Nuclear Cardio-Oncology.

Nuclear cardio-oncology is a specialized field that combines aspects of nuclear medicine, cardiology, and oncology to diagnose and manage cardiovascular complications in cancer patients. It focuses on the assessment of cardiovascular health and the detection of potential heart-related side effects caused by cancer treatments.

Transthyretin (Pro24Ser) variant amyloidosis: A case report of the first patient in Greece.

OBJECTIVE: Transthyretin cardiac amyloidosis (ATTR-CA) is a rare and potentially fatal disease caused by the accumulation of insoluble transthyretin (TTR) amyloid fibrils in the heart. The symptoms of ATTR-CA are often non-specific, often leading to underdiagnosis. Early diagnosis and treatment have a significant impact on disease progression and mortality. CASE PRESENTATION: In this case we report a 73-year-old male presented with dyspnea on exertion. The patient had a medical history of peripheral neuropathy, bilateral carpal tunnel syndrome, spinal fusion, and a family history of coronary artery disease. Upon his presentation at the Cardiology department, cardiac echo study revealed left and right ventricular hypertrophy with pulmonary hypertension, diastolic dysfunction and a restrictive pattern. Because of the high probability of amyloidosis, the patient underwent a technetium-99m-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) bone scintigraphic study, which confirmed the diagnosis of ATTR-CA. Transthyretin gene sequencing analysis revealed the rare p. Pro24Ser pathogenic variant. Final diagnosis was ATTR-CA associated with the proline replaced by serine at position 24 (Pro24Ser) TTR variant, which is rare and only a few cases have been reported worldwide. The patient was treated with tafamidis and inotersen and followed up. CONCLUSION: This case highlights the importance of considering amyloidosis as a differential diagnosis for non-specific symptoms and the need for early diagnosis and management of ATTR-CA.

Spleen visualization in both TTR and AL amyloidosis during 99mTc-DPD scintigraphy. Do we have to deal with a different than the myocardial uptake mechanism?

Technetium-99m- diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) is currently used in Europe for the diagnosis of cardiac amyloidosis, being able to distinguish light chain (AL) from transthyretin (TTR) type. We are reporting obvious spleen visualization in two patients suffering the first from proven TTR and the second from AL type of cardiac amyloidosis, with myocardial uptake-as anticipated-only in the first one. We raise the hypothesis that a common uptake mechanism exists for the spleen amyloid regardless of the type of the disease (AL or TTR), and is possibly different than the cardiac uptake mechanism.

Unusually seen pattern of 99mTc-DPD soft tissue uptake in a patient with AL amyloidosis. Is it an amyloid type indicator in specific cases?

Technetium-99m (99mTc)-labeled pyrophosphate (PYP) and 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) are currently the most established imaging agents for the diagnosis of cardiac amyloidosis, being able to distinguish light chain (AL) from transthyretin (TTR) type of the disease. We present a pattern of increased uptake in all soft tissues, sparing the organs that are usually most affected.

The prognostic significance of stress-only myocardial perfusion scan: A 5 year observational study.

OBJECTIVE: Stress-only myocardial perfusion imaging protocol has a prognostic value similar to that of a stress-rest protocol. The aim of the study was to assess stress myocardial perfusion by gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (GSMPI) in patients who had a normal stress-only study 4.9 years (mean time) before and assess the possible influence of various factors on the results. SUBJECTS AND METHODS: Three hundred and forty patients who had a normal stress-only study in the past, were reexamined with GSMPI after a mean period of 4.9 years. RESULTS: Thirty out of 340 patients (8.8%) had an ischemic result on stress and were therefore submitted to a rest study. Differences between normal and pathological results across levels of potential prognostic factors (age, gender, diabetes mellitus, dyslipidemia, arterial hypertension, smoking and family history), symptoms,left ventricular ejection fraction (LVEF) on ultrasound (U/S), coronary angiography and pre-test probability did not prove statistically significant. On multivariable analysis patients with the combination of family history, diabetes mellitus and hypertension had a 10.7 times higher risk of a pathological scan than the patients without. DISCUSSION: The information delivered by stress-only GSMPI proved to be a prognostically reliable method for follow-up of low and intermediate pretest probability coronary artery disease (CAD) patients. CONCLUSION: The 91.2% of the patients with an initial normal stress-only GSMPI had a repeat normal stress-only GSMPI after a mean period of 4.9 years. The combination of family history, diabetes mellitus and hypertension increases the risk of a pathological scan significantly.

