Comparative analysis of phasic left atrial strain and left ventricular posterolateral strain pattern to discriminate Fabry cardiomyopathy from other forms of left ventricular hypertrophy.

BACKGROUND: "Classical" echocardiographic signs of Fabry cardiomyopathy (FC), such as left ventricular hypertrophy (LVH), posterolateral strain impairment (PLSI), and papillary muscle hypertrophy may be of limited diagnostic accuracy in clinical practice. Our aim was to evaluate the diagnostic value of left atrial (LA) strain impairment compared to "classical" echocardiographic findings to discriminate FC. METHODS: In standard echocardiographic assessments, we retrospectively analyzed the diagnostic value of the "classical" red flags of FC as well as LA strain in 20 FC patients and in 20 subjects with other causes of LVH. Receiver operating characteristic (ROC) curve analysis was performed to assess the respective diagnostic accuracy. RESULTS: FC was confirmed in 20 patients by genetic testing. In the LVH group, 12 patients were classified by biopsy to have hypertrophic cardiomyopathy, two had hypertensive heart disease, and six LVH combined with borderline myocarditis. Global and regional left ventricular (LV) strain was not significantly different between groups while LA strain was significantly impaired in FC (Left atrial reservoir strain (LASr) 19.1%±8.4 in FC and 25.6%±8.9 in LVH, p = 0.009; left atrial conduction strain (LAScd) -8.4%±4.9 in FC and -15.9%±8.4 in LVH, p < 0.01). LAScd, with an area under the curve (AUC) of .81 (95% confidence interval [CI] .66-.96) showed the highest diagnostic accuracy to discriminate FC. The PLSI pattern showed an AUC of .49, quantification of papillary muscle hypertrophy an AUC of .47. CONCLUSION: Adding LA strain analysis to a comprehensive echocardiographic work-up of unclear LVH may be helpful to identify FC as a possible cause.

Phasic left atrial strain analysis to discriminate cardiac amyloidosis in patients with unclear thick heart pathology.

AIMS: Traditional echocardiographic parameters for the assessment of suspected cardiac amyloidosis (CA) are of limited diagnostic accuracy. We sought to explore differences and the discriminative value of phasic left atrial strain (LAS) reductions and of regional longitudinal left ventricular (LV) strain alterations (relative apical sparing; RELAPS) in CA and other causes of LV wall thickening (LVH). METHODS AND RESULTS: We included 54 patients with unclear LVH (mean septal diastolic wall thickness 17.8 ± 3.5 mm); CA was bioptically confirmed in 35 patients (8 mATTR, 6 wtATTR, 20 AL, and 1 AA amyloidosis) and LVH in 19 subjects. We analysed RELAPS as well as LA reservoir (LASr), conduit (LAScd), and contraction strain (LASct) using 2D speckle tracking echocardiography (EchoPAC software, GE). RELAPS was higher (1.37 ± 0.94 vs. 0.86 ± 0.29, P < 0.007), whereas atrial mechanics were significantly reduced in CA (LASr, LAScd, and LASct: 9.7 ± 5.2%, -6.5 ± 3.5%, and -5.0 ± 4.1% in CA; and 22.7 ± 7.8%, -13.9 ± 5.2%, and -13.0 ± 5.5% in LVH, respectively; P < 0.001 each). With an area under the curve (AUC) of 0.91 [95% confidence interval (CI) 0.82-0.99], LASr showed a higher diagnostic accuracy in discriminating CA than RELAPS (AUC 0.74, 95% CI 0.59-0.88). LASr and LAScd remained significantly associated with CA in a multivariate regression model. CONCLUSION: Phasic LAS was significantly reduced in patients with CA and showed a higher diagnostic accuracy in discriminating CA than RELAPS. The additional assessment of phasic LAS may be useful to rule in the possible diagnosis of CA in patients with unclear LVH.