Conversion of 99mtechnetium-pyrophosphate scintigraphy in a patient with hereditary ATTR amyloidosis: importance of repeat scanning.
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ABSTRACT:
SUBMITTER: Hussain M
PROVIDER: S-EPMC7793235 | biostudies-literature | 2020 Dec
REPOSITORIES: biostudies-literature
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Conversion of <sup>99m</sup>technetium-pyrophosphate scintigraphy in a patient with hereditary ATTR amyloidosis: importance of repeat scanning.
Hussain Muzna M Sperry Brett W BW Hanna Mazen M Jaber Wael A WA
European heart journal. Case reports 20201109 6
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Project description:Development of noninvasive imaging modalities to quantify amyloid burden over time is an unmet clinical need. Technetium pyrophosphate (99mTc-PYP) scintigraphy is a simple and widely available radiotracer useful to differentiate transthyretin from light-chain amyloidosis in patients with advanced cardiac amyloidosis. We examined the utility of serial 99mTc-PYP scanning to quantify amyloid burden over time in TTR cardiac amyloidosis (ATTR-CA).Twenty subjects with ATTR-CA (10 wild type, 10 mutant) underwent serial 99mTc-PYP planar cardiac imaging. Cardiac retention was assessed both semiquantitatively (visual score 0, no uptake to 3, uptake greater than bone) and quantitatively (region of interest drawn over the heart, copied, and mirrored over the contralateral chest) to calculate a heart-to-contralateral (H/CL) ratio. Index scan mean visual score and H/CL were 3.0 ± 0.2 and 1.79 ± 0.2, respectively, and after an average 1.5 ± 0.5 years follow-up, did not differ, 3.0 ± 0.2, P = .33 and 1.76 ± 0.2, P = .44. H/CL change was minimal, 0.03 ± 0.17, did not correlate with time between scans, r = 0.19, P = .43, and was observed despite obvious clinical progression (increase in troponin ? 0.1 ng/mL, BNP ? 400 pg/mL, NYHA class, and/or death).Serial 99mTc-PYP scanning in subjects with advanced ATTR-CA does not show significant changes over an average 1.5 years of follow-up despite obvious clinical progression.
| S-EPMC4826633 | biostudies-other
Project description:Cardiac amyloidosis is an under-appreciated cause of heart failure. Establishing a diagnosis is important because traditional heart failure treatment regimens can worsen left ventricular failure in this disease. Endomyocardial biopsy is the gold standard for diagnosis; however, scintigraphy with radiolabeled phosphate derivatives and cardiac magnetic resonance imaging have been shown to have high sensitivity and specificity in diagnosing cardiac amyloidosis. Furthermore, cardiac scintigraphy can reliably differentiate amyloid subtypes. We present a case of transthyretin-related cardiac amyloidosis with a negative endomyocardial biopsy but positive 99m-technetium pyrophosphate single photon emission computed tomography scan and cardiac magnetic resonance imaging. We discuss the utility of 99m-technetium pyrophosphate imaging in cardiac amyloidosis and the role of single photon emission computed tomography. Finally, we review the several forms of cardiac amyloidosis and how they pertain to cardiac scintigraphy.
| S-EPMC6073076 | biostudies-literature
Project description:ObjectivesThis study aimed to characterize trends in technetium Tc 99m pyrophosphate (99mTc-PYP) scanning for amyloid transthyretin cardiac amyloidosis (ATTR-CA) diagnosis, to determine whether patients underwent appropriate assessment with monoclonal protein and genetic testing, to evaluate use of single-photon emission computed tomography (SPECT) in addition to planar imaging, and to identify predictive factors for ATTR-CA.Background99mTc-PYP scintigraphy has been repurposed for noninvasive diagnosis of ATTR-CA. Increasing use of 99mTc-PYP can facilitate identification of ATTR-CA, but appropriate use is critical for accurate diagnosis in an era of high-cost targeted therapeutics.MethodsPatients undergoing 99mTc-PYP scanning 1 h after injection at a quaternary care center from 2010 to 2019 were analyzed; clinical information was abstracted; and SPECT results were analyzed.ResultsOver the decade, endomyocardial biopsy rates remained stable with scanning rates peaking at 132 in 2019 (p < 0.001). Among 753 patients (516 men, mean age 77 years), 307 (41%) had a visual score of 0, 177 (23%) of 1, and 269 (36%) of 2 or 3. Of 751 patients with analyzable heart to contralateral chest ratios, 249 (33%) had a ratio ≥1.5. Monoclonal protein testing status was assessed in 550 patients, of these, 174 (32%) did not undergo both serum immunofixation and serum free light chain analysis tests, and 331 (60%) did not undergo all 3 tests-serum immunofixation, serum free light chain analysis, and urine protein electrophoresis. Of 196 patients with confirmed ATTR-CA, 143 (73%) had genetic testing for transthyretin mutations. In 103 patients undergoing cardiac biopsy, grades 2 and 3 99mTc-PYP had sensitivity of 94% and specificity of 89% for ATTR-CA with 100% specificity for grade 3 scans. With respect to SPECT as a reference standard, planar imaging had false positive results in 16 of 25 (64%) grade 2 scans.ConclusionsUse of noninvasive testing with 99mTc-PYP scanning for evaluation of ATTR-CA is increasing, and the inclusion of monoclonal protein testing and SPECT imaging is crucial to rule out amyloid light chain amyloidosis and distinguish myocardial retention from blood pooling.
