PET/MRI for staging patients with Hodgkin lymphoma: equivalent results with PET/CT in a prospective trial

To compare FDG-PET/unenhanced MRI and FDG-PET/diagnostic CT in detecting infiltration in patients with newly diagnosed Hodgkin lymphoma (HL). The endpoint was equivalence between PET/MRI and PET/CT in correctly defining the revised Ann Arbor staging system. Seventy consecutive patients with classical-HL were prospectively investigated for nodal and extra-nodal involvement during pretreatment staging with same-day PET/CT and PET/MRI. Findings indicative of malignancy with the imaging procedures were regarded as lymphoma infiltration; in case of discrepancy, positive-biopsy and/or response to treatment were evidenced as lymphoma. Sixty of the 70 (86%) patients were evaluable having completed the staging program. Disease staging based on either PET/MRI or PET/CT was correct for 54 of the 60 patients (90% vs. 90%), with difference between proportions of 0.0 (95% CI, -9 to 9%; P=0.034 for the equivalence test). As compared with reference standard, invasion of lymph nodes was identified with PET/MRI in 100% and with PET/CT in 100%, of the spleen with PET/MRI in 66% and PET/CT in 55%, of the lung with PET/MRI in 60% and PET/CT in 100%, of the liver with PET/MRI in 67% and PET/CT in 100%, and of the bone with PET/MRI in 100% and PET/CT in 50%. The only statistically significant difference between PET/MRI and PET/CT was observed in bony infiltration detection rates. For PET/CT, iodinate contrast medium infusions' average was 86 mL, and exposure to ionizing radiation was estimated to be 4-fold higher than PET/MRI. PET/MRI is a promising safe new alternative in the care of patients with HL.

2-deoxy-2[F-18] fluoro-D-glucose positron emission tomography Deauville scale and core-needle biopsy to determine successful management after six doxorubicin, bleomycin, vinblastine and dacarbazine cycles in advanced-stage Hodgkin lymphoma

BACKGROUND

The clinical impact of the positivity of the Deauville scale (DS) of positron emission tomography (PET) performed at the end of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) in patients with advanced Hodgkin lymphoma (HL), in terms of providing rationale to shift poor responders onto a more intensive regimen, remain to be validated by histopathology.

PATIENTS AND METHODS

This prospective trial involved patients with stage IIB/IV HL who after six ABVD cycles underwent PET (PET6) and core-needle cutting biopsy (CNCB) of 2-deoxy-2[F-18] fluoro-d-glucose (FDG)-avid lymph nodes. Patients received high-dose chemotherapy/autologous haematopoietic stem cell rescue (HDCT/AHSCR) if CNCB was positive for HL, alternatively, if CNCB or PET was negative, received observation or consolidation radiotherapy (cRT) on residual nodal masses, as initially planned. The end-point was 5-year progression-free survival (PFS).

RESULTS

In all, 43 of the 169 (25%) evaluable patients were PET6 positive (DS 4, 32; DS 5, 11). Among them, histology showed malignancy (HL) in 100% of DS 5 scores and in 12.5% of DS 4 scores. Fifteen patients with positive biopsy received HDCT/AHSCR, whereas 28 patients with negative biopsy, as well as 126 patients with negative PET6, continued the original plan (cRT, 78 patients; observation, 76 patients). The 5-year PFS in the negative PET6 group, negative biopsy group and positive biopsy group was 95.4%, 100% and 52.5%, respectively.

CONCLUSION

DS positivity of end-of-ABVD PET in advanced HL carried a certain number of CNCB-proven non-malignant FDG-uptakes. The DS 4 scores which were found to have negative histology appeared to benefit from continuing the original non-intensive therapeutic plane as indicated by the successful outcome in more than 95% of them by obtaining similar 5-year PFS to the PET6-negative group. By contrast, the DS 5 score had consistently positive histology and was associated with unsuccessful conventional therapy, promptly requiring treatment intensification or innovative therapeutic approaches.

Diagnostic value of qualitative and strain ratio elastography in the differential diagnosis of non-palpable testicular lesions

The purpose of this study was to evaluate prospectively the accuracy of qualitative and strain ratio elastography (SE) in the differential diagnosis of non‐palpable testicular lesions. The local review board approved the protocol and all patients gave their consent. One hundred and six patients with non‐palpable testicular lesions were consecutively enrolled. Baseline ultrasonography (US) and SE were correlated with clinical and histological features and ROC curves developed for diagnostic accuracy. The non‐palpable lesions were all ≤1.5 cm; 37/106 (34.9%) were malignant, 38 (35.9%) were benign, and 31 (29.2%) were non‐neoplastic. Independent risk factors for malignancy were as follows: size (OR 17.788; p = 0.002), microlithiasis (OR 17.673, p < 0.001), intralesional vascularization (OR 9.207, p = 0.006), and hypoechogenicity (OR, 11.509, p = 0.036). Baseline US had 89.2% sensitivity (95% CI 74.6–97.0) and 85.5% specificity (95% CI 75.0–92.8) in identifying malignancies, and 94.6% sensitivity (95% CI 86.9–98.5) and 87.1% specificity (95% CI 70.2–96.4) in discriminating neoplasms from non‐neoplastic lesions. An elasticity score (ES) of 3 out of 3 (ES3, maximum hardness) was recorded in 30/37 (81.1%) malignant lesions (p < 0.001). An intermediate score of 2 (ES2) was recorded in 19/38 (36.8%) benign neoplastic lesions and in 22/31 (71%) non‐neoplastic lesions (p = 0.005 and p = 0.001 vs. malignancies). None of the non‐neoplastic lesions scored ES3. Logistic regression analysis revealed a significant association between ES3 and malignancy (χ² = 42.212, p < 0.001). ES1 and ES2 were predictors of benignity (p < 0.01). Overall, SE was 81.8% sensitive (95% CI 64.8–92.0) and 79.1% specific (95% CI 68.3–88.4) in identifying malignancies, and 58.6% sensitive (95% CI 46.7–69.9) and 100% specific (95% CI 88.8–100) in discriminating non‐neoplastic lesions. Strain ratio measurement did not improve the accuracy of qualitative elastography. Strain ratio measurement offers no improvement over elastographic qualitative assessment of testicular lesions; testicular SE may support conventional US in identifying non‐neoplastic lesions when findings are controversial, but its added value in clinical practice remains to be proven.