Gender-related differences in side-effects and hemodynamic response to regadenoson in patients undergoing SPECT myocardial perfusion imaging.

PURPOSE: To evaluate differences in side-effects and hemodynamic response between men and women undergoing regadenoson-stress SPECT myocardial perfusion imaging (MPI). METHODS: The initial population of the study included 858 consecutive patients who underwent regadenoson-stress MPI at our institution. These patients underwent prospective assessment and classification of regadenoson-induced side-effects in six categories and recording of heart rate (HR) and blood pressure (BP) before and after regadenoson administration. From this initial population, after adjustment with 1:1 propensity matching using gender as the dependent variable and age, BMI, diabetes mellitus, hypertension, smoking, presence of coronary artery disease, LVEF, baseline systolic and diastolic blood pressure (BP) and HR, on-going use of cardio-active medications during test, and abnormal MPI scan as independent variables, a population of 279 pairs of opposite gender was formed and studied. RESULTS: Compared with men, women had a significantly higher rate of any side-effect (71% vs. 58%, p = 0.002), chest pain (23% vs. 12%, p < 0.001), gastrointestinal discomfort (20% vs. 12%, p = 0.01), dizziness (12% vs. 5%, p = 0.002), and headache (20% vs. 13%, p = 0.03) and similar rates of dyspnea and other side-effects. Women demonstrated a higher median HR-response compared with men (41% (- 8, 127) vs. 34% (- 5, 106), p = 0.001) while men demonstrated a lower median systolic BP response (- 3% (- 27, 48) vs. 0% (- 36, 68), p = 0.02) compared with women. CONCLUSIONS: Gender is independently associated with a differential response to regadenoson with regard to overall side-effects and HR-response. These observations have the potential of important management and prognostic implications respectively.

Adenosine stress myocardial perfusion imaging in octogenarians: Safety, tolerability, and long-term prognostic implications of hemodynamic response and SPECT-related variables.

BACKGROUND: Evaluation of tolerability, safety, and prognostic implications of adenosine stress myocardial perfusion imaging (MPI) in octogenarians. METHODS: 370 octogenarians (49% known coronary artery disease) were studied. Hemodynamic response, MPI-related data, and rest-left ventricular ejection fraction (LVEF) based on echocardiography were registered per patient, and prospective follow-up was performed to document all-cause death (ACD), cardiac death (CD), myocardial infarction (MI), and late revascularization. RESULTS: No deaths or MIs were observed during adenosine infusion or the short-term post-infusion period. 86% of patients were able to tolerate a 6-minute infusion. All side effects terminated spontaneously after infusion cessation, except for one case of pulmonary oedema. After 9.3 years, there were 124 ACDs, 62 CDs, 16 MIs, and 35 revascularizations. Differences between survival curves of summed stress score (SSS)-based risk groups were significant for all end points (P < .001). SSS and LVEF were independent predictors of all end points (P ≤ .01) and lung uptake of cardiac end points. ΔHR <10 bpm (OR = 1.78, P = .004) and inability to increase HR by >10 bpm and decrease systolic blood pressure by >10 mmHg (OR = 2, P = .02) during adenosine infusion were independent predictors of ACD and CD, respectively. Hemodynamic response variables, SSS, and lung uptake provided incremental prognostic value over pre-test data for ACD and CD. CONCLUSIONS: In octogenarians, adenosine stress MPI is well tolerated and provides effective long-term risk stratification.

Stronger correlation with myocardial ischemia of high-sensitivity troponin T than other biomarkers.

