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Biomedical subjects

A Cuocolo

Publications and source records attributed to A Cuocolo.

At least 37 records · Page 2Linked to original sources
PubMed1999

Effects of valsartan on left ventricular diastolic function in patients with mild or moderate essential hypertension: comparison with enalapril.

OBJECTIVE: This study compares the effects of an AT1 angiotensin II receptor antagonist (valsartan) with those of an ACE inhibitor (enalapril) on left ventricular (LV) diastolic function in patients with mild or moderate essential hypertension and no evidence of LV hypertrophy at echocardiography. METHODS: A total of 24 patients (16 men, mean age 47 +/- 8 years) underwent radionuclide ambulatory monitoring (Vest) of LV function at rest and during upright bicycle exercise testing before and after two 4-week treatment periods with valsartan (80-160 mg/day orally) and enalapril (20-40 mg/day orally) according to a double-blind, crossover randomization scheme. RESULTS: In the overall population no differences between the two treatments were found in LV peak filling rate (PFR) either at rest or at peak exercise. In a subgroup analysis it was found that baseline PFR was normal (= 2.5 EDV/sec) in 12 patients (subgroup A) and impaired (< 2.5 EDV/sec) in the remaining 12 (subgroup B). In both subgroups, valsartan and enalapril induced a significant and comparable reduction of systolic and diastolic blood pressure. In subgroup A, valsartan and enalapril did not induce significant changes in PFR. In subgroup B, valsartan increased PFR both at rest (from 2.0 +/- 0.3 to 2.4 +/- 0.3 EDV/sec, P < 0.01) and at peak exercise (from 4.1 +/- 1.1 to 4.4 +/- 1.0 EDV/s, P < 0.05), whereas enalapril did not change PFR either at rest (2.0 +/- 0.4 EDV/s, P < 0.01 versus valsartan) or at peak exercise (3.7 +/- 1.1 EDV/sec, P < 0.05 versus valsartan). CONCLUSIONS: Valsartan-induced renin-angiotensin system blockade is able to improve LV filling in patients with mild or moderate essential hypertension and impaired diastolic function. These findings support the hypothesis of a contribution of the renin-angiotensin system in the control of LV diastolic function in these patients.

Adult↗
PubMed1999

Effects of 1-year treatment with octreotide on cardiac performance in patients with acromegaly.

The aim of the study was to investigate the effects of 1-yr treatment with octreotide (OCT) on left ventricular diastolic and systolic function, assessed at rest and during physical exercise by gated blood pool cardiac scintigraphy, in 30 patients with active acromegaly. OCT was initially given at a dose of 0.05-0.1 mg, 3 times daily, and the dose was subsequently increased to achieve GH/insulin-like growth factor I (IGF-I) normalization. Hormone normalization after treatment was considered when basal and/or oral glucose test-suppressed GH values were below 2.5 and 1 microg/L, respectively, and IGF-I values were within the normal range for age. To evaluate the response to OCT treatment in terms of cardiac performance, the 30 patients were divided into 2 groups on the basis of normalized (in 13 patients) or nonnormalized (in 17 patients) circulating GH and IGF-I levels. At study entry, hypertension was found in 6 patients (20%), abnormal left ventricular diastolic filling was found in 12 patients (40%), and impaired left ventricular ejection fraction was found in 2 patients at rest (6.6%) and in 18 patients at peak exercise (60%). Before OCT treatment, exercise duration ranged from 6-10 min, and exercise workload ranged from 50-125 watts. After 1-yr treatment with OCT, a significant decrease in circulating GH and IGF-I levels was achieved in all patients, but normalization was obtained only in 13 of 30 patients. In patients achieving circulating GH and IGF-I normalization after OCT treatment but not in those with persistently elevated hormone levels, a significant decrease in heart rate, both at rest (from 75.7 +/- 3.3 to 66.5 +/- 2.9 beats/min; P < 0.01) and after exercise (from 137.5 +/- 4.9 to 123.7 +/- 4.1 beats/min; P < 0.01), and a significant increase in left ventricular ejection fraction, both at rest (from 56.5 +/- 1.8% to 66.5 +/- 2.2%; P < 0.01) and after exercise (from 52.6 +/- 2.4% to 67.1 +/- 1.7%; P < 0.01), were found. In the 17 patients who had persistently high circulating GH and IGF-I levels after 1 yr of OCT treatment, left ventricular ejection fraction was unchanged at rest but was significantly reduced after exercise compared to the basal value (from 64.9 +/- 2.4% to 57.2 +/- 2.6%, P < 0.01); systolic blood pressure at rest was significantly increased (from 128.5 +/- 4.9 to 141.2 +/- 5.4 mm Hg; P < 0.05). In these 17 patients, the ejection fraction response to exercise was significantly impaired, mostly in those less than 40 yr of age (from 11.6 +/- 3.2% to -0.3 +/- 5.6%; P < 0.05). In particular, among 9 patients who had a normal response to exercise at study entry, 6 developed an abnormal response after 1 yr. Left ventricular diastolic filling was unchanged by OCT treatment in all patients. Exercise duration (only in young patients from 7.5 +/- 0.5 to 9.3 +/- 0.7 min; P < 0.05) and exercise workload (in all 13 patients from 80.8 +/- 6.4 to 92.3 +/- 5.9 watts; P < 0.05) were significantly increased in the group of patients with normalized GH and IGF levels, but not in the remaining 17 (from 7.6 +/- 0.4 to 7.5 +/- 0.4 min and from 89.9 +/- 5.5 to 84.4 +/- 4.5 watts, respectively). In conclusion, the results of the present study indicate that suppression of basal or glucose-suppressed GH levels below 2.5 or 1 microg/L, respectively, together with normalization of plasma IGF-I levels for 1 yr are followed by a significant improvement, but not complete normalization, of left ventricular ejection fraction either at rest or at peak exercise without significant changes in diastolic filling. By contrast, the persistence for 1 yr of elevated hormone levels caused a significant increase in systolic blood pressure and impaired cardiac performance. These data suggest that prolonged suppression of circulating GH and IGF-I levels could normalize cardiac performance and probably reverse the poor prognosis for cardiovascular disease in acromegaly.

