Uncontrolled risk factors and worsening perfusion pattern on SPECT myocardial perfusion imaging in medically treated patients with stable chronic ischaemic heart disease.

PURPOSE: Few data exist on the correlation between the effectiveness of risk factor control and the evolution of myocardial perfusion over time in patients with stable ischaemic heart disease. The aim of the study was to evaluate the changes in stress-rest myocardial perfusion in medically treated patients with stable chronic ischaemic heart disease and the relationship with risk factor control. METHODS: The study cohort included 174 consecutive patients (age 60 ± 9 years, 68 % men) undergoing stress-rest myocardial perfusion imaging (MPI) (study 1), who also underwent repeat evaluation (study 2) and who were clinically stable on medical therapy. Summed stress, rest and difference scores were calculated. According to the evolution of perfusion pattern from study 1 to study 2, patients were classified as improved, stable or worsened. RESULTS: Study 2 was performed on average 2.7 years after study 1. Of the 174 patients, 47 (26.9 %), 53 (30.8 %) and 74 (42.5 %) were classified as stable, improved and worsened, respectively. A significant trend was observed between the number of risk factors at the time of study 1 and worsening of myocardial perfusion (24 % of patients with zero or one risk factor showed worsening, 31 % with two, and 59 % with three or more; p = 0.03). Moreover, patients with worsened perfusion had a higher number of poorly controlled risk factors. CONCLUSION: Despite medical therapy and clinical stability, myocardial perfusion worsened in 42.5 % of patients. The risk profile was reclassified in half of the patients. Worsening occurred more frequently in patients with three or more risk factors at the time of study 1 and in those with poorly controlled risk factors at the time of study 2; in this subset of patients, even if clinically stable, reassessment after 2 years could be considered.

1-23I-MIBG thyroid uptake: Implications for MIBG imaging of the heart.

BACKGROUND: 123I-MIBG has been widely used in patients with heart failure and neurological disorders. The patients are pre-treated with Lugol's oral solution or potassium perchlorate to prevent thyroid uptake of unlabeled 123I to limit the thyroid radiation exposure. However, despite the inhibition of the iodide pump, the thyroid is frequently visualized. The aim of this study was to study the pattern of thyroid uptake. METHODS: We reviewed the 123I-MIBG images of 57 patients studied in three different centers in Italy for cardiac (n = 42) or neurological (n = 15) indications. They were imaged at 15 minutes and 4 hours after injection and in all patients, the thyroid was included in the imaging field of view. In 2 of the 3 centers, the patients were pre-treated with Lugol's oral solution and/or potassium perchlorate (group 1) but in the third center, they were not (group 2). The following imaging parameters were evaluated: heart-to-mediastinum ratio (H/M), thyroid-to-mediastinum ratio (T/M) at 4 hours, and tracer wash out from the heart (HWO) and from the thyroid (TWO). RESULTS: In the cardiac patients, the HWO was 22.98 ± 7.16% and TWO was 11.4 ± 11.86% (P < .0001). The TWO was 12.2 ± 13.1% in group 1 and 10.05 ± 8.97% in group 2 (P = NS). In the neurological patients the HWO was 26 ± 8.1% and the TWO was 20.32 ± 6.41 (P < .05). The difference in TWO was statistically significant (P < .01) between cardiac and neurological patients, whereas the HWO was not. The 4-hour H/M was 1.49 ± 0.23 in cardiac patients vs 1.4 ± 0.39 in neurological patients (P = NS). The 4-hour T/M was 1.33 ± 0.3 in cardiac patients vs 1.15 ± 0.13 in neurological patients (P < 0.05). CONCLUSION: The thyroid visualization in MIBG imaging is likely an expression of thyroid sympathetic innervation. The differences in TWO and T/M ratio in cardiac and neurological patients probably express differences in thyroid dopaminergic receptors. Thus, pre-treatment with potassium perchlorate or Lugol's solution may not be justified in patients undergoing 123I-MIBG imaging in whom the risk of side effects due to pre-treatment could be higher than the risk due to thyroid radiation exposure.

Comparative analysis of iterative reconstruction algorithms with resolution recovery for cardiac SPECT studies. A multi-center phantom study.

