Position statement on the non-invasive diagnosis of patients with ATTR pardiac amyloidosis, endorsed by the Hellenic Society of Nuclear Cardiology, for the Nuclear Medicine practitioners.

Cardiac amyloidosis is a rare condition characterized by the accumulation of abnormal proteins called amyloids in the heart tissue. These amyloids can disrupt the normal functioning of the heart and lead to a variety of symptoms and complications.

Level of patient and operator dose in the largest cardiac centre in Greece.

The objective of this study was to investigate the patient and staff doses in the most frequent interventional cardiology (IC) procedures performed in Onassio, the largest Cardiac Centre in Greece. Data were collected from three digital X-ray systems for 212 coronary angiographies, 203 percutaneous transluminal coronary angioplasties (PTCA) and 134 various electrophysiological studies. Patient skin dose was measured using suitably calibrated slow radiotherapy films and cardiologist dose using suitably calibrated thermoluminescent dosemeters placed on left arm, hand and foot. Patient median dose area product (DAP) (all examinations) ranged between 6.7 and 83.5 Gy cm2. Patient median skin dose in PTCA was 799 mGy (320-1660 mGy) and in RF ablation 160 mGy (35-1920 mGy). Median arm, hand and foot dose to the cardiologist were 12.6, 27 and 13 microSv, respectively, per procedure. The great range of radiation doses received by both patients and operators confirms the need for continuous monitoring of all IC techniques.

Coronary flow velocity changes after intravenous dipyridamole infusion: measurements using intravascular Doppler guide wire. A documentation of flow inhomogeneity.

OBJECTIVES: This study assessed changes in coronary flow velocity measured distal to a significant stenosis of the left anterior descending coronary artery and at the adjacent normal left circumflex coronary artery, produced by intravenous administration of dipyridamole, in patients undergoing coronary angioplasty with a documented perfusion defect on dipyridamole-thallium-201 scintigraphy. BACKGROUND: Significant flow inhomogeneity is believed to develop during coronary vasodilation induced by dipyridamole, causing a defect in the thallium-201 scintigram. The recently developed intracoronary Doppler guide wire permits assessment of flow velocity variables in normal and stenotic arteries. METHODS: In 17 patients with stable angina we studied changes in time-averaged peak velocity and the diastolic/systolic velocity ratio simultaneously using two 0.014-in. (0.36-mm) Doppler guide wires at baseline and after 4 min of dipyridamole infusion (0.56 mg/kg body weight). Coronary flow velocity reserve and relative flow reserve were correlated with the degree of stenosis on coronary angiography and quantitative analysis of thallium-201 images. RESULTS: No changes in distal flow velocity was observed in the stenotic vessel (5.5 +/- 33.7% [mean +/- SD]), in contrast to a significant increase observed in the adjacent normal vessel (162.4 +/- 39.8%). Poststenotic coronary flow velocity reserve correlated with percent lumen diameter stenosis (r = -0.66, p < 0.05). A correlation was also observed between the relative flow reserve/thallium-201 relative perfusion ratio (r = 0.90, p < 0.001). CONCLUSIONS: To our knowledge, these findings represent the first direct proof of dipyridamole-induced flow inhomogeneity producing a perfusion defect on thallium-201 imaging. The degree of inhomogeneity is related to the extent of the perfusion defect.

Simultaneous perfusion tomography and radionuclide angiography during dobutamine stress.

