Cross-sectional study to establish the relation between myocardial, skin and serum Advanced Glycation End-products (AGEs) levels

Advanced glycation end product (AGE) accumulation is found throughout the
body. Through formation of collagen cross-links, AGEs play a role in the
pathophysiology of several different diseases. AGE accumulation has been
accurately measured in tissue biopsies of the skin with gas chromatography mass
spectrometry (GC-MS) but in human myocardial tissue, AGE accumulation has only
been roughly measured with immunostaining. In addition, AGE accumulation in
both skin and serum has never been compared to AGE accumulation in myocardial
tissue. Increased AGE accumulation in skin tissue and serum have shown a
correlation with decreased left ventricular systolic and diastolic function,
but it has never been established if the decreased heart function is the result
of increased AGE accumulation in myocardial tissue.

To establish the relation between myocardial, serum and skin AGE levels.

To determine the quantitative AGE-levels in myocardial tissue

In this cross-sectional study we will include patiënts admissioned for CABG or
heart valve surgery. Patients will be screened from the waitinglist for open
heart surgery. Patients will be informed by telefone about the presence of this
study. Patients will be written informed about the purpose, the study design,
study duration, risks, and the consequences of preliminary ending of the
study.
Patients will recieve at least one week to think about the participation to the
current research. If they are willing to participate, patients will be asked to
sign written informed consent.
As usual, the patients will be admissioned the day before surgery, followed by
collection of blood, physical examination, non-invasive measurement of skin
autofluorescence and an echocardiographic examination.
Myocardial and skin biopsies will be taken by the surgeon during the open heart
surgery. The myocardial biopsies will be taken from the apex and the sternum of
the left ventricle. The skin biopsie will be taken from the sternal skin
allongside the surgical cutting line.
At any time during the study patients are allowed to stop their participation
without any consequences. Medical care will resume normally.

Patients will be examined during their admission at hospital, which does not
require an extra hospital visit. The examination will take about 30 minutes.
Patients will be physically examined by the research physician and asked at the
current condition, followed by colletcion of blood and measurement of the skin
AGE-levels by skin autofluorescence. All these measurements, apart from the
blood collection, are non-invasive and posses no additional risk.
During surgery, the surgeon will take two myocardial biopsies and one skin
biopsie. This poses a limited additional risk. Myocardial biopsy is performed
regularly and provides the risk of perforation and bleeding. The risks of skin
biopsy include bleeding, infection and formation of scar tissue.