Abstract 4121: Effect of Dark Chocolate on Coronary Vasomotion in Patients after Heart Transplantation
Introduction: Patients after heart transplantation (HTPL) have endothelial dysfunction, increased platelet activation and show accelerated coronary atherosclerosis. Traditional risk factors, high oxidative stress and reduced antioxidant defenses play a crucial role in the pathogenesis of coronary allograft vasculopathy. Dark chocolate contains high amount of flavonoids, with potent antioxidant properties that could beneficially influence endothelial and platelet function.
Hypothesis: We aimed to assess the effect of flavonoid-rich chocolate on endothelial dependent coronary vasomotion, a powerful surrogate for clinical prognosis.
Methods: 22 HTPL patients were included in this double-blind, randomized, placebo-controlled study. During elective coronary angiogram we performed quantitative coronary angiography and tested endothelial-dependent coronary vasomotion using cold pressor test (CPT), and repeated two hours after ingestion of 40g flavonoid-rich dark (70%cocoa) or placebo chocolate (same fat and sugar content), respectively. Furthermore, shear-stress dependent platelet adhesion was measured by circulating blood in polystyrene wells at a shear rate of 1875 s-1 for 2 minutes with a rotating teflon cone.
Results: Clinical characteristics and baseline vasomotion matched well between the groups. Two hours after ingestion of flavonid-rich dark chocolate, coronary artery diameter was significantly increased (from 2.36±0.5mm to 2.51±0.6mm, p<0.01), whereas did not change after placebo (form 2.26±0.5 to 2.21±0.6, p=0.59). Endothelial-dependent coronary vasomotion significantly improved after dark chocolate (4.5% versus -4.6% in the placebo group, p=0.01). Platelet adhesion decreased from 4.9±1.1% to 3.8±0.8% (p=0.04) in the flavonid-rich dark chocolate group, whereas the platelet adhesion remained unchanged in the placebo group.
Conclusion: Dark chocolate increases coronary artery diameter in patients after HTPL, probably representing an increased basal nitric oxide release. Furthermore, dark chocolate improves coronary vasomotion and decreases platelet adhesion in these patients with high oxidative stress, confirming the previously reported potent antioxidant effect of flavonid-rich chocolate.