Diagnosis and treatment of cardiac amyloidosis: position statement of the German Cardiac Society (DGK).

Systemic forms of amyloidosis affecting the heart are mostly light-chain (AL) and transthyretin (ATTR) amyloidoses. The latter is caused by deposition of misfolded transthyretin, either in wild-type (ATTRwt) or mutant (ATTRv) conformation. For diagnostics, specific serum biomarkers and modern non-invasive imaging techniques, such as cardiovascular magnetic resonance imaging (CMR) and scintigraphic methods, are available today. These imaging techniques do not only complement conventional echocardiography, but also allow for accurate assessment of the extent of cardiac involvement, in addition to diagnosing cardiac amyloidosis. Endomyocardial biopsy still plays a major role in the histopathological diagnosis and subtyping of cardiac amyloidosis. The main objective of the diagnostic algorithm outlined in this position statement is to detect cardiac amyloidosis as reliably and early as possible, to accurately determine its extent, and to reliably identify the underlying subtype of amyloidosis, thereby enabling subsequent targeted treatment.

Only strongly enhanced residual FDG uptake in early response PET (Deauville 5 or qPET ≥ 2) is prognostic in pediatric Hodgkin lymphoma: Results of the GPOH-HD2002 trial.

PURPOSE: In 2014, we published the qPET method to quantify fluorodeoxyglucose positron emission tomography (FDG-PET) responses. Analysis of the distribution of the quantified signals suggested that a clearly abnormal FDG-PET response corresponds to a visual Deauville score (vDS) of 5 and high qPET values ≥ 2. Evaluation in long-term outcome data is still pending. Therefore, we analyzed progression-free survival (PFS) by early FDG-PET response in a subset of the GPOH-HD2002 trial for pediatric Hodgkin lymphoma (PHL). PATIENTS/METHODS: Pairwise FDG-PET scans for initial staging and early response assessment after two cycles of chemotherapy were available in 93 PHL patients. vDS and qPET measurement were performed and related to PFS. RESULTS: Patients with a qPET value ≥ 2.0 or vDS of 5 had 5-year PFS rates of 44%, respectively 50%. Those with qPET values < 2.0 or vDS 1 to 4 had 5-year PFS rates of 90%, respectively 80%. The positive predictive value of FDG-PET response assessment increased from 18% (9%; 33%) using a qPET threshold of 0.95 (vDS ≤ 3) to 30% (13%; 54%) for a qPET threshold of 1.3 (vDS ≤ 4) and to 56% (23%; 85%) when the qPET threshold was ≥ 2.0 (vDS 5). The negative predictive values remained stable at ≥92% (CI: 82%; 98%). CONCLUSION: Only strongly enhanced residual FDG uptake in early response PET (vDS 5 or qPET ≥ 2, respectively) seems to be markedly prognostic in PHL when treatment according to the GPOH-HD-2002 protocol is given.

Use of myocardial perfusion imaging and estimation of associated radiation doses in Germany from 2005 to 2012.

PURPOSE: For several years the Working Group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine has been performing a regular survey to obtain information on technique, utilization and development of myocardial perfusion scintigraphy (MPS). Currently, data of six surveys from 2005 to 2012 are available. The aim of this paper is to deliver a general and comprehensive overview of all surveys documenting the course of patient doses over time and the development of the method. METHODS: A one-page questionnaire with number of MPS patients, number of stress and rest MPS, referral structure and several technical issues was sent to all centres performing MPS in Germany and evaluated. With the data on protocol utilization, effective MPS patient doses were estimated. RESULTS: MPS per million population (pmp) varied between 2,380 and 2,770. In 2012, MPS pmp showed a slight increase for the first time. From 2005 to 2009 the angiography to MPS ratio increased from 3.4 to 4.4, and the revascularization to MPS ratio decreased from 0.66 to 0.53. In 2012, both indices demonstrated an opposite trend for the first time (4.1 and 0.55). A total of 108 centres participated in all surveys. They showed an increase in MPS patients of 4.0 % over the reporting period. In 2012, more than 50 % of the centres experienced no change or an increase in MPS numbers. The leading single competitor was MRI, followed by angiography and stress echocardiography. (201)Tl studies have decreased since 2005 from 20 to 5 %. (99m)Tc MPS studies showed a mild increase in 2-day protocols. In 2012, the average effective dose per patient was estimated at 7.4 mSv. Due to the decreasing use of (201)Tl, a mild decline over the observation period can be documented. Dynamic exercise stress was the most common stress test and adenosine the leading pharmacological stress agent, with a growing percentage. In 2012, the regadenoson percentage was 9 %. Gated single photon emission computed tomography (SPECT) noted an increasing acceptance with >70 % in 2012. The segmental scoring of perfusion studies had a low acceptance. Ambulatory care cardiologists represented the major referral group. CONCLUSION: Germany has a moderate to moderate-high MPS utilization rate. Nevertheless, coronary artery disease (CAD) diagnosis and disease management are dominated by angiography. The survey data reveal a positive trend in MPS and a decrease in average patient dose reflecting good practice with guideline adherence, the implementation of technical improvements and success in training.

