Fluorodeoxyglucose PET/CT in patients with differentiated thyroid cancer and elevated thyroglobulin after total thyroidectomy and (131)I ablation.

AIM: The aim of this study was to evaluate the role of 18F fluorodeoxyglucose-positron emission tomography (FDG-PET), differentiated thyroid carcinoma (DTC) treated with therapeutic (131)I because of elevated thyroglobulin (Tg) levels during follow up. The results of FDG-PET/CT were compared with post-therapy (131)I whole body scan (131I-t-WBS) and Tg at short term follow up. METHODS: Forty-five patients with DTC underwent a new therapeutic (131I) administration based upon Tg values >1.5 ng/mL. All patients underwent (131I-t-WBS) 5-7 days after 131I therapy. A few days before 131I administration, a FDG-PET scan was performed in all patients. FDG-PET/CT was considered positive (PET+) when at least one abnormal focus of FDG uptake was found; likewise, 131I-t-WBS was considered positive(WBS+) when at least on abnormal focus of uptake was found. Assessment of short-term response to radioiodine was performed by measuring Tg values. RESULTS: FDG-PET/CT was positive in 32 patients, 23 of which had positive 131I-t-WBS and negative in 13, 8 of which had a negative 131I-t-WBS. Overall agreement was 69%. Tg values were significantly higher in FDG-PET/CT positive (502+/-1 027 ng/mL) than in FDG-PET/CT negative patients (57+/-94 ng/mL). A significant difference emerged between 131I-t-WBS positive (561 +/- 1 086 ng/mL) and 131I-t-WBS negative (65+/- 120 ng/mL) findings. In these 45 patients Tg normalized in 36%, was reduced by at least 50% in 24% and remained unchanged in the remaining 40%. Overall, at short-term follow-up, Tg values normalized in 77% of the 13 patients with negative FDG-PET/CT and in 19% of the 32 patients with positive FDG-PET/CT. CONCLUSION: FDG-PET/CT is a powerful and useful tool for assessing patients with DTC. it can provide additional information in those patients with high Tg at follow-up and eligible for 131I therapy. A negative FDG-PET/CT could also represent a prognostic tool combined with serum Tg testing a short term follow-up.

Sympathetic nervous function in patients with hypertrophic cardiomyopathy assessed by [123I]-MIBG: relationship with left ventricular perfusion and function.

AIM: The aim of the present study was to evaluate [123I] MIBG uptake and clearance in patients with hypertrophic cardiomyopathy (HCM) and to assess their relationships with left ventricular function (systolic and diastolic) and perfusion. METHODS: Eleven consecutive patients with HCM (8 men and 3 women; mean age 38+/-12 years, none in the dilated phase) underwent (in separate days, in random order) [123I]-MIBG scintigraphy, [(99m)Tc]-MIBI SPET at rest, and echocardiography. All patients were studied in fasting condition, and all medications were discontinued. [(99m)Tc]-MIBI SPET study was performed 1 hour after tracer injection. [123I]-MIBG study was acquired 5 minutes (planar) and 4 hours (planar and SPET) after the i.v. injection of [123I]-MIBG. Heart to mediastinum ratio (H/M) was computed at 4 hours. Wash out rate (WOR) was computed as: (H early - H delayed)/(H early), after decay correction. Both [123I]-MIBG and [(99m)Tc]-MIBI SPET were analyzed on 3 short axis views (apical, middle, and basal). Left ventricular outflow tract gradient (LVOTG), ejection fraction, volumes, septum thickness, and left atrial fractional shortening (LAFS) were evaluated on echocardiography. RESULTS: [123I]-MIBG WOR showed a positive relationship with LVOTG (r=0.84, p<0.001) and septum thickness (r=0.76, p<0.01), while a negative one was found with LAFS (r= -0.66, p<0.05). The study group was divided into: Group A (n=5) with higher, and Group B (n=6) with lower WOR than the median value (i.e. 11%). Group A patients had significantly lower LAFS (17.6+/-4.8 vs 26.8+/-7.2%, p<0.05), higher LVOTG (49+/-35 vs 3+/-3 mmHg), and thicker septum (21+/-2 vs 17+/-2 mm) than Group B patients. Inferior and septal wall [123I]-MIBG uptake on 4 hour SPET was significantly lower in Group A than in Group B. On the other hand, no differences were found in (99m)T-MIBI SPET rest regional uptake between the 2 subgroups of patients. CONCLUSION: These results suggest that cardiac sympathetic activity correlates to cardiac anatomy (i.e. degree of hypertrophy) and diastolic function in patients with HCM.

