Biophysical and Lipidomic Biomarkers of Cardiac Remodeling Post-Myocardial Infarction in Humans

Few studies have analyzed the potential of biophysical parameters as markers of cardiac remodeling post-myocardial infarction (MI), particularly in human hearts. Fourier transform infrared spectroscopy (FTIR) illustrates the overall changes in proteins, nucleic acids and lipids in a single signature. The aim of this work was to define the FTIR and lipidomic pattern for human left ventricular remodeling post-MI. A total of nine explanted hearts from ischemic cardiomyopathy patients were collected. Samples from the right ventricle (RV), left ventricle (LV) and infarcted left ventricle (LV INF) were subjected to biophysical (FTIR and differential scanning calorimetry, DSC) and lipidomic (liquid chromatography-high-resolution mass spectrometry, LC-HRMS) studies. FTIR evidenced deep alterations in the myofibers, extracellular matrix proteins, and the hydric response of the LV INF compared to the RV or LV from the same subject. The lipid and esterified lipid FTIR bands were enhanced in LV INF, and both lipid indicators were tightly and positively correlated with remodeling markers such as collagen, lactate, polysaccharides, and glycogen in these samples. Lipidomic analysis revealed an increase in several species of sphingomyelin (SM), hexosylceramide (HexCer), and cholesteryl esters combined with a decrease in glycerophospholipids in the infarcted tissue. Our results validate FTIR indicators and several species of lipids as useful markers of left ventricular remodeling post-MI in humans.