Acromegaly↗
PubMed1999

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 =

Adrenocorticotropic Hormone↗
PubMed1999

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)

Acromegaly↗
PubMed1999

[Heart tomography with 99mTc sestamibi and echocardiography with dobutamine in the identification of reversible left ventricular dysfunction in patients with acute myocardial infarction].

INTRODUCTION: We investigated the role of technetium-99m (99mTc) sestamibi cardiac imaging and dobutamine echocardiography in detecting myocardial viability early after acute myocardial infarction. MATERIAL AND METHODS: Nineteen patients (mean age 52 +/- 10 years) underwent coronary angiography, low-dose dobutamine echocardiography and rest 99mTc sestamibi imaging within 10 days of myocardial infarction. All patients were revascularized. Resting echocardiogram was repeated 8 months later to evaluate segmental functional recovery. RESULTS: Sixty-one of 108 akinetic or dyskinetic segments at baseline showed functional recovery after revascularization. Sensitivity in predicting segmental functional recovery was 87% for sestamibi imaging and 66% for dobutamine echocardiography (p < 0.001), while specificity and accuracy were comparable. Sestamibi activity was the strongest predictor of segmental functional recovery (p < 0.001). CONCLUSIONS: Dobutamine echocardiography predicts functional recovery after myocardial infarction. However, sestamibi imaging is useful to identify patients with dysfunctional segments without contractile reserve which may benefit by revascularization.

Cardiotonic Agents↗
PubMed1999

Prediction of recovery of left ventricular dysfunction after acute myocardial infarction: comparison between 99mTc-sestamibi cardiac tomography and low-dose dobutamine echocardiography.