Simultaneous PET/MR head-neck cancer imaging: Preliminary clinical experience and multiparametric evaluation

PURPOSE

To evaluate the role of simultaneous hybrid PET/MR imaging and to correlate metabolic PET data with morpho-functional parameters derived by MRI in patients with head-neck cancer.

METHODS

Forty-four patients, with histologically confirmed head and neck malignancy (22 primary tumors and 22 follow-up) were studied. Patients initially received a clinical exam and endoscopy with direct biopsy. Next patients underwent whole body PET/CT followed by PET/MR of the head/neck region. PET and MRI studies were separately evaluated by two blinded groups (both included one radiologist and one nuclear physician) in order to define the presence or absence of lesions/recurrences. Regions of interest (ROIs) analysis was conducted on the primary lesion at the level of maximum size on metabolic (SUV and MTV), diffusion (ADC) and perfusion (K(trans), Ve, kep and iAUC) parameters.

RESULTS

PET/MR examinations were successfully performed on all 44 patients. Agreement between the two blinded groups was found in anatomic allocation of lesions by PET/MR (Primary tumors: Cohen's kappa 0.93;

FOLLOW-UP

Cohen's kappa 0.89). There was a significant correlation between CT-SUV measures and MR (e.g., CT-SUV VOI vs.

MR-SUV VOI

ρ=0.97, p<0.001 for the entire sample). There was also significant positive correlations between the ROI area, SUV measures, and the metabolic parameters (SUV and MTV) obtained during both PET/CT and PET/MR. A significant negative correlation was observed between ADC and K(trans) values in the primary tumors. In addition, a significant negative correlation existed between MR SUV and ADC in recurrent tumors.

CONCLUSION

Our study demonstrates the feasibility of PET/MR imaging for primary tumors and recurrent tumors evaluations of head/neck malignant lesions. When assessing HNC, PET/MR allows simultaneous collection of multiparametric metabolic and functional data. This technique therefore allows for a more complete characterization of malignant lesions.

Progression of microstructural damage in spinocerebellar ataxia type 2: a longitudinal DTI study

BACKGROUND AND PURPOSE

The ability of DTI to track the progression of microstructural damage in patients with inherited ataxias has not been explored so far. We performed a longitudinal DTI study in patients with spinocerebellar ataxia type 2.

MATERIALS AND METHODS

Ten patients with spinocerebellar ataxia type 2 and 16 healthy age-matched controls were examined twice with DTI (mean time between scans, 3.6 years [patients] and 3.3 years [controls]) on the same 1.5T MR scanner. Using tract-based spatial statistics, we analyzed changes in DTI-derived indices: mean diffusivity, axial diffusivity, radial diffusivity, fractional anisotropy, and mode of anisotropy.

RESULTS

At baseline, the patients with spinocerebellar ataxia type 2, as compared with controls, showed numerous WM tracts with significantly increased mean diffusivity, axial diffusivity, and radial diffusivity and decreased fractional anisotropy and mode of anisotropy in the brain stem, cerebellar peduncles, cerebellum, cerebral hemisphere WM, corpus callosum, and thalami. Longitudinal analysis revealed changes in axial diffusivity and mode of anisotropy in patients with spinocerebellar ataxia type 2 that were significantly different than those in the controls. In patients with spinocerebellar ataxia type 2, axial diffusivity was increased in WM tracts of the right cerebral hemisphere and the corpus callosum, and the mode of anisotropy was extensively decreased in hemispheric cerebral WM, corpus callosum, internal capsules, cerebral peduncles, pons and left cerebellar peduncles, and WM of the left paramedian vermis. There was no correlation between the progression of changes in DTI-derived indices and clinical deterioration.

CONCLUSIONS

DTI can reveal the progression of microstructural damage of WM fibers in the brains of patients with spinocerebellar ataxia type 2, and mode of anisotropy seems particularly sensitive to such changes. These results support the potential of DTI-derived indices as biomarkers of disease progression.

Comparison of CE-FDG-PET/CT with CE-FDG-PET/MR in the evaluation of osseous metastases in breast cancer patients

BACKGROUND

Despite improvements in treatments, metastatic breast cancer remains difficult to cure. Bones constitute the most common site of first-time recurrence, occurring in 40-75% of cases. Therefore, evaluation for possible osseous metastases is crucial. Technetium 99 ((99)Tc) bone scintigraphy and fluorodexossyglucose (FDG) positron emission tomography (PET)-computed tomography (PET-CT) are the most commonly used techniques to assess osseous metastasis. PET magnetic resonance (PET-MR) imaging is an innovative technique still under investigation. We compared the capability of PET-MR to that of same-day PET-CT to assess osseous metastases in patients with breast cancer.

METHODS

One hundred and nine patients with breast cancer, who underwent same-day contrast enhanced (CE)-PET-CT and CE-PET-MR, were evaluated. CE-PET-CT and CE-PET-MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Binomial confidence intervals and a χ(2) test were used for categorical data, and paired t-test was used for the SUVmax data; a non-informative prior Bayesian approach was used to estimate and compare the specificities.

RESULTS

Osseous metastases affected 25 out 109 patients. Metastases were demonstrated by CE-PET-CT in 22 out of 25 patients (88%±7%), and by CE-PET-MR in 25 out of 25 patients (100%). CE-PET-CT revealed 90 osseous metastases and CE-PET-MR revealed 141 osseous metastases (P<0.001). The estimated sensitivity of CE-PET-CT and CE-PET-MR were 0.8519 and 0.9630, respectively. The estimated specificity for CE-FDG-PET-MR was 0.9884. The specificity of CE-PET-CT cannot be determined from patient-level data, because CE-PET-CT yielded a false-positive lesion in a patient who also had other, true metastases.

CONCLUSIONS

CE-PET-MR detected a higher number of osseous metastases than did same-day CE-PET-CT, and was positive for 12% of the patients deemed osseous metastasis-negative on the basis of CE-PET-CT.

Diagnostic value of FDG PET/CT imaging

Patients with differentiated thyroid cancer (DTC) have a relatively good overall prognosis, but 20% of them develop local recurrences and 10% distant metastases with relatively high mortality (8%). The current prognostic systems lack the ability to predict outcome of patients when discovered to harbor metastases years later. The introduction of 18-F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) and PET/computed tomography (CT) for evaluating patients with DTC has added new information on the disease. This review will summarize the data published so far on the use of FDG in DTC. The most appropriate indication to FDG-PET/CT is in evaluating patients with high thyroglobulin level during follow-up, mainly when radioiodine whole body scan is negative. In this setting, a high accuracy has been reported leading to change in management of patients. A clear relationship has been demonstrated between FDG-PET/CT accuracy and thyroglobulin level, with better results obtained in thyroid stimulating hormone (TSH) stimulated condition. Moreover, FDG imaging provides potentially relevant information on tumour biology, and scan results may enable to prognostically stratify DTC patients with local or distant recurrences. Based on literature data, FDG-PET/CT does not have routine clinical indication in the initial staging of DTC patients, as well as in evaluating cytologically indeterminated thyroid nodules.

