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

Abstract

Abstract Aims Transthyretin ‘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 results Sixty 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 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%. Conclusions A 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.

Keywords

• ATTRwt
• AMY score
• Cardiac amyloidosis
• Endomyocardial biopsy
• Heart failure with preserved ejection fraction
• Screening