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Background: There is limited data on the concordance of left ventricular ejection fraction (LVEF) obtained via solid state dedicated cardiac cameras (SSD) and gated cardiac blood pool scans (GCBPS). This study aimed to examine the agreement of LVEF measured during GCBPS and Tl-201 myocardial perfusion scans (MPS) using SSD. Methods: Seventy six patients were enrolled. Following stress MPS with 0.8 Mbq/kg (0.022 mCi/kg) Tl-201 and 8-frame gated rest studies after additional 15 Mbq (0.41 mCi) Tl-201, LVEFs were obtained using ECToolbox (ECT) and quantitative gated SPECT (QGS) software. Same day 16-frame planar GCBPS were performed. Interobserver variability was compared and LVEF results were compared using paired t tests, Pearson's correlation and the differences of the LVEF were plotted against GCBPS values. Results: For GCBPS, ECT and QGS, the mean (±SD) LVEF was 52% ± 14%, 61% ± 18% and 48% ± 19%, respectively. When compared to GCBPS, ECT and QGS, LVEFs had similar R values of 0.85 and 0.83, respectively, and mean differences [95% limits of agreement (LA)] of −8.6% (−27.4% to +10.2%, P < .001) and 4.2% (−17.2% to +25.6%, P = .001), respectively. Conclusion: While the LVEF obtained by ECT or QGS demonstrates a statistically significant correlation with GCBPS, they are significantly different and the wide 95% LA suggest that Tl-201 MPS LVEFs derived from either software package are not interchangeable with GCBPS results. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the reproducibility of serial re-acquisitions of gated Tl-201 and Tc-99m sestamibi left ventricular ejection fraction (LVEF) measurements obtained on a new generation solid-state cardiac camera system during myocardial perfusion imaging and the importance of manual operator optimization of left ventricular wall tracking. Methods: Resting blinded automated (auto) and manual operator optimized (opt) LVEF measurements were measured using ECT toolbox (ECT) and Cedars-Sinai QGS software in two separate cohorts of 55 Tc-99m sestamibi (MIBI) and 50 thallium (Tl-201) myocardial perfusion studies (MPS) acquired in both supine and prone positions on a cadmium zinc telluride (CZT) solid-state camera system. Resting supine and prone automated LVEF measurements were similarly obtained in a further separate cohort of 52 gated cardiac blood pool scans (GCBPS) for validation of methodology and comparison. Appropriate use of Bland-Altman, chi-squared and Levene's equality of variance tests was used to analyse the resultant data comparisons. Results: For all radiotracer and software combinations, manual checking and optimization of valve planes (+/− centre radius with ECT software) resulted in significant improvement in MPS LVEF reproducibility that approached that of planar GCBPS. No difference was demonstrated between optimized MIBI/Tl-201 QGS and planar GCBPS LVEF reproducibility ( P = .17 and P = .48, respectively). ECT required significantly more manual optimization compared to QGS software in both supine and prone positions independent of radiotracer used ( P < .02). Conclusions: Reproducibility of gated sestamibi and Tl-201 LVEF measurements obtained during myocardial perfusion imaging with ECT toolbox or QGS software packages using a new generation solid-state cardiac camera with improved image quality approaches that of planar GCBPS however requires visual quality control and operator optimization of left ventricular wall tracking for best results. Using this superior cardiac technology, Tl-201 reproducibility also appears at least equivalent to sestamibi for measuring LVEF. [ABSTRACT FROM AUTHOR]

Purpose: Changes in F-18 fluorodeoxyglucose (FDG) uptake in normal tissues after chemoradiation therapy (CRT) potentially limit the ability of positron emission tomography (PET) to provide early assessment of therapeutic response. This study evaluated whether such changes negatively impact interpretation of posttherapy PET performed within 6 weeks of CRT completion and before definitive surgery in patients with locally advanced rectal cancer. The positive predictive value (PPV) and specificity of post-CRT PET, read clinically, was determined in 63 consecutive rectal cancer patients who had undergone preoperative CRT. Methods and Materials: A schema for identifying and scoring postradiation effects on PET was prospectively defined and applied in a blinded manner. This was compared with initial clinical reporting of response. Histologic assessment of the operative specimens was used as the reference standard. Correlation between clinical proctitis during CRT and radiation changes on subsequent PET was also assessed. Results: Clinical reporting of post-CRT PET yielded a high PPV (94%; 95% confidence interval, 89--100%) but may have been exaggerated by the low prevalence of complete tumor clearance (16%). The specificity was 80% with only two false-positive results. On blinded reading, significant post-CRT effects on PET were recorded in 4 of 63 patients (6% 95% confidence interval, 0–13%), but pattern recognition converted both false-positive PET results to a complete metabolic response. Clinical CRT proctitis was not correlated with PET findings. Conclusion: Postradiation effects do not appear to significantly compromise the interpretation of PET for therapeutic response assessment. The proposed PET pattern of response may further improve the specificity of PET. [Copyright &y& Elsevier]

