ResearchPad - systole https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Retrospectively ECG-gated helical vs. non-ECG-synchronized high-pitch CTA of the aortic root for TAVI planning]]> https://www.researchpad.co/article/elastic_article_13825 Multidetector computed tomography (MDCT) plays a key role in patient assessment prior to transcatheter aortic valve implantation (TAVI). However, to date no consensus has been established on what is the optimal pre-procedural imaging protocol. Variability in pre-TAVI acquisition protocols may lead to discrepancies in aortic annulus measurements and may potentially influence prosthesis size selection.PurposeThe current study evaluates the magnitude of differences in aortic annulus measurements using max-systolic, end-diastolic, and non-ECG-synchronized imaging, as well as the impact of method on prosthesis size selection.Material and methodsFifty consecutive TAVI-candidates, who underwent retrospectively-ECG-gated CT angiography (CTA) of the aortic root, directly followed by non-ECG-synchronized high-pitch CT of the entire aorta, were retrospectively included. Aortic root dimensions were assessed at each 10% increment of the R-R interval (0–100%) and on the non-ECG-synchronized scan. Dimensional changes within the cardiac cycle were evaluated using a 1-way repeated ANOVA. Agreement in measurements between max-systole, end-diastole and non-ECG-synchronized scans was assessed with Bland-Altman analysis.ResultsMaximal dimensions of the aortic root structures and minimum annulus-coronary ostia distances were measured during systole. Max-systolic measurements were significantly and substantially larger than end-diastolic (p<0.001) and non-ECG-synchronized measurements (p<0.001). Due to these discrepancies, the three methods resulted in the same prosthesis size selection in only 48–62% of patients.ConclusionsThe systematic differences between max-systolic, end-diastolic and non-ECG-synchronized measurements for relevant aortic annular dimensions are both statistically significant and clinically relevant. Imaging strategy impacts prosthesis size selection in nearly half the TAVI-candidates. End-diastolic and non-ECG-synchronized imaging does not provide optimal information for prosthesis size selection. Systolic image acquisition is necessary for assessment of maximal annular dimensions and minimum annulus-coronary ostia distances. ]]> <![CDATA[Right ventricular pressure overload directly affects left ventricular torsion mechanics in patients with precapillary pulmonary hypertension]]> https://www.researchpad.co/article/elastic_article_8470 This study examined the impact of septal flattening on left ventricular (LV) torsion in patients with precapillary pulmonary hypertension (PH). Fifty-two patients with proven precapillary PH and 13 healthy controls were included. Ventricular function was assessed including 4D-measurements, tissue velocity imaging, and speckle tracking analysis. Increased eccentricity index (1.39 vs. 1.08, p<0.001), systolic pulmonary artery pressure (64 vs. 29mmHg, p<0.001) and right ventricular Tei index (0.55 vs. 0.28, p = 0.007), and reduced tricuspid annular plane systolic excursion (19.0 vs. 26.5mm, p<0.001) were detected in PH patients as compared to controls. With increasing eccentricity of left ventricle, LV torsion was both decreased and delayed. Torsion rate paralleled this pattern of change during systole, but not during diastole. In conclusion, right ventricular pressure overload directly affects LV torsion mechanics. The echocardiographic methodology applied provides novel insights in the interrelation of right- and left ventricular function.

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<![CDATA[Quantification of left coronary bifurcation angles and plaques by coronary computed tomography angiography for prediction of significant coronary stenosis: A preliminary study with dual-source CT]]> https://www.researchpad.co/article/5989db52ab0ee8fa60bdc966

Purpose

To evaluate the diagnostic performance of left coronary bifurcation angles and plaque characteristics for prediction of coronary stenosis by dual-source CT.

Methods

106 patients suspected of coronary artery disease undergoing both coronary computed tomography angiography (CCTA) and invasive coronary angiography (CAG) within three months were included. Left coronary bifurcation angles including the angles between the left anterior descending artery and left circumflex artery (LAD-LCx), left main coronary artery and left anterior descending artery (LM-LAD), left main coronary artery and left circumflex artery (LM-LCx) were measured on CT images. CCTA plaque parameters were calculated by plaque analysis software. Coronary stenosis ≥ 50% by CAG was defined as significant.

