Do echocardiographic parameters differentiate infiltrative and storage disorders from hypertensive heart disease in patients with increased left ventricular wall thickness?
Simple echocardiographic parameters, particularly mass-to-strain ratio and a linear discriminant analysis model, can accurately differentiate between cardiac amyloidosis, Anderson-Fabry disease, and hypertensive heart disease in patients with increased left ventricular wall thickness.
Aims Differentiating phenotypes of cardiac “hypertrophy” characterised by increased wall thickness on echocardiography is essential for management and prognostication. Transthoracic echocardiography is the most commonly used screening test for this purpose. We sought to identify echocardiographic markers that distinguish infiltrative and storage disorders that present with increased left ventricular (LV) wall thickness, namely, cardiac amyloidosis (CA) and Anderson–Fabry disease (AFD), from hypertensive heart disease (HHT). Methods Patients were retrospectively recruited from Westmead Hospital, Sydney, and Princess Alexandra Hospital, Brisbane. LV structural, systolic, and diastolic function parameters, as well as global (LVGLS) and segmental longitudinal strains, were assessed. Previously reported echocardiographic parameters including relative apical sparing ratio (RAS), LV ejection fraction-to-strain ratio (EFSR), mass-to-strain ratio (MSR) and amyloidosis index (AMYLI) score (relative wall thickness × E / e ′) were evaluated. Results A total of 209 patients 120 CA 58 transthyretin amyloidosis (ATTR) and 62 light-chain (AL) amyloidosis, 31 AFD and 58 HHT patients; mean age 64. 1 ± 13. 7 years, 75% male comprised the study cohort. Echocardiographic measurements differed across the three groups, The LV mass index was higher in both CA median 126. 6 interquartile range (IQR) 106. 4–157. 9 g/m 2 and AFD median 134 (IQR 108. 8–152. 2 g/m 2) vs. HHT median 92. 7 (IQR 79. 6–102. 3 g/m 2), p 0. 05. LVGLS was lowest in CA median 12. 29 (IQR 10. 33–15. 56%) followed by AFD median 16. 92 (IQR 14. 14–18. 78%) then HHT median 18. 56 (IQR 17. 51–19. 97%), p 0. 05. Diastolic function measurements including average e ′ and E / e ′ were most impaired in CA and least impaired in AFD. Indexed left atrial volume was highest in CA. EFSR and MSR differentiated secondary (CA + AFD) from HHT receiver operating curve–area under the curve (ROC-AUC) of 0. 80 and 0. 91, respectively. RAS and AMYLI score differentiated CA from AFD (ROC-AUC of 0. 79 and 0. 80, respectively). A linear discriminant analysis with stepwise variable selection using linear combinations of LV mass index, average e ′, LVGLS and basal strain correctly classified 79% of all cases. Conclusion Simple echocardiographic parameters differentiate between different “hypertrophic” cardiac phenotypes. These have potential utility as a screening tool to guide further confirmatory testing.
Ferkh et al. (Mon,) studied this question.