Abstract 3671: Myocardial Perfusion Scintigraphy versus Intracoronary Flow Velocity Reserve in Multivessel Coronary Artery Disease: Long Term Clinical Follow-up
Background: Assessment of functional significance of intermediate coronary narrowings is important for clinical decision making. We investigated in a multicenter study the long term prognostic value of intracoronary derived Doppler flow velocity compared to the results of myocardial perfusion scintigraphy (MPS) for patient management of intermediate lesions in the presence of multivessel disease.
Methods: A total of 191 patients (mean age: 61; male: 70%) with stable angina were included. Patients were referred for angioplasty of a severe lesion in the presence of an intermediate coronary lesion (40–70% diameter stenosis) in another coronary artery. MPS was performed in all patients to determine the presence of reversible perfusion defects in the area of the intermediate lesion. MPS was considered negative™ when no reversible defect was present in this area. At angiography, in all patients the coronary flow velocity reserve (CFVR) was determined distal to the intermediate lesion. CFVR >= 2.0 was considered negative™. Next to angioplasty of the severe lesion, angioplasty of the intermediate lesion was only performed if both MPS and CFVR were positive. Long term follow up (>1 year) was performed to document the occurrence of any major cardiac events (PTCA, CABG, myocardial infarction, death). The relative risk was calculated for SPECT and for CFVR to predict future events.
Results: In 9 (5%) patients, the intermediate lesion was treated with angioplasty based on the results of MPS and CFVR. The mean follow up time was 793 days (range: 360–1525). In total 67 events occurred in 49 patients (3 deaths, 9 myocardial infarctions, 9 CABGs, 46 PTCAs). In total, 10 events (33%) occurred if MPS was positive (n=30) and 57 (35%) events if MPS was negative (n=161); 32 events (67%) if CFVR was positive (n=46) and 35 events if CFVR was negative (n=145). The relative risk for was 0.9 (95% CI: 0.5–1.6) for MPS and 2.9 (95% CI: 2.0 – 4.1) for CFVR (p<0.05).
Conclusion: Selective evaluation of an intermediate lesion using CFVR allows a more adequate risk stratification in patients with multivessel disease than MPS. A CFVR<2.0 was associated a three fold increase of the occurrence of cardiac events during long term follow up (mean of 2 year).