Left ventricular functional changes after adenosine vasodilator stress evaluated by gated single-photon emission computed tomography.

OBJECTIVES: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging is useful in assessing left ventricular (LV) myocardial perfusion and function. This study evaluated the LV functional changes after adenosine vasodilator stress, using gated SPECT. METHODS: The study population consisted of 70 patients who underwent adenosine-mediated stress and rest SPECT. All patients underwent coronary angiography. Semi-quantitative assessment of perfusion was analyzed and produced the summed rest score (SRS), the summed stress score (SSS) and the summed difference score (SDS). The global LV function parameters [ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV)] and regional LV function [the summed motion score (SMS) and the summed thickening score (STS)] were quantified by gated SPECT. RESULTS: Patients were divided into 2 groups: group 1 comprised 16 patients with worsening of LVEF (LVEFrest-LVEFado ≥5%), and group 2 comprised the other 54 patients. Compared with group 2, patients in group 1 had a significantly higher SSS and SDS (9.1 ± 6.8 vs. 5.6 ± 4.5 and 6.6 ± 3.8 vs. 3.6 ± 4.0, respectively; p < 0.05) and the severity of coronary artery stenosis was more serious (p < 0.05). CONCLUSION: Worsening of LVEF after adenosine-induced vasodilator stress, as shown by (99m)Tc-MIBI gated SPECT, is a valuable nonperfusion marker of significant CAD.

[Impact of viable myocardium assessed by 99Tcm-MIBI SPECT and 18F-FDG PET imaging on clinical outcome of patients with left ventricular aneurysm underwent revascularization].

OBJECTIVE: To evaluate the impact of viable myocardium assessed by (99)Tc()m-MIBI SPECT and (18)F-fluorodeoxyglucose (FDG) PET imaging in patients with left ventricular aneurysm (LVA) underwent revascularization (RVS). METHODS: Forty-six consecutive patients with LVA (mean LVEF 36% +/- 7%), underwent (99)Tc(m)-sestamibi SPECT and (18)F-FDG PET examinations and received RVS therapy, were followed-up for a mean period of 80 +/- 27 months. Viable myocardium in aneurysm was defined as perfusion-metabolism mismatch score (MMS) >/= 2.0. Patients were divided into four groups by aneurysm viability and aneurysmectomy. Group A1 (n = 8): viability-; Group A2 (n = 15): viability-, aneurysmectomy; Group B1 (n = 10): viability +; and Group B2 (n = 13): viability +, aneurysmectomy. RESULTS: The cardiac event rates during follow up were similar among groups [A1 (25%, 2/8), B1 (40%, 6/15), A2 (20%, 2/10) and B2 (31%, 4/13; P > 0.05)]. After revascularization, LVEF was improved (> 10%) in groups A2, B1 and B2 (P < 0.05). Multivariate logistic regression analysis showed that LV-MMS (OR = 2.34, 95% CI 1.08 - 5.06, P < 0.05), distal vessel disease (OR = 0.008, 95% CI 0.001 - 0.560, P < 0.05) and nonaneurysm perfusion score (OR = 0.24, 95% CI 0.07 - 0.85, P < 0.05) were significantly associated with the improvement of LVEF after revascularization. CONCLUSIONS: Long term cardiac events rate post revascularization was not affected by viable myocardium or aneurysmectomy in LVA patients. Viable myocardium in LVA patients was associated with better LVEF improvement after revascularization.

Phase analysis by gated F-18 FDG PET/CT for left ventricular dyssynchrony assessment: a comparison with gated Tc-99m sestamibi SPECT.

PURPOSE: To investigate the value of gated F-18 FDG PET/CT on left ventricular (LV) dyssynchrony assessment in comparison with gated Tc-99m sestamibi SPECT in patients with coronary artery disease (CAD). METHODS: The data of 100 consecutive CAD patients who underwent both gated myocardial Tc-99m sestamibi SPECT and F-18 FDG PET/CT imaging were analyzed. Phase standard deviation (SD) and histogram bandwidth (BW) were derived from phase analysis using Cedars software package. The correlation and agreement of SD and BW between Tc-99m sestamibi SPECT and F-18 FDG PET/CT were examined. Myocardial viability and the site of latest activation assessed by the two imaging methods were compared as well. RESULTS: A moderate correlation for SD (r = 0.58, p < 0.0001) and BW (r = 0.60, p < 0.0001) was found between gated SPECT and gated F-18 FDG PET/CT. Bland-Altman analysis revealed an overestimation of SD and BW (6.4° ± 14.3° and 22.0° ± 46.8°) by gated F-18 FDG PET/CT. Multivariate logistic regression analysis identified that significant LV remodeling on SPECT imaging, LV functional parameters and F-18 FDG uptake ratio of myocardium to blood pool (SUVM/B) were associated with the overestimation. Myocardial SPECT and F-18 FDG PET/CT had a 67.1 % identity in determining the latest activation site and 5.2 % more viable myocardium was detected by F-18 FDG PET/CT than SPECT. CONCLUSION: Gated F-18 FDG PET/CT moderately correlated with gated Tc-99m sestamibi SPECT in assessing LV dyssynchrony. Gated F-18 FDG PET/CT phase analysis should be cautiously applied in CAD patients with significant LV remodeling on SPECT imaging, severe LV functional impairment or poor myocardial F-18 FDG uptake.

Evaluation of left and right ventricular ejection fraction and volumes from gated blood-pool SPECT in patients with dilated cardiomyopathy: comparison with cardiac MRI.

UNLABELLED: This prospective study evaluated the accuracy of electrocardiogram-gated blood-pool SPECT (GBPS) for the assessment of left ventricular (LV) and right ventricular (RV) ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) in patients with dilated cardiomyopathy (DCM), using cardiac magnetic resonance (CMR) imaging as the reference standard. METHODS: Thirty-two patients (24 men and 8 women; mean age, 51 y) with a diagnosis of idiopathic DCM underwent GBPS and CMR. LV and RV parameters including EDV, ESV, and EF from GBPS were calculated using fully automated gradient software and compared with those obtained by CMR. RESULTS: Biventricular volumes were underestimated by GBPS, compared with CMR (P < 0.001). We found no statistical difference between these 2 methods in the assessment of LV EF (P = 0.23), whereas RV EF was overestimated by GBPS (P < 0.001 vs. CMR). Regression analysis yielded significant correlations between GBPS and CMR in the assessments of biventricular parameters (r = 0.83 for LV EDV, 0.88 for LV ESV, 0.89 for LV EF, 0.86 for RV EDV, 0.86 for RV ESV, and 0.62 for RV EF; all P < 0.001). Comparison of the deviations of RV indices between GBPS and CMR with the ratio of RV EDV to LV EDV showed that there was a statistically significant trend for RV volumes to be underestimated and for RV EF to be overestimated as the biventricular volumetric ratio decreased (r = 0.61 for RV EDV, 0.68 for RV ESV, and -0.55 for RV EF; all P < 0.001). CONCLUSION: For patients with DCM, GBPS correlated well with CMR for the assessment of biventricular parameters, but RV indices should be cautiously interpreted.

Coronary spasm after completion of adenosine pharmacologic stress test.

Adenosine is a frequently used pharmacologic stress agent in myocardial perfusion imaging. Its safety profile is well established, and most of its side effects are mild and transient. Coronary vasospasm occurs occasionally during or after adenosine stress test in rare cases, which may lead to seriously adverse outcomes. This study reported 3 such cases after completion of adenosine pharmacologic stress test.