BACKGROUND: Acute myocardial infarction (AMI) is considered a major cause of death and disability. Myocardial perfusion scintigraphy (MPS) as a non-invasive diagnostic imaging procedure and certain biomarkers associated with myocardial ischemia (ISCH), such as ischemia-modified albumin (IMA), neuropeptide Y (NPY), N-terminal pro b-type natriuretic peptide (NT-proBNP), and high-sensitivity troponin T (hsTnT) could probably aid in the detection of myocardial infarction. METHODS: Between December 2011 and June 2012, we prospectively analyzed patients who underwent a MPS study with the clinical question of myocardial ISCH. An exercise test was performed along with a MPS. Blood was drawn from the patients before exercise and the within 3 minutes from achieving maximum load and was analyzed for the aforementioned biomarkers. RESULTS: A total of 71 patients (56 men and 15 women) were enrolled with a mean age of 61 ± 12 years. Twenty-six patients (36.6%) showed reduced uptake on stress MPS images that normalized at rest, a finding consistent with ISCH. Between ISCH and non-ISCH groups, only hsTnT levels showed a significant difference with the highest levels pertaining to the former group both before (0.0075 ng/ml vs 0.0050 ng/ml, P = 0.023) and after stress exercise (0.0085 vs 0.0050, P = 0.015). The most prominent differences were seen in higher stages of the Bruce protocol (stress duration > 9.05 minutes - P < 0.017). None of the IMA, NPY, and NP-pro BNP showed significant differences in time between the two groups. CONCLUSIONS: Although IMA, NPY, and NT-pro BNP may not detect minor ischemic myocardial insults, serum hsTnT holds a greater ability of detecting not only myocardial infarction but also less severe ischemia. Further studies with larger cohorts of patients are warranted in order to better define the role of hsTnT as a screening tool for myocardial ischemia.

Tumor Protein p53 (TP53) Gene and Left Main Coronary Artery Disease.

Patients with left main (LM) coronary artery disease (CAD) are at the highest risk of cardiovascular events. We evaluated possible gene polymorphisms of tumor protein 53 ( TP53, rs1042522, p.Arg72Pro) that can differentiate LM-CAD from patients with more peripheral CAD (MP-CAD) and healthy participants (control group) in 520 individuals (LM-CAD, n = 175; MP-CAD, n = 185; and control group, n = 160). Patients with LM-CAD had the lowest Arg/Arg genotype frequency (36.0%) compared with the MP-CAD (57.3%) and control groups (61.9%), P < .001 for both comparisons. Similarly, the Arg allele was more frequent in the control group than in patients with MP-CAD (78.8% vs 73.2%; P = .007) and LM-CAD (78.8% vs 64.0%; P < .001). The Arg/Pro genotype was more frequent in the LM-CAD group compared with the MP-CAD and control groups (56.0, 31.9, and 33.8, respectively, P < .001 for both comparisons). Furthermore, the frequency of Arg/Arg genotypes was the lowest in the LM-CAD group compared with the MP-CAD and control groups. Knowing that TP53 is an antioncogene protein that acts as a tumor suppressor and regulator of apoptosis, the lowest frequency of Arg/Arg genotype observed in these high-risk patients may indicate lower protection from the atherosclerosis process. Replication studies are needed to evaluate this association.

Long-term prognostic implications of myocardial perfusion imaging in octogenarians: an all-comer, cohort study.

