Predicting which patients may have ATTR-CM can be complicated and this study attempts to develop a simple and useful way to determine which patients would benefit from further ATTR-CM testing.
Transthyretin amyloid cardiomyopathy (ATTR-CM) can drastically decrease patients’ life expectancies and quality of life, so determining which patients are at risk of this disease is a high priority, although challenging. This study, published in JAMA Cardiology, analyzed which patients with heart failure and preserved ejection fraction have sufficiently increased risk of ATTR-CM, to warrant technetium Tc 99m pyrophosphate scintigraphy (PYP). The study relied on a risk score comprised of 3 clinical factors (age, sex, and hypertension diagnosis) and 3 echocardiographic factors (ejection fraction, posterior wall thickness, and relative wall thickness).
The retrospective cohort study comprised 666 patients with heart failure and suspected ATTR-CM referred for PYP at Mayo Clinic in Rochester, MN, from 2013 to 2020. A logistic regression model was used to predict ATTR-CM and was converted to a point-based ATTR-CM risk score. The score was subsequently analyzed and validated in a community of ATTR-CM epidemiology study of older patients with increased left ventricular wall thickness, as well as other studies. Participant cohorts included referral validation, community validation, and external validation. Precision-recall curves and predictive value versus prevalence plots indicated clinically useful classification performance for a score of 6 or more in clinically relevant ATTR-CM prevalence scenarios.
The authors conclude that the 6-variable clinical score that they developed is useful in determining which patients should receive PYP, and that it can increase recognition of ATTR-CM in patients with heart failure and preserved ejection fraction. They note further validation in larger and more diverse populations is required.
Davies, D. R., Redfield, M. M., Scott, C. G., Minamisawa, M., Grogan, M., Dispenzieri, A., Chareonthaitawee, P., Shah, A. M., Shah, S. J., Wehbe, R. M., Solomon, S. D., Reddy, Y. N. V., Borlaug, B. A., & AbouEzzeddine, O. F. (2022). A Simple Score to Identify Increased Risk of Transthyretin Amyloid Cardiomyopathy in Heart Failure With Preserved Ejection Fraction. JAMA Cardiol, 7(10), 1036-1044. https://doi.org/10.1001/jamacardio.2022.1781