weeks. Functional, hemodynamic, and imaging (cardiac magnetic resonance imaging and echocardiography) assessments at baseline and 36 weeks included changes in right ventricular (RV) mass and pulmonary vascular resistance as co-primary endpoints and stroke volume/pulmonary pulse pressure ratio, tricuspid annular plane systolic excursion, 6-minute walk distance, and N-terminal pro-brain natriuretic peptide as secondary endpoints.

RESULTS

At 36 weeks, we found that treatment had resulted in significant reductions in median (interquartile range [IQR]) RV mass (28.0 g [IQR, 20.6-32.9] vs. 32.5 g [IQR, 23.2-41.4]; P < 0.05) and median pulmonary vascular resistance (3.1 Wood units [IQR, 2.0-5.7] vs. 6.9 Wood units [IQR, 4.0-12.9]; P < 0.0001) and in improvements in median stroke volume/pulmonary pulse pressure ratio (2.6 ml/mm Hg [IQR, 1.8-3.5] vs. 1.4 ml/mm Hg [IQR 8.9-2.4]; P < 0.0001) and mean ( ± SD) tricuspid annular plane systolic excursion (2.2 ± 0.12 cm vs. 1.65 ± 0.11 cm; P < 0.0001), 6-minute walk distance (395 ± 99 m vs. 343 ± 131 m; P = 0.001), and serum N-terminal pro-brain natriuretic peptide (647 ± 1,127 pg/ml vs. 1,578 ± 2,647 pg/ml; P < 0.05).

CONCLUSIONS

Up-front combination therapy with ambrisentan and tadalafil significantly improved hemodynamics, RV structure and function, and functional status in treatment-naive patients with SSc-PAH and may represent a very effective therapy for this patient population. In addition, we identified novel hemodynamic and imaging biomarkers that could have potential value in future clinical trials. Clinical trial registered with www.clinicaltrials.gov (NCT01042158).

Pulmonary artery to aorta ratio for the detection of pulmonary hypertension: cardiovascular magnetic resonance and invasive hemodynamics in heart failure with preserved ejection fraction

BACKGROUND

Previous work indicates that dilatation of the pulmonary artery (PA) itself or in relation to the ascending aorta (PA:Ao ratio) predicts pulmonary hypertension (PH). Whether these results also apply for heart failure with preserved ejection fraction (HFpEF) is unknown. In the present study we evaluated the diagnostic and prognostic power of PA diameter and PA:Ao ratio on top of right ventricular (RV) size, function, and septomarginal trabeculation (SMT) thickness by cardiovascular magnetic resonance (CMR) in HFpEF.

METHODS AND RESULTS

159 consecutive HFpEF patients were prospectively enrolled. Of these, 111 underwent CMR and invasive hemodynamic evaluation. By invasive assessment 64 % of patients suffered from moderate/severe PH (mean pulmonary artery pressure (mPAP) ≥30 mmHg). Significant differences between groups with and without moderate/severe PH were observed with respect to PA diameter (30.9 ± 5.1 mm versus 26 ± 5.1 mm, p < 0.001), PA:Ao ratio (0.93 ± 0.16 versus 0.78 ± 0.14, p < 0.001), and SMT diameter (4.6 ± 1.5 mm versus 3.8 ± 1.2 mm; p = 0.008). The strongest correlation with mPAP was found for PA:Ao ratio (r = 0.421, p < 0.001). By ROC analysis the best cut-off for the detection of moderate/severe PH was found for a PA:Ao ratio of 0.83. Patients were followed for 22.0 ± 14.9 months. By Kaplan Meier analysis event-free survival was significantly worse in patients with a PA:Ao ratio ≥0.83 (log rank, p = 0.004). By multivariable Cox-regression analysis PA:Ao ratio was independently associated with event-free survival (p = 0.003).

CONCLUSION

PA:Ao ratio is an easily measureable noninvasive indicator for the presence and severity of PH in HFpEF, and it is related with outcome.

The right ventricle in scleroderma (2013 Grover Conference Series)

