Author + information
- Received December 1, 1994
- Revision received March 3, 1995
- Accepted March 9, 1995
- Published online August 1, 1995.
- Paolo Marzullo, MD, FESC, FACC1,
- Oberdan Parodi, MD,
- Gianmario Sambuceti, MD,
- Assuero Giorgetti, MD,
- Eugenio Picano, MD, FESC,
- Alessia Gimelli, MD,
- Piero Salvadori, PhD and
- Antonio L'Abbate, MD, FESC, FACC
- ↵1Address for correspondence: Dr. Paolo Marzullo, CNR Institute of Clinical Physiology, Via Savi 8, 56100 Pisa, Italy.
Objectives. The aim of this study was to determine whether the presence of residual coronary reserve can in itself identify viable segments.
Background. Experimental data suggest that despite hypoperfusion at rest, viable myocardium may exhibit persistence of coronary reserve. Preliminary observations in patients show that in basally dyssynergic areas, a residual vasodilator capability is present despite hypoperfusion at rest and that a flow-mediated increase in regional wall motion identifies residual viability.
Methods. Fourteen patients with evidence of previous myocardial infarction, infarct-related single-vessel coronary artery disease and impaired regional ventricular function at rest underwent positron emission viability imaging by fluorine-18 deoxyglucose. In addition, blood flow at rest and vasodilator capability were regionally evaluated in all patients by means of nitrogen-13 ammonia.
Results. Of a total of 252 segments, 133 were dyssynergic at rest. Of these 133 segments, 60 (group 1) showed normal metabolic activity and only mild reduction in myocardial blood flow. The other 73 segments showed a marked reduction in flow; of these, 25 (group 2, viable) had persistent metabolic activity, whereas 48 (group 3, necrotic) did not. Despite similar levels of hypoperfusion at rest, group 2 segments showed a preserved coronary reserve that was virtually absent in necrotic segments (2.6 ± 1.3 vs. 1.3 ± 0.5, p < 0.01). This value was similar to that observed in viable group 1 segments (2.5 ± 1.6, p = NS).
Conclusions. In addition to characterizing myocardium at risk, imaging of coronary flow at baseline and after dipyridamole by positron emission tomography provides helpful information on myocardial viability that may integrate the “static” viability information obtained with the baseline flow/metabolic approach.
☆ This study was supported in part by CNR-targeted project “Prevention and Control Disease Factors,” subproject “Control of Cardiovascular Disease,” from the National Research Council, Rome, Italy and by the Ministero Pubblica Istruzione, Rome, Italy. It was presented in part at the 43rd Annual Scientific Session of the American College of Cardiology, Atlanta, Georgia, March 1994.
- Received December 1, 1994.
- Revision received March 3, 1995.
- Accepted March 9, 1995.