[Myocardial perfusion scintigraphy 2008 in Germany - results of the fourth query]. / Myokard-Perfusions-Szintigraphie 2008 in Deutschland - Ergebnisse der vierten Erhebung.

AIM: The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society herewith present the results of the 4th survey on myocardial perfusion scintigraphy (MPS) of the year 2008. METHOD: 310 questionnaires (191 private practices (PP), 93 hospitals (HO), 31 university hospitals (UH)) were evaluated. RESULTS: MPS of 98947 patients were reported. 15% of them were younger than 50 y, 57% between 50 and 70 y and 28% older than 70 y. 88% [2007: 83%] of all were studied with Tc-99m perfusion tracers. The patient radiation exposure of a stress and rest protocol considering German standard recommended doses was 8.5 mSv, of a stress-only protocol 1.9 mSv. 77% [2007: 76%] of the MPS were performed in PP, 15% [2007: 15%] in HO and 8% [2007: 9%] in UH. From 2005 to 2008 there was a mild increase in the MPS numbers by 1.2% (PP +7.1%, HO -5.5%, UH -31.4%). The type of stress was pharmacological in 30% [2007: 27%]; 68% adenosine (of these 22% with exercise), 29% dipyridamole (of these 64% with exercise), and <1% dobutamine. Gated SPECT was performed in 46% [2007: 47%] of all rest and in 42% [2007: 44%] of all stress MPS. 62% [2007: 61%] of all institutions did not use perfusion scores. CONCLUSION: The MPS numbers from 2005 to 2008 in Germany can be regarded as stable. However, there are considerable shifts from HO and UH to PP. The well known potential of MPS considering risk stratification and functional analysis has not been tapped so far. Both gated SPECT and a quantitative perfusion analysis should be performed routinely in every patient.

[Myocardial perfusion scintigraphy 2007 in Germany--results of the query and current status]. / Myokardperfusionsszintigraphie 2007 in Deutschland--Ergebnisse der Erhebung und Standortbestimmung.

AIM: This third survey of the working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine in cooperation with the working group Nuclear Cardiology of the German Cardiac Society was to deliver information on the procedures and in particular on the development of myocardial perfusion scintigraphy (MPS) from 2005 to 2007. METHOD: 370 questionnaires (222 private practices (PP), 117 hospitals (HO), 31 university hospitals (UH)) were evaluated. RESULTS: MPS of 114,374 patients were reported, 83% were investigated with 99mTc-perfusion tracers. 76% [2006=74%] were performed in PP, 15% [2006=17%] in HO and 9% [2006=9%] in UH. Diabetics represented 21% of all MPS patients in 2007. Data of 215 institutions which participated all from 2005 to 2007 showed an increase in MPS of 2.3% (PP +6.8%, HO -4.5%, UH -18.2%). The type of stress was pharmacological in 27% [2006 = 27%]; 67% adenosine (of these 25% with exercise), 31% dipyridamole (of these 55% with exercise), and 2% dobutamine. Gated SPECT was performed in 47% [2006 = 42%] of all rest and in 44% [2006 = 39%] of all stress MPS. 61% [2006 = 83%] of all institutions did not apply perfusion scores. 20% [2006 = 24%] of the institutions reported changes in the use of MPS by competing methods. CONCLUSION: There is a small increase of MPS between 2005 and 2007 despite competing methods. Gated SPECT has experienced more acceptance, but is still underrepresented. As compared to the European average and general standards of MPS a considerable backlog accounts to pharmacological stress tests, gated SPECT and perfusion scores.