Cardiac performance during exercise in hypertensive patients without ventricular hypertrophy

BACKGROUND

Reduced systolic reserve on effort may be present in subjects with hypertension but no evidence of hypertensive cardiomyopathy. We assessed the determinants of abnormal cardiac performance during exercise in hypertensive patients without left ventricular hypertrophy.

MATERIALS AND METHODS

Thirty-five newly diagnosed, never-treated-earlier hypertensive patients without definite indication for left ventricular hypertrophy at echocardiography underwent radionuclide ambulatory monitoring of left ventricular function at rest and during upright bicycle exercise testing.

RESULTS

The patients were classified into two groups according to their ejection fraction response to exercise. In 21 patients (group 1), the ejection fraction increased > or = 5% with exercise and in 14 patients (group 2), the ejection fraction either increased < 5% or decreased with exercise. Patients of group 1 had lower peak filling rate at rest and less augmentation in end-diastolic volume during exercise (both P < 0.01) when compared with patients of group 2. A significant relationship between the magnitude of change in ejection fraction with exercise and both peak filling rate at rest (r = 0.58, P < 0.01) and exercise-induced change in end-diastolic volume (r = 0.45, P < 0.01) was found.

CONCLUSIONS

In newly diagnosed, never-treated-earlier hypertensive subjects with no evidence of hypertensive cardiomyopathy, the cardiac response to exercise is dependent on adequate diastolic filling volume to maintain systolic performance.

[18F]FDG-PET-CT for early monitoring of tumor response: when and why

(18)F-fluorodeoxyglucose positron emission tomography ([(18)F]FDG PET) has been recognized as a suitable tool in tumor response assessment of patients complaining with solid tumors who have undergone chemo- and radiotherapy. It offers the advantage of functional tissue characterization, which is independent from morphologic criteria allowing to differentiate disease relapse from therapy-induced fibrosis. At present, there is a growing body of evidence that PET semi-quantitative assessment of treatment-induced changes in tumor [(18)F]FDG avidity may predict early tumor response and patient outcome. Patient management might be changed. For instance, in non responder patients this novel diagnostic approach would hamper useless ''wait and watch'' attitude in implementing further options or identifying those needing additional therapeutic strategies. On the other hand, for those patients revealing promptly a favourable metabolic response a cost-sparing approach could be implemented avoiding expensive diagnostic procedures during the follow-up as well as the risk of over-treating. In any case, since even a partial metabolic response may be an indication for continuing therapy, the advantage of metabolic assessment over conventional procedures may be clinically relevant. Although a morphological assessment has been considered for long time the standard for detecting therapy response, limitations of conventional computed tomography-based evaluation in solid tumors are well-known. PET provides an independent means of assessing malignancy. However, no consensus has been achieved until now regarding the optimal timing in performing PET during or at completion of treatment.

Cardiac performance during exercise in patients with Fabry's disease

BACKGROUND

Fatigability and dyspnoea on effort are present in many patients with Fabry's disease. We assessed the determinants of cardiac performance during exercise in patients with Fabry's disease and preserved left ventricular ejection fraction at rest.

MATERIALS AND METHODS

Sixteen patients with Fabry's disease and 16 control subjects underwent radionuclide angiography at rest and during exercise, tissue Doppler echocardiography and magnetic resonance imaging at rest.

RESULTS

The exercise-induced change in stroke volume was +25 +/- 14% in controls and +5.8 +/- 19% in patients with Fabry's disease (P < 0.001). In 10 patients (group 1), the stroke volume increased (+19 +/- 10%), and in 6 patients (group 2) it decreased (-16 +/- 9%) with exercise. Patients of group 2 were older, had worse renal function, higher left ventricular mass and impaired diastolic function compared to group 1. The abnormal stroke volume response to exercise in group 2 was associated with a decrease in end-diastolic volume (P < 0.001) and a lack of reduction of end-systolic volume (P < 0.01) compared with both controls and group 1. The ratio of peak early-diastolic velocity from mitral filling to peak early-diastolic mitral annulus velocity was the only independent predictor of exercise-induced change in stroke volume (B -0.44; SE 0.119; beta-0.70; P < 0.005).

CONCLUSIONS

The majority of patients with Fabry's disease were able to augment stroke volume during exercise by increasing end-diastolic volume, whereas patients with more advanced cardiac involvement may experience the inability to increase cardiac output by the Frank Starling mechanism.

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.

Comparison of bioelectrical impedance analysis and dual-energy X-ray absorptiometry for the assessment of appendicular body composition in anorexic women

OBJECTIVE

To establish the accuracy of bioelectrical impedance analysis (BIA) for the assessment of appendicular body composition in anorexic women.

DESIGN

Cross-sectional study.

SETTING

Outpatient University Clinic.

SUBJECTS

A total of 39 anorexic and 25 control women with a mean (s.d.) age of 21 (3) y.

METHODS

Total, arm and leg fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry and predicted from total and segmental BIA at 50 kHz. The predictor variable was the resistance index (Rl), that is, the ratio of height (2) to body resistance for the whole body and the ratio of length(2)/limb resistance for the arm and leg.

RESULTS

Predictive equations developed on controls overestimated total, arm and leg FFM in anorexics (P<0.0001). Population-specific equations gave a satisfactory estimate of total and appendicular FFM in anorexics (P=NS) but had higher percent root mean square errors (RMSEs%) as compared to those developed on controls (8% vs 5% for whole body, 12% vs 10% for arm and 10% vs 8% for leg). The accuracy of the estimate of total and leg FFM in anorexics was improved by adding body weight (Wt) as a predictor with Rl (RMSE%=5% vs 8% and 7% vs 10%, respectively). However, the same accuracy was obtained using Wt alone, suggesting that in anorexics, BIA at 50 kHz is not superior to Wt for assessing total and leg FFM.

CONCLUSION

BIA shows some potential for the assessment of appendicular body composition in anorexic women. However, Wt is preferable to BIA at 50 kHz on practical grounds. Further studies should consider whether frequencies >50 kHz give better estimates of appendicular composition in anorexics as compared to Wt.