BACKGROUND: This investigation used image data generated by a physical phantom over a wide range of count statistics to evaluate the effectiveness of several of the newer commercially available SPECT reconstruction iterative algorithms (IRR) in improving perfusion defect contrast and spatial resolution, while controlling image noise. METHODS: A cardiac phantom was imaged using four different gamma cameras over a wide range of counts statistics (from 6 to 0.8 Mcounts). Images were reconstructed with FBP, OSEM, and the IRR available on site. IRR were applied without corrections (IRR NC), with attenuation correction (IRR AC), scatter correction (IRR SC), and attenuation + scatter corrections (IRR SCAC). Four image performance indices related to spatial resolution, contrast, and image noise were analyzed. RESULTS: IRR NC always determined significant improvements in all indices in comparison to FBP or OSEM. Improvements were emphasized with IRR SC and IRR SCAC. Count reduction from 6 to 1.5 Mcounts did not impair the performances of any of the considered indices. CONCLUSIONS: This is the first study comparing the relative performance of different, commercially available, IRR software, over a wide range of count statistics; the additional effect of scatter and attenuation corrections, alone or in combination, was also evaluated. Our results confirm that IRR algorithms produce substantial benefits with respect to conventional FBP or OSEM reconstruction methods, as assessed through different figures of merit, in particular when SC and/or SCAC are also included.

Wide beam reconstruction for half-dose or half-time cardiac gated SPECT acquisitions: optimization of resources and reduction in radiation exposure.

PURPOSE: A new iterative reconstruction algorithm (WBR™) has been recently proposed for cardiac single photon emission computed tomography (SPECT). The WBR™ technology is designed to reduce noise, improving lesion identification without affecting the image resolution, allowing SPECT studies with reduced count statistic. This allows for either half-time (HT) or half-dose (HD) cardiac SPECT, with image quality and quantitative data comparable to standard-time (ST) or standard-dose (SD) SPECT. Few data exist on the comparison between conventional filtered backprojection (FBP) and this new algorithm in a clinical setting. The aim of this study was to compare the performance of FBP and WBR™. METHODS: Phantoms studies were performed to compare spatial resolution and contrast recovery with FBP, ordered subset expectation maximization (OSEM) and WBR™. A group of 92 patients, with different cardiac pathology, scheduled for a stress-rest SPECT were studied: 52 patients (group A) were injected with a SD of tracer and underwent both ST and HT SPECT; 40 patients (group B) were injected with a half dose of tracer and underwent ST SPECT and immediately after an additional SPECT at double time/projection (DT), to compensate for the low count statistic. A 2-day (99m)Tc-sestamibi protocol was used in all patients. SD/ST and HD/DT SPECT were reconstructed with a conventional FBP; SD/HT and HD/ST SPECT were reconstructed with WBR™. The summed stress score (SSS) and summed rest score (SRS) were calculated; the left ventricular ejection fraction (LVEF) was automatically derived. RESULTS: In group A (SD), no significant differences were observed between ST FBP SPECT and HT WBR™ in SSS (11.1 and 11.7, respectively) and SRS (9.4 and 10.3, respectively, NS). LVEF on rest acquisitions was also comparable (50% on ST SPECT and 49% on HT SPECT, NS); LVEF on post-stress studies in HT SPECT (46%) was lower than ST SPECT (50%), although not statistically significant. In group B (HD), SSS (6.2 in ST and 5.3 in DT) and SRS (4.0 in ST and 3.3 in DT) were also comparable. No differences were documented between ST and DT in rest (47 and 48%, respectively) and stress (48 and 50%, respectively) LVEF. CONCLUSION: WBR™ performance and image quality were comparable to those of conventional FBP, allowing for either HT or HD studies. The former allows for an increased patient throughput and optimization of resources. The latter modalities would allow for a significant reduction in both patients' and operators' exposure. Further studies are needed to validate the clinical use of this method.

Conditional cardiovascular response to growth hormone therapy in adult patients with Prader-Willi syndrome.

