Suspicion, screening, and diagnosis of wild-type transthyretin amyloid cardiomyopathy: a systematic literature review

Right heart and left atrial strain to differentiate cardiac amyloidosis and Fabry disease

Echocardiographic differentiation of cardiac amyloidosis (CA) and Fabry disease (FD) is often challenging using standard echocardiographic parameters. We retrospectively analyzed the diagnostic accuracy of right heart and left atrial strain parameters to discriminate CA from FD using receiver operating characteristic curve analyses and logistic regression models. A total of 47 FD and 88 CA patients with left ventricular wall thickening were analyzed. The comparison of both cardiomyopathies revealed significantly reduced global and free wall longitudinal right ventricular strain (RVS; global RVS: CA - 13 ± 4%, n = 67, vs. FD - 18 ± 4%, n = 39, p < 0.001) as well as right atrial strain (RAS; reservoir RAS: CA 12 ± 8%, n = 70, vs. FD 26 ± 9%, n = 40, p < 0.001) and left atrial strain (LAS) in CA patients. Individually, global RVS as well as phasic LAS and RAS showed the highest diagnostic accuracy to distinguish CA and FD. The best diagnostic accuracy was achieved by combining the age, basal RV diameter, global RVS, and reservoir and conduit RAS (area under the curve 0.96 [95% CI 0.90-1.00]). Differential echocardiographic diagnostic work-up of patients with suspected CA or FD can be improved by integrating structural and functional parameters of the right heart and the left atrium.Trial registration: DRKS00027403.

Diagnostic value of heart-to-mediastinum ratio in 99mTc-pyrophospate SPECT/CT for transthyretin cardiac amyloidosis

BACKGROUND

In transthyretin cardiac amyloidosis (ATTR-CA), 99mTc-pyrophosphate myocardial scintigraphy (99mTc-PYP) is a diagnostic tool that utilizes visual and quantitative evaluation. However, false positive cases can occur because of tracer accumulation in the blood. We investigated the effectiveness of the heart-to-mediastinum (H/M) ratio of 99mTc-PYP in ATTR-CA diagnosis.

METHODS

We retrospectively included 164 patients who underwent 99mTc-PYP single-photon emission computed tomography/computed tomography between March 2019 and January 2022. The diagnostic accuracy of ATTR-CA was examined by the heart-to-contralateral lung (H/CL) and H/M ratio calculated at 3 hours post-tracer administration.

RESULTS

After the exclusion of patients who did not undergo endomyocardial biopsy, 30 patients (15 each with ATTR-CA and without ATTR-CA) were included. The receiver operating characteristic curve used to distinguish ATTR-CA from non-ATTR-CA patients revealed an area under the curve of 0.986 and 0.943, respectively. A H/M ratio of > 1.41 identified ATTR-CA patients with a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100, 93.3, 93.3, and 100%, respectively. Conversely, an H/CL ratio of > 1.3 identified ATTR-CA patients with 100% sensitivity, 40.0% specificity, 62.5% PPV, and 100% NPV.

CONCLUSION

The H/M ratio obtained at 3 hours post-injection has the potential to be a novel indicator for ATTR-CA.

Health-related quality of life among transthyretin amyloid cardiomyopathy patients

AIMS

Transthyretin amyloid cardiomyopathy (ATTR CM) is a progressive and severe heart disease with physical and psychological implications. The Nordic PROACT study was conducted to investigate the health-related quality of life (HRQoL) in ATTR CM patients.

METHODS AND RESULTS

The Nordic PROACT study was a cross-sectional non-interventional study conducted in 12 cardiology hospital clinics across Norway, Sweden, Finland and Denmark. Men and women aged ≥18 years diagnosed with symptomatic ATTR CM were included. The investigator provided information on medical history, biomarkers, current treatment, co-morbidities and disease severity according to the New York Heart Association (NYHA) class and the National Amyloidosis Centre (NAC) staging. Patients completed the HRQoL questionnaires in the form of the Kansas City Cardiomyopathy Questionnaire (KCCQ), the EQ-5D-5L index with Visual Analog Scale (VAS), and the Major Depression Inventory (MDI). A total of 169 patients (mean ± SD age 77.7 ± 6.2 years) were included. Ninety-two per cent were men. Seventy-six per cent had wildtype ATTR CM (ATTRwt CM) and 15% had a hereditary form of ATTR CM (ATTRv CM) while 9% were genetically unclassified. Most patients were in NYHA class II (54%) and NAC stage 1 (53%). Participation in randomized clinical trials (RCT) was noted in 58% of the patients. The 169 ATTR CM patients had a mean ± SD KCCQ score of 64.3 ± 23.1 for total symptom score, 64.8 ± 20.9 for overall summary score (OSS) and 65.1 ± 21.5 for clinical summary score. The EQ-5D-5L total utility score was 0.8 ± 0.2 and the EQ-5D-5L VAS score was 62.9 ± 20.6. The vast majority (89%) did not report any signs of depression. Patients with ATTRv CM had a higher KCCQ OSS as compared with ATTRwt CM, while EQ-5D-5L utility score, EQ-5D-5L VAS and MDI were similar. Non-RCT participants had a poorer HRQoL as compared with RCT participants as reflected in lower KCCQ OSS and EQ-5D-5L VAS scores and a higher MDI score. Patients with higher NYHA classes and NAC disease stages had a poorer HRQoL as demonstrated by lower KCCQ and EQ-5D-5L scores and higher MDI scores. Correlation between KCCQ, EQ-5D-5L and MDI and the covariate NYHA class remained significant (P < 0.05) after adjusting for multiple testing.

CONCLUSIONS

KCCQ scores were lower than previously reported for patients with other heart diseases of non-ATTR CM origin. The HRQoL measures correlated well to NYHA class and NAC disease stage. The prevalence of depression appeared to be low.

Identification of wild-type transthyretin cardiac amyloidosis in patients with carpal tunnel syndrome surgery (CACTuS)

AIMS

Wild-type transthyretin cardiac amyloidosis (ATTRwt) is an infiltrative cardiomyopathy with a poor prognosis. The condition is associated with carpal tunnel syndrome (CTS), which often precedes the ATTRwt diagnosis by several years. The aim of the study was (i) to screen patients with a recent history of CTS for ATTRwt using red flags, (ii) to determine whether patients with screened ATTRwt had less advanced disease compared with patients with clinical ATTRwt, and (iii) to assess the sensitivity and specificity of known red flags in ATTRwt.

METHODS AND RESULTS

Patients aged ≥60 years at the time of CTS surgery were invited for screening. Red flags were defined as elevated biomarker levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) or cardiac troponin, an electrocardiogram pattern associated with ATTRwt, left ventricular hypertrophy (LVH), and impaired longitudinal strain with apical sparring. All patients with a red flag were referred for a diagnostic scintigraphy. Patients with ATTRwt diagnosed by screening were compared with patients with clinical ATTRwt (n = 51) matched by age, gender, and CTS surgery. Among the 120 enrolled subjects (mean age 74.5 years, 90% male), the suspicion of ATTR was raised in 67 (55.8%), and 10 (8.3%) were diagnosed with ATTRwt. Patients identified with ATTRwt were predominantly asymptomatic and had mildly elevated NT-proBNP, mildly increased LVH, preserved left ventricular ejection fraction, and systolic longitudinal function, which differed significantly from clinical ATTRwt controls (P < 0.001).

CONCLUSIONS

The study found an ATTRwt prevalence of 8.3% in a population of age and gender-selected patients with a recent history of CTS. The identified patients with ATTRwt had less structural and functional cardiac involvement than clinical ATTRwt controls.