UNLABELLED: The aim of this study was to evaluate the role of 99mTc-sestamibi cardiac imaging and dobutamine echocardiography in detecting myocardial viability early after acute myocardial infarction. METHODS: Forty-nine patients (mean age 52 +/- 10 y) underwent coronary angiography, low-dose dobutamine echocardiography, radionuclide angiography and rest 99mTc-sestamibi imaging within 10 d after myocardial infarction. Of these patients, 19 were revascularized and 30 were treated medically. Resting echocardiogram and radionuclide angiography were repeated 8 mo later to evaluate segmental functional recovery and changes in left ventricular (LV) ejection fraction, respectively. RESULTS: In revascularized patients, 61 of 108 akinetic or dyskinetic segments showed functional recovery. In these patients, sensitivity in predicting segmental functional recovery was 87% for sestamibi imaging and 66% for dobutamine echocardiography (P < 0.001), whereas specificity and accuracy were comparable. Sestamibi activity (> or =55% of peak) was the strongest predictor of segmental functional recovery (P < 0.001) and of LV ejection fraction improvement > or =5% (P < 0.01) after revascularization. In medically treated patients, 60 of 149 akinetic or dyskinetic segments showed functional recovery. In these patients, the majority (94%) of segments with contractile reserve on dobutamine were viable on sestamibi imaging and 86% of them improved function at follow-up. Functional recovery was poor in segments without contractile reserve either with (38%) or without (62%) preserved sestamibi uptake. Inotropic response was the best predictor of segmental (P < 0.001) and global (P < 0.01) LV functional improvement in medically treated patients. CONCLUSION: Dobutamine echocardiography predicts spontaneous functional recovery after acute myocardial infarction. However, sestamibi imaging is useful to identify patients with dysfunctional myocardium without contractile reserve who may benefit from coronary revascularization.

Acute Disease↗
PubMed1998

Successful coronary revascularization improves prognosis in patients with previous myocardial infarction and evidence of viable myocardium at thallium-201 imaging.

The role of coronary revascularization of dysfunctional myocardium with preserved thallium-201 uptake in determining the prognosis in patients after myocardial infarction remains to be defined. This study was designed to evaluate the effects of successful revascularization on survival and left ventricular (LV) function in patients with previous myocardial infarction and evidence of dysfunctional but still viable myocardium at rest-redistribution 201Tl imaging. Seventy-six consecutive patients with LV dysfunction related to previous myocardial infarction and evidence of viable myocardium at rest-redistribution 201Tl tomography were followed for 17+/-8 months. LV ejection fraction (EF) was assessed by radionuclide angiography at baseline and after 13+/-2 months. Thirty-nine patients were revascularized (group A) and 37 treated medically (group B). During the follow-up there were nine cardiac deaths. Survival rate was 97% in group A and 66% in group B (P<0.01). By Cox multivariate analysis, the extent of viable myocardium was the best predictor of cardiac death (chi2=8.67, P<0.01) and provided additional information to clinical and functional data (P<0.01). The inclusion of revascularization as a variable improved the global chi2 of the model from 14.1 to 21.9 (P<0.01). At follow-up, EF had improved by >/=5% in 16 patients. By multivariate logistic analysis, the extent of viable myocardium was the best predictor of EF improvement (chi2=15.49, P<0.001) and provided additional information to clinical and functional data (P<0.01). The inclusion of revascularization as a variable improved the global chi2 of the model from 16.8 to 22.5 (P<0.01). These results demonstrate that the total extent of dysfunctional myocardium with preserved 201Tl uptake is the strongest predictor of cardiac death in patients after myocardial infarction. Successful revascularization of dysfunctional but viable myocardium improves survival and LVEF in such patients.

Angiocardiography↗
PubMed1998

Combined evaluation of rest-redistribution thallium-201 tomography and low-dose dobutamine echocardiography enhances the identification of viable myocardium in patients with chronic coronary artery disease.

The purpose of this study was to evaluate whether combined evaluation by discriminant analysis of rest-redistribution thallium-201 tomography and low-dose dobutamine echocardiography enhances the accuracy in identifying viable myocardium in patients with chronic coronary artery disease. Rest-redistribution 201Tl has high sensitivity but low specificity in identifying viable myocardium, while the opposite is true for low-dose dobutamine echocardiography. Forty-six patients underwent low-dose dobutamine echocardiography and rest-redistribution 201Tl tomography on the same day. Rest echocardiography was repeated at least 30 days (mean 40+/-20) after myocardial revascularization. Discriminant analysis was applied to the results of 201Tl tomography and dobutamine echocardiography to classify a/dyskinetic segments as viable or non-viable. In 92 a/dyskinetic segments that were revascularized, rest-redistribution 201Tl tomography yielded an accuracy of 75%, while the accuracy of dobutamine echocardiography was 70% (P<0.05). When discriminant analysis was used, the combined evaluation gave an accuracy of 83% (P<0.05 vs both tests). These findings demonstrate that low-dose dobutamine echocardiography and 201Tl imaging are useful and complementary techniques for identifying viable myocardium in patients with chronic coronary artery disease. Combined evaluation by discriminant analysis significantly improves accuracy, although the cost-effectiveness of such an approach remains to be determined.