Relationship of coronary calcium and myocardial perfusion in individuals with chest pain. Assessed by integrated rubidium-82 PET-CT.

AIM: The integrated value of coronary calcium scoring added to myocardial perfusion assessment in hybrid PET-CT imaging remains poorly defined. In the present study, we sought to determine the relationship between calcium burden, other risk factors, and tissue perfusion in a group of patients with chest pain and predominantly intermediate likelihood for coronary artery disease. PATIENTS, METHODS: In 70 patients, coronary calcium scores (CCS) were obtained in addition to rest/dipyridamole stress 82Rb perfusion images using a GE Discovery Rx hybrid PET-CT system. From static perfusion images, summed rest, stress and difference scores (SRS, SSS, SDS) were calculated using a 20-segment model. Absolute CCS was determined according to Agatston and age-, gender-, and ethnicity-matched CCS percentiles were calculated using the MESA database. RESULTS: SSS, SRS and SDS were abnormal (>or=4) in 25 (36%), 17 (24%), and 12 (17%) patients. Mean CCS according to Agatston was 180+/-446(range 0-2122), and CCS percentile was 42+/-43(range 0-99). Absolute CCS correlated mildly but significantly with SSS (r=0.31, p=0.01), while CCS percentile did not (r=0.11, p=0.36). Of 49 patients with normal perfusion, 25 (57%) had CCS=0, and 8 (18%) had a CCS percentile>or=75th. Of 35 patients with a CCS=0, 26 (74%) had normal perfusion. Individuals in whom review of patient records revealed events during follow-up (n=10) had significantly higher SSS than those where no events were recorded (6.0+/-7.2 versus 2.9+/-3.1, p=0.03), and there was a trend towards higher CCS percentiles (62+/-36 versus 35+/-43, p=0.06). CONCLUSION: Coronary calcifications and myocardial tissue perfusion, as interrogated in a single PET-CT imaging session, show only partial agreement in patients with chest pain. Both tests seem to reflect different pathophysiologic components, and may be complementary for definition of individual disease patterns.

[Myocardial perfusion scintigraphy 2006 in Germany. Results of the query and current status]. / Myokardperfusionsszintigraphie 2006 in Deutschland Ergebnisse der Erhebung und Standortbestimmung.

AIM: This second survey was to deliver further information on myocardial perfusion scintigraphy (MPS) in Germany in 2006. METHOD: 351 questionnaires were evaluated: 207 private practices (PP), 117 hospitals (HO), 27 from university hospitals (UH). RESULTS: MPS of 106 331 patients were reported, 85% were investigated with (99m)Tc-perfusion tracers. 74% [2005 = 72%] were performed in PP, 17% [2005 = 15%] in HO and 9% [2005 = 13%] in UH. PP, which participated in 2005 and 2006, demonstrated an increase by 3,9% (HO 0%, UH - 13,0%). The type of stress was pharmacological in 27% [2005 = 22%]; 54% adenosine (of these 29% with exercise), 37% dipyridamole (of these 56% with exercise), and 9% dobutamine. Gated SPECT was performed in 42% [2005 = 36%] of all rest- and in 39% [2005 = 32%] of all stress MPS. An attenuation correction was used by 69 [2005 = 78] institutions. 40% of all MPS were performed in patients suspected to have CAD. 24% of all institutions reported changes in the use of MPS by competing methods. CONCLUSION: There is a small increase of MPS between 2005 and 2006 despite competing methods. Gated SPECT has experienced more acceptance. Suspicion of CAD is an important indication of MPS. In order to tap the full potential of MPS a gated SPECT should be performed routinely.

[Myocardial perfusion scintigraphy in Germany. Results of the 2005 query and current status]. / Myokardszintigraphie in Deutschland. Ergebnisse der Erhebung 2005 und Standortbestimmung.

