Cardiac Efficacy Testing and Disease Modeling
Measure therapeutic responses in human 3D cardiac microtissues and develop disease-relevant models tailored to your program.
SmartHeart® combines human iPSC-derived cardiomyocytes, cardiac fibroblasts and tissue-level mechanics in a 96-well format. The platform enables quantitative assessment of how a treatment changes cardiac contraction, relaxation, beating activity and rhythm.
Use SmartHeart® for cardiac efficacy studies or work with 4Dcell to develop a fit-for-purpose model around a defined disease mechanism, cell source and therapeutic question.
SmartHeart® human 3D cardiac microtissues self-assemble around central pillars. Brightfield imaging and SmartX™ track changes in tissue geometry over time to quantify contraction strain, contraction and relaxation kinetics, beating frequency and, when mechanical calibration is available, derived contractile stress.
MEASURE THE CARDIAC RESPONSE THAT MATTERS
SmartHeart captures direct changes in cardiac function, helping teams compare candidates, concentrations and controls with endpoints that sit closer to the therapeutic phenotype than molecular readouts alone.
Contractile response
Quantify contraction strain and derived contractile stress across concentration- or time-response designs.
Beating rate and rhythm
Track beating frequency, regularity and treatment-induced instability at tissue level.
Relaxation kinetics
Detect changes in contraction and relaxation speed or timing that may reveal lusitropic effects.
Mechanistic context
Add optical calcium, action-potential, imaging or molecular readouts when the study question requires them.
Under defined operating conditions, SmartHeart®’s fit-for-purpose qualified contractility workflow detected the expected direction of inotropic effect for five positive and two negative reference compounds across three independent experiments.
The qualified core workflow used Day 21 tissues composed of human iPSC-derived cardiomyocytes and primary human ventricular cardiac fibroblasts at a 3:1 ratio, acute sequential compound addition and brightfield video analysis. Additional endpoints or materially different study conditions require appropriate assessment.
FROM CARDIAC EFFICACY TESTING
TO DISEASE-RELEVANT RESCUE
Cardiac Efficacy Studies
Measure dose response, onset, reversibility and therapeutic window in a defined tissue context; add mechanistic endpoints when needed.
This approach is suitable for comparing candidates, investigating an expected mechanism of action or determining whether a treatment produces a measurable change in cardiac function.
Custom Disease-Model Development
Establish a reproducible disease-control difference, then build a fit-for-purpose assay to test therapeutic rescue.
The development strategy is defined around the causal biology, expected phenotype, available cell lines, appropriate controls and the decision the study must support.
DEVELOP THE CARDIAC DISEASE MODEL YOUR PROGRAM NEEDS
A fit-for-purpose disease model must produce a measurable and reproducible difference between disease and control tissues that is relevant to the therapeutic question. For each program, we therefore select the cell source, matched controls, experimental conditions and readouts needed to establish the disease phenotype and determine whether a treatment produces functional rescue.
HYPERTROPHIC CARDIOMYOPATHY AND HYPERTROPHIC REMODELING
DILATED CARDIOMYOPATHY
SmartHeart could be adapted to study hypercontractility, impaired relaxation and progressive structural remodeling using disease-relevant cells or controlled pro-hypertrophic stimulation. A custom program should combine functional measurements with orthogonal evidence that the expected hypertrophic phenotype has been established.
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Potential strategies: patient-derived or isogenic HCM cells; gene-edited variants; chronic neurohumoral.
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Priority readouts: contraction strain, derived contractile stress, contraction and relaxation kinetics, beating frequency and rhythm regularity, calcium handling, tissue morphology and cardiomyocyte size, mechanism-specific molecular markers.
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Therapeutic question: does the treatment normalize the disease-associated phenotype without suppressing cell viability or baseline cardiac function?
For DCM, the objective would be to reproduce a stable hypocontractile or stress-sensitive phenotype and quantify functional rescue. Genetic programs could include LMNA-, TTN- or BAG3-related disease, subject to cell-line feasibility, appropriate controls and assay development
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Potential strategies: patient-derived cardiomyocytes, CRISPR-engineered isogenic controls, enginnered disease-associated variants, disease-relevant stress conditions with matched controls.
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Priority readouts: contractile deficit, kinetics, rhythm stability, calcium handling, tissue integrity and mechanism-specific biomarkers.
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Therapeutic question: does the intervention restore cardiac function, and is the observed rescue consistent with the intended mechanism of action?
Conceptual illustration of contractile impairment and functional rescue. Not experimental data.
CASE STUDY REVEALING A FUNCTIONAL RESCUE MECHANISM IN LMNA CARDIOMYOPATHY
A peer-reviewed study using 4Dcell’s ring-shaped cardiac microtissue architecture demonstrates how a human 3D model can connect a pathogenic LMNA variant to mitochondrial dysfunction, impaired contraction and pharmacological rescue.