Results

106 patients with 318 left coronary bifurcation angles and 126 vessels were analyzed. The bifurcation angle of LAD-LCx was significantly larger in left coronary stenosis ≥ 50% than stenosis < 50%, and significantly wider in the non-calcified plaque group than calcified. Multivariable analyses showed the bifurcation angle of LAD-LCx was an independent predictor for significant left coronary stenosis (OR = 1.423, P = 0.002). In ROC curve analysis, LAD-LCx predicted significant left coronary stenosis with a sensitivity of 66.7%, specificity of 78.4%, positive predictive value of 85.2% and negative predictive value of 55.8%. The lipid plaque volume improved the diagnostic performance of CCTA diameter stenosis (AUC: 0.854 vs. 0.900, P = 0.045) in significant coronary stenosis.

Conclusions

The bifurcation angle of LAD-LCx could predict significant left coronary stenosis. Wider LAD-LCx is related to non-calcified lesions. Lipid plaque volume could improve the diagnostic performance of CCTA for coronary stenosis prediction.

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<![CDATA[False Lumen Flow Patterns and their Relation with Morphological and Biomechanical Characteristics of Chronic Aortic Dissections. Computational Model Compared with Magnetic Resonance Imaging Measurements]]> https://www.researchpad.co/article/5989db4fab0ee8fa60bdba64

Aortic wall stiffness, tear size and location and the presence of abdominal side branches arising from the false lumen (FL) are key properties potentially involved in FL enlargement in chronic aortic dissections (ADs). We hypothesize that temporal variations on FL flow patterns, as measured in a cross-section by phase-contrast magnetic resonance imaging (PC-MRI), could be used to infer integrated information on these features. In 33 patients with chronic descending AD, instantaneous flow profiles were quantified in the FL at diaphragm level by PC-MRI. We used a lumped-parameter model to assess the changes in flow profiles induced by wall stiffness, tear size/location, and the presence of abdominal side branches arising from the FL. Four characteristic FL flow patterns were identified in 31/33 patients (94%) based on the direction of flow in systole and diastole: BA = systolic biphasic flow and primarily diastolic antegrade flow (n = 6); BR = systolic biphasic flow and primarily diastolic retrograde flow (n = 14); MA = systolic monophasic flow and primarily diastolic antegrade flow (n = 9); MR = systolic monophasic flow and primarily diastolic retrograde flow (n = 2). In the computational model, the temporal variation of flow directions within the FL was highly dependent on the position of assessment along the aorta. FL flow patterns (especially at the level of the diaphragm) showed their characteristic patterns due to variations in the cumulative size and the spatial distribution of the communicating tears, and the incidence of visceral side branches originating from the FL. Changes in wall stiffness did not change the temporal variation of the flows whereas it importantly determined intraluminal pressures. FL flow patterns implicitly codify morphological information on key determinants of aortic expansion in ADs. This data might be taken into consideration in the imaging protocol to define the predictive value of FL flows.

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<![CDATA[Quantification of Left Ventricular Torsion and Diastolic Recoil Using Cardiovascular Magnetic Resonance Myocardial Feature Tracking]]> https://www.researchpad.co/article/5989da91ab0ee8fa60ba04fe

Objectives

Cardiovascular magnetic resonance feature tracking (CMR-FT) offers quantification of myocardial deformation from routine cine images. However, data using CMR-FT to quantify left ventricular (LV) torsion and diastolic recoil are not yet available. We therefore sought to evaluate the feasibility and reproducibility of CMR-FT to quantify LV torsion and peak recoil rate using an optimal anatomical approach.

Methods

Short-axis cine stacks were acquired at rest and during dobutamine stimulation (10 and 20 µg·kg−1·min−1) in 10 healthy volunteers. Rotational displacement was analysed for all slices. A complete 3D-LV rotational model was developed using linear interpolation between adjacent slices. Torsion was defined as the difference between apical and basal rotation, divided by slice distance. Depending on the distance between the most apical (defined as 0% LV distance) and basal (defined as 100% LV distance) slices, four different models for the calculation of torsion were examined: Model-1 (25–75%), Model-2 (0–100%), Model-3 (25–100%) and Model-4 (0–75%). Analysis included subendocardial, subepicardial and global torsion and recoil rate (mean of subendocardial and subepicardial values).