SPONSORSHIP

University of Napoli.

Body composition changes in patients with anorexia nervosa after complete weight recovery

OBJECTIVE

To assess body composition changes occurring in female anorectic patients after complete weight recovery.

DESIGN

Longitudinal study.

SUBJECTS

: Ten female patients with anorexia nervosa (age at baseline: 19.7+/-5.8 y) were studied both when undernourished (body mass index, BMI 14.8+/-1.3 kg/ m(2)) and after the achievement of a BMI >18.5 kg/m(2). The control group comprised 18 well-nourished women (age 20.1+/-4.4 y; BMI 19.0-23.0 kg/ m(2)).

INTERVENTIONS

Fat mass and fat-free mass were determined by dual-energy X-ray absorptiometry. Skinfold thicknesses and circumferences were also measured. Arm muscle area and arm fat area were calculated by standard formulas.

RESULTS

The undernourished patients had lower fat-free mass, fat mass, skinfold thicknesses and circumferences. After refeeding, fat mass represented 25-71% (mean 56%) of the mass regained, this percentage being directly related to the extent of weight gain. The increases in skinfolds and circumferences depended upon the site considered and were correlated to a various extent with those in weight or BMI. Skinfolds at biceps and abdominal sites and the waist-to-hip ratio remained significantly higher, whereas arm muscle circumference was significantly lower, in the refed group than in the control one.

CONCLUSION

The percentage of fat in the weight regained by refed female anorectic patients was directly related to the extent of body mass increase. Refed anorectic patients appear to preferentially regain fat in the abdominal and triceps regions. Abnormalities in skinfolds (at biceps and abdominal sites), arm muscle area and waist-to-hip ratio still persist in refed anorectic patients in comparison to control healthy controls.

Functional dyspepsia symptoms, gastric emptying and satiety provocative test: analysis of relationships

BACKGROUND

The correlation between symptoms and observed impaired function in functional dyspepsia is still inconsistent. The aims of the study were to obtain a measure of satiety by a meal test; to verify whether this compares with severity of symptoms assessed using a reproducible questionnaire; and to correlate the parameters of satiety test and gastric emptying with all the dyspeptic symptoms.

METHODS

Fifty-two functional dyspepsia patients reported their symptoms on a standardized questionnaire that considered belching, bloating, early satiety, epigastric pain and burning, nausea, postprandial fullness and vomiting. They were monitored for gastric emptying of a solid caloric meal using a radionuclide technique and underwent a test to quantify meal-induced satiety by a liquid caloric meal.

RESULTS

The number of kilocalories ingested during the satiety test until the occurrence of maximum satiety in healthy subjects was 110% higher than in the dyspeptic group (mean +/- s(mean): 1110 +/- 23 versus 532 +/- 56; P < 0.01). We found a significant positive correlation between gastric emptying rate and kcal of the satiety test (P < 0.01; r = 0.428). Logistic regression showed a significant inverse association between severity of early satiety-coded as absent, mild, moderate or severe, kcal of meal test (P = 0.01), and gastric emptying lag phase (P = 0.03). Bloating was associated directly with t(1/2) of gastric emptying (P = 0.03) and inversely with lag phase (P = 0.02).

CONCLUSIONS

The satiety test gives a fine numerical measure of satiety and confirms the results of a symptoms questionnaire. Our study showed an indirect correlation between severity of early satiety--as measured by the satiety test, and gastric emptying rate, as well as an association between bloating and delayed gastric emptying.

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.

Dipyridamole-atropine stress echocardiography versus exercise SPECT scintigraphy for detection of coronary artery disease in hypertensives with positive exercise test

OBJECTIVES

Many different stress echocardiographic and radionuclide perfusion imaging tests have been proposed for detecting epicardial coronary artery disease (CAD) in hypertensive patients. Their relative diagnostic and prognostic value has not been exactly established.

BACKGROUND

A positive exercise electrocardiography test has a low diagnostic specificity in hypertensive patients and warrants for a complementary imaging test to confirm the diagnosis of coronary artery disease.

METHODS

Hypertensive patients (n = 53), (29 males, aged 58 +/- 10 years) with normal left ventricular function detected by echocardiography and previous positive exercise test ( > or = 0.15 mV of ST segment depression on 12 lead electrocardiogram) underwent dipyridamole-atropine stress echocardiography (DASE) and thallium-201 stress/ rest myocardial single-photon emission computed tomography (SPECT). All patients had coronary angiography within 15 days and independently of imaging test results.

RESULTS

Coronary angiogram showed significant ( > or = 50% qualitatively assessed diameter reduction) epicardial coronary artery disease in 23 (43%) patients. Sensitivity for detection of coronary artery disease was significantly higher for scintigraphy (DASE = 78% versus SPECT = 100%, P < 0.05) while specificity was higher for echo (DASE = 100% versus SPECT = 47%, P < 0.00001). Diagnostic accuracy was also higher for echo (DASE = 91% versus SPECT = 70%, P < 0.01).

CONCLUSION

In patients with exercise-nduced ST segment depression, dipyridamole stress echo and SPECT perfusion scintigraphy are both good diagnostic options, with DASE characterized by higher specificity, lower sensitivity, and at least comparable diagnostic accuracy than SPECT.

Technetium 99m furifosmin regional myocardial uptake in patients with previous myocardial infarction: relation to thallium-201 activity and left ventricular function

BACKGROUND

This study was designed to compare the results of rest-redistribution thallium-201 imaging with those of rest technetium 99m furifosmin single photon emission computed tomography in the same patients with chronic ischemic left ventricular (LV) dysfunction.

METHODS

Twenty-one patients (mean age 62 +/- 9 years) with chronic myocardial infarction and LV dysfunction (mean LV ejection fraction 34% +/- 8%) underwent rest-redistribution thallium imaging and resting furifosmin single photon emission computed tomography on the same day. In each patient, regional thallium and furifosmin activity was quantitatively measured in 13 myocardial segments. Regional LV function was assessed in corresponding segments by echocardiography.

RESULTS

At thallium imaging, 91 (33%) segments had normal uptake, 16 (6%) showed reversible defects, and the remaining 166 (61%) irreversible defects. Of these 166 irreversible defects, 74 (45%) had moderate (> or =58% of peak activity) and 92 (55%) severe (<58% of peak activity) reduction of thallium uptake. Regional furifosmin uptake was significantly related to both rest (r = 0.87, P < .0001) and redistribution (r = 0.90, P < .0001) thallium activity. Agreement in the evaluation of regional perfusion status between thallium and furifosmin imaging was observed in 70% of the 84 hypokinetic segments (kappa = 0.54) and in 76% of the 78 akinetic or dyskinetic segments (kappa = 0.60). Concordance in the detection of myocardial viability between thallium and furifosmin imaging was observed in 69 (82%) of hypokinetic regions (kappa = 0.60) and in 65 (83%) of akinetic or dyskinetic regions (kappa = 0.67).

