Right ventricular plasticity and functional imaging

Long-term prognostic value of right ventricular dysfunction on cardiovascular magnetic resonance imaging in anthracycline-treated cancer survivors

AIMS

We aimed to determine the prevalence of right ventricular (RV) systolic dysfunction on cardiovascular magnetic resonance imaging (CMR) and its impact on long-term adverse outcomes in a large cohort of cancer survivors treated with anthracycline-based chemotherapy.

METHODS AND RESULTS

Consecutive cancer survivors treated with anthracyclines who underwent clinical CMR for suspected anthracycline-related cardiomyopathy were studied. The primary endpoint was a composite of all-cause death or major adverse cardiac events (MACE): heart failure hospitalization, heart transplantation, ventricular assist device implantation, resuscitated cardiac arrest, or life-threatening ventricular arrhythmia. The secondary endpoints were all-cause death, and cardiac death or MACE. Among 249 survivors who underwent CMR at a median of 2.9 years after cancer treatment, RV systolic dysfunction was present in 54 (21.7%). Of these, 50 (92.6%) had an abnormal left ventricular ejection fraction (LVEF). At a median follow-up time after the CMR of 2.7 years, 105 survivors experienced the primary endpoint. On Kaplan-Meier analyses, the cumulative incidence of the primary endpoint was significantly higher in survivors with abnormal RVEF compared with those with normal RVEF (P = 0.002). However, on Cox multivariable analyses, RVEF was not associated with the primary endpoint (HR 1.04 per 5% decrease; 95% CI 0.93-1.17; P = 0.46) after adjustment for non-imaging variables and LVEF. RVEF was also not associated with the secondary endpoints.

CONCLUSION

Among anthracycline-treated cancer survivors undergoing CMR for suspected cardiotoxicity, RV systolic dysfunction was present in one in five cases, accompanied by LV systolic dysfunction in nearly all cases, and was not independently associated with long-term outcomes.

Prognostic value of right ventricular free wall longitudinal strain in a large cohort of outpatients with left-side heart disease

AIMS

Right ventricular free wall longitudinal strain (RVFWLS) has been proposed as an accurate and sensitive measure of right ventricular function that could integrate other conventional parameters such as tricuspid annulus plane systolic excursion (TAPSE) and fractional area change (FAC%). The aim of the present study was to evaluate the relationship between RVFWLS and outcomes in stable asymptomatic outpatients with left-sided structural heart disease.

METHODS AND RESULTS

We enrolled 458 asymptomatic patients with left-side heart diseases and any ejection fraction who were referred for echocardiography to two Italian centres. The composite endpoint of death for any cause and heart failure hospitalization was used as primary outcome of this analysis. After a mean follow-up of 5.4 ± 1.2 years, 145 patients (31%) reached the combined endpoint. Most of echocardiographic parameters were related to outcomes, including right ventricular functional parameters. Mean value of RVFWLS in our cohort was -21 ± 8% and it was significantly related to the combined endpoint and in multivariable Cox-regression model; when tested with other echocardiographic parameters that were significantly related to outcome at univariate analysis, RVFWLS maintained its independent association with outcome (hazard ratio 0.963, 95% confidence interval 0.948-0.978; P = 0.0001). The best cut-off value of RVFWLS to predict outcome was -22% (area under the curve 0.677; P < 0.001; sensitivity 70%; 65% specificity).

CONCLUSION

RVFWLS may help clinicians to identify patients with left-sided structural heart disease at higher risk for first heart failure hospitalization and death for any cause.

Limitations of right ventricular annular parameters in the early postoperative period following pulmonary endarterectomy: an observational study

OBJECTIVES

Echocardiographic right ventricular (RV) annular parameters are probably not as reliable to evaluate the surgical success in the postoperative period after pulmonary endarterectomy (PEA), whereas RV end-diastolic/left ventricular end-diastolic area ratio (RVEDA/LVEDA ratio) could be more useful. This study examined the relationship between RV annular parameters or RVEDA/LVEDA ratio and ideal cardiac index (ICI), before and after PEA.

METHODS

Among 80 patients who underwent PEA, the relationships between RVEDA/LVEDA ratio (21 patients), or tricuspid annular plane systolic excursion (32 patients), or systolic tricuspid annular velocity (55 patients) and ICI were modelled.

