Every year, an estimated 805,000 Americans have a heart attack – that’s one every 40 seconds, according to the Centers for Disease Control and Prevention.
But not all heart attacks are the same, and the development of better treatment approaches requires understanding the distinction between heart attacks that result from blood clots after a plaque rupture and those that do not.
Research now underway at New Mexico State University seeks to advance the understanding of what causes heart attacks and differentiate between heart attack types at a molecular level.
Patrick Trainor, assistant professor of applied statistics at NMSU, leads a team of physicians and scientists from three universities who are working on an in-depth study of blood samples from heart attack patients. The project is part of a long-term collaboration with Dr. Andrew DeFilippis, a cardiologist and clinician-scientist at Vanderbilt University.
In February, Trainor’s research team received an $888,000 grant from the National Institutes of Health to fund the project over the next four years. The research team also includes Tanner Schaub, director of NMSU’s Research Cores Program, NMSU post-doctoral researcher Maha Abutokaikah, and NMSU graduate students Hossein Mousavi and Alanna Cover.
“Our work involves measuring thousands of molecules present in the blood of patients who were experiencing heart attacks to learn how to differentiate heart attack types from blood samples. We also want to understand the metabolic differences between heart attack types,” said Trainor, who joined the Department of Economics, Applied Statistics and International Business in the NMSU College of Business in 2019.
The research involves statistical classification methods, machine-learning techniques for biomarker discovery and validation, mass spectrometry techniques for detecting and quantifying metabolites and proteins in circulation, as well as the study of metabolism, Trainor said.
Trainor’s work on the research began about a decade ago at the University of Louisville. As a graduate student working in DeFilippis’ lab, Trainor collected blood and specimen samples from hundreds of heart attack patients. He said he was initially drawn to the research because of the high prevalence of heart disease in America.
“Heart disease is the No. 1 killer in the United States. The numbers are astronomical, and the consequences on families can be devastating when they lose someone following a heart attack,” he said. “Most of us can point to someone in our lives who has died from heart disease.”
The four-year NIH grant allowed Trainor, Schaub, their graduate students and postdoc to start analyzing the collected blood samples from about 225 patients using measurement technique called high resolution mass spectrometry.
“For the first two years of the grant,” Trainor said, “we’ll be doing a lot of analytical chemistry to try to figure out how the composition of blood differs between these heart attack types. We’ll be measuring thousands of proteins, thousands of small molecules and thousands of lipids.”
The team is using a high-resolution mass spectrometry instrumentation platform housed in the Chemical Analysis and Instrumentation Laboratory, which is part of the Research Cores Program at NMSU and the Office of the Vice President for Research. This approach provides detailed identification of molecules present in complex mixtures and provides a detailed molecular “fingerprint” for each sample.
“This instrument gives us a fingerprint that tells us whether it’s a specific protein, metabolite or lipid,” he said. “We’ll end up detecting tens of thousands of features, and then we’ll try to get a molecular fingerprint of those to identify what those features are.”
It will take about two years to fully characterize all of the molecules present in the blood samples, Trainor said. During the final two years of the grant, he and his team will focus their efforts on understanding the different biological processes between the various heart attack types.
“Once we’ve measured all these thousands of molecules in these different blood samples, we’ll use advanced bioinformatics and statistics to try and figure out what is different between these different samples and start building a model that can differentiate the heart attack types,” he said.
Trainor said he hopes the research leads to a diagnostic test that can determine heart attack types in a noninvasive manner at the point of care and help ensure patients suffering from heart attacks receive optimal treatment decisions. Currently, he said, patients have to undergo “invasive imaging procedures” to determine which type of heart attack they’re experiencing. In some cases, he added, the lack of an informative diagnostic can lead to severe or fatal bleeding events.
“If we’re able to understand or detect the underlying cause of a heart attack through our research,” he said, “then physicians can appropriately treat it without inappropriately increasing the risk of fatal bleeding events – which will save lives.”