Abstract: Background: Statins decrease mortality in patients with coronary artery disease. However, chronic heart failure (CHF) patients were often excluded in such trials. Statins possess pharmacologic properties (independent of cholesterol lowering) that may be beneficial on ventricular remodeling in such patients. Methods and Results: We conducted a 6-month randomized placebo (PBO)-controlled study of rosuvastatin (ROS) in patients with systolic (left ventricular ejection fraction [LVEF] <40%) CHF of ischemic or nonischemic etiology. The primary end point was change in LVEF by radionuclide ventriculogram. Secondary end points included change in echocardiographic parameters, neurohormonal and inflammatory markers, Packer composite score, death, and heart failure hospitalization. Patients were well matched for baseline values. Compared with PBO (n = 46), ROS patients (n = 40) had a decrease in low-density lipoprotein cholesterol (PBO +3, ROS −54%, P < .001). There was no significant change in LVEF by radionuclide ventriculogram (PBO +5.3, ROS +3.2%), fractional shortening by echocardiographic (PBO +2.7, ROS +1.8%), left ventricular end-diastolic diameter (PBO −1.7, ROS +0.8 mm), left ventricular end-systolic diameter (PBO −1.9, ROS +0.1 mm). Plasma norepinephrine, endothelin-1, brain natriuretic peptide, hsCRP, tumor necrosis factor-α and interleukin-6, patient global assessment, Packer composite, death/heart failure hospitalization, and adverse events were similar between PBO and ROS. Conclusions: Despite being safe and effective at decreasing plasma cholesterol, high-dose ROS did not beneficially alter parameters of LV remodeling. Reasons for absence of benefit are uncertain, but may include patient population studied, high dose of ROS used or high use of effective background CHF medications. [Copyright &y& Elsevier]

Background: Subdiaphragmatic activity and diaphragmatic motion both contribute to inferior wall artifacts in technetium 99m myocardial perfusion single photon emission computed tomography (SPECT).Methods and Results: We used an anthropomorphic phantom with ventricular wall activity, liver/spleen inserts containing variable Tc-99m activity, and variable vertical (diaphragmatic) motion amplitude. SPECT and transmission scans were obtained on a GE Optima NX camera. Data were processed by use of filtered backprojection or attenuation correction (AC). Resulting myocardial activity maps were analyzed with standardized inferior-anterior and anterior-lateral wall ratios. At a subdiaphragmatic-myocardial activity ratio of 0.5:1, inferior wall attenuation predominates, producing a cold artifact. AC corrects inferior wall activity to the level of the anterior wall irrespective of diaphragmatic motion. At a subdiaphragmatic-myocardial activity ratio of 1:1, inferior wall counts vary widely depending on the proximity of subdiaphragmatic activity to the ventricle. With increasing diaphragmatic amplitude, the overlap of subdiaphragmatic activity and inferior wall worsens, leading to a complex mixture of cold and hot artifacts, not corrected by AC.Conclusions: Concentration and proximity of subdiaphragmatic Tc-99m activity relative to myocardium comprise a major factor in the nature and severity of inferior wall artifacts. If the subdiaphragmatic Tc-99m concentration is equivalent to that in the myocardium, complex, potentially uninterpretable hot and cold inferior wall artifacts are produced. [ABSTRACT FROM AUTHOR]