Adrenergic beta-Agonists↗
PubMed1998

Left ventricular function in young adults with childhood and adulthood onset growth hormone deficiency.

OBJECTIVE: The impairment of heart structure and function in adults with childhood onset GH deficiency has been recently described. However, previous echocardiographic studies have reported no differences in cardiac mass and function between adulthood onset GH deficient patients and healthy subjects. DESIGN: The aim of this study was to evaluate cardiac performance in adult patients with childhood and adulthood onset GH deficiency, using equilibrium radionuclide angiography, a method more accurate than echocardiography. PATIENTS: Eleven patients with childhood onset GH deficiency, 9 patients with adulthood onset GH deficiency and 12 age-, gender-, height- and weight-matched healthy subjects entered the study. MEASUREMENTS: All the study population underwent equilibrium radionuclide angiography at rest and during physical exercise. RESULTS: Both childhood and adulthood onset GH deficient patients had an impaired left ventricular systolic performance both at rest (ejection fraction was 55 +/- 6%, 55 +/- 10% and 66 +/- 6% in childhood and adulthood onset GH deficient patients and control group, respectively; P < 0.0001) and during physical exercise (ejection fraction was 54 +/- 9% in childhood onset GH deficient patients, 53 +/- 9% in adulthood onset GH deficient patients and 76 +/- 7% in normal subjects; P < 0.0001). Peak ejection rate was 3.2 +/- 0.8 end-diastolic volume/second, 3.0 +/- 0.6 end-diastolic volume/second and 3.9 +/- 0.8 end-diastolic volume/ second in childhood and adulthood onset GH deficient patients and control group, respectively (P < 0.01). Exercise-induced changes in end-systolic volume were increased in both groups of patients compared with healthy subjects. In contrast, exercise-induced end-diastolic volume changes were not different between GH deficient patients and controls. Resting peak filling rate was 2.6 +/- 0.7 end-diastolic volume/second, 2.5 +/- 0.7 end-diastolic volume/ second and 3.1 +/- 0.3 end-diastolic volume/second in the 2 groups of patients and healthy subjects, respectively (P < 0.05). Reduced exercise tolerance in all patients, as shown by the significantly lower values of peak workload (P < 0.0001), peak rate-pressure product (P < 0.01) and exercise duration (P < 0.0001) was observed. CONCLUSION: Patients affected by GH deficiency have left ventricular systolic dysfunction at rest and during physical exercise, suggesting that GH plays a physiological role in maintaining normal cardiac performance in humans. Furthermore, no difference between childhood and adulthood onset GH deficient patients was found indicating that both group of patients have an impairment of cardiac function.

Adult↗
PubMed1998

Sympathetic deactivation by growth hormone treatment in patients with dilated cardiomyopathy.

AIMS: We examined the effects of growth hormone administration on the sympathetic nervous system in patients with idiopathic dilated cardiomyopathy. BACKGROUND: Growth factor therapy is emerging as a new potential option in the treatment of heart failure. Although growth hormone provides functional benefit in the short term, it is unknown whether it affects the sympathetic nervous system, which plays a role in the progression of heart failure. METHODS: Seven patients with idiopathic cardiomyopathy received 3 months treatment with recombinant human growth hormone (0.15-0.20 IU.kg-1.week-1). Standard medical therapy was unchanged. Myocardial norepinephrine release, both at rest and during submaximal physical exercise, plasma aldosterone, and plasma volume were measured before and after growth hormone treatment. Myocardial norepinephrine release was assessed from arterial and coronary venous plasma concentrations of unlabelled and tritiated norepinephrine and coronary plasma flow (thermodilution). RESULTS: Growth hormone induced a significant fall in myocardial norepinephrine release in response to physical exercise (from 180 +/- 64 to 99 +/- 34 ng.min-1; P < 0.05). Basally, plasma aldosterone was 189 +/- 28 and 311 +/- 48 pg.ml-1 in the supine and upright position, respectively, and fell to 106 +/- 16 (P < 0.01) and 182 +/- 29 pg.ml-1 (P < 0.05) after growth hormone therapy. Growth hormone increased plasma volume from 3115 +/- 493 ml to 3876 +/- 336 ml (P < 0.05), whereas serum sodium and potassium concentrations were unaffected. CONCLUSIONS: The data demonstrate that growth hormone administration to patients with idiopathic cardiomyopathy reduces myocardial sympathetic drive and circulating aldosterone levels. This neurohormonal deactivation may be relevant to the potential, long-term use of growth hormone in the treatment of patients with heart failure.