RESULTS

Forty-eight hours following PEA, mean pulmonary artery pressure decreased (26 ± 6 vs 46 ± 12 mmHg, P < 0.0001) and ICI improved (2.8 ± 0.8 vs 3.0 ± 0.9 l/min/m2, P = 0.02). In contrast to the moderate association between RV annular indices and ICI in the preoperative period, no significant relationship was found in the postoperative period (r = 0.54 and 0.17 for tricuspid annular plane systolic excursion and r = 0.46 and 0.16 for systolic tricuspid annular velocity, respectively). The RVEDA/LVEDA ratio significantly decreased postoperatively (0.97 ± 0.21 vs 1.19 ± 0.43, P = 0.002) and was correlated with ICI both in preoperative and postoperative periods (r = 0.57 and 0.57, respectively). There was a significant correlation between changes in RVEDA/LVEDA ratio and changes in total pulmonary resistance.

CONCLUSIONS

Improved ICI and RVEDA/LVEDA ratio reflected the surgical success of PEA and lowering of total pulmonary resistances. In contrast to the RV/left ventricular area ratio, annular RV indices associated poorly with postoperative ICI. Recognizing this limitation is important in minimizing the overdiagnosis of RV dysfunction after PEA.

Pulmonary Hypertension and Right Ventricular Failure: Lung Transplant Versus Heart-Lung Transplant

Pulmonary arterial hypertension is a highly morbid disease with limited treatment options that improve survival and currently the only curative treatment is transplantation. There is a small body of literature comparing the efficacy of lung and heart-lung transplantation in this population. The bulk of evidence suggests that most patients with severe right ventricular failure undergoing transplant will have recovery of right ventricular function after lung transplantation. Existing data suggest that, in the absence of complex congenital heart disease or significant left ventricular dysfunction, double-lung transplant is the surgical procedure of choice.

Myocardial velocity, intra-, and interventricular dyssynchrony evaluated by tissue phase mapping in pediatric heart transplant recipients

BACKGROUND

Endomyocardial biopsy (EMB) is the standard method for detecting allograft rejection in pediatric heart transplants (Htx). As EMB is invasive and carries a risk of complications, there is a need for a noninvasive alternative for allograft monitoring.

PURPOSE

To quantify left and right ventricular (LV & RV) peak velocities, velocity twist, and intra-/interventricular dyssynchrony using tissue phase mapping (TPM) in pediatric Htx compared with controls, and to explore the relationship between global cardiac function parameters and the number of rejection episodes to these velocities and intra-/interventricular dyssynchrony.

STUDY TYPE

Prospective.

SUBJECTS

Twenty Htx patients (age: 16.0 ± 3.1 years, 11 males) and 18 age- and sex-matched controls (age: 15.5 ± 4.3 years, nine males).

FIELD STRENGTH/SEQUENCE

5T; 2D balanced cine steady-state free-precession (bSSFP), TPM (2D cine phase contrast with three-directional velocity encoding).

ASSESSMENT

LV and RV circumferential, radial, and long-axis velocity-time curves, global and segmental peak velocities were measured using TPM. Short-axis bSSFP images were used to measure global LV and RV function parameters.

STATISTICAL TESTS

A normality test (Lilliefors test) was performed on all data. For comparisons, a t-test was used for normally distributed data or a Wilcoxon rank-sum test otherwise. Correlations were determined by a Pearson correlation.

RESULTS

Htx patients had significantly reduced LV (P < 0.05-0.001) and RV (P < 0.05-0.001) systolic and diastolic global and segmental long-axis velocities, reduced RV diastolic peak twist (P < 0.01), and presented with higher interventricular dyssynchrony for long-axis and circumferential motions (P < 0.05-0.001). LV diastolic long-axis dyssynchrony (r = 0.48, P = 0.03) and RV diastolic peak twist (r = -0.64, P = 0.004) significantly correlated with the total number of rejection episodes.

DATA CONCLUSION

TPM detected differences in biventricular myocardial velocities in pediatric Htx patients compared with controls and indicated a relationship between Htx myocardial velocities and rejection history.

LEVEL OF EVIDENCE

2 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:1212-1222.

Left Ventricular Function Before and After Aerobic Exercise Training in Women With Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a chronic debilitating illness. The effects of vigorous aerobic exercise training (AET) on heart function in PAH are poorly understood.

METHODS

Eighteen women with PAH (aged 56.2 ± 8.8 yr, body mass index: 28.8 ± 7.3 kg/m) underwent 10 wk of vigorous AET. Cardiac function was observed at rest and peak exercise using bioelectrical impedance cardiography before and after the AET. Cardiac function was observed in a small PAH subset (n = 7) for 10 wk before beginning the AET. A cohort of sedentary women (n = 19) served as healthy controls.