UNLABELLED: The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine (DGN), in cooperation with the working group Nuclear Cardiology of the German Cardiac Society (DGK), decided to conduct a national survey on myocardial perfusion scintigraphy (MPS). METHOD: A questionnaire to evaluate MPS for the year 2005 was sent. RESULTS: 346 completed questionnaires had been returned (213 private practices, 99 hospitals and 33 university hospitals). MPS of 112 707 patients were reported with 110 747 stress and 95 878 rest studies. The majority (>75%) was performed with (99m)Tc-MIBI or tetrofosmin. (201)Tl stress-redistribution was used in 22 637 patients (20%). The types of stress were exercise in 78%, vasodilation with adenosine or dipyridamol in 21% and dobutamine in 1%. 99.97% of all MPS were SPECT studies. Gated SPECT was performed in 36% of the stress and in 32% of the rest studies. An attenuation correction was used in 21%. 29 institutions (8%) performed gated SPECT (stress and rest) and attenuation correction. 47% of all MPS were requested by ambulatory care cardiologists, 17% by internists, 12% by primary care physicians, 21% by hospital departments and 2% by others. CONCLUSION: In Germany, MPS is predominantly performed with (99m)Tc-perfusion agents. The common type of stress is ergometry. Gated SPECT and attenuation correction do not yet represent standards of MPS practice in Germany, which indicates some potential of optimization.

Standardised uptake values from PET/CT images: comparison with conventional attenuation-corrected PET.

PURPOSE: In PET/CT, CT-derived attenuation factors may influence standardised uptake values (SUVs) in tumour lesions and organs when compared with stand-alone PET. Therefore, we compared PET/CT-derived SUVs intra-individually in various organs and tumour lesions with stand-alone PET-derived SUVs. METHODS: Thirty-five patients with known or suspected cancer were prospectively included. Sixteen patients underwent FDG PET using an ECAT HR+scanner, and subsequently a second scan using a Biograph Sensation 16PET/CT scanner. Nineteen patients were scanned in the reverse order. All images were reconstructed with an iterative algorithm (OSEM). Suspected lesions were grouped as paradiaphragmatic versus distant from the diaphragm. Mean and maximum SUVs were also calculated for brain, lung, liver, spleen and vertebral bone. The attenuation coefficients (mu values) used for correction of emission data (bone, soft tissue, lung) in the two data sets were determined. A body phantom containing six hot spheres and one cold cylinder was measured using the same protocol as in patients. RESULTS: Forty-six lesions were identified. There was a significant correlation of maximum and mean SUVs derived from PET and PET/CT for 14 paradiaphragmatic lesions (r=0.97 respectively; p<0.001 respectively) and for 32 lesions located distant from the diaphragm (r=0.87 and r=0.89 respectively; p<0.001 respectively). No significant differences were observed in the SUVs calculated with PET and PET/CT in the lesions or in the organs. In the phantom, radioactivity concentration in spheres calculated from PET and from PET/CT correlated significantly (r=0.99; p<0.001). CONCLUSION: SUVs of cancer lesions and normal organs were comparable between PET and PET/CT, supporting the usefulness of PET/CT-derived SUVs for quantification of tumour metabolism.

Myocardial scars determined by delayed-enhancement magnetic resonance imaging and positron emission tomography are not common in right ventricles with systemic function in long-term follow up.

OBJECTIVE: To test the hypothesis that myocardial scars are common in patients with systemic right ventricles. METHODS: 27 consecutive patients with systemic right ventricle were studied with delayed-enhancement magnetic resonance imaging and positron emission tomography. Of the 27 patients, 18 had had an atrial switch operation a mean of 21.8 (SD 4.5) years previously and were 23.4 (SD 5.3) years old. Nine patients without previous heart surgery had congenitally corrected transposition of the great arteries and were 35.3 (SD 15.6) years old. RESULTS: Only one patient had a subendocardial scar identified by delayed-enhancement magnetic resonance imaging. Positron emission tomography identified no myocardial scars. CONCLUSIONS: This study shows that the hypothesis that myocardial scars are common in patients with systemic right ventricles is not correct.

Effects of nateglinide on myocardial microvascular reactivity in Type 2 diabetes mellitus--a randomized study using positron emission tomography.