Results

Quantification of torsion and recoil rate was feasible in all subjects. There was no significant difference between the different models at rest. However, only Model-1 (25–75%) discriminated between rest and stress (Global Torsion: 2.7±1.5°cm−1, 3.6±2.0°cm−1, 5.1±2.2°cm−1, p<0.01; Global Recoil Rate: −30.1±11.1°cm−1s−1,−46.9±15.0°cm−1s−1,−68.9±32.3°cm−1s−1, p<0.01; for rest, 10 and 20 µg·kg−1·min−1 of dobutamine, respectively). Reproducibility was sufficient for all parameters as determined by Bland-Altman analysis, intraclass correlation coefficients and coefficient of variation.

Conclusions

CMR-FT based derivation of myocardial torsion and recoil rate is feasible and reproducible at rest and with dobutamine stress. Using an optimal anatomical approach measuring rotation at 25% and 75% apical and basal LV locations allows effective quantification of torsion and recoil dynamics. Application of these new measures of deformation by CMR-FT should next be explored in disease states.

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<![CDATA[Closing the Loop: Modelling of Heart Failure Progression from Health to End-Stage Using a Meta-Analysis of Left Ventricular Pressure-Volume Loops]]> https://www.researchpad.co/article/5989da11ab0ee8fa60b79b7c

Introduction

The American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for the classification of heart failure (HF) are descriptive but lack precise and objective measures which would assist in categorising such patients. Our aim was two fold, firstly to demonstrate quantitatively the progression of HF through each stage using a meta-analysis of existing left ventricular (LV) pressure-volume (PV) loop data and secondly use the LV PV loop data to create stage specific HF models.

Methods and Results

A literature search yielded 31 papers with PV data, representing over 200 patients in different stages of HF. The raw pressure and volume data were extracted from the papers using a digitising software package and the means were calculated. The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased. A 2-element lumped parameter model was employed to model the mean loops and the error was calculated between the loops, demonstrating close fit between the loops. The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).

Conclusions

For the first time, the authors have created a visual and quantitative representation of the AHA/ACC stages of LVSD-HF, from normal to end-stage. The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification. The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF. Such information will enable cardiovascular modellers with an interest in HF, to create more accurate models of the heart as it fails.

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<![CDATA[The Prevalence and Prognosis of Resistant Hypertension in Patients with Heart Failure]]> https://www.researchpad.co/article/5989db3dab0ee8fa60bd57aa

Background

Resistant hypertension is associated with adverse clinical outcome in hypertensive patients. However, the prognostic significance of resistant hypertension in patients with heart failure remains uncertain.

Methods and Results

The 1 year survival and heart failure re-hospitalization rate of 1288 consecutive patients admitted to a university hospital for either newly diagnosed heart failure or an exacerbation of prior chronic heart failure was analyzed. Resistant hypertension was defined as uncontrolled blood pressure (>140/90 mmHg) despite being compliant with an antihypertensive regimen that includes 3 or more drugs (including a diuretic). A total of 176 (13.7%) heart failure patients had resistant hypertension. There was no difference in all cause mortality, cardiovascular mortality, and heart failure related re-hospitalization between patients with versus without resistant hypertension. Diabetes [hazard ratio = 1.62, 95% confidence interval = 1.13–2.34; P = 0.010] and serum sodium >139 mmol/L (hazard ratio = 1.54, 95% confidence interval = 1.06–2.23; P = 0.024) were independently associated with resistant hypertension. Patients with resistant hypertension had a relatively higher survival rate (86.9% vs. 83.8%), although the difference was not significant (log-rank x2 = 1.00, P = 0.317). In patients with reduced ejection fraction, heart failure related re-hospitalization was significantly lower in patients with resistant hypertension (45.8% vs. 59.1%, P = 0.050).

Conclusions

Resistant hypertension appears to be not associated with adverse clinical outcome in patients with heart failure, in fact may be a protective factor for reduced heart failure related re-hospitalization in patients with reduced ejection fraction.

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<![CDATA[All-Cause Mortality in Patients with Type 2 Diabetes in Association with Achieved Hemoglobin A1c, Systolic Blood Pressure, and Low-Density Lipoprotein Cholesterol Levels]]> https://www.researchpad.co/article/5989da20ab0ee8fa60b7e774

Background

To identify the ranges of hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and low-density lipoprotein cholesterol (LDL-C) levels which are associated with the lowest all-cause mortality.