CONTEXT: In Prader-Willi syndrome (PWS), an altered GH secretion has been related to reduced cardiac mass and systolic function when compared with controls. OBJECTIVES: The objective of the study was to evaluate the cardiovascular response to GH therapy in adult PWS patients. STUDY PARTICIPANTS: Thirteen obese PWS adults (seven males and six females, aged 26.9+/-1.2 yr, body mass index 46.3+/-1.6 kg/m2) participated in the study. METHODS: Determination of IGF-I, metabolic parameters, echocardiography, and cardioscintigraphy with dobutamine stimulation was made during 12 months GH therapy, with results analyzed by repeated-measures ANOVA. RESULTS: GH therapy increased IGF-I (P<0.0001); decreased C-reactive protein levels (P<0.05); and improved lean mass (P<0.001), fat mass (P<0.05), and visceral fat (P<0.001). Echocardiography showed that 6- and 12-month GH therapy increased left ventricle mass in 76 and in 61% of patients, respectively (P<0.05), did not change diastolic function, and slightly decreased the left ventricle ejection fraction (LVEF) (P=0.054). Cardioscintigraphy documented stable values of LVEF throughout the study, whereas right ventricle ejection fraction decreased significantly (P<0.05) being normally responsive to dobutamine infusion. A positive association between IGF-I z-scores and LVEF occurred at the 6- and 12-month follow-up (P<0.05). CONCLUSIONS: In PWS, GH therapy increased cardiac mass devoid of diastolic consequences. The observation of a slight deterioration of right heart function as well as the association between IGF-I and left ventricular function during GH therapy suggest the need for appropriate cardiac and hormonal monitoring in the therapeutic strategy for Prader-Willi syndrome.

The impact of growth hormone/insulin-like growth factor-I axis and nocturnal breathing disorders on cardiovascular features of adult patients with Prader-Willi syndrome.

CONTEXT: Adult patients with Prader-Willi syndrome (PWS) are prone to develop obesity, GH deficiency (GHD), and their related complications, with cardiopulmonary failure explaining more than half of PWS fatalities. OBJECTIVE AND STUDY PARTICIPANTS: This study was undertaken to examine the effect of GHD and sleep breathing disorders on cardiovascular risk factors and heart features of 13 PWS (age 26.9 +/- 1.2 yr) and 13 age-, gender-, and body mass index-matched obese individuals (age 26.2 +/- 0.8 yr). RESULTS: Compared with controls, PWS patients had lower GH response to arginine+GHRH, IGF-I levels, triglycerides, total and LDL-cholesterol, insulin, and insulin resistance measured by a homeostatic model approach. Dual-energy x-ray absorptiometry, abdominal computed tomography scans, and polysomnography revealed a greater fat mass, similar abdominal fat, but greater sleep breathing disorders in PWS than obese subjects. Echocardiography showed no systolic or diastolic alteration, although PWS had lower left ventricle (LV) mass (135.7 +/- 7.7 vs. 163.5 +/- 8.4 g, P < 0.05) and near significantly lower values of LV end-diastole diameter (P = 0.08), compared with obese controls. Baseline radionuclide angiography documented comparable values of systolic and diastolic values between groups. However, adrenergic stimulation with dobutamine caused a lower increase of LV ejection fraction (71.9 +/- 1.9 vs. 76.3 +/- 1.2%, P < 0.05) and heart rate (103 +/- 6.9 vs. 128 +/- 2.8 beats/min, P < 0.05) in PWS than obese individuals. By multivariate analysis, nocturnal oxygen desaturation and IGF-I levels were main significant predictors of LV mass and heart rate in PWS patients. CONCLUSIONS: PWS differs from simple obesity by a healthier metabolic profile, impaired nocturnal breathing, decreased heart geometry, and systolic and chronotropic performance. GHD and the predictive role of IGF-I on structural and functional heart parameters suggest a GH/IGF-I-mediated control of cardiac risk in PWS.

Long-term echocardiographic and cardioscintigraphic effects of growth hormone treatment in adults with Prader-Willi syndrome.