Diagnostic accuracy of low-dose dobutamine echocardiography in predicting post-revascularisation recovery of function in patients with chronic coronary artery disease: relationship to thallium-201 uptake.

It is known that contractile reserve may be blunted if perfusion and coronary flow reserve are reduced. Thus, it is conceivable that the predictive accuracy of dobutamine echocardiography may differ according to perfusion tracer uptake. The aim of this study was therefore to assess the relationship between the level of thallium-201 uptake and the accuracy of dobutamine echocardiography in identifying reversible dysfunction. Sixty-nine patients (age 59+/-8 years, ejection fraction 40%+/-11%) with chronic coronary artery disease scheduled for coronary revascularisation were studied. All patients underwent rest 201Tl single-photon emission tomography and two-dimensional echocardiography at rest and during low-dose dobutamine infusion on the same day before revascularisation and repeated echocardiography at least 30 days thereafter. At follow-up, recovery of function was observed in 49% of 339 dysfunctional segments. The percentage of segments with post-revascularisation recovery of function and the percentage with contractile reserve increased in parallel with 201Tl uptake both in the total group of segments (chi2=35.5, P<0.0001 and chi2=35.9, P<0.0001, respectively) and among the 183 akinetic segments (chi2=44.4, P<0.0001 and chi2=14.6, P<0.05, respectively). The dysfunctional segments were divided into three groups according to 201Tl uptake: (a) uptake <65%, (b) uptake between 65% and 79%, (c) uptake >80%. The positive predictive value increased significantly with the level of 201Tl uptake, and was suboptimal (46%) in akinetic segments with severely reduced 201Tl uptake. The negative predictive value decreased significantly with 201Tl uptake, and it was less than suboptimal (29%) in akinetic segments with normal tracer uptake. Sensitivity was lower in the subset of akinetic segments (42%-63%) than in all dyssynergic segments (63%-76%), whereas specificity was very high in akinetic segments (80%-84%). It is concluded that the accuracy of low-dose dobutamine echocardiography in predicting reversibility of regional dysfunction varies considerably according to 201Tl uptake at rest and to the severity of regional dysfunction.

Is the acromegalic cardiomyopathy reversible? Effect of 5-year normalization of growth hormone and insulin-like growth factor I levels on cardiac performance.

Acromegalic patients are considered to be exposed to a doubled mortality rate, mostly for cardiovascular diseases. This open prospective study was designed to evaluate whether the impairment of cardiac performance could be reversed by the long-term suppression of GH and insulin-like growth factor I (IGF-I) levels. Eighteen patients with active acromegaly were studied before and 5 yr after surgery, followed by sc octreotide in 11 patients. Disease control (GH levels < or =1 microg/L after glucose load or < or =2.5 microg/L after fasting, respectively, together with normalized IGF-I levels for age) was achieved in seven patients after surgery and in six patients after 0.3--0.6 mg/day sc octreotide. Five patients were not controlled during the 5-yr follow-up. Cardiac performance at rest and at peak exercise was assessed by equilibrium radionuclide angiography at study entry and 5 yr after surgery alone or plus octreotide. Thirty-six sex- and age-matched healthy subjects served as controls. At study entry, patients had a lower left ventricular ejection fraction (LVEF) at peak exercise and LVEF exercise-induced changes, exercise duration, and capacity than controls (P < 0.001). After 5 yr of treatment, a significant decrease of resting heart rate (P = 0.03) and a significant increase of LVEF at peak exercise (P = 0.003) was found in patients achieving disease control. LVEF response at peak exercise worsened in none of the patients with controlled disease and in three patients with uncontrolled disease (60%) (chi(2) = 5.5; P = 0.02). Diastolic filling, exercise duration, and workload did not significantly change during the 5-yr follow-up. No difference was found between patients controlled by surgery alone or by surgery plus octreotide. This 5-yr prospective study demonstrated that the LVEF response at peak exercise improved in all patients achieving disease control, while it was worsened in 60% of uncontrolled ones. These results strengthen the need of a stable suppression of GH and IGF-I hypersecretion to restore a normal cardiac performance in acromegaly.

