Transthyretin amyloid cardiomyopathy among patients with heart failure and preserved ejection fraction: the AMY score

Abstract

AbstractAimsTransthyretin ‘wild‐type’ amyloid cardiomyopathy (ATTRwt‐CM) is a differential diagnosis of heart failure with preserved ejection fraction (HFpEF). The clinical work‐up for ATTRwt‐CM is challenging. Considering a combination of clinical variables specific for ATTRwt‐CM might aid in identifying patients at risk.Methods and resultsSixty patients (78 ± 6 years, 8% female) were diagnosed with ATTRwt‐CM by endomyocardial biopsy. Preserved ejection fraction (LVEF >45%) was present in 41 of the patients. Those were 1:1 propensity score age‐ and sex‐matched to a cohort of patients with HFpEF. ATTRwt‐CM patients had less obesity (P = 0.01) and higher septal thickness (IVSd, P < 0.01) as well as more diastolic dysfunction (E/e′, P < 0.01). On multivariable regression IVSd > 14 mm, E/e′ > 14 and absence of obesity (P > 0.01 for all) were identified as predictors for ATTRwt‐CM. A weighted point‐based score was derived with IVSd > 14 mm = 1 point; absence of obesity = 2 points; and E/e′ > 14 = 3 points. Area under the curve (AUC) for the summation score was 0.91 (0.84–0.97, P < 0.01) and a score of more than 3 points predicted ATTRwt‐CM with good sensitivity (78%) and specificity (90%). The score was validated in an external cohort of 142 patients with ATTRwt‐CM and 419 HFpEF patients showing sufficient accuracy (AUC 0.91, 0.88–0.94, P < 0.01). A value greater than 3 points demonstrated a high sensitivity (93%) and a negative predictive value of 97%.ConclusionsA score based on basic clinical and echocardiographic features helps to distinguish ATTRwt‐CM from typical HFpEF. This could facilitate the diagnostic work‐up for these patients and enable earlier disease screening on a large scale.