Myocardial bradykinin production during coronary balloon angioplasty in humans

BACKGROUND: Recent studies have implicated the peptide bradykinin as a potential trigger of ischaemic preconditioning, the phenomenon whereby a brief episode of myocardial ischaemia induces an increased tolerance to subsequent more prolonged ischaemia. Brief myocardial ischaemia occurring during percutaneous transluminal coronary balloon angioplasty in humans is reported to be capable of inducing preconditioning. DESIGN: We studied the intracardiac production of bradykinin in eight patients (seven men, mean age 53.5 years) undergoing elective percutaneous transluminal coronary angioplasty for a single left anterior descending coronary artery stenosis. Paired blood samples were obtained from the coronary sinus and the proximal aorta at baseline, immediately before balloon deflation after a 2-min inflation, and at 1, 3 and 5 min post deflation. Bradykinin levels were measured by radioimmunoassay. RESULTS: There was no significant change either in aortic or coronary sinus bradykinin levels at any time point. CONCLUSIONS: Intracardiac production of bradykinin is unlikely to be a trigger for ischaemic preconditioning after brief myocardial ischaemia in humans.