Early cardiac-chamber-specific fingerprints in heart failure with preserved ejection fraction detected by FTIR and Raman spectroscopic techniques

Abstract

The pathophysiology of heart failure with preserved ejection fraction (HFpEF) is a matter of investigation and its diagnosis remains challenging. Although the mechanisms that are responsible for the development of HFpEF are not fully understood, it is well known that nearly 80% of patients with HFpEF have concomitant hypertension. We investigated whether early biochemical alterations were detectable during HFpEF progression in salt-induced hypertensive rats, using Fourier-transformed infrared (FTIR) and Raman spectroscopic techniques as a new diagnostic approach. Greater protein content and, specifically, greater collagen deposition were observed in the left atrium and right ventricle of hypertensive rats, together with altered metabolism of myocytes. Additionally, Raman spectra indicated a conformational change, or different degree of phosphorylation/methylation, in tyrosine-rich proteins. A correlation was found between tyrosine content and cardiac fibrosis of both right and left ventricles. Microcalcifications were detected in the left and right atria of control animals, with a progressive augmentation from six to 22 weeks. A further increase occurred in the left ventricle and right atrium of 22-week salt-fed animals, and a positive correlation was shown between the mineral deposits and the cardiac size of the left ventricle. Overall, FTIR and Raman techniques proved to be sensitive to early biochemical changes in HFpEF and preceded clinical humoral and imaging markers.

Vibrational Spectroscopy Identifies Myocardial Chemical Modifications in Heart Failure with Preserved Ejection Fraction

“…Perivascular fibrosis appears to be low and similar between Ln and Ob rats (Figure S2e). Differently, in DSS rats 4 abundant collagen deposition was observed in both perivascular and interstitial areas. Thus, the differences between spectroscopic data obtained for the two models, are coherent with histochemical results.…”

“…This was indicated by the decrease of 1245 cm -1 intensity and the corresponding enhancement of 1660 cm -1 spectral component 17 . A different result was obtained for the heart tissue of a different animal model of HFpEF, induced by a high salt diet 4 . On tissues from Dsalt-sensitive (DSS) rats, an increase of intensity for the amide III band, together with a blue shift of the amide I band was assigned to the increase of collagen concentration in diseased compared to normal animals.…”

“…The application of FTIR and Raman spectroscopy to the diagnosis of cardiovascular diseases has been poorly investigated [6][7][8][9] . Recent research from Tombolesi et al 4 has shown the advantages of the combined use of these techniques in the characterization of cardiac tissue and early diagnosis of heart failure. Heart failure (HF) is a complex clinical syndrome resulting from structural and functional impairment of ventricular blood filling or ejection.…”

Vibrational Spectroscopy Identifies Myocardial Chemical Modifications in 1 Heart Failure with Preserved Ejection Fraction

“…Differently, in DSS rats [4] abundant collagen deposition was observed in both perivascular and interstitial areas. Thus, the differences between spectroscopic data obtained for the two models, are coherent with histochemical results.…”

FTIR Analysis of Renal Tissue for the Assessment of Hypertensive Organ Damage and proANP31–67 Treatment

“…However, the application of FTIR for the assessment of hypertension-related kidney lesions has not been reported. We recently demonstrated that vibrational spectroscopic techniques are efficient diagnostic tools that are capable of detecting early chemical changes that precede the structural and functional cardiac alterations induced by prolonged hypertension [ 16 ].…”