Methods

A retrospective cohort of 12,643 type 2 diabetic patients (aged ≥18 years) were generated from 2002 to 2010, in Far-Eastern Memorial Hospital, New Taipei city, Taiwan. Patients were identified to include any outpatient diabetes diagnosis (ICD-9: 250), and drug prescriptions that included any oral hypoglycemic agents or insulin prescribed during the 6 months following their first outpatient visit for diabetes. HbA1c, SBP, and LDL-C levels were assessed by the mean value of all available data, from index date to death or censor date. Deaths were ascertained by matching patient records with the Taiwan National Register of Deaths.

Results

Our results showed general U-shaped associations, where the lowest hazard ratios occurred at HbA1c 7.0–8.0%, SBP 130–140 mmHg, and LDL-C 100–130 mg/dL. The risk of mortality gradually increases if the patient's mean HbA1c, SBP, or LDL-C during the follow-up period was higher or lower than these ranges. In comparison to the whole population, the adjusted hazard ratio (95% CI) for patients with HbA1c 7.0–8.0%, SBP 130–140 mmHg, and LDL-C 100–130 mg/dL were 0.69 (0.62–0.77), 0.80 (0.72–0.90), and 0.68 (0.61–0.75), respectively.

Conclusions

In our type 2 diabetic cohort, the patients with HbA1c 7.0–8.0%, SBP 130–140 mmHg, or LDL-C 100–130 mg/dL had the lowest all-cause mortality. Additional research is needed to confirm these associations and to further investigate their detailed mechanisms.

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<![CDATA[Local versus global aortic pulse wave velocity in early atherosclerosis: An animal study in ApoE-/--mice using ultrahigh field MRI]]> https://www.researchpad.co/article/5989db52ab0ee8fa60bdc4e9

Increased aortic stiffness is known to be associated with atherosclerosis and has a predictive value for cardiovascular events. This study aims to investigate the local distribution of early arterial stiffening due to initial atherosclerotic lesions. Therefore, global and local pulse wave velocity (PWV) were measured in ApoE-/- and wild type (WT) mice using ultrahigh field MRI. For quantification of global aortic stiffness, a new multi-point transit-time (TT) method was implemented and validated to determine the global PWV in the murine aorta. Local aortic stiffness was measured by assessing the local PWV in the upper abdominal aorta, using the flow/area (QA) method. Significant differences between age matched ApoE-/- and WT mice were determined for global and local PWV measurements (global PWV: ApoE-/-: 2.7±0.2m/s vs WT: 2.1±0.2m/s, P<0.03; local PWV: ApoE-/-: 2.9±0.2m/s vs WT: 2.2±0.2m/s, P<0.03). Within the WT mouse group, the global PWV correlated well with the local PWV in the upper abdominal aorta (R2 = 0.75, P<0.01), implying a widely uniform arterial elasticity. In ApoE-/- animals, however, no significant correlation between individual local and global PWV was present (R2 = 0.07, P = 0.53), implying a heterogeneous distribution of vascular stiffening in early atherosclerosis. The assessment of global PWV using the new multi-point TT measurement technique was validated against a pressure wire measurement in a vessel phantom and showed excellent agreement. The experimental results demonstrate that vascular stiffening caused by early atherosclerosis is unequally distributed over the length of large vessels. This finding implies that assessing heterogeneity of arterial stiffness by multiple local measurements of PWV might be more sensitive than global PWV to identify early atherosclerotic lesions.

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<![CDATA[Accuracy of subject-specific prediction of end-systolic time in MRI across a range of RR intervals]]> https://www.researchpad.co/article/5989db5dab0ee8fa60be04db

Background

Prediction of End-Systole time is of utmost importance for cardiac MRI to correctly associate acquired k-space lines during reconstruction of cine acquisitions. This prediction is usually based on the patient’s heart rate using Weissler’s formula, which was calibrated by linear regression within a population and cannot account for individual variability.

Objective

We propose an automatic method to build a personalized model that better predicts end-systole.

Methods

A phase contrast sequence was modified to acquire only central k-space line with 6.6ms temporal resolution, in a slice passing through the aorta during 128 heartbeats in 35 subjects. Segmentation of aorta and detection of end of systolic ejection was automatic. Duration of electromechanical systole duration as function of heart rate was determined for each subject separately.

