ABSTRACT: BackgroundThe value of gated single photon emission computed tomography (SPECT) in the assessment of wall motion (WM) in patients with
severe perfusion defects and in the evaluation of low-dose dobutamine (LDD)-induced changes is not yet established. In patients
with chronic coronary artery disease who have left ventricular (LV) dysfunction, the results of nitrate-enhanced technetium
99m sestamibi (sestamibi) gated SPECT for the evaluation of resting and LDD WM were compared with those of baseline and LDD
Methods and ResultsThirty-seven patients underwent echocardiography and nitrateenhanced sestamibi gated SPECT within 1 week at rest and during
LDD infusion. WM was scored from 1 (normal) to 4 (dyskinetic) by using a 16-segment model. Segments with sestamibi uptake
less than 30% were considered unsuitable for WM analysis (36 of 592 segments). Echocardiography was technically unreliable
in 10 of 592 segments. The precise agreement between echocardiography and gated SPECT for baseline regional WM was 68.4% (kappa
= 0.54), without significant differences for the involved coronary artery territory. The agreement for ± 1 WM scoring was
96.5% (kappa = 0.94). Contractile reserve during LDD was detected by means of echocardiography in 36% and by means of sestamibi
gated SPECT in 33% of baseline asynergic segments. Agreement for detection of WM improvement in response to LDD was 74% (kappa
= 0.41). The overall and ± 1 WM score agreement for LDD WM was 67.5% (kappa = 0.50) and 94.7% (kappa = 0.91), respectively.
A significant correlation between echocardiography and gated SPECT was observed for both baseline (ρ= 0.78) and LDD (ρ= 0.74)
WM score index.
ConclusionsIn patients with coronary artery disease who have LV dysfunction, nitrateenhanced sestamibi gated SPECT allows a reliable
WM evaluation, both at rest and during LDD infusion, in almost all segments and provides results in agreement with LDDE. (J
Nucl Cardiol 2000;7:426–31.)
Journal of Nuclear Cardiology 04/2012; 7(5):426-431. · 2.67 Impact Factor
ABSTRACT: BackgroundThe role of gated single photon emission computed tomography (SPECT) in improving viability detection with the use of perfusion
imaging is uncertain. This study aimed to verify whether the classification of baseline regional dysfunction with gated SPECT
helps to predict functional recovery with the use of quantitative perfusion imaging.
Methods and ResultsResting nitrate-enhanced sestamibi gated SPECT was performed in 31 patients with left ventricular dysfunction, who later underwent
coronary revascularization. With the use of a 16-segment model, tracer activity was quantified, and wall motion and thickening
were estimated with a 4-point scoring scheme. Reversible dysfunction was assessed with follow-up gated SPECT. According to
receiver operating characteristic curve analysis, the best overall cutoff for predicting reversible dysfunction in asynergic
segments was 50% of peak activity or greater, with 83% sensitivity, 54% specificity, and 64% accuracy. When the segments were
divided according to wall motion in resting gated SPECT, the optimal activity cutoff was greater than 68% for hypokinetic
and 50% or greater for adyskinetic segments. With the use of 2 thresholds, the overall sensitivity remained good (76%), whereas
specificity increased to 73% (P < .0005) and accuracy to 74% (P < .02).
ConclusionsRegional dysfunction assessment directly on perfusion images permits use of different activity thresholds with an improvement
over a single cutoff for all asynergic segments. Therefore combining perfusion and functional data with nitrate-enhanced gated
SPECT at rest appears to be a promising approach for viability detection.
Journal of Nuclear Cardiology 04/2012; 8(5):555-560. · 2.67 Impact Factor
ABSTRACT: The incremental prognostic value of combined regional wall motion and perfusion over perfusion alone by gated single-photon emission computed tomographic myocardial perfusion scintigraphy has not been evaluated. Of the 402 consecutive patients who underwent stress single-photon emission computed tomographic myocardial perfusion scintigraphy for suspected myocardial ischemia, we identified 333 patients (217 men, mean age 63 +/- 10 years; exercise in 249 and dipyridamole adminstered to 84). Visual scoring of perfusion images and regional wall motion used 20 segments and a scale of 0 to 4. Resting and poststress left ventricular ejection fraction was automatically generated. On follow-up (median 13 months), 30 hard cardiac events (17 cardiac deaths, 13 nonfatal acute myocardial infarctions) and 66 total cardiac events (including hard events, 26 with unstable angina, and 10 who underwent late revascularization) occurred. After adjustment for prescan information, the best independent predictors of hard events were summed stress score for wall motion (Wald's chi-square 8.3, p <0.004) and several vascular territories with ischemia by perfusion/function (Wald's chi-square 6.2, p <0.01). The strongest predictors of all cardiac events were the number of ischemias (Wald's chi-square 32.1, p <0.0001) and the number of ischemic vascular territories by perfusion (Wald's chi-square 13.1, p <0.0001). Addition of function data to the combined model of perfusion data yielded an incremental value of 26% for predicting hard events but not for all events. In conclusion, the assessment of combined perfusion/function provides incremental prognostic information for further hard events with perfusion data alone; perfusion data best predict all cardiac events.
