Correlation of Endogenous Mineralization-Inhibitory Activity of Arterial Conduits With Gensini Score in Patients Undergoing Coronary Artery Bypass Grafting: A Cross-Sectional Study

IntroductionArterial conduits used in coronary artery bypass grafting (CABG) harbour loosely associated, matrix-bound biomolecules that inhibit calcium-phosphate mineralization in vitro.Whether the potency of this endogenous inhibitory activity varies with the angiographic severity of the underlying coronary artery disease (CAD) has not been examined.We investigated the relationship between the mineralizationinhibitory activity of arterial-conduit extraction fluid and the Gensini score in patients undergoing CABG. MethodsIn this cross-sectional study, arterial conduit segments surplus to CABG requirement were prospectively collected from 60 male patients at All India Institute of Medical Sciences (AIIMS) Bathinda, India, and stratified into three groups of 20 each by Gensini score tertile (Group I -severe, 140-258; Group IImoderate, 90-136; Group III -mild, 51-85).To prepare the organic matrices from arterial conduits for in vitro mineralization studies, conduits were incubated in extraction fluids for the release of loosely bound biomolecules.Extraction fluids were tested in homogeneous (matrix-free) and heterogeneous (matrixdependent) in vitro mineralization assay systems; percentage inhibition of Ca²⁺ and HPO₄²⁻ precipitation was calculated relative to controls without extraction fluid.Patient-level one-way ANOVA (with Welch's correction where variances were unequal), Tukey post-hoc comparisons, and Pearson correlation against each patient's exact Gensini score were applied; p < 0.05 was considered significant. ResultsExtraction-fluid inhibitory potency showed a significant, monotonic inverse relationship with Gensini score in both assay systems (all p < 0.001).Heterogeneous-system Ca²⁺ inhibition rose from 3.88 ± 0.70% in Group I to 12.86 ± 1.97% in Group III; homogeneous-system Ca²⁺ inhibition rose correspondingly from 8.92 ± 1.00% to 18.07 ± 1.83%.In both systems, inhibition of Ca²⁺ precipitation exceeded that of HPO₄²⁻ precipitation, and inhibitory potency was consistently greater in the homogeneous than the heterogeneous system.Pearson correlation coefficients against each patient's exact Gensini score ranged from -0.84 to -0.89 across the four inhibition parameters (all p < 0.001). ConclusionsThe inverse gradient between arterial-conduit mineralization-inhibitory activity and angiographic disease severity supports the hypothesis that depletion of loosely associated endogenous inhibitors accompanies, and may contribute mechanistically to, the atherosclerotic calcification process reflected by the Gensini score.These findings are hypothesis-generating and require confirmation with molecular characterisation of the responsible inhibitors and multivariable analysis.