Pulmonary arterial hypertension (PAH) results from severe remodeling of the distal lung vessels leading irremediably to death through right ventricular (RV) failure. PAH (Group 1 of the World Health Organization classification of pulmonary hypertension) can be idiopathic (IPAH) or associated with other disorders, such as connective tissue diseases. Prominent among the latter is systemic sclerosis (SSc), a heterogeneous disorder characterized by endothelium dysfunction, dysregulation of fibroblasts resulting in excessive collagen production, and immune abnormalities. For as-yet-unknown reasons, SSc-associated PAH (SSc-PAH) carries a significantly worse prognosis compared with any other form of PAH in Group 1, including IPAH. We have previously shown that patients with SSc-PAH have a median survival of only 3 years, compared with 8 years for IPAH, despite modern PAH therapy. Because death is principally due to RV failure, we speculated that RV adaptation to PAH differed between the two entities due to disparate pulmonary artery loading, perhaps from vessel stiffening, or intrinsic RV myocardial disease that might limit function and adaptation to high afterload. In SSc, RV function may also be impaired by inflammatory processes, excess fibrosis of the myocardium, or altered angiogenesis, which may all contribute to impaired contractile reserve exacerbating cardiopulmonary impedance mismatch. This is now suggested by recent findings from our group that demonstrate that, although pulmonary vascular load may be similar between patients with IPAH and those with SSc-PAH, the latter display reduced myocardial contractility as assessed by pressure-volume loop measurements. This review focuses on fundamental hemodynamic, structural, and functional differences in RV from patients with SSc-PAH compared with IPAH, which may account for survival discrepancies between the two populations. Possible underlying basic mechanisms are discussed.

RV mass measurement at end-systole: Improved accuracy, Reproducibility, and reduced segmentation time

PURPOSE

To evaluate the accuracy, reproducibility, and contouring time of RV mass in end-systole (ES) and end-diastole (ED). Magnetic resonance imaging (MRI) has been shown to be accurate and reproducible for the evaluation of right ventricular (RV) volume and function. RV mass, assessed in end-diastolic (ED) phase, is one of the least reproducible variables. The choice of end-systolic (ES) phase could offer an alternative to improve reproducibility, since the selection of the basal slice and the visualization of the usually thin RV wall are easier in this phase.

MATERIALS AND METHODS

To evaluate accuracy, 11 sheep were imaged in vivo and their RV free walls were weighed after removing epicardial fat. To evaluate reproducibility, 30 normal subjects and 30 subjects with pulmonary arterial hypertension (PAH) were imaged and interobserver and intraobserver variabilities were assessed in the ES and the ED. Segmentation time was recorded after visual selection of ES and ED phases.

RESULTS

ES RV mass measurement has less absolute variability (5.2% ± 3.2) compared to ED (10.6% ± 6.3) using weighed RV mass in sheep as the gold standard (P < 0.001). ES segmentation yielded higher intraobserver (intraclass correlation coefficients [ICC] = 0.94-0.99; coefficient of variability [CoV] = 6-7.3%) and interobserver (ICC = 0.85-0.98; CoV = 10.9-11.7%) reproducibility than ED segmentation. Segmentation time in humans was 25-28% faster in ES (P < 0.001).

CONCLUSION

The MRI assessment of RV mass is more accurate, reproducible, and faster in the ES phase.

Imaging pitfalls, normal anatomy, and anatomical variants that can simulate disease on cardiac imaging as demonstrated on multidetector computed tomography

Advances in computed tomography have led to continuous improvement in cardiac imaging. Dedicated postprocessing capabilities, faster scan times, and cardiac gating methods reveal details of normal cardiac anatomy and anatomic variants that can mimic pathologic conditions. This article will review normal cardiac anatomy and variants that can mimic disease. Radiologists should be familiar with normal cardiac anatomy and anatomic variants to avoid misinterpretation of normal findings for pathologic processes.

Cardiac mass and function decrease in bronchiolitis obliterans syndrome after lung transplantation: relationship to physical activity?

Rationale

There is a need to expand knowledge on cardio-pulmonary pathophysiology of bronchiolitis obliterans syndrome (BOS) following lung transplantation (LTx).

Objectives

The purpose of this study was to assess MRI-derived biventricular cardiac mass and function parameters as well as flow hemodynamics in patients with and without BOS after LTx.

Methods

Using 1.5T cardiac MRI, measurements of myocardial structure and function as well as measurements of flow in the main pulmonary artery and ascending aorta were performed in 56 lung transplant patients. The patients were dichotomized into two gender matched groups of comparable age range: one with BOS (BOS stages 1–3) and one without BOS (BOS 0/0p).

Measurements and Main Results

Significantly lower biventricular cardiac mass, right and left ventricular end-diastolic volume, biventricular stroke volume, flow hemodynamics and significant higher heart rate but preserved cardiac output were observed in patients with BOS 1–3 compared to the BOS 0/0p group (p<0.05). In a stepwise logistic regression analysis global cardiac mass (p = 0.046) and days after LTx (p = 0.0001) remained independent parameters to predict BOS. In a second model an indicator for the physical fitness level - walking number of stairs - was added to the logistic regression model. In this second model, time after LTx (p = 0.005) and physical fitness (p = 0.01) remained independent predictors for BOS.

Conclusion

The observed changes in biventricular cardiac mass and function as well as changes in hemodynamic flow parameters in the pulmonary trunk and ascending aorta are likely attributed to the physical fitness level of patients after lung transplantation, which in turn is strongly related to lung function.