CONTEXT: In Prader-Willi syndrome (PWS), an altered GH secretion has been related to reduced cardiac mass and systolic function compared to controls. OBJECTIVE: The objective was to evaluate the cardiovascular response to a 4-year GH therapy in adult PWS patients. STUDY PARTICIPANTS: Study participants were nine severely obese PWS adults (three females, six males) and 13 age-, gender-, and body mass index-matched obese controls. METHODS: In an open-label prospective study, assessment of endocrine parameters and metabolic outcome, whole-body and abdominal fat scans, echocardiography, and radionuclide angiography in unstimulated and dobutamine-stimulated conditions were conducted at baseline and after 1 and 4 years of GH treatment. RESULTS: GH treatment increased IGF-1 (P < .0001), decreased C-reactive protein levels (P < .05), improved visceral fat mass (P < .05), and achieved near-significant changes of fat and fat-free body mass in PWS patients. Left ventricle mass indexed by fat mass increased significantly after 1 and 4 years of GH therapy (P < .05) without evident abnormalities of diastolic function, while a trend toward a reduction of the ejection fraction was documented by echocardiography (P = .054). Radionuclide angiography revealed stable values throughout the study of both the left and right ventricle ejection fractions, although this was accompanied by a statistically nonsignificant reduction of the left ventricle filling rate. A positive association between lean body mass and left ventricle ejection fraction was evident during the study (P < .05). CONCLUSIONS: GH therapy increased the cardiac mass of PWS adults without causing overt abnormalities of systolic and diastolic function. Although the association between lean mass and left ventricle ejection fraction during GH therapy corroborates a favorable systemic outcome of long-term GH treatment in adults with PWS, subtle longitudinal modifications of functional parameters advocate appropriate cardiac monitoring in the long-term therapeutic strategy for PWS.

Posttraumatic epilepsy: neuroradiologic and neuropsychological assessment of long-term outcome.

PURPOSE: We sought to detect the incidence and the risk factors of posttraumatic epilepsy (PTE) in rehabilitation patients; to define the influence of PTE for late clinical and functional outcome; and to assess the cognitive and behavioral features of the patients with PTE. METHODS: Patients were examined with (a) cognitive and behavioral examinations, which included a clinical interview and psychometric tests performed by an expert clinical psychologist; (b) single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI); and (c) functional evaluation including the Glasgow Outcome Scale (GOS) and the Functional Independence Measure (FIM). RESULTS: Of the 143 patients examined in this study, in 27 (19%), seizures developed after a mean time from trauma of 11.9 +/- 8.6 months. The occurrence of PTE was significantly correlated with the hypoperfusion in temporal lobes (p < 0.004), the degree of hydrocephalus (p < 0.04), the evidence of intracerebral hematoma (p < 0.01), and operative brain injury (p < 0.001). Patients with epilepsy showed a significantly higher incidence of personality disorders than did patients without epilepsy. The uninhibited behavior, irritability, and agitated and aggressive behavior were significantly more frequent and severe in PTE patients. The psychometric tests intended to explore memory, language, intelligence, attention, and spatial cognition did not show any significant difference between those with and without epilepsy. PTE also was significantly correlated with a worse functional outcome 1 year after the trauma. CONCLUSIONS: The degrees of hydrocephalus and of hypoperfusion in the temporal lobes are significant risk factors for late PTE. Another main finding of our study is the absence of influence of epilepsy on cognitive disorders; its influence on neurobehavioral disorders and functional outcome is discussed.

Posttraumatic hydrocephalus: a clinical, neuroradiologic, and neuropsychologic assessment of long-term outcome.

OBJECTIVES: To detect the clinical and radiologic characteristics of posttraumatic hydrocephalus (PTH), to define its prognostic value, and to assess the effects of shunt surgery. DESIGN: Correlational study on a prospective cohort. SETTING: Brain injury rehabilitation center. PARTICIPANTS: One hundred forty patients with severe traumatic brain injury (TBI) referred to an inpatient intensive rehabilitation unit of primary care in a university-based system. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Glasgow Outcome Scale (GOS), Disability Rating Scale (DRS), FIM instrument, and Neurobehavioural Rating Scale (NRS), as well as single-photon emission computed tomography (SPECT) and magnetic resonance imaging. RESULTS: PTH was found in 45% of patients. Risk factors for PTH were as follows: age (P<.04), duration of coma (P<.0001), and decompressive craniectomy (P<.0001). PTH correlated with the degree of hypoperfusion in the temporal lobes (P<.001). Patients who showed clinical deterioration improved after surgery. PTH correlated significantly with GOS, DRS, FIM, and NRS (P<.0001) 1 year after the trauma, and it influenced the appearance of posttraumatic epilepsy (P<.02). CONCLUSIONS: PTH concerns about 50% of patients with severe TBI. It influences functional and behavioral outcome and the appearance of posttraumatic epilepsy. The selection of patients for surgery can be defined principally on a clinical basis. SPECT may be helpful for differentiating ventricular enlargement due to cortical atrophy and hydrocephalus.