A national repository of cardiac safety data stored by the University of Rochester Medical Center (URMC) in the US will benefit from a large set of electrocardiographic (ECG) recordings supplied by Pfizer from a clinical study of an unnamed drug that fell short of the marketplace.

Last July, URMC announced that it was collaborating with the US Food and Drug Administration to develop the Telemetric and Holter Electrocardiogram Warehouse (THEW), comprising a digital catalogue of continuous recordings from both cardiac patients and healthy individuals.

The THEW database, which is part of the Medical Center’s Heart Research Follow-up Program, can be accessed by academic researchers, pharmaceutical companies, contract research organisations, device manufacturers and other interested parties as an aid to studying the electrical activity of the heart and developing new tools to ensure the safety of drugs in development.

Pfizer Global Research and Development’s Sandwich Laboratory in the UK has released to URMC a full complement of study data from which more than 1.5 million individual ECG datasets can be extracted. According to the Center, this is the first time a major pharmaceutical company has agreed publicly to share anonymised data from one of its drug safety trials, including data on the evaluated compound.

The donation consists of several important ECG datasets from different phases of a study involving a drug that did not reach the market due to its adverse effect on cardiac ventricular repolarisation, URMC explained. This process is the split second between the heart’s contraction and recovery phases. If a drug prolongs repolarisation, it is generally believed to heighten the risk of adverse cardiac events such as dangerous arrhythmias and heart attacks, the Center noted.

In an ECG recording, the process of ventricular repolarisation is measured in terms of the QT interval (the time between the start of the Q wave and the end of the T wave in the heart’s electrical cycle). Prolongation of the QT interval associated with episodes of fatal ventricular arrhythmias is a leading cause of drugs being taken off the market and a leading impetus for international collaboration to develop specialised studies that monitor the QT prolongation effects of new drugs, URMC pointed out, adding that the THEW project “is part of this initiative”.

The Pfizer dataset is “extremely valuable because it enables scientists to evaluate the electrical activity in the heart before and after study participants took the drug and compare that data to study subjects who received a placebo or a control drug that is known to prolong the repolarisation process”, the Center said.

Before the THEW project was set up, researchers at URMC had already been collecting and studying ECG data for decades through the Heart Research Follow-up Program. The ECG data repository is owned and maintained by the Center, while the FDA is represented on the THEW executive committee as well as providing scientific input on research projects to improve drug safety, such as identifying patterns in ECG data that reveal drug side-effects.