Adenosine stress thallium-201 myocardial perfusion imaging for detecting coronary artery disease at an early stage

Adenosine triphosphate stress 99mTc-methoxyisobutylisonitrile gated myocardial perfusion imaging efficacy in diagnosing stent restenosis following coronary stent implantation

Coronary stent restenosis rate following implantation is considerably high. The adenosine stress gated myocardial perfusion imaging (G-MPI) method has been widely used in the diagnosis, risk stratification and prognosis evaluation of coronary heart disease; however, the high cost of adenosine limits its clinical application. The aim of the present study was to investigate the efficacy of adenosine triphosphate (ATP) stress ^99mTc-methoxyisobutylisonitrile (^99mTc-MIBI) G-MPI for diagnosis in-stent restenosis following coronary stent implantation. Data from 66 patients with typical angina pectoris symptoms who had undergone percutaneous coronary stent implantation >3 months prior to participation in the study were analyzed. All the patients underwent ATP stress ^99mTc-MIBI G-MPI and coronary artery angiography as the criterion diagnostic standard within 1 month. The sensitivity, specificity, and accuracy of ATP stress ^99mTc-MIBI G-MPI in the assessment of in-stent restenosis were calculated. In addition, Fisher's exact probability methods were used to compare differences between experimental groups. Among 66 patients with a total of 99 implanted coronary arterial branches, 39 patients (59%) with 45 coronary arteries (45%) presented in-stent restenosis. The diagnostic sensitivity, specificity, accuracy, positive predictive and negative predictive value of ATP stress ^99mTc-MIBI G-MPI for assessing stent restenosis in all patients were 85, 89, 86, 92 and 80%, respectively. Similarly, these values in patients with myocardial infarction were 79, 88, 83, 88 and 78%, respectively, while in patients without myocardial infarction the values were 90, 91, 90, 95 and 83%, respectively. Therefore, the diagnostic efficacy of ATP stress ^99mTc-MIBI G-MPI in patients without myocardial infarction was higher compared with those with myocardial infarction; however, no significant difference was observed between the two groups. Furthermore, the sensitivity, specificity and accuracy for diagnosing LAD stent restenosis were higher compared with LCX and RCA stent restenosis, but with no significant differences observed (P>0.05). The present results indicated that ATP stress ^99mTc-MIBI G-MPI had a high clinical application value for diagnosing in-stent restenosis following coronary stent implantation as a non-invasive examination tool, with the advantages of safety and low cost.

Predictors and Diagnostic Significance of the Adenosine Related Side Effects on Myocardial Perfusion SPECT/CT Imaging

OBJECTIVE

The aim of this study was to investigate the relationship between patient characteristics and adenosine-related side-effects during stress myocard perfusion imaging (MPI). The effect of presence of adenosine-related side-effects on the diagnostic value of MPI with integrated SPECT/CT system for coronary artery disease (CAD), was also assessed in this study.

METHODS

Total of 281 patients (109 M, 172 F; mean age:62.6±10) who underwent standard adenosine stress protocol for MPI, were included in this study. All symptoms during adenosine infusion were scored according to the severity and duration. For the estimation of diagnostic value of adenosine MPI with integrated SPECT/CT system, coronary angiography (CAG) or clinical follow-up were used as gold standard.

RESULTS

Total of 173 patients (61.6%) experienced adenosine-related side-effects (group 1); flushing, dyspnea, and chest pain were the most common. Other 108 patients completed pharmacologic stress (PS) test without any side-effects (group 2). Test tolerability were similar in the patients with cardiovascular or airway disease to others, however dyspnea were observed significantly more common in patients with mild airway disease. Body mass index (BMI) ≥30 kg/m2 and age ≤45 years were independent predictors of side-effects. The diagnostic value of MPI was similar in both groups. Sensitivity of adenosine MPI SPECT/CT was calculated to be 86%, specificity was 94% and diagnostic accuracy was 92% for diagnosis of CAD.

CONCLUSION

Adenosine MPI is a feasible and well tolerated method in patients who are not suitable for exercise stress test as well as patients with cardiopulmonary disease. However age ≤45 years and BMI ≥30 kg/m2 are the positive predictors of adenosine-related side-effects, the diagnostic value of adenosine MPI SPECT/CT is not affected by the presence of adenosine related side-effects.

Validation of automated quantification of myocardial perfusion single-photon emission computed tomography using Heart Score View in patients with known or suspected coronary artery disease

Heart Score View (HSV) is a free software package for automated quantification of myocardial single photon emission computed tomography (SPECT) imaging using a standard Windows computer. We compared scoring results of myocardial perfusion among visual analysis, Quantitative Perfusion SPECT (QPS), and HSV in patients with known or suspected coronary artery disease.This study included 75 consecutive patients with known or suspected coronary artery disease who underwent adenosive stress-rest Tl-201 SPECT. Analysis of myocardial perfusion SPECT was performed on a standard 17-segment model visually and using QPS and HSV.There were 54 male and 21 female patients with a mean age of 70.5 ± 10.7 years. Thirteen patients (17%) had prior myocardial infarction. Summed stress score (SSS) and summed rest score (SRS) in the mid and basal areas were significantly higher on HSV than visual analysis or QPS. There was no significant difference in SDS in the whole area among the 3 methods. Similar results were found even in patients without prior myocardial infarction. Manual setting of the left ventricular cavity improved the correlations of SSS, SRS and SDS between HSV and the other methods.Our data suggested that HSV was comparable with visual analysis or QPS in scoring myocardial perfusion when manual setting of the left ventricular cavity is applied.