AIMS: To evaluate effects of the oral antidiabetic insulinotropic agent nateglinide on myocardial blood flow (MBF) and microvascular reactivity in Type 2 diabetic patients. METHODS: Forty-seven Type 2 diabetic patients were randomly assigned 2 : 1 to nateglinide 120 mg (t.i.d., n = 33) or placebo (n = 14). At baseline and after 16 weeks of treatment, MBF was quantified using positron emission tomography with N-13 ammonia at rest, during endothelial-dependent stimulation by cold pressor test and during adenosine-mediated vasodilation. Additional blood samples were taken to assess glycaemic control and lipid profile. RESULTS: MBF at rest and during adenosine did not change during the study. The percentage of flow increase from rest during cold pressor test did not improve significantly in the nateglinide group vs. placebo (from 26.1 +/- 37.2% to 29.1 +/- 27.8% between week 0 to week 16 for nateglinide vs. 14.9 +/- 37.1% to 18.1 +/- 28.4% for placebo; P = 0.07 for nateglinide when adjusted for higher baseline values). Nateglinide decreased HbA1c by 0.4% (from 7.6 +/- 0.9% to 7.2 +/- 1.3%) compared to an increase of 0.5% in the placebo group (from 7.9 +/- 0.8% to 8.4 +/- 1.7%; P = 0.02 for nateglinide). No differences between the two groups were observed in insulin levels and lipid status. CONCLUSIONS: Nateglinide neither improved, nor impaired myocardial blood flow in Type 2 diabetic patients. Potential effects on endothelial-dependent myocardial blood flow remain to be investigated further. Positron emission tomography is a sensitive approach to assess the effects of therapeutic agents on myocardial blood flow in patients with diabetes.

Myocardial blood flow and coronary flow reserve in children with "normal" epicardial coronary arteries after the onset of Kawasaki disease assessed by positron emission tomography.

Myocardial blood flow (MBF) was investigated in children (14.2 +/- 5.01 years) with "resolved" coronary involvement after the onset of Kawasaki disease and angiographically normal epicardial coronary arteries. Ten asymptomatic children with a history of Kawasaki disease had electrocardiography, echocardiography, and positron emission tomography (PET) 10.3 +/- 6.01 years after onset of the acute illness. Myocardial perfusion was assessed by NH(3)- PET at rest and after vasodilatation and compared with that of 10 healthy volunteers (26.1 +/- 6.3 years). No patient had signs of myocardial ischemia; on echocardiography ventricular function was normal without dyskinetic areas or signs of enlargement or stenosis of the proximal coronary arteries. There was no statistical significant difference between patients and volunteers in MBF at rest (0.86 +/- 0.27 vs 0.77 +/- 0.17 ml/g/min), whereas MBF after vasodilatation (2.42 +/- 0.81 vs 3.10 +/- 0.8 ml/g/min) and coronary flow reserve (CFR) (2.89 +/- 0.26 vs 4.09 +/- 1.01 mmHg/ml/g/min) were significantly attenuated in the Kawasaki group. No stress-induced perfusion defects could be detected. In children with a history of Kawasaki disease and angiographically normal epicardial coronary arteries, there is a significant attenuation of MBF after vasodilatation and a significant reduction of CFR. Impairment of vasoreactive ability may indicate residual damage of the coronary arteries and may be a risk factor for atherosclerosis in adulthood.

Impaired myocardial blood flow and coronary flow reserve of the anatomical right systemic ventricle in patients with congenitally corrected transposition of the great arteries.

OBJECTIVES: To investigate myocardial blood flow of the morphological right systemic ventricle in unoperated patients with congenitally corrected transposition of the great arteries (CCTGA) by positron emission tomography (PET). DESIGN: Prospective cross sectional clinical study. SETTING: Tertiary referral centre for paediatric cardiology. PATIENTS: 15 patients with CCTGA were investigated by PET with nitrogen-13 ammonia at rest and during adenosine vasodilatation. A subgroup of seven patients had isolated CCTGA (group A, mean (SD) age 30.3 (11.9) years) and the remaining eight patients had complex CCTGA associated with subpulmonary stenosis; four of this second group also had ventricular septal defect (group B, mean (SD) age 30.6 (16.4) years). Eleven healthy adults (mean (SD) age 26.2 (5.1) years) served as the control group. RESULTS: Resting myocardial blood flow was not different between both groups of patients with CCTGA and the controls. Hyperaemic blood flows were significantly lower in both groups of CCTGA than in the control group (mean (SD) 195 (21) ml/100g/min in group A, 201 (27) ml/100g/min in group B, 309 (74) ml/100g/min in the control group; p < 0.001). Thus, coronary flow reserve was significantly lower in both groups of CCTGA than in the control group (mean (SD) 2.5 (0.28) in group A, 2.6 (0.48) in group B, and 4.0 (0.73) in the control group; p < 0.001). CONCLUSION: Blood flow measurements suggest that coronary reserve is decreased in the absence of ischaemic symptoms in patients with CCTGA. The global impairment of stress flow dynamics may indicate altered global vasoreactivity, and quantitative changes in microcirculation suggest that their role in the pathogenesis of systemic right ventricular dysfunction is important.