UNLABELLED: The purpose of this investigation was to evaluate the changes in left ventricular function and volumes concurrently with tomographic myocardial perfusion during dobutamine infusion. METHODS: Ninety-two patients underwent first-pass radionuclide angiography using a multicrystal gamma camera and myocardial tomography after high-dose (40 micrograms/kg/min) dobutamine infusion and 99mTc-sestamibi administration. RESULTS: Dobutamine increased systolic blood pressure (p < 0.0001), heart rate (p < 0.00017), left ventricular ejection fraction (p = 0.0001), cardiac output (p = 0.0001) and stroke volume (p = 0.042). The end-diastolic (p = 0.009) and end-systolic volumes (p = 0.0007) significantly decreased. Of 38 patients with cardiac catheterization, 28 had significant coronary artery disease and 10 had normal coronaries. The sensitivity and specificity for coronary artery disease detection by myocardial perfusion tomography were 78% and 90%, respectively. By radionuclide angiography, only 9 of 27 coronary artery disease patients experienced deterioration of wall motion during dobutamine (sensitivity 33%). CONCLUSION: Changes in myocardial perfusion are more sensitive than changes in left ventricular function for detecting coronary artery disease during dobutamine stress.

Cardiac denervation after radiofrequency ablation of supraventricular tachycardias.

Inappropriate sinus tachycardia and atrial arrhythmias have been reported after radiofrequency ablation. Previous studies have suggested that cardiac denervation is a possible explanation for these rhythm disturbances. The aim of this study was to investigate possible alterations in autonomic innervation of the heart after ablation using the techniques of heart rate variability (HRV) analysis and metaiodobenzylguanidine (I-123 MIBG) scintigraphy. The subjects of this study were 30 consecutive patients aged 25 to 40 years, without structural heart disease, who underwent radiofrequency ablation of atrioventricular nodal slow pathways, and posteroseptal and left lateral accessory pathways because of symptomatic recurrent reentrant tachycardias. Time and frequency domain analysis of HRV after ablation revealed a significant reduction in the indexes of the mean of all 5-minute standard deviation of RR intervals (p = 0.042), low frequency (p = 0.0005), and total frequency (p = 0.008) compared with preablation values in the group of patients who underwent atrioventricular nodal slow pathway ablation. Patients who underwent ablation of a posteroseptal accessory pathway also had significant attenuation of the indexes of standard deviation about the mean RR interval (p = 0.03), standard deviation of 5-minute mean RR intervals (p = 0.006), and low-frequency (p <0.0001), and high-frequency (p <0.0001) components. Significant I-123 MIBG map defects, indicating efferent cardiac sympathetic denervation, were also found in the same groups of patients: atrioventricular nodal group (p = 0.0024), posteroseptal accessory pathway group (p = 0.0007). None of the above changes in HRV and 123-I MIBG scintigraphy were seen in patients who underwent ablation of left lateral accessory pathways. We conclude that radiofrequency ablation in the anterior, mid-, and posterior regions of the low intraatrial septum may disrupt sympathetic fibers located in these regions, causing cardiac sympathetic denervation. The density of these fibers appear to be less along the left atrioventricular groove.

Comparison of a conventional and a flat-panel digital system in interventional cardiology procedures.

The purpose of the study was to analyse the technical characteristics of a newly installed flat-panel fluoroscopy (FPF) system in an interventional cardiology (IC) department and compare it with an older conventional system. A patient survey was performed to investigate the radiation doses delivered by the X-ray systems. Finally, methods of technique optimization regarding the new digital system were investigated. Dose rates in all fluoroscopic and cine modes were measured and image quality assessed using a dedicated test tool. 200 patients were investigated, half using the conventional and half using the digital FPF system. Patient data collected were: sex, age, weight, height, dose-area product (DAP), fluoroscopy time (T) and total number of frames (F). Our results are: (1) Digital FPF system: high contrast resolution (HCR) is not affected by fluoroscopic mode, whereas low contrast resolution (LCR) is slightly decreased in the low mode. (2) The digital FPF system has 2.5 times better HCR than the conventional system, with 5 times lower dose in the fluoroscopy mode. (3) Median values of DAP, T and F, respectively, in coronary angiography (CA) are: 27.7 Gycm(2), 4.1 min and 876 for the digital and 39.3 Gycm(2), 5.3 min and 1600 for the conventional system. Median values for percutaneous transluminal coronary angioplasty (PTCA) are: 51.1 Gycm(2), 12.7 min and 1184 for the digital and 44.3 Gycm(2), 7.4 min and 1936 for the conventional system. Digital DAP in CA is reduced by 30%, suggesting that a dose reduction in the FPF system is possible. The results of the study concerning the FPF system lead to the conclusion that the lowest fluoroscopic mode and the lowest frame rate should be used in routine practice.

