Single-center analysis of cardiac amyloidosis using 99m Tc-HMDP imaging for diagnosis and evaluation after tafamidis treatment.

This study aimed to evaluate the diagnostic performance of 99m Tc-hydroxymethylene diphosphonate ( 99m Tc-HMDP) imaging for cardiac amyloidosis and to demonstrate changes in cardiac uptake of 99m Tc-HMDP after tafamidis treatment. Seventy-five patients with suspected cardiac amyloidosis who underwent 99m Tc-HMDP imaging were included. We compared visual Perugini grades and semiquantitative heart-to-contralateral (H/CL) area ratios, myocardial maximum standardized uptake value (SUVmax), and peak of SUV (SUVpeak) between cardiac transthyretin amyloidosis (ATTR) and amyloid light-chain amyloidosis (AL). Comparison of interobserver reproducibility between H/CL ratios and myocardial SUVmax/SUVpeak was performed. H/CL ratio of 99m Tc-HMDP and myocardial SUVmax/SUVpeak were compared before and after tafamidis administration for cardiac wild-type ATTR. Among 75 patients, 20 patients (26.7%) were visually positive based on Perugini grade. Fifteen and three patients were pathologically identified as cardiac ATTR and AL, respectively. ATTR group ( n  = 15) had significantly higher H/CL ratios of 99m Tc-HMDP than AL group ( n  = 3) ( P  = 0.003). ATTR group ( n  = 15) had significantly higher myocardial SUVmax/SUVpeak of 99m Tc-HMDP than AL group ( n  = 2) ( P  = 0.015). Myocardial SUVmax/SUVpeak had better interobserver reproducibility than H/CL ratios. After tafamidis treatment for cardiac wild-type ATTR, the decrease in myocardial SUVpeak was significant but not in H/CL ratios and myocardial SUVmax. H/CL ratio and SUVmax/SUVpeak in 99m Tc-HMDP imaging were useful for diagnosing cardiac ATTR. Myocardial SUVpeak may be useful for monitoring changes in cardiac uptake after tafamidis treatment for cardiac ATTR.

Egi R ，Matsusaka Y ，Watanabe K ，Seto A ，Matsunari I ，Arai T ，Nakano S ，Kuji I ... -  《-》

First report of the clinical characteristics and outcomes of cardiac amyloidosis in Saudi Arabia.

Cardiac amyloidosis (CA) is a potentially fatal multisystemic disease that remains significantly underdiagnosed, particularly in the Middle East. This study aims to evaluate the prevalence and clinical characteristics of CA in a high-risk population at a tertiary centre in Saudi Arabia. This cross-sectional, retrospective, single-centre study was conducted at a tertiary hospital in Riyadh, Saudi Arabia. We reviewed the medical records of heart failure patients seen between August 2018 and July 2022 who exhibited red flags for CA and subsequently underwent CA screening. Red flags that prompted the workup included at least two of the following factors: the presence of unilateral or bilateral carpal tunnel syndrome, a family history of transthyretin amyloid (ATTR) amyloidosis and specific electrocardiographic features (relative/absolute low QRS voltage, pseudoinfarct pattern and atrioventricular/interventricular conduction abnormalities). Echocardiographic red flags included mainly increased wall thickness (≥12 mm), significant diastolic dysfunction, reduced left ventricular (LV) longitudinal function, right ventricular (RV) dysfunction and elevated right atrial (RA)/pulmonary artery (PA) pressure. Cardiac magnetic resonance (CMR) red flags included aspects similar to those in an echocardiogram as well as a subendocardial or transmural late gadolinium enhancement (LGE) pattern. These patients were assessed for CA through technetium-99m pyrophosphate ([99mTc]Tc-PYP) bone scintigraphy, serum and urine protein electrophoresis with immunofixation and a serum-free light chain assay. A total of 177 patients were screened, of which 21.0 (11.9%) patients were diagnosed with transthyretin amyloid CA (ATTR-CA) and 13 (7.3%) patients were diagnosed with light chain CA (AL-CA). Compared with patients with negative/equivocal [99mTc]Tc-PYP scans (grades 0-1), patients with positive [99mTc]Tc-PYP scans (grades 2-3) were older (78.0 vs. 68.0 years, P < 0.001), had higher levels of troponin (P = 0.003) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (P < 0.001), had a higher LV mass index (P < 0.001), displayed a more depressed global longitudinal strain (GLS) (P < 0.001) with a greater prevalence of a relative apical sparing pattern (P < 0.001) and demonstrated a higher incidence of first-degree atrioventricular block (P = 0.008) and low voltage patterns on electrocardiography (P < 0.001). Patients with ATTR-CA and AL-CA were more likely to have a subendocardial or transmural LGE pattern on CMR (P < 0.001) and had a significantly lower overall survival (P < 0.001) when compared with other heart failure aetiologies. This is the first study to describe the clinical characteristics and outcomes of CA in the Middle East and Saudi Arabia. The prevalence of CA among screened heart failure patients here aligns with major international studies, suggesting significant underdiagnosis in the region. Therefore, larger multicentric studies and regional screening programmes are urgently needed to accurately characterize the epidemiology and outcomes of CA in the Middle East.

