Changes in the diagnostic trajectory of transthyretin cardiac amyloidosis over six years.

Awareness of transthyretin amyloid cardiomyopathy (ATTR-CM) has increased over the years due to diagnostic and therapeutic developments. Timely initiation of novel disease-modifying treatments improves both morbidity and mortality, which underlines the necessity for a prompt diagnosis. Nevertheless, early diagnosis of ATTR-CM remains challenging. This is a retrospective observational cohort study of patients diagnosed with ATTR-CM. Between 2016 and 2023, 87 patients were diagnosed with cardiac amyloidosis of which 65 (75%) patients with ATTR-CM and 22 (25%) patients with light chain amyloidosis. This study included 65 ATTR-CM patients (mean age 77 ± 7 years; 86% male) of whom 59 (91%) with wild-type ATTR-CM (ATTRwt) and six (9%) with variant ATTR-CM. We observed a surge in ATTR-CM diagnoses from 3 patients/year (2016-2020) to 16 patients/year (2021-2023), driven by ATTRwt. Nevertheless, the interval between the onset of heart failure symptoms and ATTR-CM diagnosis has not changed significantly (2016-2020 27.3 months [18.6-62.4]; 2021-2023 30.0 months [8.6-57.2]; p = 0.546), driven by time to referral. Red flags for ATTR-CM preceded diagnosis by several years: left ventricular hypertrophy (79%, 5.8 years [3.3-7.0]) and carpal tunnel syndrome (49%, 6.8 years [2.3-12.1]). Despite the presence of typical red flags, symptom-to-diagnosis duration has remained similar driven by time to referral. Improved recognition of red flags for ATTR-CM could reduce the time to diagnosis and improve overall recognition.

Prognostic value of hypoxaemic burden from overnight oximetry in heart failure with preserved ejection fraction.

AIMS: Nocturnal hypoxaemic burden, quantified as time spent with oxygen saturation below 90% (T90), is an established independent predictor of mortality in heart failure (HF) with reduced ejection fraction. The prognostic value of T90 in HF with preserved ejection fraction (HFpEF) is unknown. This study aims to determine the association of T90 with adverse outcomes in HFpEF. METHODS AND RESULTS: One hundred twenty-six patients prospectively included from our specialised HFpEF outpatient clinic underwent ambulatory home sleep monitoring to obtain oximetry data, including T90. We investigated the association between T90 and a composite endpoint of HF hospitalisations or all-cause mortality. Nocturnal hypoxaemic burden in this HFpEF population was high, with a median T90 of 13.7 min. In only 10 patients (7.9%), oxygen saturation was at no time point below 90%. After median 34 months [IQR 18.4-52.0] of follow-up, 32 patients (25%) reached the composite endpoint. T90 was significantly associated with the composite endpoint, also after adjusting for potential confounders (HR 1.004 (95% CI 1.001-1.007, P = 0.019) per 1 min T90 increase or HR 1.265 (95% CI 1.061-1.488) per 1 h T90 increase). Patients with HFpEF in the highest T90 tertile (T90 ≥ 31.4 min) had a significantly higher event rate compared to patients in the lowest two T90 tertiles, with 19 (45%) versus 13 (15%) events, respectively (P < 0.001). CONCLUSIONS: Nocturnal hypoxaemic burden is an independent prognostic marker for the composite of HF hospitalisations or all-cause mortality in HFpEF. Whether reduction of T90 improves the prognosis of patients with HFpEF warrants further research.

Diversity of heart failure phenotypes in transthyretin amyloid cardiomyopathy. More than just heart failure with preserved ejection fraction.

INTRODUCTION: Current guidelines recommend suspecting transthyretin amyloid cardiomyopathy (ATTR-CM) in patients over 65 years of age with unexplained left ventricular (LV) hypertrophy in a non-dilated LV, heart failure (HF) and preserved ejection fraction (HFpEF), hypertrophic cardiomyopathy or severe aortic stenosis. However, there is evidence indicating a high prevalence of ATTR-CM in other HF phenotypes. As such, this study aimed to characterize the diversity of HF phenotypes of ATTR-CM by examining the LV ejection fraction and LV dilatation using echocardiography. METHODS: This multicentre, retrospective observational study included patients diagnosed with ATTR-CM between 2015-2023. The diagnosis was based on a positive cardiac biopsy or positive bone scintigraphy without monoclonal gammopathy. Echocardiographic measurements were categorized according to LV ejection fraction (LVEF) into HFpEF (LVEF ≥50%), HF with mildly reduced EF (HFmrEF, LVEF 40-49%), and HF with reduced EF (HFrEF, LVEF <40%). LV cavity size was categorized by LV end-diastolic diameter (LVEDD) and volume index (LVEDVi) as normal, moderately increased and severe dilatation. RESULTS: The study included 135 patients with ATTR-CM (mean age, 78 years; 89% male; 89% wild-type ATTR-CM). Most patients were screened for ATTR-CM because of unexplained HF and increased LV wall thickness (57%). Echocardiography showed LVEF <50% in 60% of the patients, with a significant portion presenting with HFrEF. Patients with LVEF <50% had higher NYHA class and elevated N-terminal pro-B-type natriuretic peptide levels than HFpEF patients. LV dilatation was observed in 43% of the patients, with 10% presenting with both LVEF <50% and severe LV dilatation. CONCLUSION: This study revealed significant variability in HF phenotypes among patients with ATTR-CM, from HFpEF without LV dilatation to HFrEF with severe LV dilatation. Relying solely on HFpEF for screening may lead to under-diagnosis. These findings suggest the need for more comprehensive diagnostic criteria beyond echocardiographic measures to improve ATTR-CM detection and management.

