Long-term Prognostic Value of Dipyridamole Stress Myocardial SPECT / 대한핵의학회잡지

PURPOSE: Dipyridamole stress myocardial perfusion SPECT could predict prognosis, however, long-term follow-up showed change of hazard ratio in patients with suspected coronary artery disease. We investigated how long normal SPECT could predict the benign prognosis on the long-term follow-up. MATERIALS AND METHODS: We followed up 1169 patients and divided these patients into groups in whom coronary angiography were performed and were not. Total cardiac event rate and hard event rate were predicted using clinical, angiographic and SPECT findings. Predictive values of normal and abnormal SPECT were examined using survival analysis with Mantel-Haenszel method, multivariate Cox proportional hazard model analysis and newly developed statistical method to test time-invariance of hazard rate and changing point of this rate. RESULTS: Reversible perfusion decrease on myocardial perfusion SPECT predicted higher total cardiac event rate independently and further to angiographic findings. However, myocardial SPECT showed independent but not incremental prognostic values for hard event rate. Hazard ratio of normal perfusion SPECT was changed significantly (p<0.001) and the changing point of hazard rate was 4.4 years of follow up. However, the ratio of abnormal SPECT was not. CONCLUSION: Dipyridamole stress myocardial perfusion SPECT provided independent prognostic information in patients with known and suspected coronary artery disease. Normal perfusion SPECT predicted least event rate for 4.4 years.

Prognostic Value of Rest Tl-201/Dipyridamole Stress Tc-99m-MIBI Myocardial Single Photon Emission Computed Tomography (SPECT)

BACKGROUND AND OBJECTIVES: Dual isotope myocardial SPECT, rest thallium-201/dipyridamole stress Tc-99m sestamibi is used to diagnose coronary artery disease. We examined predictive value of myocardial SPECT for the prognosis of patients having or suspected coronary artery disease. MATERIALS AND METHOD: We examined 692 patients referred for dipyridamole stress myocardial perfusion SPECT. Cardiac events (hard and soft events) were followed up with medical record review and telephone interview. Survival analysis and multivariate Cox proportional hazard model were used to find significant predictors and the incremental predictive value of myocardial SPECT. Patients with coronary angiography (n=246) were analyzed in separate group. RESULTS: There were 4 hard events and 3 soft events in 341 normal SPECT group (1.20%/yr). There were 5 hard events and 21 soft events in 351 abnormal SPECT group (4.69%/yr). Survival curve was separated between normal SPECT group and abnormal SPECT group (p<0.01). In univariate analysis, smoking, history of myocardial infarction, typical chest pain and SPECT findings were important variables. In multivariate analysis, SPECT result was the single most independent predictor. Large reversible perfusion abnormality predicted worse prognosis. In patients with coronary angiography, SPECT did not add statistically significant predictive value to the coronary angiography. CONCLUSION: Dipyridamole stress Tl-201/ MIBI dual isotope myocardial perfusion SPECT provided excellent prognostic information. Extent of reversible perfusion decrease was the independent predictor of future cardiac events.

Transient Prolonged Stunning by Dipyridamole Stress Proved by Post-stress ( 1 hour ) and 24 hour Tc-99m-MIBI Gated SPECT / 대한핵의학회잡지

We performed 1st day Tc-99m-sestamibi gated SPECT with dipyridamole/rest T1-201 SPECT and 2nd day 24 hour delay T1-201 SPECT/rest Tc-99m-sestamibi gated SPECT in 27 patients with coronary artery disease(24) or having chest pain(3). Stress and rest Tc-99m- sestamibi gated SPECT was acquired at 60min post-injection. A 4-point scoring system(0 to 3 for normal to absent tracer uptake) for 17 segments was used. Wall motion was scored on another 4 point scale(0 to 3 for normal to dyskinesia) in the lst day post-stress gated and the 2nd day rest gated SPECT. Post-stress gated SPECT showed wall motion abnormality in 94 segments(20%). Fifty-five segments among these 94 showed the same wall motion between post-stress and rest gated SPECT:i.e. 1-1: 23 segments, 2-2: 29 segments, 3-3: 3 segments. Re-maining 39 segments (41.5%) showed different wall motion between post-stress and rest Tc-99m-sestamibi gated SFECT. Twenty one segments with wall motion abnormality had normal perfusion(rest:15 segments, 24 hour delay: 6 segments) at either rest or 24 hour delay. Fifteen among these 21 segments showed persistent post-stress and the 2nd day rest wall motion abnormality(persistent stunning). However, in 6 segments with prolonged (1 hour after stress) stunning, abnormal wall motion did improve in the 2nd day rest Tc-99m-sestamibi gated SPECT(transient prolonged stunning). These 6 segments had normal perfusion at rest(n=4) or at 24 hour delay(n=2). Post stress wall motions showed significantly higher scores in persistent stunning than in prolonged transient stunning(P value<0.05). It was concluded that we could find stunned myocardium with gated Tc-99m-sestamibi SPECT at either post-stress or rest and that some myocardial walls of post-stress 1 hour gated SPECT did not show truly rest wall motion. So, we should be cautious if we use post-stress Tc-99m-sestamibi wall motion to assess rest wall motion.