The American Journal of Cardiology 06/2005; 95(11):1351-7. · 3.37 Impact Factor
ABSTRACT: A main goal of revascularization in patients with chronic ischemic cardiomyopathy is to improve global left ventricular (LV) function. This study aimed to verify whether it is possible to predict an increase in LV ejection fraction (EF) after revascularization on the basis of the extent of LV asynergy, myocardial viability, and revascularization completeness. We studied 77 patients with chronic LV ischemic dysfunction using baseline resting and nitrate-enhanced technetium-99m sestamibi single-photon emission computed tomography. Regional wall motion and global LVEF were assessed with echocardiography before and after revascularization, which was complete in 51 patients and incomplete in 26. The number of viable asynergic segments included in revascularized coronary artery territories was the strongest predictor of significant (> or = 5 EF U) functional improvement in univariate discriminant analysis. According to multivariate stepwise discriminant analysis, this parameter, together with the number of baseline asynergic segments, allowed the detection of patients with significant LVEF improvement with 75% accuracy. With use of a multivariate regression model, including the 2 mentioned variables, the measure of postrevascularization LVEF increase could be accurately quantified (R(2) 0.43, p <0.000001). In conclusion, this study suggests that the severity of baseline asynergy, the extent of myocardial viability, and the completeness of revascularization are the main determinants of postrevascularization functional recovery in patients with LV ischemic dysfunction, and that on the basis of these variables it is possible to predict the measure of LVEF increase.
The American Journal of Cardiology 06/2002; 89(12):1369-73. · 3.37 Impact Factor
ABSTRACT: Gated single-photon emission computed tomography (SPECT) imaging allows analysis of myocardial perfusion and assessment of baseline global and regional left ventricular (LV) function and their changes during low-dose dobutamine infusion. The study examined whether the changes in LV ejection fraction induced by dobutamine and evaluated using technetium-99m sestamibi- gated SPECT predict the evolution of ejection fraction after revascularization in patients with ischemic cardiomyopathy. Thirty-seven patients underwent resting and dobutamine nitrate-enhanced sestamibi-gated SPECT before revascularization and baseline-resting sestamibi gated SPECT after intervention to assess global functional changes. A postrevascularization improvement in ejection fraction > or =5 U was defined as significant. At follow-up, ejection fraction increased significantly in 19 patients. According to receiver-operating characteristic curve analysis, an increase in ejection fraction > or =5 U during dobutamine was the optimal cutoff value for predicting a significant postrevascularization improvement, with 79% sensitivity, 78% specificity, and 78% accuracy. A significant correlation was found between dobutamine and postrevascularization ejection fraction (r = 0.85; p <0.0001). The increase in ejection fraction during dobutamine is a good predictor of an improvement in ejection fraction after revascularization. This represents another important diagnostic contribution obtained using gated SPECT imaging for the assessment of myocardial viability in patients with ischemic cardiomyopathy.
