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Preconditioning during percutaneous transluminal coronary angioplasty by endogenous and exogenous adenosine
U E Heidland1, M P Heintzen, B Schwartzkopff
1School of Internal Medicine, Department of Cardiology, Pneumology, and Angiology, Heinrich-Heine-University, Düsseldorf, Germany. heidland@med.uni-duesseldorf.de
Insights
Pharmacologic preconditioning with adenosine, either endogenous or exogenous, improves cardiac function during percutaneous transluminal coronary angioplasty (PTCA). This protective effect is linked to ischemic preconditioning, with endogenous adenosine showing superior results.
Area of Science:
- Cardiology
- Pharmacology
- Ischemic Preconditioning
Background:
- Myocardial ischemia during percutaneous transluminal coronary angioplasty (PTCA) can impair cardiac function.
- Adenosine is a key mediator in the heart's natural resistance to ischemia (ischemic preconditioning).
Purpose of the Study:
- To determine if pharmacologic preconditioning using adenosine can prevent cardiac dysfunction during PTCA.
- To compare the effects of endogenous versus exogenous adenosine on hemodynamic function and left ventricular performance.
Main Methods:
- 30 patients undergoing PTCA were randomized to receive intracoronary dipyridamole (to release endogenous adenosine), exogenous adenosine, or saline (control).
- Evaluated outcomes included chest pain, balloon inflation time, ST-segment changes, and left ventricular hemodynamic and performance indexes.
Main Results:
- Patients receiving adenosine (endogenous or exogenous) tolerated longer balloon inflation times compared to controls.
- Deterioration in left ventricular ejection fraction was less severe with adenosine treatment.
- Intracoronary dipyridamole significantly prevented the decline in ejection fraction compared to the control group.
Conclusions:
- Both endogenous and exogenous adenosine enhance tolerance to ischemia and protect left ventricular function during PTCA.
- These protective effects are attributed to ischemic preconditioning.
- Endogenous adenosine demonstrated a greater protective effect than exogenous adenosine in this study.
Background:
The purpose of this study was to assess whether pharmacologic preconditioning by exogenous or endogenous adenosine prevents the deterioration of hemodynamic function and left ventricular performance during percutaneous transluminal coronary angioplasty (PTCA). Ischemic preconditioning renders the heart more resistant to subsequent ischemia. Adenosine plays a key role in its pathogenesis. Coronary angioplasty is a suitable model for the induction of myocardial ischemia.
Methods And Results:
We investigated 30 patients receiving PTCA of the left anterior descending coronary. Patients were randomly allocated to either dipyridamole, leading to the liberation of endogenous adenosine (0.5 mg/kg body weight, intracoronary), exogenous adenosine (20 mg intracoronary), or an equal amount of saline. Chest pain, tolerated inflation time, and ST-segment shift were registered. Left ventricular hemodynamics, isovolumetric phase indexes, indexes of volume, ejection fraction, and indexes of diastolic dysfunction were analyzed. Patients receiving endogenous or exogenous adenosine tolerated longer balloon inflation times (dipyridamole, 208 +/- 23 seconds; adenosine, 188 +/- 41 seconds; control, 153 +/- 36 seconds; P <.05). Deterioration of left ventricular ejection fraction was less severe after adenosine (72% +/- 5% before PTCA vs 64% +/- 6% during angioplasty; P =.11) and could be prevented by intracoronary dipyridamole (69% +/- 12% before PTCA vs 68% +/- 11% after PTCA; P <. 01) compared with the control group (71% +/- 7% before PTCA vs 60% +/- 7% during angioplasty).
Conclusions:
Intracoronary application of exogenous adenosine and liberation of endogenous adenosine increase the tolerance to ischemia and prevent deterioration of left ventricular function during ischemia. These findings can be attributed to ischemic preconditioning. However, endogenous adenosine exceeds the protective effects of exogenous adenosine.