Results

In comparison with the global models, the adapted cardiac model predicted significantly better both echocardiographic end-systolic reference (bias = 0ms vs 17ms, p<0.001) and MRI measurements (bias = 6.8ms vs 17ms). Favorable impact was shown on the cine reconstruction of the 5 subjects with the higher cardiac variability (p = 0.02).

Conclusions

Personalization of cardiac model to the subject is feasible in MRI and reduces the error of prediction of systole.

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<![CDATA[Prevalence and Associated Factors of Hypertension among Adults in Durame Town, Southern Ethiopia]]> https://www.researchpad.co/article/5989dacfab0ee8fa60bb596f

Background

To date, non-communicable diseases, such as cardiovascular diseases, are becoming severe public health challenges particularly in developing countries. Hypertension is a modifiable risk factor that contributes the leading role for mortality. The problem is significant in low- and middle-income countries like sub-Saharan Africa. However, there are limited studies in developing countries, particularly in Ethiopia. Hence, determining the magnitude of hypertension and identifying risk groups are important.

Methods

A community based cross sectional study was conducted in April 2013 among adults (age>31 years) old. A systematic sampling technique was used to select a total of 518 study participants. Data were collected after full verbal informed consent was obtained from each participant. Multivariable logistic regressions were fitted to control the effect of confounding. Adjusted Odds ratios (OR) with their 95% confidence intervals (95% CI) were calculated to measure associations. Variables having P-value <0.05 were considered as significant.

Results

The overall prevalence of hypertension in Durame town was 22.4% (95% CI: 18.8–26.0). Nearly 40% of hypertensive patients were newly screened. Male sex [AOR  = 2.03, 95% CI; 1.05–3.93], age [AOR  = 29.49, 95% CI; 10.60–81.27], salt use [AOR  = 6.55, 95% CI; 2.31–18.53], eating vegetable three or fewer days per week [AOR  = 2.3,95% CI; 1.17–4.51], not continuously walking at least for 10 minutes per day [AOR  = 7.82, 95% CI; 2.37–25.82], having family history of hypertension [AOR  = 2.46, 95%CI; 1.31–4.61] and being overweight/obese [AOR  = 15.7, 95% CI 7.89–31.21)] were found to be risk factors for hypertension.

Conclusions

The prevalence of hypertension is found to be high. Older age, male sex, having family history of hypertension, physical inactivity, poor vegetable diet, additional salt consumption and obesity were important risk factors associated with hypertension among adults. Community level intervention measures with a particular emphasis on prevention by introducing lifestyle modifications are recommended.

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<![CDATA[Fluid Overload, Pulse Wave Velocity, and Ratio of Brachial Pre-Ejection Period to Ejection Time in Diabetic and Non-Diabetic Chronic Kidney Disease]]> https://www.researchpad.co/article/5989d9daab0ee8fa60b67367

Fluid overload is one of the characteristics in chronic kidney disease (CKD). Changes in extracellular fluid volume are associated with progression of diabetic nephropathy. Not only diabetes but also fluid overload is associated with cardiovascular risk factors The aim of the study was to assess the interaction between fluid overload, diabetes, and cardiovascular risk factors, including arterial stiffness and left ventricular function in 480 patients with stages 4–5 CKD. Fluid status was determined by bioimpedance spectroscopy method, Body Composition Monitor. Brachial-ankle pulse wave velocity (baPWV), as a good parameter of arterial stiffness, and brachial pre-ejection period (bPEP)/brachial ejection time (bET), correlated with impaired left ventricular function were measured by ankle-brachial index (ABI)-form device. Of all patients, 207 (43.9%) were diabetic and 240 (50%) had fluid overload. For non-diabetic CKD, fluid overload was associated with being female (β = –2.87, P = 0.003), heart disease (β = 2.69, P = 0.04), high baPWV (β = 0.27, P = 0.04), low hemoglobin (β = –1.10, P<0.001), and low serum albumin (β = –5.21, P<0.001) in multivariate analysis. For diabetic CKD, fluid overload was associated with diuretics use (β = 3.69, P = 0.003), high mean arterial pressure (β = 0.14, P = 0.01), low bPEP/ET (β = –0.19, P = 0.03), low hemoglobin (β = –1.55, P = 0.001), and low serum albumin (β = –9.46, P<0.001). In conclusion, baPWV is associated with fluid overload in non-diabetic CKD and bPEP/bET is associated with fluid overload in diabetic CKD. Early and accurate assessment of these associated cardiovascular risk factors may improve the effects of entire care in late CKD.