Adult↗
PubMed1998

Technetium-99m-tetrofosmin uptake in brain tumors by SPECT: comparison with thallium-201 imaging.

UNLABELLED: Thallium-201 is clinically used for the assessment of primary and recurrent brain tumors. The biologic properties of 201Tl that allow it to accumulate within the tumor cells render 201Tl useful in evaluating tumor malignancy, but its physical characteristics and nonroutine availability limits its use in some institutions, as compared to 99mTc-labeled compounds. The aim of this study was to assess the feasibility of using 99mTc-tetrofosmin for imaging brain tumors and to compare its uptake with that of 201Tl. METHODS: Twenty-six patients with 27 intracranial masses were studied with SPECT. In the first group of seven patients (Group A), the timing for optimal acquisition of the 99mTc-tetrofosmin scan was assessed. In the second group of 19 patients (Group B), two sequential 201Tl (74-148 MBq intravenous) and 99mTc-tetrofosmin (740-925 MBq intravenous) studies were performed 20 min after tracer injection and compared. RESULTS: In Group A, no significant difference in the tumor-to-background (T/B) ratio among the 20-, 40- and 120-min postinjection studies was observed. In Group B, the quality of reconstructed images with 99mTc-tetrofosmin, judged visually, was superior to that of 201Tl in 47% of all studies and was comparable in the remaining 53%. A significant relationship between 201Tl and 99mTc-tetrofosmin T/B ratio (r = 0.75, p < 0.01) was found. The T/B ratio of 99mTc-tetrofosmin was significantly higher than that of 201Tl (23.3 +/- 21.5 compared to 6.1 +/- 2.9, p < 0.005). CONCLUSION: Technetium-99m-tetrofosmin is a suitable radiotracer for the imaging of intracranial lesions with SPECT. Moreover, a better definition of tumor margins and a higher contrast between neoplastic and normal brain tissue can be achieved.

Brain Neoplasms↗
PubMed1998

Identification of viable myocardium in patients with chronic coronary artery disease using rest-redistribution thallium-201 tomography: optimal image analysis.

UNLABELLED: With the widely used 50% threshold, sensitivity is high, but specificity is low in detecting viable myocardium on 201Tl SPECT. In this study, we sought to identify the best threshold for semiquantitative 201Tl analysis. METHODS: Rest-redistribution 201Tl SPECT was performed in 46 patients with chronic coronary artery disease before and after myocardial revascularization. Regional function was evaluated by two-dimensional echocardiography before and after myocardial revascularization using a 3-point scale (1 = normal, 2 = hypokinetic, 3 = a/dyskinetic). Myocardial segments with abnormal systolic function were defined as viable if the systolic function score decreased > or = 1 after myocardial revascularization. A second group of 12 patients with chronic coronary artery disease constituted the validation population. Sensitivity-specificity curves, as well as receiver operating characteristic curves, for rest and redistribution mages were generated by varying the 201Tl uptake threshold. RESULTS: A 65% threshold uptake using resting images was found to be the best for detecting a/dyskinetic segments that improve after myocardial revascularization from those that do not improve. Sensitivity was lower with a 65% threshold (75%) than with a 50% threshold (90%, p < 0.05), but specificity was higher (76% versus 26%, p < 0.05) resulting in better accuracy (76% versus 57%, p < 0.05) and positive predictive value (77% versus 55%), while the negative predictive value was not different (69% versus 75%, p not significant). The area under the receiver operating characteristic curve was significantly (p < 005) larger for rest (0.80 +/- 0.05) as opposed to redistribution (0.72 +/- 0.05) images. Similar results were obtained in a subgroup of patients with low ejection fraction. Significant correlations between the percentage of revascularized viable segments and both the change in ejection fraction and in postrevascularization ejection fraction were found. When these findings were applied in the validation group, a gain in specificity, accuracy and positive predictive value was obtained with the 65% threshold compared with the 50% threshold. CONCLUSION: This study demonstrated that analysis of resting images and use of the 65% 201Tl uptake threshold is preferable for separating viable from not viable dyssynergic myocardial segments in patients with chronic coronary artery disease.

Case-Control Studies↗
PubMed1997

Incremental prognostic value of thallium reinjection after stress-redistribution imaging in patients with previous myocardial infarction and left ventricular dysfunction.