Patient dose values in a dedicated Greek cardiac centre.

The purpose of this study was to collect information on the practice and patient doses in a major Greek cardiac centre, investigate differences between senior cardiologists of various levels of experience and compare results with the literature, in order to optimize angiographic and interventional cardiology procedures. Radiation doses from 292 patients have been studied, 195 of which had undergone coronary angiography and 97 percutaneous transluminal coronary angioplasty. All procedures were undertaken on a Siemens Angioscop X-ray equipment. The system performed under automatic exposure control using pulsed fluoroscopy of 12.5 pulses s(-1) and cine frame rate of 25 frames s(-1). Dose-area product values, fluoroscopy times, total number of cine frames as well as operator's name were collected for each patient. Only senior cardiologists have participated in the study. Median values for dose-area product were 39.1 Gy cm(2) for coronary angiography and 58.3 Gy cm(2) for percutaneous transluminal coronary angioplasty. Median fluoroscopy time was 5.0 min and 9.7 min and median number of frames was 1588 and 1823 for coronary angiography and percutaneous transluminal coronary angioplasty, respectively. Comparison showed that patient dose-area product values were lower than other studies and fluoroscopy time values were comparable. However, the total number of frames used was much higher than other published results. Differences between cardiologists with increased experience have been found. Analysis of the patient dose values obtained initiated a program of radiation protection optimization. The need for continuous training in radiation protection for interventionalists has been verified.

Recombinant interferon-alpha therapy for acute hepatitis B: a randomized, double-blind, placebo-controlled trial.

In spite of the availability of hepatitis B vaccine, acute hepatitis B continues to be a worldwide problem for which no specific therapy is available. We investigated the safety and the effectiveness of recombinant interferon-alpha2b (rIFN-alpha2b) in the treatment of acute hepatitis B by determining overall severity and duration of symptoms, time required to clear viral antigens and hepatitis B virus (HBV) DNA, and titre of antibodies to hepatitis B surface antigen (HBsAb), 24 weeks after the onset of therapy. One hundred patients were randomly assigned to treatment with either 3 million units (MU) (n = 34) or 10 MU (n = 33) rIFN-alpha2b or to placebo (n = 33), three times weekly for 3 weeks. Follow-up was for 24 weeks. A significantly shorter duration of the symptoms and signs of acute hepatitis was observed in patients who received 3 MU rIFN-alpha2b compared with those who received 10 MU rIFN-alpha2b or placebo. Twenty-one weeks post-therapy, patients treated with 10 MU rIFN-alpha2b showed a significantly higher geometric mean HBsAb titre than those treated with placebo (85.1 vs 35.5 IU l-1, P < 0.05). rIFN-alpha2b administration was well tolerated even in jaundiced patients. No serious side-effects were observed necessitating reduction in dose or discontinuation of the drug. The effect of rIFN-alpha2b on transition of HBV infection to chronicity could not be evaluated in this trial because such an unfavourable course was not seen in any of the treated or the control patients. In conclusion, rIFN-alpha2b was safe in acute hepatitis B, and at low dose was found to ameliorate symptoms and to shorten significantly the duration of illness.

Quantitative detection of hepatitis B virus DNA in sera from patients with acute hepatitis B.

