Validation of Biomarkers for risk stratification in Sudden Cardiac Death in cardiomyopathy

Aims
• To identify a pattern of proteins accurately measured in the plasma of cardiomyopathy patients who have been identified as at high risk of Sudden Cardiac death (SCD).
• To validate a LC-MS/MS-SRM (liquid chromatography tandem mass spectrometry selected reaction monitoring) method for the measurement of multiple proteins in the plasma of patients at high risk of SCD.
• To develop a statistical model to provide stratification information for at-risk patients.
• If time and progress permits, to reverse translate these findings such that we study the potential mechanisms of this disease.

Background
First line preventative treatment of Sudden cardiac death (SCD) is intra-cardiac defibrillators (ICDs). However in about 40% of those fitted with ICDs there is no activation within the first four years after implant. This means that the current strategy for identifying high risk patients is generating a lot of false positives leading to unnecessary interventions which are costly to the health service. Within the John and Lucille van Geest Biomarker Facility at the University of Leicester we have identified but not verified or validated a small set of proteins which collectively add to a statistical model which accurately stratifies high risk patients who would be more appropriately implanted with an ICD, allowing a precision medicine approach to ICD implantation.

Hypothesis
A pattern of proteins enables accurate stratification of at-risk patients with SCD.

Experimental Methods and Research Plan
• Develop a targeted method for several proteins identified in previous agnostic discovery experiments using LC-MS/MS-SRM with stable isotope labelled standards.
• Validate the above method using FDA bioanalytical method validation criteria (including (not exclusively) precision, accuracy, linearity, robustness etc.)
• All these preliminary findings will be clinically validated by developing SRM assays using TQ-MS (triple quadrupole mass spectrometry) and results verified within the original ischemic cardiomyopathy patient’s samples and in an independent cohort (MINERVA - a 12 centre UK clinical trial that commenced in September 2016 with Prof A Ng as the UK chief investigator) to assess the utility of LifeMapTM (R2I2) in predicting sudden death and ventricular arrhythmia events in ischaemic cardiomyopathy.
• Time and progress permitting we would investigate the role of these proteins in prediction of the LifeMap risk stratifier (R2I2), to clarify the roles of these proteins in determining ventricular electrical instability.

Expected outcome and Impact
• Validated LC-MS assay for the accurate measurement of multiple proteins in a single, high-throughput assay.
• This assay will be used to see if it can improve on current clinical markers and a recent improvement in diagnosing SCD developed in Leicester called R2I2.
• Potential commercialisation of assay in partnership with Waters Corporation.