Ahmad O ，Omer MH ，Janjua M ，Alayary I ，Fathala A ，Alsergani H ，Alamro B ，Damy T ，Fadel B ，Mohty D ... -  《ESC Heart Failure》

Global and Regional Reduction of Myocardial Perfusion in Patients with Transthyretin Type of Cardiac Amyloidosis: A Dual SPECT Study Using (99m)Tc Pyrophosphate and (201)Thallium.

Purpose: We aimed to clarify the clinical characteristics of global and regional myocardial perfusion in patients with transthyretin type of cardiac amyloidosis (ATTR) using dual single-photon emission computed tomography (SPECT) with 99mTc pyrophosphate (PYP) and 201TL (TL). Methods: Consecutive 178 (mean age 78±12, male 79) patients known or suspect of ATTR who underwent PYP-TL dual SPECT were retrospectively enrolled. Patients were categorized according to the visual grading for planar PYP uptake using Perugini grading, and the patients with grade greater than or equal to 2 were analyzed. In planar analysis, the heart/contralateral ratio (H/CL) for PYP, and heart/lung ratio (H/L) for TL were obtained to evaluate global myocardial uptake. In TL-SPECT polar map analysis, the heterogeneity of myocardial uptake was evaluated using segmental mean %uptake. Cardiac function and left ventricular function and end-diastolic ventricular mass (LVmass) were measured by echocardiography. Results: Among 178 patients, 39 patients showed PYP uptake with grade 2 or 3 and H/CL >1.3 (81±5 ys, male 28). Of those, 4 patients showed significant perfusion defect in TL scan. Among 35 patients without perfusion defect, H/L showed a significant inverse correlation to H/CL, and LVmass (r=-0.3, p=0.02; r=-0.4, p=0.03. 95% confidence interval -0.4 to 0.2, and -0.7 to -0.04 for H/CL and LVmass). Polar map analysis demonstrated significantly lower mean %uptake for TL in septum compared to lateral (79.4±8.4 vs. 84.3±6.2, p=0.006 for TL in septum vs. lateral, respectively). Conclusion: In ATTR, TL uptake surrogated the reduction of global myocardial perfusion. A significant regional heterogeneity was observed with a notable reduction in septum despite the diffuse hypertrophy.

Suenaga H ，Fukushima K ，Ishii S ，Hasegawa O ，Muto Y ，Yamakuni R ，Sugawara S ，Sekino H ，Sato A ，Oikawa M ，Takeishi Y ，Ito H ... -  《-》

A multicenter study of clinical predictors of positive pyrophosphate scintigraphy findings in the diagnosis of transthyretin amyloidosis.

Shingu M ，Fujimoto W ，Onishi T ，Kuragaichi T ，Murai R ，Matsuo K ，Inoue T ，Takaya T ，Matsumoto K ，Matsue Y ，Okuda M ，Tanaka H ... -  《-》

From transthyretin cardiac amyloidosis diagnosis to tafamidis treatment: Association of drop-off with patient sociodemographic characteristics.

Compared to estimated population prevalence rates, relatively few patients at risk are diagnosed with and treated for transthyretin cardiac amyloidosis (ATTR-CA). Where along the clinical pathway patient drop-off occurs, as well as the association of drop-off with patient sociodemographic characteristics, remains unknown. Using data from a healthcare system-wide cardiovascular imaging repository and specialty pharmacy, we characterized the clinical pathway from diagnosis with pyrophosphate scintigraphy (PYP) to tafamidis prescription, initiation, and adherence. Standardized differences (d values of ≥0.20, indicating at least a small effect size) were used to compare sociodemographics (age, sex, race, Area Deprivation Index) among patients with PYP-identified ATTR-CA by tafamidis prescription status and among patients prescribed tafamidis by initiation status. Tafamidis adherence was measured with the proportion of days covered (PDC). Of 97 patients with ATTR-CA, 58.8% were prescribed tafamidis, with 80.7% of those initiating therapy. Patients with ATTR-CA prescribed tafamidis were younger than those not prescribed tafamidis (d = -0.30). Utilization of a specialty pharmacy resulted in enrichment of treatment in subgroups traditionally undertreated in cardiovascular medicine, with higher rates of tafamidis initiation among women (100% initiation), patients of Black/African American race (d = 0.40), and those living in more economically disadvantaged areas (d ≥ 0.30). Adherence was high (PDC of >80%) in 88.4% of those initiating tafamidis. These findings highlight the tremendous opportunity for more robust ATTR-CA clinical programs, identifying potential patient subgroups that should be targeted to reduce disparities. For patients diagnosed with ATTR-CA, utilization of a specialty pharmacy process appears to ensure equitable provision of tafamidis therapy.

Walenczyk KM ，Singh A ，Tong K ，Burg MM ，Miller EJ ... -  《-》