2Department of Cardiac Surgery, Institute of Cardiology, Faculty of Medicine, University of Debrecen, Hungary
3Division of Clinical Laboratory Science, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Hungary
4Department of Cardiology, Borsod County Hospital, Miskolc-Hungary
5Department of Cardiology, Géza Hetényi County Hospital and Outpatient Centre, Szolnok-Hungary
6Faculty of Informatics University of Debrecen, Debrecen-Hungary
Abstract
Objective: Saphenous venous grafts (SVGs) are established choices for coronary artery bypass grafting (CABG); however, their lumen patency is limited. Our goal was to investigate the risk factors of SVG degeneration.
Materials and Methods: Seventy-five patients (mean age, 57.5±10.4 years) with 133 SVG conduits who had cardiac catheterization ≥1 year after CABG were selected; follow-up period was 67.6±36.8 months. Patients were divided into 3 groups according to angiographic status at follow up [intact: <20% (n=23); narrowed: 20–99% (n=24); and occluded (n=28)]. Baseline clinical conditions were evaluated in relation to follow-up angiography. As onset date of chronic total occlusions is usually uncertain, they arise typically from thrombotic lesions; thus, their value in evaluation is limited. Results: There were no significant differences between the 3 groups in clinical parameters. Linear correlation analysis found significant (p<0.01) positive connection of SVG disease (luminal diameter reduction 20–99%) with C-reactive protein (CRP) and homocysteine (Hcy), as well as between CRP and Hcy. Multiple regression analysis showed plasma Hcy level to be significantly related to graft diameter reduction normalized to time elapsed until angiography in narrowed grafts: 1 μmol/L increase of Hcy was associated with 0.053%/month decrease in lumen diameter (p<0.01; R2=0.428); extrapolating: +10 μmol/L higher Hcy level during 5 years is associated with 32.1% lumen reduction.
Conclusion: Medium- to long-term SVG degeneration is related to elevated plasma total Hcy in patients with sub-occlusive graft stenosis, while in cases with intact SVGs, the beneficial local flow conditions may protect the grafts from degeneration. (Anatol J Cardiol 2016; 16: 868-73)