CONCLUSIONS

These results suggest that in patients with chronic coronary artery disease and LV dysfunction, quantitative rest-redistribution thallium scintigraphy and furifosmin tomography at rest provide similar results in the evaluation of perfusion status and in the detection of myocardial viability.

Does the age of onset of growth hormone deficiency affect cardiac performance? A radionuclide angiography study

BACKGROUND

GH and IGF-I seem to play a relevant role in cardiac development and performance. Long-standing GH deficiency (GHD) causes several abnormalities in cardiac structure and performance which ultimately determine an increased cardiovascular morbidity and mortality.

OBJECTIVE

To investigate whether the age of onset of GHD plays a role in determining the negative effects on the heart.

DESIGN

Open cross-sectional

PATIENTS

55 patients with adulthood-onset GHD and 36 healthy sex- and age-matched controls. Patients and controls were divided into 2 groups in line with age: 32 patients and 16 controls, were aged </= 35 years (young); while 23 patients and 20 controls were aged between 36 and 60 years (middle-aged). The estimated disease duration was similar in young (6.7 +/- 0.5 years) and middle-aged patients (8.1 +/- 1.2 years, P = 0.2).

STUDY PROTOCOL

All subjects underwent ECG, blood pressure and heart rate measurement, plasma IGF-I level assay, and equilibrium radionuclide angiography.

RESULTS

Plasma IGF-I levels were significantly lower in patients than in controls (P < 0.0001). When considered as a whole, no difference in systolic (SBP) and diastolic blood pressure (DBP) at peak exercise was found between patients and controls. However, a significant decrease of SBP at rest was found in young patients as compared to age-matched controls (P = 0.009), while a significant increase of DBP at rest was found in middle-aged patients as compared to age-matched controls (P = 0.03). In addition, in young patients, both resting (P = 0.02) and exercise heart rate (P = 0.01) were significantly lower than in controls. Diastolic filling when measured as end-diastolic volume (EVD/sec), was significantly reduced in middle-aged patients (P = 0.04). An impaired peak filling rate (PFR) (< 2.5 EDV/sec) was found in 30 patients (54.5%) and 10 controls (27.7%, chi2 = 5.3, P = 0.02): 17 young (53.1%) and 13 middle-aged patients (56.5%). A significant decrease of left ventricular (LV) ejection fraction (EF) at peak exercise was found in both patients groups (P < 0.0001) while LVEF at rest was lower only in middle-aged patients (P = 0.004). An impaired LVEF at rest (< 50%) was found in 13 patients (23.6%) and in none of controls (chi2 = 8.1, P = 0.004). The exercise induced changes in LVEF (DeltaEF) were significantly lower in both patients groups than in age-matched controls (P < 0.0001). Impaired LVEF response to exercise (< 5% increase vs. basal value) was found in 36 patients (65.4%) and in 5 controls (13.8%, chi2 = 21.3, P < 0.000): 21 young (65.6%) and 15 middle-aged patients (65.2%). The peak ejection rate (PER) was also significantly lower in young GHD patients than in controls (P < 0.001). Exercise duration and capacity were significantly reduced in both groups of GHD patients. In the patient group, age was significantly correlated with SBP and DBP levels both at rest (r = 0.612, and r = 0.516, respectively, P < 0.001) and at peak exercise (r = 0.4, P < 0.005 and r = 0.34, P < 0. 01, respectively), with exercise duration (r = - 0.383, P < 0.005) and capacity (r = - 0.355, P = 0.005). Disease duration was also correlated with IGF-I levels (r = - 0.319, P < 0.01), SBP levels at peak exercise (r = 0.352, P = 0.005), and LVEF at rest (r = - 0.254, P < 0.05). Finally, a significant correlation was found between IGF-I levels and DBP at peak exercise (r = 0.3, P < 0.05) and between GH peak at ARG + GHRH test and LVEF at rest (r = 0.232, P < 0.05). Exercise-induced changes in LVEF were significantly correlated with SBP levels at peak exercise (r = - 0.401, P < 0.005), PFR expressed as EDV/sec (r = - 0.306, P < 0.05) and SV/sec (r = - 0.292, P < 0.05). At multiple regression analysis in the patient group, age was the strongest predictor of SBP both at rest (t = 4.17, P < 0.0001) and at peak exercise (t = 2.32, P = 0.025), and capacity (t = - 2.84, P = 0.007). IGF-I levels were the strongest predictor of DBP at peak exercise (t = 2.2, P = 0.

Quantitative thallium-201 and technetium 99m sestamibi tomography at rest in detection of myocardial viability in patients with chronic ischemic left ventricular dysfunction

BACKGROUND

This study was designed to determine the most effective quantitative threshold for thallium-201 and technetium 99m sestamibi uptake on tomographic imaging after rest injection for the detection of myocardial viability in patients with chronic myocardial infarction.

METHODS AND RESULTS

Thallium and sestamibi cardiac tomography at rest was performed in 43 patients with chronic myocardial infarction and impaired left ventricular (LV) function undergoing coronary revascularization. In all patients, echocardiography and radionuclide angiography were performed at baseline and repeated 12 months later to evaluate recovery of regional LV function and LV ejection fraction, respectively. Optimal threshold cutoff points to separate reversible from irreversible dysfunction were determined by receiver operating characteristic analysis. When all dysfunctional segments were considered, the best cutoff point in the identification of reversible LV dysfunction for both thallium and sestamibi activity was 67%. When only akinetic or dyskinetic segments were considered, the best cutoff point in the identification of reversible LV dysfunction was 58% for thallium and 55% for sestamibi. In these segments, the area under the receiving operating characteristic curves constructed for thallium and sestamibi activity were 0.74+/-0.05 and 0.75+/-0.04, respectively (P = not significant). LV ejection fraction was 33%+/-7% at baseline and increased to 37%+/-7% after revascularization (P<.0001). A significant relation between the number of akinetic or dyskinetic but viable myocardial segments and revascularization-induced changes in LV ejection fraction was observed for both thallium (r = 0.60, P<.0001) and sestamibi (r = 0.64, P<.0001) imaging.