| S-EPMC8113330 | biostudies-literature
Project description:BackgroundIn [99mTc]Tc-DPD scintigraphy for myocardial ATTR amyloidosis, planar images 3 hour p.i. and SPECT/CT acquisition in L-mode are recommended. This study investigated if earlier planar images (1 hour p.i.) are beneficial and if SPECT/CT acquisition should be preferred in H-mode (180° detector angle) or L-mode (90°).MethodsIn SPECT/CT phantom measurements (NaI cameras, N = 2; CZT, N = 1), peak contrast recovery (CRpeak) was derived from sphere inserts or myocardial insert (cardiac phantom; signal-to-background ratio [SBR], 10:1 or 5:1). In 25 positive and 38 negative patients (reference: endomyocardial biopsy or clinical diagnosis), Perugini scores and heart-to-contralateral (H/CL) count ratios were derived from planar images 1 hour and 3 hour p.i.ResultsIn phantom measurements, accuracy of myocardial CRpeak at SBR 10:1 (H-mode, 0.95-0.99) and reproducibility at 5:1 (H-mode, 1.02-1.14) was comparable for H-mode and L-mode. However, L-mode showed higher variability of background counts and sphere CRpeak throughout the field of view than H-mode. In patients, sensitivity/specificity were ≥ 95% for H/CL ratios at both time points and visual scoring 3 hour. At 1 hour, visual scores showed specificity of 89% and reduced reader's confidence.ConclusionsEarly DPD images provided no additional value for visual scoring or H/CL ratios. In SPECT/CT, H-mode is preferred over L-mode, especially if quantification is applied apart from the myocardium.
| S-EPMC8709821 | biostudies-literature
Project description:BackgroundTechnetium Tc 99m pyrophosphate scintigraphy (99mTc PYP imaging) is a diagnostic tool for transthyretin amyloid cardiomyopathy (ATTR-CM). Cardiac biomarkers, particularly high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), may help identify patients at low or high risk for ATTR-CM.ObjectivesThe authors sought to evaluate the predictive value of hs-cTnT and NT-proBNP in patients undergoing 99mTc PYP imaging for suspected ATTR-CM in a large U.S. cohort.MethodsThis was a retrospective study of patients who underwent 99mTc PYP imaging between May 2013 and September 2022, including those with at least 1 hs-cTnT measurement within 6 months of the scan.ResultsATTR-CM was diagnosed in 427 of 1,442 patients (29.6%). A hs-cTnT level <6 ng/L (n = 50, 3.5%) showed a negative predictive value of 100% (95% CI: 93%-100%) and sensitivity of 100% (95% CI: 99%-100%) for ruling out ATTR-CM. As the hs-cTnT threshold increased, the number of patients who could be ruled out also increased, but false negatives emerged. The positive predictive value for ruling in ATTR-CM remained low. NT-proBNP showed similar results (n = 1,378). The combination of hs-cTnT <14 ng/L and NT-proBNP <60 ng/L identified 45 patients (3.3%) without ATTR-CM.ConclusionsIn patients undergoing 99mTc PYP imaging for suspected ATTR-CM, very low hs-cTnT levels can effectively rule out the diagnosis, although in a small subset of patients. Higher thresholds increase the risk of false negatives. NT-proBNP and combined biomarker strategies showed similar trends, the utility of hs-cTnT and NT-proBNP for ruling in the disease is limited.