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<![CDATA[Permanent Cardiac Sarcomere Changes in a Rabbit Model of Intrauterine Growth Restriction]]> https://www.researchpad.co/article/5989d9d5ab0ee8fa60b656db

Background

Intrauterine growth restriction (IUGR) induces fetal cardiac remodelling and dysfunction, which persists postnatally and may explain the link between low birth weight and increased cardiovascular mortality in adulthood. However, the cellular and molecular bases for these changes are still not well understood. We tested the hypothesis that IUGR is associated with structural and functional gene expression changes in the fetal sarcomere cytoarchitecture, which remain present in adulthood.

Methods and Results

IUGR was induced in New Zealand pregnant rabbits by selective ligation of the utero-placental vessels. Fetal echocardiography demonstrated more globular hearts and signs of cardiac dysfunction in IUGR. Second harmonic generation microscopy (SHGM) showed shorter sarcomere length and shorter A-band and thick-thin filament interaction lengths, that were already present in utero and persisted at 70 postnatal days (adulthood). Sarcomeric M-band (GO: 0031430) functional term was over-represented in IUGR fetal hearts.

Conclusion

The results suggest that IUGR induces cardiac dysfunction and permanent changes on the sarcomere.

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<![CDATA[Patient-Specific MRI-Based Right Ventricle Models Using Different Zero-Load Diastole and Systole Geometries for Better Cardiac Stress and Strain Calculations and Pulmonary Valve Replacement Surgical Outcome Predictions]]> https://www.researchpad.co/article/5989daf5ab0ee8fa60bc2c34

Background

Accurate calculation of ventricular stress and strain is critical for cardiovascular investigations. Sarcomere shortening in active contraction leads to change of ventricular zero-stress configurations during the cardiac cycle. A new model using different zero-load diastole and systole geometries was introduced to provide more accurate cardiac stress/strain calculations with potential to predict post pulmonary valve replacement (PVR) surgical outcome.

Methods

Cardiac magnetic resonance (CMR) data were obtained from 16 patients with repaired tetralogy of Fallot prior to and 6 months after pulmonary valve replacement (8 male, 8 female, mean age 34.5 years). Patients were divided into Group 1 (n = 8) with better post PVR outcome and Group 2 (n = 8) with worse post PVR outcome based on their change in RV ejection fraction (EF). CMR-based patient-specific computational RV/LV models using one zero-load geometry (1G model) and two zero-load geometries (diastole and systole, 2G model) were constructed and RV wall thickness, volume, circumferential and longitudinal curvatures, mechanical stress and strain were obtained for analysis. Pairwise T-test and Linear Mixed Effect (LME) model were used to determine if the differences from the 1G and 2G models were statistically significant, with the dependence of the pair-wise observations and the patient-slice clustering effects being taken into consideration. For group comparisons, continuous variables (RV volumes, WT, C- and L- curvatures, and stress and strain values) were summarized as mean ± SD and compared between the outcome groups by using an unpaired Student t-test. Logistic regression analysis was used to identify potential morphological and mechanical predictors for post PVR surgical outcome.

Results

Based on results from the 16 patients, mean begin-ejection stress and strain from the 2G model were 28% and 40% higher than that from the 1G model, respectively. Using the 2G model results, RV EF changes correlated negatively with stress (r = -0.609, P = 0.012) and with pre-PVR RV end-diastole volume (r = -0.60, P = 0.015), but did not correlate with WT, C-curvature, L-curvature, or strain. At begin-ejection, mean RV stress of Group 2 was 57.4% higher than that of Group 1 (130.1±60.7 vs. 82.7±38.8 kPa, P = 0.0042). Stress was the only parameter that showed significant differences between the two groups. The combination of circumferential curvature, RV volume and the difference between begin-ejection stress and end-ejection stress was the best predictor for post PVR outcome with an area under the ROC curve of 0.855. The begin-ejection stress was the best single predictor among the 8 individual parameters with an area under the ROC curve of 0.782.

Conclusion

The new 2G model may be able to provide more accurate ventricular stress and strain calculations for potential clinical applications. Combining morphological and mechanical parameters may provide better predictions for post PVR outcome.

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