title: Application of time-resolved autofluorescence to label-free in vivo optical mapping of changes in tissue matrix and metabolism associated with myocardial infarction and heart failure.
abstract: We investigate the potential of an instrument combining time-resolved spectrofluorometry and diffuse reflectance spectroscopy to measure structural and metabolic changes in cardiac tissue in vivo in a 16 week post-myocardial infarction heart failure model in rats. In the scar region, we observed changes in the fluorescence signal that can be explained by increased collagen content, which is in good agreement with histology. In areas remote from the scar tissue, we measured changes in the fluorescence signal (p < 0.001) that cannot be explained by differences in collagen content and we attribute this to altered metabolism within the myocardium. A linear discriminant analysis algorithm was applied to the measurements to predict the tissue disease state. When we combine all measurements, our results reveal high diagnostic accuracy in the infarcted area (100%) and border zone (94.44%) as well as in remote regions from the scar (> 77%). Overall, our results demonstrate the potential of our instrument to characterize structural and metabolic changes in a failing heart in vivo without using exogenous labels.
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ UK ; Authors contributed equally to this work.
authors.forename: João
authors.initials: J
authors.lastname: Lagarto
authors.affiliation: National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN UK ; Authors contributed equally to this work.
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Dyer
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ UK.
authors.forename: Clifford
authors.initials: C
authors.lastname: Talbot
authors.affiliation: National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN UK.
authors.forename: Markus B
authors.initials: MB
authors.lastname: Sikkel
authors.affiliation: National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN UK.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Peters
authors.affiliation: National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN UK.
authors.forename: Paul M W
authors.initials: PM
authors.lastname: French
authors.affiliation: National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN UK ; Authors contributed equally to this work.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Lyon
authors.affiliation: Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ UK ; Authors contributed equally to this work.
authors.forename: Chris
authors.initials: C
authors.lastname: Dunsby
keywords: (170.1610) Clinical applications; (170.3650) Lifetime-based sensing; (170.3890) Medical optics instrumentation; (170.4580) Optical diagnostics for medicine; (170.6935) Tissue characterization; (300.6500) Spectroscopy, time-resolved