DOI: 10.5061/dryad.tx95x6b6f
title: Patient-specific models of dyssynchronous heart failure for assessment of regional work in patients undergoing cardiac resynchronization therapy

description: Cardiac resynchronization therapy (CRT) can improve the synchrony of
 contraction between the right and left ventricles in DHF and reduce
 morbidity and mortality and increase quality of life. However, regional
 work before CRT and changes with CRT are not well understood. We used
 three-dimensional multi-scale patient-specific computational models
 parameterized by anatomic, functional, hemodynamic, and
 electrophysiological measurements to assess changes in eight patients with
 heart failure and left bundle branch block (LBBB) who received CRT. To
 increase clinical translatability, we also explored the utility of
 streamlined methods to estimate regional myocardial work. We found that
 CRT increased global myocardial work efficiency with significant
 improvements in non-responders. Reverse ventricular remodeling after CRT
 was greatest in patients with the highest heterogeneity of regional work
 at baseline. Decreases in early-activated regions of myocardium performing
 negative myocardial work with CRT best explained patient variations in
 reverse remodeling. These findings were also observed when regional
 myocardial work was estimated using ventricular pressure as a surrogate
 for myocardial stress and changes in endocardial surface area as a
 surrogate for strain. These findings suggest that CRT promotes reverse
 ventricular remodeling in human dyssynchronous heart failure by increasing
 regional myocardial work in early-activated regions of the ventricles and
 that measurement of these changes can be performed using streamlined
 approaches.
description: We built three-dimensional multi-scale patient-specific
 computational models parameterized by anatomic, functional, hemodynamic,
 and electrophysiological measurements in eight patients with heart failure
 and left bundle branch block (LBBB) who received CRT.
 To increase clinical translatability, we also explored whether
 streamlined computational methods provide accurate estimates of regional
 myocardial work.
description: **Paper: Patient-Specific Models of Dyssynchronous Heart Failure for
 Assessment of Regional Work in Patients Undergoing Cardiac
 Resynchronization Therapy** **Authors:** Amanda Craine, Adarsh
 Krishnamurthy, Christopher T Villongco, Kevin Vincent, David E Krummen,
 Sanjiv M Narayan, Roy CP Kerckhoffs, Jeffery Omens, Francisco Contijoch,
 Andrew D McCulloch **Description:** This README file describes the data
 package accompanying the publication above. The data is split into two
 parent files corresponding to two different features of this study:
 Patient-Specific Modeling, and Simplified Work Estimates. **File
 Structure** **Patient-Specific Modeling Dataset:** **Files:** **Simulation
 Data** folder: This folder contains the simulation results for each
 subject of this study, separated by subject. Below is an example of the
 file structure and its contents for one subject. The same file structure
 applies to all subjects (BiV1-8). **BiV1**: Biventricular simulation data
 for subject 1 *Parameter1*: Simulation results at baseline (labeled LBBB)
 1. BiV1_CT_unloaded_DT_CA_LBBB_FullBeat.cont6: Continuity file of
 biventricular model at baseline, generated with patient-specific
 parameters 2. FullBeat10.zip: All deformed meshes for the 10th beat of
 simulation 3. iphases.mat: timing information for opening and closing of
 mitral and aortic valves 4. SimulationBiV1Par1_HemodataFullBeatCALBBB.xls:
 Simulated hemodynamics data for all beats at baseline. The measurements
 for each column are listed in CircAdapt_Hemodata_Columns_Units.xlsx 5.
 stress10.xls: simulated myocardial stress results for the 10th beat 6.
 stretch10.xls: simulated myocardial stretch results for the 10th beat
 *Parameter4*: Simulation results after CRT (labeled CRT) 1.