CONCLUSIONS

In patients with chronic myocardial infarction, quantitative analysis of thallium and sestamibi activity on tomographic imaging at rest predicts recovery of regional and global LV dysfunction after revascularization procedures. The most effective quantitative threshold for detecting reversible LV dysfunction is comparable for thallium and sestamibi tomographic imaging. However, the optimal cutoff point is different for both tracers when all dysfunctional segments are considered or when the analysis is focused only on segments with more severe functional impairment (i.e., akinetic or dyskinetic segments).

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 =

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

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.

Independent and incremental prognostic value of heart rate variability in patients with chronic heart failure

BACKGROUND

Decreased heart rate variability (HRV), indicating derangement in cardiac autonomic control, has been reported in patients with chronic heart failure. However, the independent and incremental prognostic value of HRV over clinical data and measures of left ventricular dysfunction has been less thoroughly investigated. This study was designed to evaluate the predictive value of HRV and Poincaré plots as assessed by 24-hour Holter recording in patients with chronic heart failure.

METHODS

Ninety-seven patients, mean age 55 +/- 13 years, with radionuclide left ventricular ejection fraction </=40% underwent echocardiographic examination and 24-hour Holter recording. Heart failure was caused by coronary artery disease in 57 patients (59%) and idiopathic dilated cardiomyopathy in 40 (41%).

RESULTS

During follow-up (39 +/- 18 months), 32 cardiac deaths occurred. By Cox multivariate analysis, significant predictors of death were left ventricular end-systolic volume (hazard ratio 1.04), low- to high-frequency ratio (hazard ratio 0.09), percentage of differences between successive normal R-R intervals >50 ms (hazard ratio 0.93), and age (hazard ratio 1.06). Furthermore, HRV analysis improved (P <. 001) the prognostic power of a model including clinical and echocardiographic data, left ventricular ejection fraction, and ventricular arrhythmias at Holter recording, whereas the inclusion of Poincaré plots did not add further predictive value.

CONCLUSIONS

Our investigation demonstrated that HRV has independent and incremental prognostic value in patients with chronic heart failure and seems useful to stratify patients at high risk of cardiac death.

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)

Exercise-test Tc-99m tetrofosmin SPECT in patients with chronic ischemic left ventricular dysfunction: direct comparison with Ti-201 reinjection

BACKGROUND

This study was designed to compare the results of exercise-rest technetium-99m tetrofosmin single photon emission computed tomography (SPECT) with those of thallium-201 reinjection at rest after exercise-redistribution imaging in the same patients with chronic ischemic left ventricular (LV) dysfunction.

METHODS

Within 1 week, 33 patients with chronic myocardial infarction and LV dysfunction underwent exercise-rest tetrofosmin SPECT and Tl-201 reinjection at rest after exercise-redistribution imaging. In each patient, regional tetrofosmin and Tl-201 activity was quantitatively measured in 22 myocardial segments. Regional LV function was assessed in corresponding segments by echocardiography.

RESULTS

Agreement in the evaluation of regional perfusion status between tetrofosmin and Tl-201 imaging was observed in 78% of the 726 total segments, with a kappa value of 0.61. In segments with normal function at echocardiography (n = 436), no difference between Tl-201 and tetrofosmin uptake was observed. In hypokinetic segments (n = 138), exercise tetrofosmin uptake was lower (P < .01) as compared with exercise Tl-201 activity, whereas no difference was observed between tetrofosmin uptake at rest as compared with Tl-201 activity on redistribution and reinjection images. In segments with severe functional impairment (akinetic or dyskinetic, n = 152), tetrofosmin uptake on exercise images was reduced (P < .01) as compared with exercise Tl-201 activity; furthermore, tetrofosmin uptake at rest was lower (P < .01) as compared with Tl-201 activity on both redistribution and reinjection images. In these segments, concordance in the detection of myocardial viability between tetrofosmin and Tl-201 imaging was observed in 138 (91%) of the 152 segments, with a kappa value of 0.77.

CONCLUSIONS

In patients with chronic coronary artery disease and LV dysfunction quantitative exercise-rest tetrofosmin and Tl-201 reinjection SPECT provide similar information in the assessment of perfusion status and in the detection of myocardial viability.

[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.

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.

[Dipyridamole-echocardiography and thallium exercise myocardial scintigraphy in the diagnosis of obstructive coronary or microvascular disease in hypertensive patients with left ventricular hypertrophy and angina]

BACKGROUND

Hypertensive patients with left ventricular hypertrophy can be affected with angina pectoris for significant epicardial coronary stenosis or microvascular disease with normal coronarography. Exercise-electrocardiography test is positive in both conditions. The aim of the present study was to assess the accuracy of dipyridamole-echocardiography test and thallium exercise myocardial scintigraphy in the diagnosis of epicardial coronary stenosis or microvascular disease in hypertensive patients with left ventricular hypertrophy and angina pectoris.

METHODS

Forty-two hypertensive patients (22 males, age 40-76 years, mean 58.6 +/- 10.1), with left ventricular hypertrophy, typical angina pectoris, ischemia that can be induced by exercise-electrocardiography test, without previous myocardial infarction, myocardial revascularization or diabetes mellitus, underwent dipyridamole-echocardiography test, thallium exercise myocardial scintigraphy and coronarography. Dipyridamole-echocardiography test was performed with dipyridamole (0.56 mg/kg over 4 minutes, followed by 0.28 mg/kg from the 8th to the 10th minute) + atropine (1 mg from the 12th to 15th min.) and was positive for a transient dyssynergy of contraction of at least 2 myocardial segments; the left ventricle was divided into 16 segments. SPECT thallium myocardial scintigraphy was performed after bicycle exercise and then three hours later, and it was positive for reversible uptake defects of at least 2 segments with a 22-segment model. Coronarography was performed with Judkin's technique and was positive if at least one large epicardial vessel was narrowed by more than 50%.

RESULTS

Coronarography: normal in 25 cases (59.5%, 8 males), pathologic in 17 (40.5%, 14 males): left main coronary artery in 1 (5.9%), three vessels in 5 (29.4%), two vessels in 3 (17.7%), 1 vessel in 8 (47%). Dipyridamole-echocardiography-test: positive in 15 cases (35.7%), negative in 27 (64.3%); sensitivity 88.2%, specificity 100%, diagnostic accuracy 95.2%, positive predictive value 100%, negative predictive value 92.6%. Thallium exercise myocardial scintigraphy: positive in 30 cases (71.4%), negative in 12 (28.6%); sensitivity 100%, specificity 48%, diagnostic accuracy 69%, positive predictive value 56.7%, negative predictive value 100%.