| S-EPMC11781999 | biostudies-literature
Project description:Background99mTc-pyrophosphate imaging has emerged as an important non-invasive method to diagnose transthyretin cardiac amyloidosis (ATTR-CM). Quantitation of 99mTc-pyrophosphate activity, on SPECT images, could be a marker of ATTR-CM disease burden. We assessed the diagnostic accuracy and clinical significance of 99mTc-pyrophosphate quantitation.Methods and resultsPatients who underwent 99mTc-pyrophosphate imaging for suspected ATTR-CM were included. Using SPECT images, radiotracer activity in the myocardium was calculated using cardiac pyrophosphate activity (CPA) and volume of involvement (VOI), with thresholds for abnormal activity derived from LVBP activity. Diagnostic accuracy was assessed using area under the receiver operating characteristic curve (AUC). In total, 124 patients were identified, mean age 73.9 ± 11.4, with ATTR-CM diagnosed in 43 (34.7%) patients. CPA had the highest diagnostic accuracy (AUC .996, 95% CI .987-1.00), and was significantly higher compared to the Perugini score (AUC .952, P = .016). In patients with ATTR-CM, CPA was associated with reduced left ventricular ejection fraction (adjusted odds ratio 1.28, P = .035) and heart failure hospitalizations (adjusted hazard ratio 1.29, P = .006).ConclusionQuantitative assessment of myocardial radiotracer activity with CPA or VOI have high diagnostic accuracy for ATTR-CM. Both measures are potential non-invasive markers to follow progression of disease or response to therapy.
| S-EPMC8497047 | biostudies-literature
Project description:Introduction/aimsTransthyretin amyloidosis (ATTR) proteins can infiltrate skeletal muscle and infrequently cause a myopathy. 99m Technetium-pyrophosphate (99m Tc-PYP) is a validated biomarker for cardiac involvement in variant and wild-type ATTR (ATTRv and ATTRwt, respectively). The aim of this study was to test the hypothesis that 99m Tc-PYP is a biomarker for muscle burden of ATTR.MethodsRadioisotope uptake in the deltoid muscles of patients with ATTR was compared to uptake in control subjects without amyloidosis in a retrospective study. 99m Tc-PYP scans were evaluated in 11 patients with ATTR (7 ATTRv, 4 ATTRwt) and 14 control subjects. Mean count (MC) values were measured in circular regions of interest (ROIs) 2.5-3.8 cm2 in area. Tracer uptake was quantified in the heart, contralateral chest (CC), and deltoid muscles.ResultsTracer uptake was significantly higher over the deltoids and heart but not the CC, in patients with ATTR than in control subjects. MC values were 120.1 ± 43.7 (mean ± SD) in ATTR patients and 78.9 ± 20.4 in control subjects over the heart (p = 0.005), 73.3± 21.0 and 63.5 ± 14.4 over CC (p = 0.09), and 37.0 ± 11.7 and 26.0 ± 7.1 averaged over both deltoid muscles (p = 0.014).Discussion99m Tc-PYP is a potential biomarker for ATTR amyloid burden in skeletal muscle.
| S-EPMC10092886 | biostudies-literature
Project description:PurposeThere is a need for early quantitative markers of potential treatment response in patients with hereditary transthyretin (ATTRv) amyloidosis to guide therapy. This study aims to evaluate changes in cardiac tracer uptake on bone scintigraphy in ATTRv amyloidosis patients on different treatments.MethodsIn this retrospective cohort study, outcomes of 20 patients treated with the transthyretin (TTR) gene silencer patisiran were compared to 12 patients treated with a TTR-stabilizer. Changes in NYHA class, cardiac biomarkers in serum, wall thickness, and diastolic parameters on echocardiography and NYHA class during treatment were evaluated.ResultsMedian heart/whole-body (H/WB) ratio on bone scintigraphy decreased from 4.84 [4.00 to 5.31] to 4.16 [3.66 to 4.81] (p < .001) in patients treated with patisiran for 29 [15-34] months. No changes in the other follow-up parameters were observed. In patients treated with a TTR-stabilizer for 24 [20 to 30] months, H/WB ratio increased from 4.46 [3.24 to 5.13] to 4.96 [ 3.39 to 5.80] (p = .010), and troponin T increased from 19.5 [9.3 to 34.0] ng/L to 20.0 [11.8 to 47.8] ng/L (p = .025). All other parameters did not change during treatment with a TTR-stabilizer.ConclusionA change in cardiac tracer uptake on bone scintigraphy may be an early marker of treatment-specific response or disease progression in ATTRv amyloidosis patients.