The American Journal of Cardiology 04/2002; 89(7):817-21. · 3.37 Impact Factor
ABSTRACT: Acceptance of technetium-99m sestamibi as a tracer of myocardial viability is growing, particularly when nitrate-enhanced imaging is used. However, few data are available on the ability of 99mTc-sestamibi to predict the evolution of global left ventricular ejection fraction (EF). The aim of this study was to examine the ability of resting and nitrate 99mTc-sestamibi single-photon emission tomography (SPET) to predict EF changes after revascularisation in patients who have chronic coronary artery disease with left ventricular dysfunction. Using baseline resting and nitrate 99mTc-sestamibi SPET, we studied 61 patients scheduled for revascularisation because of left ventricular dysfunction. EF was estimated using two-dimensional echocardiography before and after the intervention. A post-revascularisation improvement of ̓ EF units was defined as significant. Using a 13-segment model, 99mTc-sestamibi activity was quantified and the nitrate-induced activity changes calculated. Three different criteria for detecting viability (defined as post-revascularisation reversible dysfunction) in asynergic segments were compared: (1) resting 99mTc-sestamibi activity ₨%; (2) nitrate 99mTc-sestamibi activity ₭%; and (3) nitrate-induced increase >+10% or nitrate-induced increase h+10% and nitrate activity ₭%. EF increased significantly in 32 patients. The number of viable asynergic segments was significantly higher in these patients than in the remaining 29 subjects, and the difference was greater (P<0.0002) using definition (3) than using either baseline (P<0.002) or nitrate activity (P<0.0005). There was a significant relationship between EF changes and number of viable asynergic segments: Spearman R=0.38, P<0.005 using baseline; Spearman R=0.39, P<0.002 using nitrate activity; and Spearman R=0.55, P<0.000005 using definition (3). According to receiver operating characteristic (ROC) curve analysis, this last criterion achieved the best results (81% sensitivity, 69% specificity and 75% accuracy), with an area under the ROC curve of 0.838; this area was significantly larger than when using either baseline (0.744, P<0.02) or nitrate activity (0.747, P<0.005). 99mTc-sestamibi SPET appears able to predict the evolution of global left ventricular EF after revascularisation, thereby confirming the value of 99mTc-sestamibi as a tracer of myocardial viability. The combination of baseline resting and nitrate imaging seems to significantly improve the diagnostic accuracy of 99mTc-sestamibi SPET for this particular purpose.
European journal of nuclear medicine and molecular imaging 01/2001; 28(6):680-687. · 4.99 Impact Factor
ABSTRACT: Myocardial stunning has recently been demonstrated by use of stress gated technetium 99m sestamibi single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. However, its prognostic value is less well determined. The aim of this study was to investigate the prognostic value of reversible regional wall motion abnormalities (RWMAs).
We studied 303 consecutive subjects with known or suspected coronary artery disease who underwent 2-day stress-rest gated Tc-99m sestamibi SPECT and were followed up for 19 +/- 16 months. Clinical and test-derived variables were evaluated to predict cardiac death, nonfatal myocardial infarction (MI), unstable angina, and early or late coronary revascularization. Reversible RWMAs were identified in 102 patients. On Cox analysis, the presence, site, degree, and extent of reversible RWMAs did not identify an adverse outcome, except in patients without prior MI. After adjustment for prescan data, the strongest predictors of hard events and all cardiac events were poststress RWMAs and the amount of ischemia. The addition of poststress RWMAs to the combined model of prescan and perfusion data yielded incremental prognostic value.
Poststress RWMAs and ischemia by perfusion were the most powerful predictive parameters of cardiac events. However, myocardial stunning should always be considered, particularly in patients without prior MI and in the referral of patients for early revascularization.
Journal of Nuclear Cardiology 12(1):20-31. · 2.67 Impact Factor
ABSTRACT: The simultaneous assessment of perfusion and function with the use of technetium 99m sestamibi gated single photon emission computed tomography (SPECT) is helpful for the detection of myocardial viability, but its value in comparison with more established methods is not yet defined.
This study compared low-dose dobutamine (LDD) nitrate-enhanced gated SPECT with LDD echocardiography for predicting recovery of regional ventricular function after revascularization in 25 patients with ischemic cardiomyopathy. In both studies, regional function (wall motion and thickening) at rest, during inotropic stimulation, and after revascularization was scored by a 4-point scale. In LDD echocardiography, the prediction of reversible dysfunction was based on the recognition of contractile reserve in asynergic (hypokinetic or a-dyskinetic) segments. In LDD gated sestamibi SPECT, reversible dysfunction was predicted on the basis of perfusion quantification (sestamibi uptake >or= 50%) in a-dyskinetic segments and on the basis of contractile reserve in hypokinetic segments. LDD echocardiography predicted reversible dysfunction with sensitivity, specificity, and global accuracy of 57%, 85%, and 75%, respectively. The sensitivity and specificity of LDD gated SPECT for identifying dysfunctional segments capable of functional recovery were 77% and 88%, respectively, with a diagnostic accuracy of 84% (P <.02 vs LDD echocardiography).
The combined use of 2 different markers of viability, such as cellular integrity in a-dyskinetic segments and contractile reserve in hypokinetic segments, as permitted by LDD gated sestamibi SPECT, showed higher predictive accuracy for reversible dysfunction than the assessment of contractile reserve in all asynergic segments with LDD echocardiography.
Journal of Nuclear Cardiology 9(4):402-6. · 2.67 Impact Factor