CONCLUSIONS

Dipyridamole-echocardiography test has higher diagnostic accuracy and when positive, it predicts significant epicardial coronary stenosis. It can be less sensitive in one-vessel patients (2 false negatives were stenosis 75% of left anterior descending and 60% of 1st diagonal). Thallium exercise myocardial scintigraphy is complementary because when negative, it excludes epicardial coronary stenosis and confirms microvascular disease. In hypertensive patients with left ventricular hypertrophy and suspected angina pectoris, the following flow-chart may be proposed: the first test is exercise-electrocardiography test. Only those who are positive at low-to-intermediate workload then undergo dipyridamole-echocardiography test. Those who are positive in this then undergo coronarography, while the negative ones undergo thallium exercise myocardial scintigraphy. Those who are positive at thallium exercise myocardial scintigraphy perform the coronarography, while cases with negative results do not undergo further diagnostic tests since they are affected with microvascular disease.

Combined assessment of left ventricular function and rest-redistribution regional myocardial thallium-201 activity for prognostic evaluation of patients with chronic coronary artery disease and left ventricular dysfunction

BACKGROUND

This study evaluated the prognostic value of combined assessment of left ventricular (LV) function and regional myocardial thallium activity in patients with nonrecent myocardial infarction and LV dysfunction.

METHODS AND RESULTS

Eighty-two patients with previous myocardial infarction (>8 weeks) and echocardiographic evidence of LV dysfunction underwent thallium-201 rest-redistribution tomography and cardiac catheterization. During the follow-up period (mean 25 months) there were 18 cardiac events (14 deaths and 4 nonfatal myocardial infarctions). Multivariate Cox regression analysis on clinical, angiographic, and thallium variables showed that the number of echocardiographic dysfunctional segments with preserved thallium uptake (> or =50% of peak activity; chi-square 11.03; p<0.005) and age (chi-square 8.12, p<0.01) were predictive of poor outcome. At incremental analysis, combined echocardiographic and thallium data provided significant additional information to clinical, thallium, and LV functional data, increasing global chi-square value from 22.4 to 31.5 (p< 0.01). Similarly, combined data gave additional information after considering clinical, echocardiographic, and LV functional data, increasing global chi-square from 17.8 to 22.3 (p <0.05). Differently, the number of diseased vessels at coronary angiography did not add further prognostic information.

CONCLUSIONS

In patients with previous myocardial infarction and chronic LV dysfunction, the combination of echocardiographic and thallium rest-redistribution imaging data gives prognostic information incremental to those of clinical and LV functional data and to those of each technique considered separately.

Direct comparison of technetium 99m-sestamibi and technetium 99m-tetrofosmin cardiac single photon emission computed tomography in patients with coronary artery disease

BACKGROUND

Technetium 99m-labeled sestamibi and tetrofosmin tomography have shown high diagnostic accuracy in the detection of coronary artery disease (CAD). However, few data are available comparing sestamibi and tetrofosmin imaging in the same patients. The aim of the study was to determine the image quality of the two tracers and to compare the results of exercise sestamibi and tetrofosmin tomography in the same patients.

METHODS

The results of exercise-rest sestamibi and tetrofosmin myocardial tomography were compared in 32 patients with suspected or known CAD who underwent coronary angiography. Image quality was evaluated subjectively. Regional tracer distribution was visually assessed and quantitatively measured in 22 segments/patient.

RESULTS

At coronary angiography, 7 patients had normal coronary vessels, 11 single-vessel, and 14 multivessel CAD (> or =50% luminal stenosis). Image quality judged visually was comparable with the two tracers. Heart/lung and heart/liver ratios for sestamibi and tetrofosmin were not different. At visual analysis, 68% of the patients with CAD had abnormal findings with sestamibi and 76% with tetrofosmin (p = NS). At quantitative analysis, 92% of the patients with CAD had abnormal findings with sestamibi and 96% with tetrofosmin (p = NS). At both visual and quantitative analyses, sensitivity, specificity, and diagnostic accuracy in the detection of individual stenosed vessels were not different between the two tracers. Moreover, for both tracers sensitivity, specificity, and diagnostic accuracy in the detection of diseased vessels were significantly higher (all p < 0.05) at quantitative compared with visual analysis. Finally, defect size and severity were similar for the two tracers.

CONCLUSIONS

Exercise-rest sestamibi and tetrofosmin tomography yielded images of comparable quality and provided similar results in the identification of patients with CAD and in the detection of the individual stenosed coronary vessels.

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.

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.

Cardiological aspects of growth hormone and insulin-like growth factor-I

In recent years it has been demonstrated that both GH deficiency and excess include in their advanced clinical manifestations an impaired cardiovascular function, which may reduce life expectancy. This observation has allowed the investigation of the role played by the GH/IGF-I axis on cardiac structure and function. In particular, several recent experimental and clinical studies support the evidence implicating GH and/or IGF-I in the regulation of heart development. Acromegalic cardiomyopathy is characterized by myocardial hypertrophy with interstitial fibrosis, lymphomononuclear infiltration and areas of monocyte necrosis which often result in increased right and left ventricular mass and concentric hypertrophy. Conversely, patients with childhood or adulthood-onset GH deficiency (GHD) have a reduced left ventricular mass and ejection fraction and the indexes of left ventricular systolic function remained markedly depressed during exercise. In addition, a significant increase in the thickness of the vascular intima-media wall and a higher number of atheromatous plaques have been reported. These abnormalities of the cardiovascular system are partially reversed after normalization of GH and IGF-I levels, by octreotide in acromegaly or after GH replacement therapy in GHD patients. The evidence that GH is able to increase cardiac mass suggested its use in the treatment of idiopathic dilated cardiomyopathy. In a recent study on such patients, the administration of rhGH was demonstrated to increase myocardial mass and to reduce the size of the left ventricular chamber, resulting in an improvement in hemodynamics, myocardial energy metabolism and clinical status. These promising results might open a new field for GH treatment.

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

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.

Prognostic value of coronary angiography in patients with chronic ischemic left ventricular dysfunction and evidence of viable myocardium on thallium reinjection imaging

BACKGROUND

We evaluated the independent and incremental prognostic value of cardiac catheterization and coronary angiographic data over thallium reinjection after stress redistribution imaging in patients with myocardial infarction and left ventricular dysfunction.