 BiV1_CT_unloaded_DT_CA_CRT_FullBeat.cont6: Continuity file of
 biventricular model after CRT, generated with patient-specific parameters
 2. FullBeat10.zip: All deformed meshes for the 10th beat of simulation 3.
 iphases.mat: timing information for opening and closing of mitral and
 aortic valves 4. SimulationBiV1Par1_HemodataFullBeatCACRT.xls: Simulated
 hemodynamics data for all beats after CRT. The measurements for each
 column are listed in CircAdapt_Hemodata_Columns_Units.xlsx 5.
 stress10.xls: simulated myocardial stress results for the 10th beat 6.
 stretch10.xls: simulated myocardial stretch results for the 10th beat
 **Simplified Work Estimates Dataset** This directory contains data and
 functions needed to generate simplified myocardial work measurements from
 finite element meshes of patient-specific left ventricular (LV)
 endocardium. **Files:** **Data folder:** This folder contains the results
 of all regional strain, stress, and myocardial work estimates as .mat
 files. This folder also contains a subfolder called Generic
 Pressure-Strain Estimate, which stores a digitized generic LV pressure
 waveform as a .csv file. The variables and units for this work at
 in Simplified_Work_Estimate_Units.xlsx. 1. all_seg_strain_all_pats.mat:
 segmental strain for all patients. Segments are defined by the 17-segment
 AHA model. Variables contained in this mat file are seg_strain_all_pats
 (segmental PSM-based strain measurements) and segRSCT_allpats (segmental
 simplified strain measurements). 2. all_seg_work_all_pats.mat: segmental
 work measurements for all patients. Variables contained in this mat file
 are segWork_allpats (segmental PSM-based work), segMWCT_allpats (segmental
 PLHCSA results). 3. Generic Pressure-Strain Estimate 1. Generic_LVP.csv:
 generic pressure waveform digitized from Wigger's diagram (Human Bio
 Media) 4. GenericLVP_work_all_patches.mat: generic pressure-based
 simplified regional work estimates (PgenSA and Pgen,scaledSA) for each
 patch of the LV geometry for all patients. Variables included are
 MWCTgenericLVP (PgenSA results) and MWCTgenericLVP_patES (Pgen,scaledSA
 results). 5. genericLVPs.mat: stores the digitized generic LV pressure
 waveform (variable genericLVP) and generic pressure waveforms scaled to
 patient-specific peak pressure for each patient (variable genericLVP_ESP).
 6. Laplace_measurements.mat: stored the local effective radius (variable
 r_eff_allpats) and wall thickness measurements (variable thickness_data)
 for each patient to compute wall stresses.  7.
 Laplace_work_all_patches.mat: wall stress-based simplified regional work
 estimates (WSEDSA and WSTVSA) for each patch of the LV geometry for all
 patients. Variables included are MWCTLP (WSEDSA results) and MWCTLPTV
 (WSTVSA results). 8. MWCT_tris.mat: catheterization pressure-based
 simplified regional work estimate (PLHCSA) for each patch of the LV
 geometry for all patients (variable MWCT_tris). 9. PatchAreas.mat: area of
 each patch on the LV surface for each patient (variable PatchAreas). 10.
 RS_CT.mat: simplified regional strain estimate (RSCT) for each patch of
 the LV geometry for all patients (variable RSCT_tris). 11.
 seg_strain_allpats.mat: segmental strain measurements for each patient
 derived from patient-specific model (variable seg_strain_allpats). Also
 stored in all_seg_strain_all_pats.mat. 12. segMWCT_effrad_allpats.mat:
 segmental wall-stress-based simplified work measurements for all patients.
 Variables contained in this mat file are segMWCTLP (segmental WSEDSA),
 segMWCTLPTV (segmental WSTVSA). 13. segMWCT_genericLVP_allpats.mat:
 segmental generic pressure-based simplified work measurements for all
 patients. Variables contained in this mat file are segMWCT_genericLVP
 (segmental PgenSA results), and segMWCT_genericLVP_patES (segmental
 Pgen,scaledSA results). 14. dataPSMLBBBCRT.mat: data from patient-specific
 modeling. **LV Geometric Models folder:** Contains LV geometric models for
 all 8 patients. The models are stored in the following structure for a
 sample case: BiV1-8/BiV1/LVPointsXYZ where XYZ is the relative time of the
 recording of each model. Each case is then represented as a collection of
 geometric models demonstrating LV motion over one cardiac cycle. Each time
 frame is stored in three file formats: .obj, .txt, and .xls. ##### Scripts
 folder: Contains the functions and scripts used to compute and
 analyze regional strain, stress, and myocardial work. User will need to
 download two packages from MATLAB to process the data: readObj and
 ellipsoid_fit. Below, the scripts are organized by use. **Function
 files**: 1. calculate_RSCT.m: computes simplified regional strain from LV
 geometric model 2. calculatePatchWorkEstimates.m: computes work estimated
 for every patch of the geometric model 3.
 calculateSegmentalWorkEstimates.m: computes simplified work for each
 segment of the LV using the 17 segment AHA model. 4. data_analysis.m:
 performs statistical analysis for comparison of two datasets. 5.
 getNegWorkFractions.m: computes the fraction of the LV areas performing
 negative work 6. getSegmentLabels.m: generates an array indicated which
 patch on the LV model corresponds to each AHA segment. 7.