Prediction of improvement in global left ventricular function in patients with chronic coronary artery disease and impaired left ventricular function: rest thallium-201 SPET versus low-dose dobutamine echocardiography.

Accurate assessment of myocardial viability permits selection of patients who would benefit from myocardial revascularization. Currently, rest-redistribution thallium-201 scintigraphy and low-dose dobutamine echocardiography are among the most used techniques for the identification of viable myocardium. Thirty-one consecutive patients (all men, mean age 60 +/- 8 years) with chronic coronary artery disease and reduced left ventricular ejection fraction (31% +/- 7%) were studied. Rest 201Tl single-photon emission tomography (SPET), low-dose dobutamine echocardiography and radionuclide angiography were performed before revascularization. Radionuclide angiography and echocardiography were repeated after revascularization. An a/dyskinetic segment was considered viable on 201Tl SPET when tracer uptake was >65%, while improvement on low-dose dobutamine echocardiography was considered a marker of viability. Increase in global ejection fraction was considered significant at > or = 5%. In identifying viable segments, rest 201Tl SPET showed higher sensitivity than low-dose dobutamine echocardiography (72% vs 53%, P<0.05), while specificity was not significantly different (86% vs 88%). In 17 patients, global ejection fraction increased > or = 5% (group 1) while in 14 it did not (group 2). A higher number of a/dyskinetic segments were viable on 201Tl SPET in group 1 than in group 2 (2.6 +/- 1.9 vs 0.6 +/- 1.2, P < 0.005), while no significant differences were observed on low-dose dobutamine echocardiography (1.7 +/- 1.6 vs 1.1 +/- 1.6). A significant correlation was found between the number of a/dyskinetic segments viable on 201Tl SPET and post-revascularization changes in ejection fraction (r = 0.52, P < 0.05), but such a correlation was not observed for low-dose dobutamine echocardiography. Using as the cut-off the presence of at least one viable a/dyskinetic segment, rest 201Tl SPET had a higher sensitivity (82% vs 53%, P = 0.07) and showed a trend towards higher accuracy and specificity (77% vs 58%, and 71% vs 64%, respectively) as compared with low-dose dobutamine echocardiography. In conclusion, these findings suggest that when severely reduced global function is present, rest 201Tl SPET evaluation of viability is more accurate than low-dose dobutamine echocardiography for the identification of patients who will benefit most from revascularization.

Impaired cardiac performance in elderly patients with growth hormone deficiency.