METHODS AND RESULTS

Sixty-nine patients with a first myocardial infarction (> 8 weeks) and left ventricular ejection fraction < or = 40% underwent thallium-201 reinjection after stress redistribution tomographic imaging and cardiac catheterization. During follow-up (mean 26 months) 11 cardiac events (8 cardiac deaths and 3 nonfatal myocardial infarctions) occurred. On Cox regression analysis independent predictors of cardiac events were the sum of reversible and moderately irreversible defects at thallium reinjection (chi 2, 16.4, p < 0.005) and the number of reversible defects at stress redistribution (chi 2, 5.1, p < 0.05). Moreover, thallium reinjection imaging improved the prognostic power of clinical, exercise, and stress redistribution data (p < 0.01). The inclusion of left ventricular ejection fraction produced a borderline improvement (p = 0.06), whereas the number of vessels with coronary disease did not. In contrast, in patients at high risk such as those with at least 25% of viable myocardium at reinjection, the number of diseased vessels provided additional prognostic information (p < 0.05).

CONCLUSIONS

In patients with chronic ischemic left ventricular dysfunction, left ventricular ejection fraction, but not the number of diseased vessels, provides additional prognostic information to thallium imaging. Therefore coronary angiography seems unnecessary in these patients, unless a significative amount of viable myocardium is detectable.

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

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.

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

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.

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

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.

Impaired cardiac reserve and exercise capacity in patients receiving long-term thyrotropin suppressive therapy with levothyroxine

To assess cardiac function and exercise tolerance in patients receiving long term TSH-suppressive therapy with levothyroxine (L-T4), we studied maximal exercise capacity with a bicycle ergometer and left ventricular function at rest and during physical exercise by radionuclide angiography. The evaluation was performed in 10 patients receiving L-T4 therapy (2.31 +/- 0.13 microgram/kg) for 5-9 yr, presenting with effort dyspnea and symptoms of adrenergic overactivity, and 10 matched control subjects. The patients were reassessed after 4 months of administration of the selective beta-adrenergic blocker bisoprolol (4.25 +/- 0.4 mg/day); L-T4 therapy remained unchanged. The results showed that at rest, left ventricular diastolic filling was impaired in the patients (P < 0.05), whereas systolic function was unaltered. During submaximal physical exercise, left ventricular ejection fraction increased in the controls from 58 +/- 2% to 65 +/- 2% (P < 0.001), whereas in the patients it fell from 63 +/- 2% to 53 +/- 2% (P < 0.01), mainly because of increased end-systolic left ventricular volume (P < 0.05). Exercise capacity was markedly reduced in the patients in terms of both peak workload (P < 0.001) and exercise duration (P < 0.001). beta-Adrenergic blockade prevented both the fall in ejection fraction and the increase in end-systolic volume during exercise, and improved exercise tolerance. In conclusion, our data show that long term TSH-suppressive therapy with L-T4 is not as harmless as believed, because it may cause marked impairment of cardiac functional reserve and physical exercise capacity. Administration of a beta-blocking drug for 4 months caused significant improvement of cardiac performance and exercise tolerance.

[Tetrofosmin: a new compound labeled with 99mTc for the study of myocardial perfusion. Correlations with coronary anatomy in patients with suspected ischemic cardiopathy]

The aim of this study was to investigate the accuracy of quantitative one-day exercise-rest 99mTc tetrofosmin tomography in the identification of patients with suspected coronary artery disease (CAD) and in the detection of single stenosed coronary vessels. Sixty-one patients with suspected CAD and submitted to coronary angiography were examined. All patients were given 2 i.v. injections of 99mTc tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 hours after exercise (images 15-30 min after injection for both studies). All patients with CAD (> or = 50% luminal stenosis) (n = 50) had abnormal 99mTc tetrofosmin tomogram (100% sensitivity). Only one patient without CAD had abnormal 99mTc tetrofosmin tomogram (91% specificity). Overall sensitivity, specificity, and diagnostic accuracy in the detection of single stenosed vessels were 77%, 93% and 85%, respectively. No significant differences among single vascular areas were observed. Sensitivity and diagnostic accuracy in the identification of single stenosed coronary vessels were significantly higher (p < 0.05) in the patients with single-vessel disease (n = 21) than in those with multivessel disease (n = 29). Sensitivity, specificity and diagnostic accuracy in detecting single diseased vessels were similar in the patients without (n = 26) and in those with previous myocardial infarction (n = 35). The results of this study demonstrate that quantitative one-day exercise-rest 99mTc tetrofosmin SPECT imaging is a suitable and accurate technique to identify patients with suspected CAD and to detect single stenosed coronary vessels.

Quantitative exercise technetium-99m tetrofosmin myocardial tomography for the identification and localization of coronary artery disease

The aim of this study was to evaluate the accuracy of quantitative 1-day exercise-rest technetium-99m tetrofosmin tomography in the identification of patients with coronary artery disease (CAD) and in the detection of individual stenosed coronary vessels. Sixty-one patients with suspected CAD who underwent coronary angiography and 13 normal volunteers were studied. All patients were submitted to two i.v. injections of 99mTc-tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 h after exercise (images 15-30 min after injection for both studies). All patients with CAD (>/=50% luminal stenosis) (n=50) had an abnormal 99mTc-tetrofosmin tomogram. Only one patient without significant coronary narrowing showed abnormal findings. Overall sensitivity, specificity and diagnostic accuracy in the detection of individual stenosed vessels were 77%, 93% and 85%, respectively. Sensitivity and diagnostic accuracy in the identification of individuals stenosed coronary vessels were significantly higher (P<0.05) in patients with single-vessel disease (n=21) than in those with multivessel disease (n=29). Sensitivity, specificity and accuracy for detecting individual diseased vessels were similar in patients without previous myocardial infarction (n=26) and in those with previous myocardial infarction (n=35). In myocardial territories related to non-infarcted areas (n=128), sensitivity and specificity in the detection of stenosed vessels were 70% and 95%, respectively. In infarcted areas (n=55), sensitivity and specificity in the detection of stenosed vessels were 85% (P=NS vs non-infarcted areas) and 75% (P<0.05 vs non-infarcted areas), respectively. Finally, sensitivity was significantly lower (P<0.05) in vascular territories supplied by vessels with moderate stenosis (50%-75%) than in those supplied by vessels with severe stenosis (>75%). The results of this study demonstrate that quantitative 1-day exercise-rest 99mTc-tetrofosmin single-photon emission tomographic imaging is a suitable and accurate technique to identify patients with CAD and to detect individual stenosed coronary vessels.