Two hundred forty-four serial serum samples from 30 adults hospitalized with benign (nonfulminant) acute hepatitis B were tested for the presence of hepatitis B virus (HBV) DNA by a quantitative solution hybridization assay using a 125I-labeled DNA probe complementary to HBV-DNA sequences. Acute hepatitis B was self-limiting in 28 and progressed to chronicity in the remaining two patients. Of the 28 patients with self-limiting hepatitis, 21 (75%) were hepatitis B e antigen (HBeAg) positive, 26 (93%) were HBV-DNA positive, and one patient (3.6%) was negative for both markers on admission to the hospital. HBV-DNA cleared after HBeAg clearance in 20 (71.4%), before HBeAg clearance in five (17.9%) and simultaneously with the loss of HBeAg in the remaining two (7.1%) of the 27 initially HBV-DNA- and/or HBeAg-positive patients. Moreover, HBV-DNA remained detectable in serum for 13.3 +/- 6.6 (range: 4-22) days after the appearance of anti-HBe in 71.4% of these patients. In contrast, HBV-DNA and HBeAg remained persistently positive in the two patients who developed chronic HBV infection. These data show that (1) viremia frequently persists after disappearance of HBeAg and (2) appearance of anti-HBe does not indicate the cessation of HBV replication in adults with acute self-limiting hepatitis B.

Diagnostic significance of IgM antibody to hepatitis delta virus in fulminant hepatitis B.

The prevalence of hepatitis delta virus (HDV) infection was studied in 25 adult patients with fulminant hepatitis who were admitted consecutively to our unit from February, 1986, to September, 1988. Enzyme and radioimmunoassays were used for the detection of serological markers of HAV, HBV, and HDV (HDAg, IgM anti-HD, total [IgG] anti-HD) infections. Two hundred twenty-nine serum samples (three to 19 samples/patient) were tested for serological markers of HDV infection. Of the 25 patients, 17 (68%) were HBsAg-positive, and the remaining eight (32%) were HBsAg-negative on admission to the hospital. All patients were seropositive for IgM anti-HBc. Serological markers of HDV infection were detected in 13 (52%) of the 25 patients. In particular, HDV infection was observed in nine (53%) of the 17 HBsAg-positive and in four (50%) of the eight HBsAg-negative patients with type B fulminant hepatitis. Survival was 16.7% for patients with hepatitis B and 57.8% for patients with B and D coinfection. Coinfections were responsible for fulminant hepatitis in 100% of drug addicts and 40% in patients who were not drug addicts. All patients with HBV/HDV coinfections became seropositive for IgM anti-HD. The results show that HDV infection has a significant role (52%) in type B fulminant hepatitis in an area with a moderate prevalence of HBV infections, that it should be tested in cases with early clearance of HBsAg, and that it does not seem to be accompanied by a high fatality rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of hepatitis C virus in acute non-A, non-B hepatitis in Greece: a 5-year prospective study.

The prevalence of hepatitis C virus (HCV) infection in 182 prospectively followed adult patients (110 males, 72 females) with acute non-A, non-B hepatitis and its correlation with progression to chronic hepatitis were studied. These patients were followed for a mean of 24.7 +/- 13.1 (range, 6-57) months. By using a specific enzyme immunoassay for the detection of antibodies against C100-3 polypeptide of HCV, 96 (52.7%) were found antibody positive. HCV was implicated in 64/89 (71.9%) of the cases with classical parenteral exposure but only in 18/64 (28.1%) of the community-acquired cases. Progression to chronic hepatitis was observed more frequently in antibody-positive than in antibody-negative cases (60/96 or 62.5% vs. 27/86 or 31.4%, P = 0.00002). Progression was also observed more often in males than in females (66/112 or 58.9% vs. 21/70 or 30.0% P = 0.0001), both in the antibody positive (48/68 or 70.6% vs. 12/28 or 42.9%, P = 0.01) and in the antibody negative (18/44 or 40.9% vs. 9/42 or 21.4%, P = 0.043) cases. These data indicate that (a) acute hepatitis due to HCV is characterized by a high rate of chronicity, especially in males, and (b) a non-A, non-B, non-C agent or a different strain of HCV may be responsible for the majority of the community-acquired cases of non-A, non-B hepatitis in Greece.