PURPOSE: Evaluation of the long-term prognostic value of myocardial perfusion imaging (MPI) in octogenarians. METHODS: Six hundred and twenty-nine octogenarians [51% previous myocardial infarction (MI) or revascularization] who underwent single-isotope MPI (78% 201Tl, 22% 99mTc-tetrofosmin) with exercise (38% Bruce, 2% leg ergometry) or pharmacologic (58% adenosine, 2% dobutamine) stress were studied. All patients had LVEF determined by echocardiography within 1 month from MPI. Myocardial perfusion scoring was performed on a 17-segment LV-model with a 5-point grading system and three summed stress score (SSS)-based risk categories were formed [high-(SSS > 12), low-(SSS < 4), medium]. Prospective follow-up was performed to document all-cause (ACD), cardiac death (CD), MI, and revascularization. Revascularization was used to censor follow-up in survival analysis regarding ACD, CD, and CD/MI. For analysis of the CD, MI, or late revascularization (LR) composite, only revascularizations within 3 months from MPI (early revascularizations) were used for censoring. RESULTS: After 9.3 years there were 187 ACDs, 86 CDs, 28 MIs, and 77 revascularizations, including 28 early revascularizations. Adjusting for LVEF and stress-modality type, SSS was identified as an independent predictor of ACD [HR 1.03 (1.01-1.05)], CD [HR 1.05 (1.03-1.08)], CD,MI [HR 1.05 (1.02-1.07)], and CD,MI or LR [HR 1.05 (1.03-1.07)] (p ≤ 0.001 in all cases). Increased lung uptake had independent prognostic value only for the CD, MI, or LR end-point [HR 3 (1.2-7.7), p = 0.02]. Survival modeling demonstrated that LVEF and SSS, but not non-perfusion scintigraphic data provided incremental prognostic value over pre-test available clinical and historical information for all end-points. Differences between Kaplan-Meier survival curves of SSS-based risk groups were significant for all end-points (p < 0.001 in all cases). CONCLUSIONS: In octogenarians, MPI provides effective long-term risk stratification, regardless of stress type used or underlying cardiac function.

Fast myocardial perfusion imaging with 99mTc in challenging patients using conventional SPECT cameras.

BACKGROUND: We attempted to validate the performance of a fast myocardial perfusion imaging (MPI) protocol in diagnostically challenging patients. METHODS: 78 patients with ΒΜΙ > 24.9, LVH or three vessels disease underwent two sequential gated-MPI studies. The first at 15 (Early Imaging, EI) and the second at 45 (Late Imaging, LI) minutes post 99mTc-injection, at both stress and rest. Counts over heart (H), liver (Liv) and subdiaphragmatic space (Sub) and image quality, and myocardial perfusion and function parameters were compared between the two protocols. Coronary angiography was performed within 2 months from MPI, and ROC analysis was used to compare the diagnostic accuracy for the detection of ≥50% diameter luminal stenosis. RESULTS: Quality was optimal-good in 93% of EI and 98% of LI studies (P = .12), H/Liv and stress H/Sub ratios were similar, but rest H/Sub ratio was lower in EI (P = .009). SSS [10 (0 to 46) vs 9 (0 to 36), P = .006] and SDS [3 (0 to 35) vs 2 (0 to 34), P = .02] were higher in EI protocol. LVEF, motion and thickening scores did not differ between the two protocols. A highly significant (P < .001) linear relationship with clinically negligible mean differences in Bland-Altman analysis was observed for all perfusion and function-related data. Sensitivity (EI 81%, LI 80%) and specificity (65% for both) did not differ (P = .23) between the two protocols. CONCLUSION: The fast protocol is technically feasible and diagnostically accurate compared to the established protocol in diagnostically challenging patients.

Risk stratification for large artery or chronic coronary artery disease-related ischemic stroke in octogenarians undergoing exercise stress myocardial perfusion imaging: A cohort study.

OBJECTIVES: To test, if in octogenarians, treadmill exercise with myocardial perfusion imaging (exercise-MPI) can risk stratify for large artery or chronic CAD-related ischemic stroke (LACCIS). METHODS: Exercise-MPI-related data of 237 octogenarians (55% prior MI or revascularization) without previous stroke were registered and prospective follow-up was performed to document LACCIS. LACCIS was defined as acute onset of neurological symptoms with CT/MRI findings of non-lacunar-type infarcts in the absence of atrial fibrillation or intracardiac embolic sources. RESULTS: After 7.3 years, 10 LACCIS were documented. SSS [HR 1.08 (1.02-1.13 95% CIs), SDS [HR 1.1 (1.04-1.16 95% CIs)], and non-sustained VT or transient AV block during exercise [HR 3.9 (1.7-9.0 95% CIs)] were predictors of LACCIS (P < .01 for all). A SSS threshold of 16 had 81% specificity for identification of future LACCIS and risk groups formed according to this cut-off had significantly different LACCIS-free survival (P = .015). CONCLUSION: Exercise-MPI in octogenarians can provide risk stratification markers for LACCIS.

