CardioTwin HCM: A non-genetic early diagnostic test for hypertrophic cardiomyopathy risk

PROJECT SUMMARY – This project will validate CardioTwin HCM, a new test for hypertrophic cardiomyopathy (HCM) risk that will provide life-saving diagnostic information for families in whom genome- based diagnostics have failed. When sudden death occurs in an otherwise healthy young person, the most likely cause is a form of inherited cardiac disease known as hypertrophic cardiomyopathy. The prevalence of HCM in the general population is ~1:500, including undiagnosed individuals. If HCM is discovered in one family member, life-saving preventative measures can be taken for their relatives. Unfortunately, identifying at-risk family members early enough to intervene is difficult and sometimes impossible. Genetic sequencing is the current clinical standard for HCM screening in families. If a known mutation is found in an HCM patient, it can be used as a marker to identify at-risk family members - but this happens in only ~50% of index cases. A screening tool that does not rely on genetics for predicting HCM risk would reach the other 50% of families, drastically improving preventative therapy, reducing healthcare costs and anxiety in family members, and preventing deaths. In previous work, engineered heart tissues (EHTs) were made using induced pluripotent stem cells (iPSCs) from three different patients known to carry an autosomal dominant mutation for HCM. In each case, patient-derived EHTs exhibited increased strength and duration of contractions compared to EHTs made from healthy individuals. This “contraction signature” thus appears to be a robust phenotypic marker of HCM. We have streamlined this EHT approach with proprietary technology to create CardioTwin HCM: a robust and efficient system for measuring contractile signatures. To prove that CardioTwin HCM can be used as an accurate diagnostic, we will conduct a blinded study on HCM patient cell lines and non-HCM controls. If proven, CardioTwin HCM would the first HCM diagnostic to circumvent the pitfalls of genetic testing. Cardiologists will use this test when genetic testing is inconclusive, enabling the roughly 975,000 Americans with inconclusive genetic tests to finally be screened for HCM risk. The long-term goal is for CardioTwin HCM to become the standard of care for risk evaluation in HCM families for whom genetic testing is inconclusive. The specific aim of this Phase I project is to demonstrate that the CardioTwin HCM test can correctly diagnose HCM in a blinded patient cohort. Four randomly selected HCM patient iPSC lines and four additional non-HCM control lines from a commercial biobank will be obtained and put through the CardioTwin HCM testing procedure. Those with significantly altered contraction signatures will be flagged as HCM-positive. The sample identities will be unblinded and the sensitivity and specificity of CardioTwin HCM will be computed. Achieving aggregate sensitivity plus specificity rt1.5 would signal a breakthrough in HCM risk assessment, showing that a non-genetic approach is possible and justifying Phase II funding. In Phase II, Propria will expand blinded testing to a cohort of 30 individuals while optimizing production to reach cost feasibility. By our estimate, the US market for CardioTwin HCM is 975,000 tests.