Right ventricular reverse remodeling after pulmonary endarterectomy: magnetic resonance imaging and clinical and right heart catheterization assessment

The objective of this study was to assess the effect of pulmonary endarterectomy (PEA) on right ventricular (RV) reverse remodeling using magnetic resonance imaging (MRI) and to correlate MRI findings with clinical and hemodynamic outcomes postsurgery. We performed a retrospective analysis in 72 patients undergoing PEA surgery in whom MRI and right heart catheterization (RHC) were performed preoperation and 3 months postoperation. RV volumes and mass were assessed by MRI. Continuous variables were expressed as means, changes were compared with a paired t test, and associations between the variables were explored using Pearson correlation coefficients. The mean age was 57 years, and 51% were male. Both RV end-diastolic volume (EDV; 176-117 mL; P < 0.001) and RV end-systolic volume (ESV; 129-64 mL; P < 0.001) reduced significantly following PEA. Preoperative pulmonary artery pressure (PAP) correlated moderately with ESV (r = 0.46, P < 0.001). Postoperatively, PAP correlated with EDV (r = 0.45, P < 0.001) and ESV (r = 0.44, P < 0.001). Moderate correlation was present between hemodynamic parameters: PAP, pulmonary vascular resistance, and right atrial pressure with pre- and postoperation end-systolic and end-diastolic RV mass (P < 0.001). RHC and MRI measurements of cardiac output and RV volumes were significantly different (P < 0.001). In conclusion, RV reverse remodeling, as measured by improvement in RV volumes and mass by MRI, was observed for 3 months in patients who underwent PEA surgery. This is the largest series of patients with pre- and post-PEA MRI assessment so far reported. MRI detects changes in parameters reflecting cardiac remodeling and pulmonary clearance, but measurements are significantly different from those of RHC.

The importance of trabecular hypertrophy in right ventricular adaptation to chronic pressure overload

To assess the contribution of right ventricular (RV) trabeculae and papillary muscles (TPM) to RV mass and volumes in controls and patients with pulmonary arterial hypertension (PAH). Furthermore, to evaluate whether TPM shows a similar response as the RV free wall (RVFW) to changes in pulmonary artery pressure (PAP) during follow-up. 50 patients underwent cardiac magnetic resonance (CMR) and right heart catheterization at baseline and after one-year follow-up. Furthermore 20 controls underwent CMR. RV masses were assessed with and without TPM. TPM constituted a larger proportion of total RV mass and RV end-diastolic volume (RVEDV) in PAH than in controls (Mass: 35 ± 7 vs. 25 ± 5 %; p < 0.001; RVEDV: 17 ± 6 vs. 12 ± 6 %; p = 0.003). TPM mass was related to the RVFW mass in patients (baseline: R = 0.65; p < 0.001; follow-up: R = 0.80; p < 0.001) and controls (R = 0.76; p < 0.001). In PAH and controls, exclusion of TPM from the assessment resulted in altered RV mass, volumes and function than when included (all p < 0.01). Changes in RV TPM mass (β = 0.44; p = 0.004) but not the changes in RVFW mass (p = 0.095) were independently related to changes in PAP during follow-up. RV TPM showed a larger contribution to total RV mass in PAH (~35 %) compared to controls (~25 %). Inclusion of TPM in the analyses significantly influenced the magnitude of the RV volumes and mass. Furthermore, TPM mass was stronger related to changes in PAP than RVFW mass. Our results implicate that TPM are important contributors to RV adaptation during pressure overload and cannot be neglected from the RV assessment.

A systematic review of the diagnostic accuracy of cardiovascular magnetic resonance for pulmonary hypertension

BACKGROUND

The diagnostic accuracy of cardiovascular magnetic resonance (CMR) for pulmonary hypertension (PH) compared with right heart catheterization were assessed. The purpose of this systematic review was to comprehensively evaluate the diagnostic accuracy of CMR in evaluating PH.

METHODS

Published literature was obtained from PUBMED, Web of Knowledge, Cochrane library, Embase, Biosis Preview, China National Knowledge Infrastructure, and Chongqing VIP databases, and all studies were inclusive until December 2012. Studies relevant to PH and its imaging in CMR and right heart catheterization were included if correlation coefficient was elucidated clearly. Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) score was used to assess the quality of studies. Sensitivity and specificity were pooled separately and compared with overall accuracy measures: diagnostic odds ratio and symmetric summary receiver operating characteristic.

RESULTS

Sixteen studies were included in the systematic review. Of all the studies, the most widely used index was ventricular mass index (VMI) of CMR. We performed a meta-analysis for VMI among 429 patients in 5 individual studies, which showed a modest diagnostic accuracy of VMI for PH with a summary sensitivity and specificity of 84% (95% confidence interval, 79%-87%) and 82% (95% confidence interval, 73%-89%), respectively. In addition, the summary positive likelihood ratio was 4.894, indicating that VMI of CMR allows a modest ability to distinguish PH patients from healthy subjects with a cutoff point of 0.45 using functional and structural measures.