| S-EPMC10796605 | biostudies-literature
Project description:BackgroundIncreasing recognition that transthyretin cardiac amyloidosis (ATTR-CA) is much more common than previously appreciated and the emergence of novel disease-modifying therapeutic agents have led to a paradigm shift in which ATTR-CA screening is considered in high-risk populations, such as patients with heart failure with preserved ejection fraction (HFpEF) or aortic stenosis. Radiation risk from 99mTc-pyrophosphate (99mTc-PYP) scintigraphy, a test with very high sensitivity and specificity for ATTR-CA, has not been previously determined.Methods and resultsRadiation doses to individual organs from 99mTc-PYP were estimated using models developed by the Medical Internal Radiation Dose Committee and the International Commission on Radiological Protection. Excess future cancer risks were estimated from organ doses, using risk projection models developed by the National Academies and extended by the National Cancer Institute. Excess future risks were estimated for men and women aged 40-80 and compared to total (excess plus baseline) future risks. All-organ excess cancer risks (90% uncertainty intervals) ranged from 5.88 (2.45,11.4) to 12.2 (4.11,26.0) cases per 100,000 patients undergoing 99mTc-PYP testing, were similar for men and women, and decreased with increasing age at testing. Cancer risks were highest to the urinary bladder, and bladder risk varied nearly twofold depending on which model was used. Excess 99mTc-PYP-related cancers constituted < 1% of total future cancers to the critical organs.ConclusionVery low cancer risks associated with 99mTc-PYP testing suggest a favorable benefit-risk profile for 99mTc-PYP as a screening test for ATTR-CA in high-risk populations, such as such as patients with HFpEF or aortic stenosis.
| S-EPMC6269210 | biostudies-literature
Project description:ObjectivesThe purpose of this study was to examine the diagnostic value of planar 99mTc-pyrophosphate (PYP) imaging at 1 and 3 h after tracer administration in patients with suspected transthyretin cardiac amyloidosis (ATTR-CA) using SPECT as a reference standard. We also tested whether blood pool activity of PYP is associated with renal dysfunction.MethodsPYP images of 109 consecutive patients with suspected ATTR-CA were retrospectively reviewed. The myocardial PYP uptake was visually graded on a scale of 0 to 3 and quantified with the heart-to-contralateral (H/CL) ratio in accordance with the current expert consensus recommendations. The diagnostic value of planar images for identifying positive PYP SPECT was assessed by a receiver-operating characteristic curve analysis with the area under the curve (AUC). The uptake ratios of the ascending and descending aorta, left atrium, and trapezius muscle divided by the liver uptake were measured on SPECT images and compared to the renal function.ResultsA total of 41 patients (38%) had myocardial PYP uptake on SPECT images. In comparison with the visual scores on 1-h anterior planar images, those on 3-h anterior planar images had lower sensitivity (80.5% vs. 97.6%) and higher specificity (86.8% vs. 55.9%) for identifying positive PYP SPECT. The ROC analysis showed that the combination of visual scores on both 1-h and 3-h anterior planar images had significantly higher AUC values in comparison with 1-h anterior planar images alone (0.90 [95% CI 0.83-0.94] vs. 0.83 [95% CI 0.75-0.88]; P < 0.001), which was comparable to the AUC values on 3-h anterior planar images alone (0.88 [95% CI 0.80-0.92]; P = 0.071). In comparison with visual scores on 1-h or 3-h anterior planar images alone, the combination of visual scores and H/CL ratio did not significantly improve the diagnostic value for identifying positive PYP SPECT (P = 0.73 and P = 0.50, respectively). The uptake ratios of ascending aorta/liver, descending aorta/liver, left atrium/liver, and trapezius muscle/liver were not significantly associated with the serum creatinine level or estimated glomerular filtration rate (P > 0.05 for all).ConclusionsIn the assessment of ATTR-CA using PYP imaging, visual scores on 3-h anterior planar images for identifying positive PYP SPECT had lower sensitivity and higher specificity in comparison with those on 1-h anterior planar images. The diagnostic value of the visual scores on 1-h and 3-h anterior planar images was not improved by adding the H/CL ratio. Blood pool activity of PYP was not significantly associated with renal dysfunction.
| S-EPMC9646466 | biostudies-literature