Case report: role of hepatitis E virus in the etiology of community-acquired non-A, non-B hepatitis in Greece.

The aim of this study was to determine the frequency of hepatitis E virus (HEV) infection in a population of Greek adults with community-acquired (sporadic) non-A, non-B hepatitis found to be seronegative for antibodies to hepatitis C virus (anti-HCV). All patients admitted to the Liver Unit of Western Attica General Hospital and diagnosed as having acute community-acquired non-A, non-B hepatitis between February, 1986, and May, 1990, were enrolled in follow up studies (n = 66). Nineteen patients with HCV infection and 11 patients with acute non-A, non-B, non-C hepatitis that progressed to chronicity were excluded. Convalescent sera were tested for antibody to HEV (anti-HEV) by a fluorescent antibody blocking assay in 33 of 36 eligible patients. One of the 33 (3%) patients was found to be positive for anti-HEV. Anti-HEV testing of all 20 available serum specimens from this patient showed evidence of anti-HEV seroconversion at the fourth week after the onset of hepatitis. The patient had not travelled abroad or within Greece or had not had apparent contact with people from foreign countries for the previous 3 months. These data show that HEV infection is not a major cause of community-acquired non-A, non-B hepatitis in Greece. However, the reported case of HEV hepatitis suggests that HEV may retain a low endemicity in Greece. More extensive seroprevalence studies are needed for an accurate estimation of the extent of HEV infection in the southeastern European countries.

Prognostic value of exercise 201Tl tomography in patients treated with thrombolytic therapy during acute myocardial infarction.

BACKGROUND: Although myocardial perfusion scintigraphy is of proven value in the risk stratification of patients with a recent myocardial infarction who receive conventional therapy, its value in patients undergoing thrombolytic therapy remains controversial. METHODS AND RESULTS: Seventy-one patients who received thrombolytic therapy for acute myocardial infarction had exercise 201Tl tomography and coronary angiography before hospital discharge. Eleven (15%) of 71 patients had ischemic ST-segment depression during exercise, whereas 27 patients (38%) had scintigraphic ischemia. Twenty-five (37%) of 68 patients had a cardiac event consisting of either death (n = 2), recurrent myocardial infarction (n = 5), congestive heart failure (n = 7), or unstable angina (n = 11) during a follow-up of 26 +/- 18 months. Univariate predictors of cardiac events were as follows: Killip class (P = .04); left ventricular ejection fraction (P < .0005); total (P = .002) and ischemic (P < .0005) perfusion defect size; percent thallium lung uptake (P = .001); presence of infarct-zone redistribution (P = .02); and multivessel coronary artery disease (P = .01). By multivariate analysis, the significant joint predictors of risk were ejection fraction (P < .0005) and ischemic perfusion defect size (P = .005). The combination of ejection fraction and thallium tomography added significant incremental prognostic information to the clinical data, whereas angiography did not further improve a model that included clinical, ejection fraction, and tomographic variables. CONCLUSIONS: Quantitative exercise 201Tl tomography provides important incremental, long-term prognostic information in patients receiving thrombolytic therapy for acute myocardial infarction.

Preoperative risk stratification by adenosine thallium 201 single-photon emission computed tomography in patients undergoing vascular surgery.