Alterations of myocardial presynaptic sympathetic innervation in patients with multi-vessel coronary artery disease but without history of myocardial infarction.

In patients with myocardial infarction, left ventricular sympathetic denervation exceeds the size of the scar tissue. However, little is known about the regional innervation in patients with coronary artery disease (CAD) but no myocardial infarction. Using positron emission tomography (PET) with N-ammonia and C-hydroxyephedrine (HED), resting perfusion and presynaptic sympathetic innervation were studied in eight patients (seven males, one female; 58+/-9 years) with multi-vessel CAD and no history of myocardial infarction. Using polar map analysis of the PET data, the results were regionally compared with normal databases. The mean HED retention was 8.0%+/-2.0% x min(-1). Myocardial resting perfusion was normal in 23 of 24 vascular territories. Despite normal resting perfusion, significantly reduced HED retention, indicating dysinnervation, was found in 14 of 23 (61%) vascular territories (six of eight patients). Of the dysinnervated territories, 11 (79%) showed angiographically severe stenosis (>or=90% of native vessel/coronary artery bypass graft), eight (57%) showed ischaemia (myocardial perfusion scintigraphy/stress-electrocardiogram) and 12 (86%) had been revascularized. Of the nine segments with normal innervation, two (22%) revealed severe stenosis, two (22%) showed ischaemia and seven (78%) had been revascularized. It can be concluded that, in patients with advanced CAD and normal left ventricular function, dysinnervation can occur in the absence of myocardial infarction. This is consistent with the hypothesis that sympathetic neurones are more susceptible than myocytes to ischaemic damage.

Myocardial perfusion and coronary flow reserve assessed by positron emission tomography in patients after Fontan-like operations.

Ventricular dysfunction in patients after Fontan-like operations (FLOs) is a serious complication that might contribute to poor long-term results. Ischemic heart disease will have debilitating consequences on a Fontan heart. Ten patients (15.8 +/- 5.01 years) after FLO had transesophageal echocardiography and cardiac catheterization 9.3 +/- 4.2 years after surgery. Myocardial perfusion was assessed by NH3-positron emission tomography (rest/adenosine) and compared with that of 10 healthy adults (26.1 +/- 6.3 years). Ventricular function was normal in 4 and reduced in 6 patients; end systolic and end diastolic meridional wall stress was significantly elevated in the FLO group. Coronary angiography revealed no stenosis of the coronaries. Compared to normals, myocardial blood flow (MBF) at rest was higher in the FLO group (0.99 +/- 0.25 vs 0.77 +/- 0.17 ml/g/min, p <0.05), whereas MBF after vasodilatation (2.12 +/- 0.78 vs 3.10 +/- 0.85 ml/g/min, p <0.05) and coronary flow reserve (CFR) was reduced (2.5 +/- 0.88 vs 4.1 +/- 1.01, p <0.05), especially in those with impaired ventricular function. Coronary vascular resistance after vasodilatation was elevated in the FLO group (38.2 +/- 17.4 vs 24.5 +/- 8.3 mmHg/ml/g/min, p <0.05). Altered MBF, increased meridional wall stress, and impaired CFR are common findings in FLO. Attenuated CFR and reduced ventricular function are significantly correlated and may be risk factors for the long-term outcome.

Myocardial blood flow and flow reserve in response to short-term cyclical hormone replacement therapy in postmenopausal women.