RESULTS

Left ventricular ejection fraction (48 ± 9.2 vs 61.5 ± 13.3%, P = .034) and the systemic vascular resistance index (2258 ± 419.1 vs 2939 ± 962.4 dyn·sec/cm·m, P = .008) were lower at supine rest in the baseline PAH group versus the healthy group, as were peak exercise heart rate (140 ± 13.3 vs 170 ± 13.8 beats/min, P < .001) and systemic vascular resistance index (828 ± 141.1 vs 824 ± 300.9 dyn·sec/cm·m, P = .050) after controlling for age and heart rate. Systemic vascular resistance index measured at peak exercise decreased in the PAH group after AET (828 ± 141.1 vs 766 ± 139.6 dyn·sec/cm·m, P = .020). Left ventricular early diastolic filling ratio worsened in the PAH subset prior to AET (95.9 ± 19.4 vs 76.2 ± 18.9%, P = .043) and remained unchanged after AET.

CONCLUSION

Vigorous AET was not associated with significant declines in left ventricular systolic or diastolic function in women with PAH. Aerobic exercise training may be beneficial for reducing afterload and may preserve left ventricular diastolic function.

Left Ventricular Diastolic Function Assessment of a Heterogeneous Cohort of Pulmonary Arterial Hypertension Patients

BACKGROUND

Pulmonary arterial hypertension (PAH) is known to trigger right ventricular (RV) remodeling that might compromise left ventricular (LV) filling due to inter-ventricular interdependence. In this study, we aimed to examine standard echocardiographic measurements of LV diastolic function in PAH patients.

METHODS

In this retrospective study, we identified clinical as well as complete echocardiographic data from 128 chronic PAH patients to fully assess LV diastolic dysfunction (LVDD) using standard recommended Doppler guidelines. Accordingly, patients were divided into three groups: LVDD 0, LVDD 1 and LVDD 2.

RESULTS

The mean age of the studied population was 57 ± 14 years with a mean pulmonary artery systolic pressure (PASP) of 55 ± 21 mm Hg. A total of 36% of the study patients had normal LV diastolic function. However, 64% had LVDD with LVDD stage 1 being the most common (48%). In terms of echocardiographic data, significant differences were found among the three LVDD groups in regards to PASP, LV end systolic and diastolic volumes, tricuspid annular plane systolic excursion, right ventricular fractional area change as well as many other tissue Doppler imaging parameters. Finally, just age and PASP were predictors of abnormal LV diastolic function (P < 0.05).

CONCLUSIONS

Impaired relaxation is a common abnormality in PAH patients. Additional studies are warranted to determine whether LVDD alters prognosis or is related to changes in the symptomatic profile of this group of patients.

Equilibrium radionuclide angiocardiography for the evaluation of right ventricular ejection fraction in patients with cardiac disorders

OBJECTIVE

To compare correlation between right ventricular ejection fraction (RVEF) derived from MRI and equilibrium radionuclide angiocardiography (ERNA) depicted from the left anterior oblique (LAO) view and anterior (ANT) view [designated as ERNA (LAO) and ERNA (ANT), respectively].

METHODS

Twenty-one patients with cardiac disorders received ERNA and cardiac MRI examination within 2 weeks were enrolled in this study. The region of interest (ROI) in right ventricle was depicted from the LAO and anterior (ANT) views to calculate the ERNA (LAO) and ERNA (ANT). Cardiac MRI was performed as served as reference standard to compare correlation between RVEF derived from MRI and ERNA (LAO)/ERNA (ANT), respectively. The repeatability was evaluated according to the intraclass correlation coefficient (ICC).

RESULTS

RVEF obtained through MRI was closely correlated with that obtained through ERNA (LAO) view (r=0.883) and ERNA (ANT) view (r=0.891), respectively. Bland-Altam analysis indicated the RVEF derived from the ERNA (LAO) view was obviously underestimated in patients with right ventricular enlargement. Meanwhile, the RVEF derived from the anterior view was much closer to the RVEF derived from MRI compared with that obtained from the LAO view.

CONCLUSIONS

ERNA is effective for the determination of RVEF. LAO is still preferred for the determination of RVEF, but the RVEF may be underestimated in the patients with right ventricular enlargement. Determination of RVEF based on ANT is solely recommended in the determination of RVEF in patients with right ventricular enlargement and serves as a control.

The right ventricle under pressure: evaluating the adaptive and maladaptive changes in the right ventricle in pulmonary arterial hypertension using echocardiography (2013 Grover Conference series)

The importance of the right ventricle (RV) in pulmonary arterial hypertension (PAH) has been gaining increased recognition. This has included a reconceptualization of the RV as part of an RV-pulmonary circulation interrelated unit and the observation that RV function is a major determinant of prognosis in PAH. Noninvasive imaging of RV size and function is critical to the longitudinal management of patients with PAH, and continued understanding of the pathophysiology of pulmonary vascular disease relies on the response of the RV to pulmonary vascular remodeling. Echocardiography, in particular the newer echocardiographic measurements and techniques, allows easy, readily accessible means to assess and follow RV size and function.