Atherosclerotic and Non-Atherosclerotic Coronary Heart Disease in Women.

Atherosclerotic Coronary heart disease (CHD) and non-atherosclerotic CHD in individuals less than 50 years of age is considered a "men's case". Undoubtedly, premenopausal women develop atherosclerotic/non-atherosclerotic CHD relatively rarely compared with men. This is attributed mostly to the cardioprotective role of estrogens (mainly estradiol). Nevertheless, there are predisposing conditions, which also make young women vulnerable to develop atherosclerotic/non-atherosclerotic CHD. Women who have classical cardiovascular (CV) risk factors, such as hypertension, diabetes mellitus, smoking, obesity, and dyslipidaemia, are more likely to develop cardiac events, even at a young age. Moreover, there are also other conditions that cause acute coronary syndromes, even in the absence of coronary atheromatic plaques such as myocardial bridge, coronary artery dissection, coronary artery spasm, coronary artery embolism and congenital anomalies of coronary arteries. Also, autoimmune diseases, some of which are more prevalent in women can cause atherosclerotic/ non-atherosclerotic CHD. In this narrative review we have summarized some of the causes that predispose young women to develop atherosclerotic/non-atherosclerotic CHD.

Long-term prognostic value of myocardial perfusion imaging in octogenarians able to undergo treadmill exercise stress testing.

BACKGROUND: Although the use of myocardial perfusion imaging (MPI) for prognostic purposes in general population is well understood, its role in very elderly patients is not extensively studied. METHODS: 247 octgogenarians (79% male, 56% previous myocardial infarction-MI or revascularization) who underwent treadmill exercise testing (TET) with MPI were studied. TET and MPI-related data were registered per patient and prospective follow-up was performed to document all cause death (ACD), cardiac death (CD), non-fatal MI, and late revascularization (LR). Kaplan-Meier and Cox-regression analysis were used to compute event-free survival and identify significant predictors of these events. RESULTS: After 7.3 years there were 48 deaths, 17 CDs, 8 MIs, and 21 LRs. 69 patients were classified as high and 103 as low risk by SSS with annual cardiac mortality rates of 5% and 0.9%, respectively. Differences between survival curves of SSS-based risk groups were significant for ACD, CD, CD/MI, and CD/MI/LR. Summed stress (SSS) and difference scores were the only significant predictors of all endpoints. LVEF and transient ischemic LV dilatation were significant predictors of CD and CD/MI. LVEF and all MPI variables were associated with the CD, MI, and LR endpoint while only Duke treadmill score and angina severity demonstrated such a relationship among TET variables. CONCLUSIONS: In octogenarians, MPI provides effective long-term risk stratification for both hard (ACD, CD, CD/MI) and soft (CD/MI/LR) endpoints and should be preferred over simple TET.

Prognostic value of the Duke treadmill score in octogenarians undergoing myocardial perfusion imaging.

OBJECTIVES/BACKGROUND: Although Duke treadmill score (DTS) is the most widely used risk stratification method in younger patients undergoing exercise treadmill test (ETT) its specific value in the elderly is not established. METHODS: 137 patients aged ≥80 years who underwent ETT myocardial perfusion imaging (MPI) were studied. DTS and MPI (including summed stress scores, SSS) related data were registered per patient and follow up was performed to document cardiac death (CD), myocardial infarction (MI) and late (>3 months) revascularization (LR). Kaplan Meir and Cox regression survival analysis were employed to determine the prognostic value of DTS in relation to MPI data for these endpoints. RESULTS: After a median follow up duration of 6.7 years 28 deaths, 7 CDs, 4 non fatal MIs and 12 LRs were observed. Incidence rates of CD/MI were significantly different only between low and high risk SSS categories (p = 0.044). Risk groups by DTS had no significant differences in survival free of CD/MI (p = 0.743) in contrast to risk groups according to SSS (p = 0.026), while both DTS and SSS based risk groups had significantly different survival free of CD/MI or LR. SSS was a significant univariate predictor of both CD/MI (HR 1.088, p = 0.019) and CD/MI or LR (HR 1.095, p < 0.001), but DTS only of the latter endpoint (HR 0.909, p = 0.003). CONCLUSIONS: In octogenarians DTS was found to be a significant predictor of the LR related endpoint but not of the hard endpoint of CD/MI, in contrast to SSS which was a powerful predictor of both soft and hard cardiac endpoints.