OBJECTIVES: To measure the effects of combined cyclical hormone replacement therapy (HRT) on myocardial blood flow (MBF) in postmenopausal women at high risk for coronary heart disease (CHD) and in women with documented CHD. BACKGROUND: Estrogen restores endothelium-dependent vasodilation in response to acetylcholine in postmenopausal women, and it has a direct, endothelium-independent vasodilatory effect on coronary arteries. METHODS: To determine whether coronary microcirculation can be affected by short-term, combined HRT, we performed positron emission tomography (PET) in two groups of women without previous HRT. Group I (n = 10) had one or more risk factors for CHD; group II (n = 8) had documented CHD and previous myocardial infarction. Group II was older (54 +/- 4 vs 59 +/- 5 y, P = .03) and had lower total cholesterol levels at baseline because of lipid-lowering therapy (244 +/- 31 vs 203 +/- 40 mg/dL, P = .03). Patients underwent baseline dynamic PET with N-13 ammonia at rest and during maximal adenosine-induced hyperemia to assess MBF. Each then began taking HRT (conjugated equine estrogen alone or with medroxyprogesterone acetate (MPA), administered in cyclical fashion), and returned for follow-up PET 46 +/- 12 days later. RESULTS: There was no difference in resting MBF between groups I and II prior to starting therapy or at follow-up. Stress MBF and flow reserve (FR) tended to be higher in group I patients at baseline. MBF values remained unchanged at follow-up and resulted in similar FR values at baseline and during HRT for both groups. Women using only estrogen (n = 6) tended to show higher FR values after estrogen therapy, however. CONCLUSIONS: Short-term HRT in postmenopausal women did not lead to improvements in MBF or FR. Combined cyclical HRT may not exert measurable effects on coronary microcirculation. MPA may attenuate estrogen effects on the coronaries, which may be largely endothelium-dependent.

Myocardial blood flow and flow reserve after coronary reimplantation in patients after arterial switch and ross operation.

BACKGROUND: Coronary reimplantation is used in therapy for congenital heart disease, such as in the arterial switch (ASO) and Ross operations. The adequacy of myocardial perfusion may remain a matter of concern. The aim of the present study was to stratify the effect of coronary reimplantation on myocardial perfusion and to highlight the clinical relevance of any attenuation in myocardial perfusion. METHODS AND RESULTS: A total of 21 children with transposition of the great arteries at a mean interval of 11.2+/-2.9 years after ASO and 9 adolescents at a mean interval of 4.2+/-2.1 years after the Ross procedure were investigated. All patients were asymptomatic and had a normal exercise capacity. On stress echocardiography, 2 of the ASO patients had dyskinetic areas within the left ventricular myocardium, and 5 had adenosine-induced perfusion defects on positron emission tomography. No coronary obstruction was detected on coronary angiography in any patient, but a common finding was right coronary dominance and a small caliber of the distal part of the left anterior descending artery. Coronary flow reserve (CFR) was significantly reduced in all patients after ASO when compared with 10 normal healthy volunteers (age, 25.6+/-5.3 years). CFR was normal in the 9 patients who had the Ross operation (age, 19.2+/-7.6 years); exercise-induced perfusion defects were not detected in the Ross patients. CONCLUSIONS: Children after ASO are asymptomatic, without clinical signs of coronary dysfunction. In contrast to patients who had the Ross operation, stress-induced perfusion defects and an attenuated CFR were documented. The prognostic implications of these findings and the clinical consequences are unclear; nevertheless, close clinical follow-up of ASO patients is mandatory.

Preoperative evaluation of pancreatic masses with positron emission tomography using 18F-fluorodeoxyglucose: diagnostic limitations.

Identification of pancreatic cancer in patients presenting with an enlarged pancreatic mass is a major diagnostic problem. Positron emission tomography (PET) using the radiolabeled glucose analogue 18F-fluorodeoxyglucose (FDG) has been suggested to provide excellent accuracy for noninvasive determination of suspicious pancreatic masses. We conducted a prospective study to verify these results. Forty-two patients admitted for pancreatic surgery underwent PET scanning. Image analysis was based on visual film evaluation and quantification of regional tracer uptake. PET imaging was visually analyzed by three observers blinded for the results of other diagnostic tests; they qualitatively graded the scans using a five-point scale (I = low to V = high) for the presence and intensity of focal FDG uptake. Diagnosis was proven by histology (n = 38) or follow-up (n = 4). Furthermore, the results of PET were compared with helical computed tomography (CT) and conventional ultrasonography (US), done during the routine diagnostic workup before pancreatic cancer surgery. Regarding only the results with scores of IV and V as positive for representing definite malignancy yielded a sensitivity of 71% and a specificity of 64% for film reading. Quantification of regional tracer uptake contributed no significant diagnostic advantage for differentiation between benign and malignant tumors. Helical CT revealed a sensitivity of 74% and a specificity of 45.5% and abdominal US 56% and 50%, respectively. We concluded that PET imaging provides only fair diagnostic accuracy (69%) for characterizing enlarged pancreatic masses. PET does not allow exclusion of malignant tumors. In doubtful cases, the method must be combined with other imaging modalities, such as helical CT. The results indicate that the number of invasive procedures is not significantly reduced by PET imaging.