Proton NMR analysis of plasma is a weak predictor of coronary artery disease

Multivariate analysis of H-1-NMR spectra of blood sera was reported previously to predict angiographically defined advanced coronary artery disease ( CAD) with > 90% accuracy and specificity. The analysis depended mainly on the major lipid regions of the spectra, but many variables, including gender and drug treatment, affect lipid composition and are potential confounders. We have determined the predictive power of the same methodology for angiographically defined CAD using plasma samples from groups of male patients, classified by statin treatment, who had normal coronary arteries ( NCAs) or CAD. Predictions for NCA and CAD groups were only 80.3% correct for patients not treated with statins and 61.3% for treated patients, compared with random correct predictions of 50%. A confidence limit of > 99% was achieved for 36.2% of predictions for untreated groups and 6.2% for treated groups. Detection of CAD by H-1-NMR with > 99% confidence was therefore very weak compared with angiography.