Several evidences indicate that GH and/or insulin-like growth factor I (IGF-I) are involved in the regulation of cardiovascular function. In patients with childhood and adulthood-onset GH deficiency (GHD), the impairment of cardiac performance is manifest primarily as a reduction in the left ventricular (LV) mass (LVM), inadequacy of LV ejection fraction both at rest and at peak exercise, and abnormalities of LV diastolic filling. No study has been reported to date in elderly GHD patients that investigated cardiac function. In particular, it is unknown whether cardiac function is modified in accordance with patients' age as a physiological response to aging, as in normal subjects the rate and extent of LV filling are reduced with age. This study was designed to evaluate heart morphology and function, by echocardiography and equilibrium radionuclide angiography, respectively, in rigorously selected elderly patients with GHD but without evidence of other complications able to affect cardiac performance. Eleven patients with hypopituitarism (6 men and 5 women, aged 60-72 yr) and 11 sex- age- and body mass index-matched healthy subjects entered this study. None of the patients and controls presented with or had previously suffered from other concomitant diseases, such as diabetes mellitus, coronary artery diseases, long-standing hypertension, and hyperthyroidism, which could affect cardiac function. All patients had been previously operated on via the transsphenoidal and/or transcranic route for nonfunctioning pituitary adenoma, meningioma, or craniopharyngioma, and 6 of them had been irradiated. Eight patients had FSH/LH insufficiency, 5 had TSH insufficiency, and 6 had ACTH insufficiency, appropriately replaced. All subjects were tested with the combined arginine plus GHRH test showing a GH response below 9 microg/L. No significant difference was found in plasma IGF-I levels (49.2 +/- 8.5 vs. 71.8 +/- 7.5 microg/L) between patients and controls. However, IGF-I levels were lower than the normal range in 8 patients and 3 controls. Interventricular septum thickness (9.1 +/- 0.2 vs. 9.1 +/- 0.2 mm), LV posterior wall thickness (9.1 +/- 0.2 vs. 9.0 +/- 0.2 mm), and LVM after correction for body surface area (97.6 +/- 1.8 vs. 99.9 +/- 1.5 g/m2) were similar in patients and controls. Similarly, the LV ejection fraction at rest was similar in patients and controls (57.1 +/- 2% vs. 63.2 +/- 2.5%; P = NS), and it was normal (> or = 50%) in all controls and in 10 of 11 patients. By contrast, the LV ejection fraction at peak exercise was markedly depressed in elderly GHD patients compared to age-matched controls (51 +/- 2.5% vs. 73.3 +/- 3%; P < 0.001). A normal response (> or = 5% increase compared to basal value) of LV ejection fraction at peak exercise was found in 8 controls (72.7%) and in 2 of 11 patients (18.2%). No difference was found in the peak rate of LV filling, whether peak filling rate was normalized to end-diastolic volume (2.5 +/- 0.2 vs. 2.6 +/- 0.2 end-diastolic volume/s) or stroke volume (4.3 +/- 0.3 vs. 4.0 +/- 0.3 stroke volume/s), between patients and controls. Finally, exercise duration was significantly shorter in elderly GHD patients than in age-matched controls (7.2 +/- 2.1 vs. 9.1 +/- 0.2 min; P < 0.01). In the patient group, the GH peak after arginine plus GHRH test was significantly correlated with the LV ejection fraction at rest (r = 0.822; P < 0.01), whereas IGF-I was significantly correlated with the peak rate of LV filling whether the peak filling rate was normalized to end-diastolic volume (r = -0.863; P < 0.001) or stroke volume (r = -0.616; P < 0.05) or expressed as the ratio of peak filling rate to peak ejection fraction rate (r = -0.736; P < 0.01). Disease duration was significantly correlated with heart rate at peak exercise (r = 0.614; P < 0.05) and with systolic and diastolic blood pressures both at rest (r = 0.745; P < 0.01 and r = 0.650; P < 0.05) and at peak exercise (r = 0.684; P < 0.05 and r =

Impact of patient's age and disease duration on cardiac performance in acromegaly: a radionuclide angiography study.

