126 research outputs found
Ischemia burden on stress SPECT MPI predicts long-term outcomes after revascularization in stable coronary artery disease
Background: It is not entirely clear whether ischemia burden on stress single-photon emission computed tomography (SPECT) effectively identifies patients who have a long-term benefit from coronary revascularization. Methods: The study population consisted of 719 patients with ischemia on stress SPECT. Early coronary revascularization was defined as percutaneous coronary intervention or coronary artery bypass grafting β€90 days after SPECT. Patients who underwent late revascularization (>90 days after SPECT) were excluded (n = 164). Results: Of the 538 patients (73% men, mean age 59.8 Β± 11 years), 348 patients had low ischemia burden (<3 ischemic segments) and 190 patients had moderate to high ischemia burden (β₯3 ischemic segments). A total of 76 patients underwent early revascularization. During a median follow-up of 12 years (range 4-17), 283 patients died of whom 125 due to cardiac causes. Early revascularization was beneficial on all-cause mortality (HR 0.46, 95% CI 0.30-0.46) and cardiac mortality (HR 0.54, 95% CI 0.29-0.99). Conclusions: Patients with myocardial ischemia on stress SPECT who underwent early revascularization had a lower all-cause mortality and cardiac mortality during long-term follow-up as compared to patients who received pharmacological therapy alone. This difference in long-term outcomes was mainly influenced by the survival benefit of early revascularization in the patients with moderate to high ischemia burden
Prevalence of myocardial viability assessed by single photon emission computed tomography in patients with chronic ischaemic left ventricular dysfunction
OBJECTIVE: To assess the prevalence of myocardial viability by
technetium-99m (Tc-99m)-tetrofosmin/fluorine-18-fluorodeoxyglucose (FDG)
single photon emission computed tomography (SPECT) in patients with
ischaemic cardiomyopathy. DESIGN: A retrospective observational study.
SETTING: Thoraxcenter Rotterdam (a tertiary referral centre). PATIENTS:
104 patients with chronic coronary artery disease and severely depressed
left ventricular function presenting with heart failure symptoms. MAIN
OUTCOME MEASURES: Prevalence of myocardial viability as evaluated by
Tc-99m-tetrofosmin/FDG SPECT imaging. Two strategies for assessing
viability in dysfunctional myocardium were used: perfusion imaging alone,
and the combination of perfusion and metabolic imaging. RESULTS: On
perfusion imaging alone, 56 patients (54%) had a significant amount of
viable myocardium, whereas 48 patients (46%) did not. Among the 48
patients with no significant viability by perfusion imaging alone, seven
additional patients (15%) had significantly viable myocardium on combined
perfusion and metabolic imaging. Thus with a combination of perfusion and
metabolic imaging, 63 patients (61%) had viable myocardium and 41 (39%)
did not. CONCLUSIONS: On the basis of the presence of viable dysfunctional
myocardium, 61% of patients with chronic coronary artery disease and
depressed left ventricular ejection fraction presenting with heart failure
symptoms may be considered for coronary revascularisation. The combination
of perfusion and metabolic imaging identified more patients with
significant viability than myocardial perfusion imaging alone
Prognostic value of dobutamine-atropine stress myocardial perfusion imaging in patients with diabetes
OBJECTIVE: Exercise tolerance in patients with diabetes is frequently
impaired due to noncardiac disease such as claudication and
polyneuropathy. This study assesses the prognostic value of dobutamine
stress myocardial perfusion imaging in patients with diabetes. RESEARCH
DESIGN AND METHODS: A total of 207 consecutive diabetic patients who were
unable to undergo exercise stress testing underwent dobutamine-atropine
stress myocardial perfusion imaging. Follow-up was successful in 206 of
207 (99.5%) patients. A total of 12 patients underwent early (<60 days)
revascularization and were excluded from the analysis. End points during
follow-up were hard cardiac events, defined as cardiac death and nonfatal
myocardial infarction. RESULTS: Abnormal myocardial perfusion was detected
in 125 (64%) patients. During 4.1 +/- 2.4 years of follow-up, 73 (38%)
deaths occurred, 36 (49%) of which were due to cardiac causes. Nonfatal
myocardial infarction occurred in 7 (4%) patients, and 45 (23%) patients
underwent late coronary revascularization. Cardiac death occurred in 2 of
69 (3%) patients with normal myocardial perfusion and in 34 of 125 (27%)
patients with perfusion abnormalities (P < 0.0001). A multivariable Cox
proportional hazard model demonstrated that, in addition to clinical and
stress test data, an abnormal scan had an incremental prognostic value for
prediction of cardiac death (hazard ratio 7.2, 95% CI 1.7-30). The summed
stress score was an important predictor of cardiac death; the hazard ratio
was 1.2 (95% CI 1.07-1.34) per one-unit increment. CONCLUSIONS:
Dobutamine-atropine stress myocardial perfusion imaging provides
additional prognostic information incremental to clinical data in patients
with diabetes who are unable to undergo exercise stress testing
Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography
OBJECTIVE: To determine whether, compared with fundamental imaging, second
harmonic imaging can improve the accuracy of dobutamine stress
echocardiography for identifying viable myocardium, using nuclear imaging
as a reference. PATIENTS: 30 patients with chronic left ventricular
dysfunction (mean (SD) age, 60 (8) years; 22 men). METHODS: Dobutamine
stress echocardiography was carried out in all patients using both
fundamental and second harmonic imaging. All patients underwent dual
isotope simultaneous acquisition single photon emission computed
tomography (DISA-SPECT) with
(99m)technetium-tetrofosmin/(18)F-fluorodeoxyglucose on a separate day.