UNLABELLED: This study evaluated the incremental prognostic value of 201TI reinjection imaging over clinical, exercise and thallium stress-redistribution data in patients with previous myocardial infarction and left ventricular dysfunction. METHODS: Thallium-201 reinjection after stress-redistribution SPECT was performed in 104 consecutive patients with a first Q-wave myocardial infarction (> 8 wk) and left ventricular ejection fraction < or = 40%. Follow-up data (mean 22 mo) were available for 98 patients; 16 patients underwent early revascularization procedures within 3 mo after exercise testing and were not considered for the analysis. RESULTS: During follow-up there were 13 hard events (cardiac death and myocardial infarction) and 11 soft events (coronary revascularization procedures > 3 mo after thallium imaging). With multivariate Cox regression analysis, the sum of defects at stress-redistribution imaging that were reversible or moderate irreversible after reinjection was a powerful predictor of subsequent events. The addition of thallium reinjection imaging data significantly improved the prognostic power of clinical, exercise and stress-redistribution data for the occurrence of hard events (p < 0.01). CONCLUSION: In patients with previous myocardial infarction and left ventricular dysfunction, thallium reinjection imaging provides incremental prognostic information over those obtained from conventional stress-redistribution imaging.

Analysis of Variance↗
PubMed1997

Rest-redistribution thallium-201 and rest technetium-99m-sestamibi SPECT in patients with stable coronary artery disease and ventricular dysfunction.

UNLABELLED: Resting sestamibi uptake was compared with 201Tl rest-redistribution uptake in 48 patients with ischemic heart disease and regional ventricular asynergies. METHODS: In 48 patients, rest/4-hr redistribution 201Tl and resting sestamibi tomography were closely performed on separate days. Segmental tracer uptake was quantified. Wall motion in corresponding segments was also assessed by two-dimensional echocardiography in 17 patients. RESULTS: Quantitative analysis indicates that the uptake of the two tracers was comparable in normal segments as well as in segments with fixed 201Tl defects. In contrast, in segments with reversible 201Tl defects, sestamibi uptake was significantly lower than redistribution 201Tl uptake. CONCLUSION: In patients with chronic ischemic heart disease and regional asynergies, quantified sestamibi activity parallels 201Tl redistribution activity in normal segments and in those with fixed 201Tl defects. In segments showing reversible 201Tl defects, whether or not dysfunctioning, sestamibi uptake is significantly lower than 201Tl redistribution.

Aged↗
PubMed1997

Ambulatory monitoring of left ventricular function: walk and bicycle exercise in congestive heart failure.

UNLABELLED: The aim of this study was to assess changes in left ventricular (LV) function during 6-min walk test and cardiopulmonary exercise by continuous radionuclide monitoring in patients with congestive heart failure (CHF). METHODS: Seventeen patients with CHF and 10 normal subjects underwent monitoring of LV function (Vest) during 6-min walk test and during bicycle exercise with combined analysis of pulmonary gas exchange. During cardiopulmonary exercise, all parameters of LV function were measured at rest, at the anaerobic threshold (AT) and at peak oxygen uptake (peak VO2). RESULTS: In the normal subjects, during the walk test, heart rate (HR), ejection fraction (EF), end-diastolic volume (EDV), cardiac output (CO) and stroke volume (SV) significantly increased from rest to peak (all p < 0.001), while end-systolic volume (ESV) significantly decreased from rest to peak (p < 0.001). In patients with CHF, during the walk test, HR, EDV, ESV and CO significantly increased from rest to peak (p < 0.001), EF significantly decreased from rest to peak (p < 0.001) and SV did not show significant change. During cardiopulmonary exercise, normal subjects showed a significant increase in HR and CO, from rest to AT and from AT to the peak VO2 (p < 0.001). EF, EDV and SV significantly increased from rest to AT (p < 0.001), with no significant change from AT to peak VO2. ESV decreased from rest to AT (p < 0.001), showing no significant change from AT to peak VO2. In patients with CHF, HR, CO, ESV and EDV increased significantly from rest to AT (p < 0.001) and from AT to peak VO2 (p < 0.001). EF and SV did not show significant changes from rest to AT, showing a significant decrease from AT to peak VO2 (p < 0.001). CONCLUSION: Vest can be used to evaluate cardiac responses during 6-min walk test and cardiopulmonary exercise in patients with CHF. In such patients, significant impairment of LV function is already present during submaximal physical exercise becoming more evident during the anaerobic phases of bicycle exercise.