BACKGROUND: Adenosine perfusion scintigraphy is a powerful technique for diagnosing coronary artery disease and risk stratifying patients with recent myocardial infarction. METHODS AND RESULTS: We investigated the use of adenosine 201Tl tomography to risk stratify 106 patients undergoing vascular arterial reconstruction consisting of lower limb arterial grafting in 44, aortic aneurysmectomy in 36, and carotid endarterectomy in 26 patients. Abnormal tomograms occurred in 57 patients (54%), 47 (82%) of whom had reversible perfusion defects. There were three postoperative deaths, all in the group that underwent aortic aneurysmectomy. Another patient with an aortic aneurysm had unstable angina and one patient who underwent lower limb arterial surgery had pulmonary edema after surgery. No patient without transient defects had an event (negative predictive value 100%). Cardiac events occurred only in patients with transient perfusion defects. However, only 5 of 47 such patients had events (positive predictive value 11%). The perfusion defect size (23% +/- 14% vs 8.9% +/- 135; p = 0.034) and the ischemic fraction (20% +/- 16% vs 5.6% +/- 8.9%; p = 0.009) were 2.5- and 3.5-fold larger, respectively, in patients with than in those without events. A history of diabetes mellitus or previous infarction did not enhance the predictive value of the test. CONCLUSION: Thus absence of reversible hypoperfusion during adenosine scintigraphy ensures virtual absence of postoperative cardiac events. Patients undergoing aortic aneurysmectomy may be targeted preferentially for risk-stratification strategies in the future.

Differential diagnosis of acute HBsAg positive hepatitis using IgM anti-HBc by a rapid, fully automated microparticle enzyme immunoassay.

BACKGROUND/AIMS: We determined the diagnostic significance of IgM anti-HBc by a rapid, fully automated microparticle enzyme immunoassay (IMx CORE-M) in acute HBsAg positive hepatitis. METHODS: We studied prospectively for at least 6 months 100 patients with acute self-limited hepatitis B (group A) and 40 patients with acute hepatitis superimposed on histologically confirmed chronic hepatitis B (group B). On admission, all patients in group A were positive and those in group B were negative for IgM anti-HBc by a commercially available enzyme immunoassay. RESULTS: Based on the assay criteria, the rates of IMx CORE-M (> 1.2) positive serum samples on admission, 4, 12 and 24 weeks later were: in group A: 100%, 95%, 72%, 44% and in group B: 20%, 27.5%, 17.5%, and 15%, respectively. Misclassification was observed in 20-27.5% of the acute on chronic hepatitis B cases. However, the mean IMx CORE-M index value was found to be significantly higher in group A during the whole follow-up. In particular, on admission the mean IMx CORE-M index value was 2.504 +/- 0.435 (range: 1.508-3.482) in group A and 0.747 +/- 0.346 (range: 0.062-1.384) in group B (p < 0.001). Discriminant function analysis showed that the cutoff level between the two groups for IMxCORE-M index on admission was 1.5. Four to 12 weeks from admission, in the group with acute on chronic hepatitis B cases, 13 patients with HDV and/or HCV superinfection had significantly lower IMx-CORE M index values compared with 27 patients with acute hepatitis due to exacerbation of chronic hepatitis B. CONCLUSIONS: IMx CORE-M appears to be an accurate diagnostic test to differentiate acute from acute on chronic HBsAg positive hepatitis, but the cut-off level seems to be higher (1.5 instead of 1.2).

Recombinant human interferon alfa-2b treatment for acute non-A, non-B hepatitis.

To assess the safety and possible efficacy of recombinant human interferon alfa-2b in preventing the development of chronic hepatitis, 24 adults (eight men, 16 women) with acute non-A, non-B (NANB) hepatitis were recruited to a pilot study. Half of the cases were parenterally transmitted and half were community acquired. Twelve patients received 3 million units (MU) interferon three times weekly subcutaneously for six weeks and the remaining 12 patients received no treatment. Anti-hepatitis C virus (HCV) was detected in 14 (58.3%) of the 24 patients. The alanine aminotransferase activity returned to normal in nine of 12 interferon alfa-2b treated patients and six of 12 controls by week 52. Interferon alfa-2b was well tolerated, even in jaundiced patients, who only complained of mild flu like syndrome during the first week of treatment. These data are consistent with the hypothesis that interferon alfa-2b may help prevent progression to chronic hepatitis (interferon alfa-2b 25% v controls 50%), particularly in anti-HCV negative cases (interferon alfa-2b none of six v controls two of four). A randomised, double blind placebo-controlled trial is required, however, to substantiate these results further.