The aim of this study was to evaluate the impact of age and disease duration on cardiac performance in acromegaly. To address these issues, the left ventricular function at rest and during physical exercise was assessed by equilibrium radionuclide angiography in 40 rigorously selected patients with active acromegaly but without evidence of other complications able to affect heart function and in 32 healthy controls. Patients and controls were divided in two groups, on the basis of age below and above 40 yr. Circulating GH and insulin-like growth factor-I levels were significantly increased in patients, compared with controls, but were similar in the two groups of patients. At peak exercise, the systolic blood pressure was significantly higher in elderly patients (P < 0.001), whereas diastolic blood pressure was significantly higher in young patients than in age-matched controls (P < 0.01). Heart rate at peak exercise was significantly higher in young than in elderly patients and controls (P < 0.01), without any evidence of arrhythmia in both groups. The left ventricular ejection fraction at rest was normal (>50%) in all but 2 patients and in all controls. The left ventricular ejection fraction at peak exercise was significantly decreased in elderly, compared with young, patients (P < 0.01) and in age-matched controls (P < 0.001). A normal response of the left ventricular ejection fraction to exercise was found in 12 of 40 patients (30%) and in 28 of 32 controls (87.5%) (chi2, 5.764; P < 0.01). Exercise-induced changes in left ventricular ejection fraction were significantly decreased in young (+5.2 +/- 4.4% vs. +21.3 +/- 3.4%, P < 0.005) and elderly patients (-10.2 +/- 2.8% vs. +13.7 +/- 2.7%, P < 0.0001), as compared with age-matched controls. The peak rate of left ventricular filling was significantly higher in young, than in elderly, patients whether peak filling rate was normalized to end-diastolic volume (P < 0.001), or stroke volume (P < 0.0001), or expressed as the ratio of peak filling rate to peak ejection rate (P < 0.001). The peak rate of left ventricular filling was significantly decreased in elderly patients, compared with young patients and age-matched controls, whether peak filling rate was normalized to end-diastolic volume (P < 0.01), or stroke volume (P < 0.005), or expressed as the ratio of peak filling rate to peak ejection rate (P < 0.001). In the patient group, the left ventricular ejection fraction at peak exercise was significantly correlated with age (r = -0.33, P < 0.05), estimated disease duration (r = -0.34, P < 0.05), exercise-induced changes of the left ventricular ejection fraction (r = 0.34, P < 0.05), and the peak rate of left ventricular filling, whether peak filling rate was normalized to end-diastolic volume (r = 0.33, P < 0.05). Age and estimated disease duration were both significantly correlated with the peak rate of left ventricular filling, whether peak filling rate was normalized to end-diastolic volume (r = 0.55, P < 0.001 and r = -0.49, P < 0.001, respectively), or stroke volume (r = 0.5, P < 0.001 and r = -0.57, P < 0.001, respectively), or expressed as the ratio of peak filling rate to peak ejection rate (r = 0.56, P < 0.0001 and r = -0.52, P < 0.001, respectively). In the control group, the left ventricular ejection fraction at peak exercise was significantly correlated with the left ventricular ejection fraction at rest (r = 0.54, P < 0.01), exercise-induced changes of the left ventricular ejection fraction (r = 0.57, P < 0.001), but neither with age nor peak rate of left ventricular filling at all measurements. In conclusion, left ventricular performance is more frequently preserved in young patients with a short disease duration, although the left ventricular response to exercise was already reduced, as compared with controls. (ABSTRACT TRUNCATED)

[Effects left ventricle asynchrony on systolic and diastolic function in patients with non-ischemic heart failure]. / Effetti dell'asincronia del ventricolo sinistro sulla funzione sistolica e diastolica nei pazienti con scompenso cardiaco con origine non ischemica.

INTRODUCTION: The asynchrony of the left ventricle--i.e., its nonuniform contraction and relaxation--is an important factor for left ventricular function. Heart failure is often related to abnormal systolic function, sometimes associated with a diastolic dysfunction. We studied the relationship of left ventricular asynchrony to left ventricular function in patients with nonischemic heart failure. MATERIAL AND METHODS: Radionuclide angiography at rest was performed in 25 patients with nonischemic heart failure and in 26 age and sex matched normal subjects. In addition to ejection fraction and peak filling rate, two indices of left ventricular asynchrony were calculated: the coefficient of variation of regional time to end systole and the coefficient of variation of regional time to peak filling rate. These factors indicate how disperse are the regional values of time to end systole and of time to peak filling rate. In fact, the higher the value, the greater the asynchrony. RESULTS: A significant (r = .46, p < .05) inverse correlation was found between the ejection fraction and the coefficient of variation of regional time to end systole in both the normal subjects and the heart failure patients, while the ejection fraction correlated significantly (r = .46, p < .05) with the coefficient of variation of regional time to peak filling rate only in the patients. Moreover, the peak filling rate was inversely correlated (r = .57, p < .05) with the coefficient of variation of regional time to peak filling rate in the heart failure patients but not in the normal subjects. CONCLUSIONS: These results suggest that left ventricular systolic and diastolic asynchrony may contribute to impair left ventricular systolic and diastolic function in patients with nonischemic heart failure.