A significant body of evidence now suggests that clinically adequate planar and SPECT myocardial perfusion/FDG metabolism studies can be performed for assessment of myocardial viability with conventional gamma cameras. This might reduce the need for more sophisticated PET scanners in this patient subgroup and also increase the general applicability of metabolic assessment of myocardial viability with FDG. The procedure is technically demanding in terms of both equipment and interpretation, and requires further careful evaluation before it can be recommended for widespread use. Nevertheless, it appears to have enough potential to warrant evaluation along with improving techniques of using myocardial perfusion tracers, PET imaging, and stress echocardiography to identify the most cost-effective options for assessing viability of myocardium in clinical situations in which this becomes important. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia leads to alterations in myocardial substrate metabolism that have been shown to reflect severity of ischemic injury. The purpose of this study was to correlate oxidative metabolism with recovery of contractile function in patients with acute myocardial infarction. Methods and Results: Regional blood flow and oxidative metabolism were assessed by dynamic positron emission tomography early after myocardial infarction treated with thrombolytic therapy in 18 patients. The extent of myocardial perfusion abnormality (carbon 11-labeled acetate uptake; relative amplitude ≤50%) was inversely correlated with the ejection fraction obtained within 8 hours of the onset of chest pain ( r=0.81; p=0.01) but not clearly with that at follow-up 1 week later ( r=0.64; p=0.09). Oxidative metabolism (carbon 11-labeled acetate; monoexponential clearance) was higher in periinfarct territories with early or late recovery of contractile function than in those without, but there was a large overlap in absolute values limiting the predictive power of a single measurement. Relatively preserved oxidative metabolism compared with perfusion in low-flow areas was predictive of early (day 1 to 1 week) and delayed (week 1 to beyond 1 month) recovery. Normal resting perfusion with regionally decreased oxidative metabolism predicted early recovery of contractile function. Conclusion: Thus in patients studied with positron emission tomography early after myocardial infarction, comparison of regional perfusion and oxidative metabolism was more predictive of recovery in contractile function than was assessment of either one alone. [ABSTRACT FROM AUTHOR]

Scintigraphy using iodine-123-metaiodobenzylguanidine (I-123-MIBG) has been used to demonstrate that >50% of orthotopically transplanted hearts undergo partial cardiac sympathetic re-innervation and that this occurs no earlier than 1 year post-transplant. This study used planar and singe-photon emission computed tomography (SPECT) I-123 MIBG scintigraphy to show that cardiac re-innervation was not detectable in any of the 8 patients studied 1.1 to 6.3 years post-heterotopic transplantation. Thus, potential for cardiac re-innervation varies according to the type of procedure performed. [Copyright &y& Elsevier]

Background: In this study we investigate the time sequence and extent of the sustained decrease in native heart ejection fraction (EF) after heterotopic heart transplantation (HHTx) when using gated cardiac blood pool scanning (GCBPS) and transthoracic echocardiography (TTE) One case report of 2 patients used post-operative GCBPS and TTE and found a significant deterioration in native heart EF post-operatively over the course of several years. Comparison with pre-operative measurements using these techniques in a series of patients has not been performed previously.Methods: Thirteen of 16 HHTx patients with adequate pre- and post-operative GCBPS follow-up were included in this study. All patients also underwent TTE post-operatively and the GCBPS results were correlated with the TTE findings.Results: GCBPS demonstrated a marked (21.1 ± 4.7% vs 10.5 ± 3.7%, p < 0.0001) decrease in native EF post-HHTx. Spontaneous echo contrast in the native left ventricle and/or poor opening of the mitral/aortic valves was noted at Day 1 in 4 of 5 patients who had a TTE at this stage. No further decline was noted between the first and last post-operative GCBPS (10.8 ± 3% vs 8.6 ± 2.1%, p = NS).Conclusions: A dramatic decrease in native heart EF post-HHTx occurs as early as Day 1 post-transplant. Dissociation of ventricular contraction is the most likely cause. Studies have demonstrated that paced linkage (counterpulsation) between the ventricles results in improved hemodynamics. This may have clinical implications as to the timing of ejection of blood from a left ventricular assist device (LVAD) and for providing the best hemodynamics for the ventricle being assisted and for optimizing its chances of long-term recovery. [Copyright &y& Elsevier]

We assessed glycoprotein (GP) IIb/IIIa independent platelet activation in coronary sinus and peripheral blood from patients who underwent angioplasty for acute myocardial infarction and stable angina. Despite complete blockade of the activated GP IIb/IIIa receptor with abciximab in patients with acute myocardial infarction, unsuppressed local GP IIb/IIIa independent activation was associated with a lack of recovery of left ventricular function. [ABSTRACT FROM AUTHOR]