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The effects of intracoronary adenosine on preconditioning during coronary angioplasty
R A Kerensky1, M A Kutcher, G A Braden
1Section of Cardiology, Bowman Gray School of Medicine, Wake Forest University, North Carolina Baptist Hospital, Winston-Salem, USA.
Insights
The first balloon inflation during percutaneous transluminal coronary angioplasty (PTCA) acts as a preconditioning stimulus. Intracoronary adenosine administration before PTCA alters this protective effect, suggesting adenosine
Area of Science:
- Cardiology
- Pharmacology
- Physiology
Background:
- The initial balloon inflation in coronary angioplasty may precondition the myocardium, reducing ischemia in subsequent inflations.
- Endogenous adenosine is a potential mediator of ischemic preconditioning.
Purpose of the Study:
- To investigate if intracoronary adenosine administration modifies the preconditioning effect of the first balloon inflation during percutaneous transluminal coronary angioplasty (PTCA).
Main Methods:
- A double-blind, randomized study involving 41 patients undergoing PTCA.
- Patients received either 100 mcg of intracoronary adenosine or a placebo before the first balloon inflation.
- Intracoronary electrocardiograms were used to measure ST-segment elevation changes between inflations.
Main Results:
- In the placebo group, the mean ST elevation reduction between the first and second inflations was 4.8 mm, with 7/9 patients showing decreased ischemia.
- In the adenosine group, the mean ST elevation change was -0.8 mm, with only 2/11 patients showing reduced ischemia (p < 0.05).
Conclusions:
- The first balloon inflation during PTCA serves as a preconditioning stimulus, reducing ischemia during subsequent inflations.
- Intracoronary adenosine administration prior to PTCA significantly alters this preconditioning effect.
- These findings suggest a role for adenosine in human ischemic preconditioning during PTCA.
Abstract:
There is evidence that the first balloon inflation during coronary angioplasty provides a preconditioning stimulus leading to decreased ischemia during subsequent balloon inflations. Endogenous adenosine release may play a role in ischemic preconditioning. Therefore, intracoronary adenosine administration prior to the first balloon inflation during percutaneous transluminal coronary angioplasty (PTCA) might modify the preconditioning response to the first balloon inflation. Forty-one patients underwent double-blind randomization to treatment with 100 mcg of intracoronary adenosine or placebo prior to coronary angioplasty. Twenty patients (11 adenosine, 9 placebo) had complete resolution of ischemia between inflations allowing comparison between the first and second inflation. An angioplasty guidewire was used to obtain an intracoronary electrocardiogram. The mean reduction in ST elevation during the second inflation compared with the first was 4.8 mm in the placebo group and -0.8 in the adenosine group (p < 0.05 placebo vs. adenosine). Seven of 9 placebo patients had a decrease in ischemia during the second inflation compared with the first, while only 2 of 11 adenosine patients showed a reduction. It was concluded that (1) the first inflation during PTCA is a preconditioning stimulus leading to a decrease in ischemia during later inflations, and (2) intracoronary adenosine administration prior to PTCA modifies the preconditioning effect of the first inflation. These data suggest that adenosine plays a role in ischemic preconditioning in humans.