THE SCIENTIFIC CHALLENGE
LMNA-related cardiomyopathy can lead to severe electrical and mechanical dysfunction, yet the pathway from nuclear-envelope mutation to contractile failure remains difficult to resolve in conventional cell culture.
THE EXPERIMENTAL MODEL
Researchers compared patient-derived hiPSC cardiomyocytes carrying the LMNA p.H222P variant with a CRISPR-corrected isogenic control. The two cell lines showed comparable cardiac differentiation and sarcomere organization, allowing the researchers to investigate functional, calcium-handling and metabolic differences associated with the LMNA variant.
WHAT THE MODEL REVEALED
Researchers compared patient-derived hiPSC cardiomyocytes carrying the LMNA p.H222P variant with a CRISPR-corrected isogenic control. The cells showed comparable cardiac differentiation and sarcomere organization, allowing the team to interrogate functional and metabolic differences in 3D cardiac tissues.
Tissue-level contractile dysfunction
SmartHeart® tissues generated with LMNA p.H222P cardiomyocytes showed lower contraction frequency, lower derived contractile stress and slower contraction and relaxation velocities than tissues generated with the CRISPR-corrected isogenic control. Genetic correction restored contractility toward the non-isogenic control.
Nuclear phenotype revealed in 3D
The 3D tissues revealed smaller and more elongated nuclei in LMNA-mutant cardiomyocytes than in the isogenic control. This phenotype differed from the nuclear changes observed in 2D monolayers and was consistent with increased nuclear deformability under the mechanical constraints of the 3D tissue environment.
Functional Rescue in 3D Tissues
Because contractility measurements were non-destructive, LMNA-mutant tissues could be recorded at baseline and again after seven days of treatment. Amorolfine increased contractility and improved contraction and relaxation parameters compared with vehicle-treated tissues.
COMPLEMENTARY MECHANISTIC FINDINGS IN hiPSC-DERIVED CARDIOMYOCYTES
Separate experiments performed in hiPSC-derived cardiomyocytes—not in the 3D SmartHeart® tissues—identified higher calcium-transient amplitude, slower calcium reuptake, altered MCU-complex stoichiometry, reduced mitochondrial respiration and lower ATP levels. These cellular findings provided mechanistic context for the tissue-level contractile phenotype.
WHAT SMARTHEART ADDED TO THE STUDY
SmartHeart® translated the LMNA genotype into a quantifiable tissue-level functional phenotype, revealed a distinct nuclear response under 3D mechanical constraints, enabled non-destructive longitudinal measurements before and after treatment, and supported in situ immunofluorescence within the ring-shaped tissue architecture.
Published configuration: The study used LMNA p.H222P hiPSC-derived cardiomyocytes combined with healthy human dermal fibroblasts at a 3:1 ratio in the published SmartHeart® ring configuration. This experimental configuration differs from the current SmartHeart® platform, which uses cardiac fibroblasts and nine microtissues per well.
Seguret M, Jouve C, Ruiz-Velasco A, et al. “LMNA p.H222P mutation causes contractile dysfunction via impaired mitochondrial calcium uptake in human cardiac laminopathy.” Cardiovascular Research. 2026. DOI: 10.1093/cvr/cvag163.
WHY SMARTHEART FOR A CUSTOM CARDIAC PROGRAM
SmartHeart® combines non-destructive functional measurements with in situ imaging and complementary mechanistic readouts. This enables efficacy studies to connect treatment exposure with changes in tissue function, morphology and mechanism over time.
Non-destructive direct contractility
Brightfield imaging quantifies contraction strain, contraction and relaxation kinetics, beating frequency and regularity without destroying the tissues. When pillar calibration is available, contractile stress can also be derived. The same tissues can therefore be followed across multiple time points to investigate delayed responses, repeated dosing and chronic exposure.
Multiple readouts for mechanistic hypotheses
Contractility measurements can be combined with optical membrane-potential recordings, calcium-transient analysis, targeted gene-expression assays or RNA sequencing when the study requires mechanistic interpretation. The selected readouts and their experimental configuration are defined for each program.
In situ morphological assessment
The glass-bottom plate supports live imaging and in situ immunofluorescence, allowing functional changes to be related to tissue organization, sarcomeric structure, cell morphology and disease-relevant nuclear phenotypes.
Quality-Controlled and Traceable Data
Each well contains nine microtissues, providing multiple tissue-level measurements per condition. SmartX™ applies documented segmentation and quality-control criteria, while analyses report exclusions, variability and statistical methods.
Independent wells and experiments remain essential because microtissues within one well are not independent biological replicates. The qualified workflow characterizes tissue- and experiment-level variability and readout-specific detection limits.
Automation-Compatible 96-Well Format
SmartHeart® uses a standard 96-well format with fixed imaging positions and is compatible with automated microscopes and scalable image-analysis workflows. Deployment for larger screening studies depends on achieving the required well-level tissue-formation and quality-control performance.