For what endpoint does myocardial 123I-MIBG scintigraphy have the greatest prognostic value in patients with chronic heart failure? Results of a pooled individual patient data meta-analysis.

AIMS: The purpose of this study was to determine the most appropriate prognostic endpoint for myocardial (123)I-metaiodobenzylguanidine (MIBG) scintigraphy in patients with chronic heart failure (CHF) based on aggregate results from multiple studies published in the past decade. METHODS AND RESULTS: Original individual late (3-5 h) heart/mediastinum (H/M) ratio data of 636 CHF patients were retrieved from six studies from Europe and the USA. All-cause mortality, cardiac mortality, arrhythmic events, and heart transplantation were investigated to determine which provided the strongest prognostic significance for the MIBG imaging data. The majority of patients was male (78%), had a decreased left ventricular ejection fraction (31.1 ± 12.5%), and a mean late H/M of 1.67 ± 0.47. During follow-up (mean 36.9 ± 20.1 months), there were 83 deaths, 67 cardiac deaths, 33 arrhythmic events, and 56 heart transplants. In univariate regression analysis, late H/M was a significant predictor of all event categories, but lowest hazard ratios (HRs) were for the composite endpoint of any event (HR = 0.30, 95% CI 0.19-0.46), all-cause (HR = 0.29, 95% CI 0.16-0.53), and cardiac mortality (HR = 0.28, 95% CI 0.14-0.55). In multivariate analysis, late H/M was an independent predictor for all event categories, except for arrhythmias. CONCLUSIONS: This pooled individual patient data meta-analysis showed that, in CHF patients, the late H/M ratio is not only useful as a dichotomous predictor of events (high vs. low risk), but also has prognostic implication over the full range of the outcome value for all event categories except arrhythmias.

Reversible reduction of cardiac sympathetic innervation after coronary artery bypass graft surgery: an observational study using serial iodine 123-labeled meta-iodobenzyl-guanidine (MIBG) imaging.

OBJECTIVES: Various types of surgical and interventional procedures have been reported to cause cardiac sympathetic denervation. We aimed at evaluating the effects of coronary artery bypass grafting (CABG) in cardiac sympathetic innervation through meta-iodobenzyl-guanidine (MIBG) imaging. METHODS: MIBG imaging was performed in 21 patients with coronary artery disease (CAD) 1 day before and 1 week and 6 months after CABG with concomitant measurements of corrected QT interval. In each study we evaluated MIBG defect score in a 16-segment left ventricular model, MIBG-defect size (percent) from generated polar maps, and heart/mediastinum ratio. RESULTS: Mean MIBG defect score and size were increased (32 ± 9.5 vs 24 ± 5, P < .0001, and 49.5% ± 20.4% vs 37% ± 8.7%, P = .004, respectively) and mean heart/mediastinum ratio was reduced (1.5 ± 0.4 vs 1.9 ± 0.3, P < .0001) at 1 week after CABG. At 6 months these indices had no significant differences compared with their pre-CABG values. Mean corrected QT interval demonstrated no significant changes. Increase in MIBG score in the second imaging was associated with adverse events related to arrhythmia and myocardial dysfunction during the 6-month follow-up period in a binary logistic regression model. CONCLUSIONS: CABG is associated with clinically important but reversible reduction in cardiac sympathetic nerve function, with periprocedural effects (cardioplegia, hypothermia, ischemia, direct nerve injury) being possible mechanisms for this finding.

Bone marrow stem cell adherence into old anterior myocardial infarction: a scintigraphic study using Tl-201 and Tc-99m-HMPAO.