 PolyAreaSigned.m: computes area of a polygon. **CRT Analysis Scripts**:
 subfolder containing functions to evaluate utility of simplified work
 estimated to predict CRT response (figures 5 and 9, table 4 in main
 manuscript) 1. calculateNegWorkFraction.m: computes the fraction of the LV
 volume performing negative work 2. plotCorrelationPatientData.m: generates
 correlation plots between simplified work estimates and PSM-based work. 3.
 plotHistogram.m: generates histogram of work metrics for CRT responders
 and non-responders. 4. plotResponderBoxplot.m: generates boxplots that
 compare work metrics from PSM-based work estimates between CRT responders
 and non-responders 5. plotResponderBoxplotAllEsimates.m: generates
 boxplots that compares the ability for work metrics from PSM-based work
 and simplified work estimates to stratify CRT responders and
 non-responders. 6. plotResponderBoxplotCOV.m: generates boxplots that
 compares the ability for COVW computed with PSM-based work and simplified
 work estimates to stratify CRT responders and non-responders. **Scripts**:
 1. calculateSimpleWork.m: calculates 4 of the 5 simplified work
 measurements: generic LV pressure-regional strain area (PgenSA), generic
 LV pressure scaled to patient specific LV pressure-regional strain area
 (Pgen,scaledSA), end-diastolic wall stress-strain area (WSEDSA) and
 time-varying wall stress-strain area (WSTVSA). Results are stored as
 Laplace_work_all_patches.mat and GenericLVP_work_all_patches.mat in the
 data folder. 2. CalculateTriMW.m: Computes work as the left heart
 catheterization derived LV pressure-strain area (PLHCSA). Results stored
 as MWCT_tris.mat. Also computes segmental work based on 17 AHA segment
 model for PLHCSA and PSM-based work. Results for each work metric are
 stored in the data folder as segMWCT_allpats.mat and
 all_seg_work_all_pats.mat respectively. 3. CalculateTriStrain.m: computes
 simplified regional strain for all patches on the LV surface and for each
 AHA segment. Regional strain results for all patches are stored as
 RS_CT.mat. Segmental strain results are stores as seg_strain_allpat.mat.
 results are stored in the data folder. 4. CRT_responder_analysis2.m:
 compares ability for metrics of PSM-based work and simplified estimates of
 work to predict CRT responders. 5. evaluateLVPestimates.m: computes
 generic pressure waveform scaled to patient-specific peak LV pressures
 (Pgen,scaled). Generic pressure waveform stored as genericLVP.mat and
 Pgen,scaled results for each patient stored in genericLVP_ESP.mat in data
 folder. 6. getPatchAreas.m: computes the areas of each patch on the
 surface of the geometric LV models. Results stored as PatchAreas.mat in
 data folder. 7. paper_results_figures.m: computes figures in Supplement 2
 (Simplified Work Estimates: Methodology for simplified estimates of
 myocardial work). 8. PrincipalCurvatureAnalysis2.m: generates principal
 curvatures for each case and stores results along with wall thickness
 measurements in Laplace_measurements.mat in the data folder. Computes
 segmental wall stress-strain area work estimates (WSEDSA and WSTVSA) and
 stores them in seg_MWCT_effrad_allpats.mat in the data folder. 9.
 WorkMetrics.m: computes work metrics from PSM-based work measurements. 10.
 WorkPatAllMetric.m: plots correlations between a particular work metric of
 interest and a clinical parameter of interest. **Segmental Wall Thickness
 Measurements folder**: Contains .txt files of regional LV wall thickness
 measurements over time for each case. For example, data for one case is
 stored as BiV1/ WallThicknessWholeLVTimeVar.txt. **Sharing/Access
 Information** All necessary data is stored within the repository.