Right ventricular myocardial biomarkers in human heart failure

BACKGROUND

Right ventricular (RV) dysfunction contributes to mortality in chronic heart failure (HF). However, the molecular mechanisms of RV failure remain poorly understood, and RV myocardial biomarkers have yet to be developed.

METHODS AND RESULTS

We performed RNA sequencing (RNA-seq) on 22 explanted human HF RVs and 5 unused donor human heart RVs (DON RV) and compared results to those recently reported from 16 explanted human LVs We used Bowtie-Tophat for transcript alignment and transcriptome assembly, DESeq for identification of differentially expressed genes (DEGs) and Ingenuity for exploration of gene ontologies. In the HF RV, RNA-seq identified 130,790 total RNA transcripts including 13,272 protein coding genes, 10,831 long non-coding RNA genes and 8,605 pseudogenes. There were 800-1000 DEGs between DON and HF RV comparison groups with differences concentrated in cytoskeletal, basement membrane, extracellular matrix (ECM), inflammatory mediator, hemostasis, membrane transport and transcription factor genes, lncRNAs and pseudogenes. In an unbiased approach, the top 10 DEGs SERPINA3, SERPINA5, LCN6, LCN10, STEAP4, AKR1C1, STAC2, SPARCL1, VSIG4 and F8 exhibited no overlap in read counts between DON and HF RVs, high sensitivities, specificities, predictive values and areas under the receiver operating characteristic curves. STEAP4, SPARCL1 and VSIG4 were differentially expressed between RVs and LVs, supporting their roles as RV-specific myocardial biomarkers.

CONCLUSIONS

Unbiased, comprehensive profiling of the RV transcriptome by RNA-seq suggests structural changes and abnormalities in inflammatory processes and yields specific, novel HF RV vs HF LV myocardial biomarkers not previously identified by more limited transcriptome profiling approaches.

Prostanoids but not oral therapies improve right ventricular function in pulmonary arterial hypertension

OBJECTIVES

This study hypothesized that right ventricular stroke work index (RVSWI) and pulmonary capacitance (PC) would increase after treatment for pulmonary arterial hypertension (PAH) and that prostanoids would have a stronger effect than oral therapy.

BACKGROUND

Right ventricular (RV) function is a major determinant of outcome in patients with PAH. Little is known about the response of RV function or its hemodynamic determinants to PAH-specific therapy.

METHODS

We reviewed hemodynamic and health data on 58 patients from an institutional registry and analyzed changes in hemodynamic status between diagnostic and first repeat catheterization after initiation of therapy for PAH.

RESULTS

The RVSWI and PC increased significantly after therapy (p = 0.007 and p = 0.02, respectively). Improvement in RV function was limited to patients treated with prostanoid-only therapy (p = 0.04); no improvement was found in patients treated with oral therapy (p = 0.25). Patients with the poorest baseline RV function (lowest tertile) had the greatest improvement post-therapy (p = 0.005 and p < 0.001 vs. middle and highest tertiles). The major determinant of RVSWI was change in stroke volume (r(s) = 0.54, p < 0.001), indicating RVSWI is an accurate reflection of RV function.

CONCLUSIONS

Right ventricular function improves after therapy with regimens including prostanoids but not oral-only regimens. Patients with the least compensated RV function at diagnosis might derive the most benefit from therapy. Larger studies are needed to determine whether changes in RVSWI after therapy are associated with outcomes.

Echocardiographic assessment of the right heart in mice

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential therapies. Given the expense and time involved in creating animal models of disease, it is critical that researchers have tools to accurately assess phenotypic expression of disease. Right ventricular dysfunction is the major manifestation of pulmonary hypertension. Echocardiography is the mainstay of the noninvasive assessment of right ventricular function in rodent models and has the advantage of clear translation to humans in whom the same tool is used. Published echocardiography protocols in murine models of PAH are lacking. In this article, we describe a protocol for assessing RV and pulmonary vascular function in a mouse model of PAH with a dominant negative BMPRII mutation; however, this protocol is applicable to any diseases affecting the pulmonary vasculature or right heart. We provide a detailed description of animal preparation, image acquisition and hemodynamic calculation of stroke volume, cardiac output and an estimate of pulmonary artery pressure.