CONCLUSIONS

This systematic review and meta-analysis indicates that VMI seems to have a moderate sensitivity and specificity for detection of PH. The application values of other parameters still need further investigation.

A historical overview of magnetic resonance imaging, focusing on technological innovations

Magnetic resonance imaging (MRI) has now been used clinically for more than 30 years. Today, MRI serves as the primary diagnostic modality for many clinical problems. In this article, historical developments in the field of MRI will be discussed with a focus on technological innovations. Topics include the initial discoveries in nuclear magnetic resonance that allowed for the advent of MRI as well as the development of whole-body, high field strength, and open MRI systems. Dedicated imaging coils, basic pulse sequences, contrast-enhanced, and functional imaging techniques will also be discussed in a historical context. This article describes important technological innovations in the field of MRI, together with their clinical applicability today, providing critical insights into future developments.

Right ventricular plasticity and functional imaging

Right ventricular (RV) function is a strong independent predictor of outcome in a number of distinct cardiopulmonary diseases. The RV has a remarkable ability to sustain damage and recover function which may be related to unique anatomic, physiologic, and genetic factors that differentiate it from the left ventricle. This capacity has been described in patients with RV myocardial infarction, pulmonary arterial hypertension, and chronic thromboembolic disease as well as post-lung transplant and post-left ventricular assist device implantation. Various echocardiographic and magnetic resonance imaging parameters of RV function contribute to the clinical assessment and predict outcomes in these patients; however, limitations remain with these techniques. Early diagnosis of RV function and better insight into the mechanisms of RV recovery could improve patient outcomes. Further refinement of established and emerging imaging techniques is necessary to aid subclinical diagnosis and inform treatment decisions.

Regional and global biventricular function in pulmonary arterial hypertension: a cardiac MR imaging study

PURPOSE

To determine whether chronic pulmonary arterial pressure (PAP) elevation affects regional biventricular function and whether regional myocardial function may be reduced in pulmonary arterial hypertension (PAH) patients with preserved global right ventricular (RV) function.

MATERIALS AND METHODS

After informed consent, 35 PAH patients were evaluated with right heart catheterization and cardiac magnetic resonance (MR) imaging and compared with 13 healthy control subjects. Biventricular segmental, section, and mean ventricular peak systolic longitudinal strain (E(LL)), as well as left ventricular (LV) circumferential and RV tangential strains were compared between PAH patients and control subjects and correlated with global function and catheterization of the right heart indexes. Spearman ρ correlation with Bonferroni correction was used. Multiple linear regression analysis was performed to determine predictors for regional myocardial function.

RESULTS

In the RV of PAH patients, longitudinal contractility was reduced at the basal, mid, and apical levels, and tangential contractility was reduced at the midventricular level. Mean RV E(LL) positively correlated with mean PAP (r = 0.62, P < .0014) and pulmonary vascular resistance index (PVRI) (r = 0.77, P < .0014). Mean PAP was a predictor of mean RV E(LL) (β = .19, P = .005) in a multiple linear regression analysis. In the LV, reduced LV longitudinal and circumferential contractility were noted at the base. LV anteroseptal E(LL) positively correlated with increased mean PAP (r = 0.5, P = .03) and septal eccentricity index (r = 0.5, P = .01). In a subgroup of PAH patients with normal global RV function, significantly reduced RV longitudinal contractility was noted at basal and mid anterior septal insertions, as well as the mid anterior RV wall (P < .05 for all).

CONCLUSION

In PAH patients, reduced biventricular regional function is associated with increased RV afterload (mean PAP and PVRI). Cardiac MR imaging helps identify regional RV dysfunction in PAH patients with normal global RV function.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12111599/-/DC1.

A case with double-chambered right ventricle and left ventricular-right atrial communication (Gerbode defect): potential pitfall for Eisenmenger syndrome

The ventricular septal defect (VSD) can rarely be associated with other malformations such as double-chambered right ventricle (DCRV) in which hypertrophied muscle bundles divide the right ventricle into two chambers causing progressive obstruction (Mao et al., Asia Pac J Thorac Cardiovasc Surg 5:14-17, 1996). Most VSDs close spontaneously by apposition of the tricuspid leaflets, but the process is rarely disrupted, resulting in communication between left ventricle and right atrium called Gerbode defect [Cho et al., J Cardiovasc Ultrasound 19(3):148-151, 2011]. Hence, the Gerbode defect involves potential misinterpretation of its high-velocity shunt as pulmonary hypertension. Here we present a case with DCRV and Gerbode defect initially misdiagnosed to have Eisenmenger syndrome.