AIM: The precise localization of bone marrow stem cells (SCs) into the necrotic tissue after intracoronary infusion (ICI) may be important for the therapeutic outcome. This study aims to examine the correlation between Tl-201 and Tc-99m-hexa-methyl-propylene-amine-oxime (HMPAO) images. METHODS: Thirteen patients, aged 36-62 years, with an old, nonviable, anterior myocardial infarction (MI) and reduced myocardial contractility (LVEF <40%), underwent ICI of selected CD133(+) and CD133(neg)CD34(+) SCs. One hour after the ICI, SPECT imaging with Tc-99m-HMPAO was performed in all patients and the acquired images were compared with the images obtained during the initial imaging for demonstration of viability (myocardial perfusion imaging with pharmacologic stress and Tl-201). Furthermore, two fused bull's eye images of Tc-99m-HMPAO and Tl-201 rest reinjection were created in six patients and regions of interest were set on Tl-201 and Tc-99m-HMPAO bull's eye images. RESULTS: The comparison of the two sets of images revealed an intense accumulation of the SCs in the infarcted area with absence of viability as assessed by Tl-201 reinjection images. In the subset of patients in whom fused bull's eye images were produced, the comparison demonstrated that the percentage of the infarcted area with SCs' adherence was 83.2 ± 17%. CONCLUSIONS: Tl-201 images are complementary with the respective Tc-99m-HMPAO ones, revealing a precise localization of SCs in the infarcted area. Tc-99m-HMPAO labeling of SCs is a reliable method for cell monitoring after ICI in nonviable myocardium after an anterior MI.

Heart type fatty acid binding protein in relation to pharmacologic scintigraphy in coronary artery disease.

BACKGROUND: Heart-type fatty acid-binding protein (H-FABP) is a marker of myocardial necrosis, but whether it increases during myocardial ischemia is not known. This study investigated whether serum levels of H-FABP change during adenosine stress testing and nuclear imaging in patients with stable coronary artery disease. METHODS: Thirty stable patients with established coronary artery disease on their medications were studied. Sampling was performed before the stress test, at the end of adenosine infusion, as well as 1, 2 and 3 h after the completion of the infusion. RESULTS: No difference in H-FABP serum levels were found at the five pre-specified time points in the overall group (p=0.99); furthermore, there was no significant difference regardless of the test result--positive (p=1) or negative (p=0.98). CONCLUSIONS: It is concluded that H-FABP does not change significantly during pharmacologic stress testing in patients with known coronary artery disease and there is no difference whether there is inducible ischemia or not.

Disorders of the autonomic nervous system in patients with Brugada syndrome: a pilot study.

INTRODUCTION: The aim of this study was to examine autonomic disorders in patients with Brugada syndrome by performing a cardiac sympathetic innervation evaluation, a head-up tilt-test (HUT) and heart rate variability (HRV) analysis. METHODS AND RESULTS: We enrolled 20 patients with Brugada syndrome (mean age 42.5 +/- 8.8 years), 9 with spontaneous and 11 with an induced type 1 electrocardiogram (ECG) in the setting of symptoms and 20 age-matched controls. All subjects underwent a HUT with parallel measurements of plasma catecholamines and cortisol, a (123)I-metaiodobenzylguanidine single photon emission tomography, and HRV evaluation. Ten control subjects participated in the innervation portion of the study. The tilt-test with clomipramine challenge was positive in 15 of 20 (75%) patients (7 spontaneous, 8 induced) and in 1 in controls (P < 0.01). A sympathoadrenal imbalance was shown in positive tests. The pattern of innervation in all groups was heterogenic and similar to controls with a trend towards lower measurements in patients with a spontaneous type 1 ECG and a positive HUT. HRV analysis did not reveal any significant differences during day and night. Four patients (20%) had sustained ventricular arrhythmias during a follow-up of 31.1 +/- 8.6 months, but no correlations with innervation or response to tilting were found. CONCLUSION: A high susceptibility to vasovagal syncope was observed in patients with Brugada syndrome, which could be disease-related symptoms. Conversely, sympathetic innervation was observed to follow a physiological, heterogenic pattern; however, these factors did not have prognostic value for life-threatening arrhythmias.