Detection of cardiac amyloidosis on routine bone scintigraphy: an important gatekeeper role for the nuclear medicine physician.

Cardiac amyloidosis (CA)-mostly transthyretin-related (ATTR-CA)-has recently gained interest in cardiology. Bone scintigraphy (BS) is one of the main screening tools for ATTR-CA but also used for various other reasons. The objective was to evaluate whether all CA cases are detected and what happens during follow-up. All routine BS performed at the Maastricht University Medical Center (May 2012-August 2020) were screened for the presence of CA. Scans performed for suspected CA were excluded. A Perugini stage ≥1 was classified as positive necessitating further examination. The electronic medical record system was evaluated for any contact with cardiology or other specialists until 2021. Of the 2738 BS evaluated, 40 scans (1.46%; median age 73.5 [IQR: 65.8-79.5], 82.5% male) were positive (Perugini grade 1: 31/77.5%, grade 2: 6/15%, grade 3: 3/7.5%); the potential diagnosis ATTR-CA was not seen in 38 patients (95%) by the nuclear medicine specialist. During follow-up, 19 out of those 40 patients (47.5%) underwent cardiac evaluation without diagnosing CA. Available echocardiograms of patients with a positive BS showed left ventricular hypertrophy, a preserved ejection fraction, and diastolic dysfunction ≥2 in 9/47%, 10/53%, and 4/21% of patients, respectively. Additionally, 20 (50%) patients presented to at least one specialty with symptoms indicative of cardiac amyloidosis. The prevalence of a positive BS indicating potential CA in an unselected population is low but substantial. The majority was not detected which asks for better awareness for CA of all involved specialists to ensure appropriate treatment and follow-up.

Evaluation of the 2021 ESC recommendations for family screening in hereditary transthyretin cardiac amyloidosis.

AIMS: The 2021 European Society of Cardiology (ESC) screening recommendations for individuals carrying a pathogenic transthyretin amyloidosis variant (ATTRv) are based on expert opinion. We aimed to (i) determine the penetrance of ATTRv cardiomyopathy (ATTRv-CM) at baseline; (ii) examine the value of serial evaluation; and (iii) establish the yield of first-line diagnostic tests (i.e. electrocardiogram, echocardiogram, and laboratory tests) as per 2021 ESC position statement. METHODS AND RESULTS: We included 159 relatives (median age 55.6 [43.2-65.9] years, 52% male) at risk for ATTRv-CM from 10 centres. The primary endpoint, ATTRv-CM diagnosis, was defined as the presence of (i) cardiac tracer uptake in bone scintigraphy; or (ii) transthyretin-positive cardiac biopsy. The secondary endpoint was a composite of heart failure (New York Heart Association class ≥II) and pacemaker-requiring conduction disorders. At baseline, 40/159 (25%) relatives were diagnosed with ATTRv-CM. Of those, 20 (50%) met the secondary endpoint. Indication to screen (≤10 years prior to predicted disease onset and absence of extracardiac amyloidosis) had an excellent negative predictive value (97%). Other pre-screening predictors for ATTRv-CM were infrequently identified variants and male sex. Importantly, 13% of relatives with ATTRv-CM did not show any signs of cardiac involvement on first-line diagnostic tests. The yield of serial evaluation (n = 41 relatives; follow-up 3.1 [2.2-5.2] years) at 3-year interval was 9.4%. CONCLUSIONS: Screening according to the 2021 ESC position statement performs well in daily clinical practice. Clinicians should adhere to repeating bone scintigraphy after 3 years, as progressing to ATTRv-CM without signs of ATTRv-CM on first-line diagnostic tests or symptoms is common.

Association between phonocardiography and echocardiography in heart failure patients with preserved ejection fraction.

Aims: Heart failure with preserved ejection fraction (HFpEF) is associated with stiffened myocardium and elevated filling pressure that may be captured by heart sound (HS). We investigated the relationship between phonocardiography (PCG) and echocardiography in symptomatic patients suspected of HFpEF. Methods and results: Consecutive symptomatic patients with sinus rhythm and left ventricular ejection fraction >45% were enrolled. Echocardiography was performed to evaluate the patients' diastolic function, accompanied by PCG measurements. Phonocardiography features including HS amplitude, frequency, and timing intervals were calculated, and their abilities to differentiate the ratio between early mitral inflow velocity and early diastolic mitral annular velocity (E/e') were investigated. Of 45 patients, variable ratio matching was applied to obtain two groups of patients with similar characteristics but different E/e'. Patients with a higher E/e' showed higher first and second HS frequencies and more fourth HS and longer systolic time intervals. The interval from QRS onset to first HS was the best feature for the prediction of E/e' > 9 [area under the curve (AUC): 0.72 (0.51-0.88)] in the matched patients. In comparison, N-terminal pro-brain natriuretic peptide (NT-proBNP) showed an AUC of 0.67 (0.46-0.85), a value not better than any PCG feature (P > 0.05). Conclusion: Phonocardiography features stratify E/e' in symptomatic patients suspected of HFpEF with a diagnostic performance similar to NT-proBNP. Heart sound may serve as a simple non-invasive tool for evaluating HFpEF patients.