Myocardial viability was considered present by dobutamine stress
echocardiography when segments with severe dysfunction showed a biphasic
sustained improvement or an ischaemic response. Viability criteria on
DISA-SPECT were normal or mildly reduced perfusion and metabolism, or
perfusion/metabolism mismatch. RESULTS: Using fundamental imaging, 330
segments showed severe dysfunction at baseline; 144 (44%) were considered
viable. The agreement between dobutamine stress echocardiography by
fundamental imaging and DISA-SPECT was 78%, kappa = 0.56. Using second
harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were
viable. The agreement between dobutamine stress echocardiography and
DISA-SPECT was significantly better when second harmonic imaging was used
(89%, kappa = 0.77, p = 0.001 v fundamental imaging). CONCLUSIONS: Second
harmonic imaging applied during dobutamine stress echocardiography
increases the agreement with DISA-SPECT for detecting myocardial
viability
Contribution of Auger/conversion electrons to renal side effects after radionuclide therapy: preclinical comparison of 161Tb-folate and 177Lu-folate
Cardiac stress imaging for the prediction of very long-term outcomes: Dobutamine stress echocardiography or dobutamine 99mTc-sestamibi SPECT?
Background: Both dobutamine stress echocardiography (DSE) and myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) are frequently used for cardiac risk stratification. The long-term relative prognostic
Lutetium-labelled peptides for therapy of neuroendocrine tumours
Treatment with radiolabelled somatostatin analogues is a promising new tool in the management of patients with inoperable or metastasized neuroendocrine tumours. Symptomatic improvement may occur with 177Lu-labelled somatostatin analogues that have been used for peptide receptor radionuclide therapy (PRRT). The results obtained with 177Lu-[DOTA0,Tyr3]octreotate (DOTATATE) are very encouraging in terms of tumour regression. Dosimetry studies with 177Lu-DOTATATE as well as the limited side effects with additional cycles of 177Lu-DOTATATE suggest that more cycles of 177Lu-DOTATATE can be safely given. Also, if kidney-protective agents are used, the side effects of this therapy are few and mild and less than those from the use of 90Y-[DOTA0,Tyr3]octreotide (DOTATOC). Besides objective tumour responses, the median progression-free survival is more than 40Β months. The patients' self-assessed quality of life increases significantly after treatment with 177Lu-DOTATATE. Lastly, compared to historical controls, there is a benefit in overall survival of several years from the time of diagnosis in patients treated with 177Lu-DOTATATE. These findings compare favourably with the limited number of alternative therapeutic approaches. If more widespread use of PRRT can be guaranteed, such therapy may well become the therapy of first choice in patients with metastasized or inoperable neuroendocrine tumours
Prediction of clinically relevant hyperkalemia in patients treated with peptide receptor radionuclide therapy
Renal uptake of different radiolabelled peptides is mediated by megalin: SPECT and biodistribution studies in megalin-deficient mice
Contains fulltext :
98302.pdf (publisher's version ) (Closed access)PURPOSE: Radiolabelled peptides used for peptide receptor radionuclide therapy are excreted mainly via the kidneys and are partly reabsorbed and retained in the proximal tubular cells. The resulting high renal radiation dose can cause nephrotoxicity, limiting the maximum activity dose and the effectiveness of peptide receptor radionuclide therapy. The mechanisms of kidney reabsorption of these peptides are incompletely understood, but the scavenger receptor megalin has been shown to play a role in the reabsorption of (111)In-octreotide. In this study, the role of megalin in the renal reabsorption of various relevant radiolabelled peptides was investigated. METHODS: Groups of kidney-specific megalin-deficient mice and wild-type mice were injected with (111)In-labelled somatostatin, exendin, neurotensin or minigastrin analogues. Single photon emission computed tomographic (SPECT) images of the kidneys were acquired and analysed quantitatively, or the animals were killed 3 h after injection and the activity concentration in the kidneys was measured. RESULTS: Megalin-deficient mice showed significantly lower uptake of all studied radiolabelled peptides in the kidneys, ranging from 22% ((111)In-octreotide) to 65% ((111)In-exendin) of uptake in wild-type kidneys. Quantitative analysis of renal uptake by SPECT and ex vivo measurements showed a very good correlation. CONCLUSION: Megalin is involved in the renal reabsorption of radiolabelled octreotide, octreotate, exendin, neurotensin and minigastrin. This knowledge may help in the design of strategies to reduce this reabsorption and the resulting nephrotoxicity in peptide receptor radionuclide therapy, enabling more effective therapy. Small-animal SPECT is an accurate tool, allowing in vivo quantification of renal uptake and serial measurements in individual mice
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