Effect of adjunctive intracoronary adenosine on myocardial ischemia, hemodynamic function and left ventricular performance during percutaneous transluminal coronary angioplasty: clinical access to ischemic preconditioning?

Background Ischemic preconditioning has been defined as a mechanism that re nders the heart more resistant to subsequent ischemia. Adenosine plays an i mportant role in the pathogenesis of ischemic preconditioning. Objective To assess whether intracoronary administration of adenosine preve nts the deterioration of left ventricular performance and hemodynamic funct ion by allowing adaptation to myocardial ischemia in the setting of percuta neous transluminal coronary angioplasty (PTCA). Design This was a prospectively randomized doubly blinded trial. Methods We investigated 20 patients undergoing PTCA of the left anterior de scending coronary artery supplying myocardium with normal left ventricular function in the setting of stable angina pectoris. Patients were randomly a llocated to be administered adenosine intracoronarily (20 mg/10 min) or an equal amount of saline, providing a control population. Results of standardized chest pain questionnaires, tolerated inflation time s, ST-segment shifts, left ventricular and aortic pressures, isovolumetric phase indexes, and indexes of volume and ejection fraction during the cours e of PTCA between the two groups were compared. Results Patients administer ed adenosine tolerated significantly longer balloon-inflation times (188 +/ - 41 versus 153 +/- 36s; P = 0.03), which were associated with less pronoun ced signs of ischemia, and exhibited less deterioration of isovolumetric ph ase indexes during PTCA. Deterioration of left ventricular ejection fractio n was slightly less severe with adenosine (72 +/- 5% before PTCA Versus 64 +/- 6% during angioplasty) than it was for the control group (71 +/- 7% bef ore PTCA versus 60 +/- 7% during angioplasty; P = 0.11). Conclusions Intracoronary application of adenosine prior to coronary angiop lasty increases tolerance of ischemia and prevents deterioration of left ve ntricular hemodynamics during ischemia. One potential explanation of these results is that induction of ischemic preconditioning took place. Coron Art ery Dis 11:421-428 (C) 2000 Lippincott Williams & Wilkins.