Case-Control Studies↗
PubMed1997

Adenosine coronary vasodilation in coronary artery disease: technetium-99m tetrofosmin myocardial tomography versus echocardiography.

UNLABELLED: This study compared the results of adenosine 99mTc-tetrofosmin cardiac tomography with those of adenosine echocardiography in identifying patients with coronary artery disease (CAD) and in localizing individual stenosed, coronary vessels. METHODS: Twenty-six consecutive patients with suspected or known CAD had simultaneous adenosine (140 micrograms/Kg/min intravenously) 99mTc-tetrofosmin tomography and two-dimensional echocardiography. All patients had coronary angiography within 4 wk from imaging studies. Regional 99mTc-tetrofosmin activity was quantitatively measured in 78 coronary vascular territories and echocardiographic left ventricular function was assessed in corresponding regions. RESULTS: At coronary angiography one patient had normal coronary vessels, 12 patients one-vessel and 13 had multivessel disease (> or = 50% luminal stenosis). Among the 25 patients with CAD, 22 showed perfusion defects at adenosine 99mTc-tetrofosmin tomography (sensitivity 88%) and 17 had abnormal echocardiographic study (sensitivity 68%, p < 0.05 versus 99mTc-tetrofosmin). Agreement for the identification of patients with CAD between adenosine 99mTc-tetrofosmin tomography and echocardiography was observed in 21 (81%) of the total 26 patients, with a kappa value of 0.45. Overall sensitivity, specificity and diagnostic accuracy for detection of individual stenosed vessels were 79%, 88% and 83% for 99mTc tetrofosmin and 57%, 68% and 61% (all p < 0.05 versus 99mTc-tetrofosmin) for echocardiography. Concordance between adenosine 99mTc-tetrofosmin tomography and echocardiography in the detection of individual stenosed coronary vessels was observed in 57 (73%) of the 78 vascular territories, with a kappa value of 0.36. CONCLUSION: Adenosine-induced coronary vasodilation associated with quantitative 99mTc-tetrofosmin tomography is more accurate than adenosine echocardiography in identifying patients with CAD and in detecting individual stenosed coronary vessels.

Adenosine↗
PubMed1997

One-year effect of myocardial revascularization on resting left ventricular function and regional thallium uptake in chronic CAD.

UNLABELLED: It is still unclear whether in patients with chronic coronary artery disease (CAD) the improvements in myocardial perfusion and left ventricular (LV) function induced by revascularization persist in the long run. This study was planned to evaluate the 1-yr effects of successful revascularization on myocardial perfusion and LV function in patients with CAD and to assess the accuracy of thallium imaging in the prediction of functional recovery 1 yr after revascularization. METHODS: Thirty-eight patients with chronic CAD who were revascularized (experimental group) underwent, while off drugs, 201Tl tomography, two-dimensional echocardiography and radionuclide angiography before and after a 1-yr follow-up. Twenty-nine patients with similar characteristics who were not revascularized (control group) and completed the 1-yr follow-up were also studied. Regional thallium activity was quantitatively measured in 13 segments per patient. Systolic function was assessed by echocardiography in corresponding segments. RESULTS: In the experimental group, at baseline, on the basis of regional LV function and thallium uptake, 276 segments were normal, 169 dysfunctional-viable and 49 nonviable. After revascularization, the majority (75%) of the dysfunctional-viable segments at baseline showed functional recovery at follow-up, whereas the majority (81%) of the nonviable segments at baseline did not. Simultaneously, LV ejection fraction increased 4 wk after revascularization (from 39% +/- 9% to 42% +/- 10%, p < 0.01) and remained unchanged after 1-yr (43% +/- 8%, p < 0.01 versus baseline study). LV wall-motion score index after 1 yr was reduced (from 1.68 +/- 0.4 to 1.42 +/- 0.3, p < 0.001) as compared with baseline. On the contrary, in the control group, no change in myocardial perfusion and LV function was detected after the 1-yr follow-up. CONCLUSION: In patients with chronic CAD, successful coronary revascularization induces a stable improvement in myocardial perfusion and LV function, which is still detectable after a 1-yr follow-up. Furthermore, preserved thallium uptake in dysfunctional regions is predictive of functional recovery after revascularization.

Angioplasty, Balloon, Coronary↗