Integrated echo-ECG indices based on the ratio of maximum septal thickness to QRS voltage in leads I and/or aVR were independently associated with CMR-derived extracellular volume (p < 0.001).
Observational (n=138)
Yes
Does the integrated echo-ECG index (MST-to-QRS voltage ratio) correlate with CMR-derived ECV in patients with cardiac amyloidosis?
The MST-to-QRS voltage ratio in leads I and/or aVR is a simple, widely accessible tool that correlates with myocardial amyloid burden assessed by CMR.
p-value: p=<0.001
BACKGROUND: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy associated with adverse outcomes. Quantification of myocardial amyloid burden is essential for risk stratification. Although cardiac magnetic resonance (CMR)-derived extracellular volume (ECV) is the reference standard for non-invasive assessment, its use is limited by cost and availability. Therefore, simple and widely accessible tools to estimate amyloid burden are needed. This study aimed to evaluate whether a novel integrated echocardiographic-electrocardiographic (echo-ECG) index, based on the ratio of maximum septal thickness (MST) to QRS voltage in lead I and/or aVR, correlates with CMR-derived ECV in patients with CA. METHODS: We retrospectively analysed 138 consecutive patients with transthyretin or light-chain CA who underwent CMR at four Italian referral centres. MST/QRS ratios (MST/QRS I, MST/QRS aVR, and MST/(QRS I + aVR)) were calculated using echocardiography and standard 12‑lead ECG. RESULTS: On multivariable linear regression with ECV as a continuous variable, the integrated echo-ECG indices were independently associated with ECV (all p < 0.001); lower QRS voltages in leads I and aVR were also independently associated with higher ECV (both p < 0.01), whereas total QRS voltage was not. In a secondary analysis dichotomising ECV at the cohort median (47%), the integrated echo-ECG indices showed moderate discrimination for higher ECV (AUC 0.71-0.73). CONCLUSIONS: MST-to-QRS voltage ratios in leads I and/or aVR are simple and widely accessible markers that correlate with myocardial amyloid burden and may support non-invasive assessment of disease severity in CA.
Sclafani et al. (Tue,) conducted a observational in Cardiac amyloidosis (n=138). Integrated echo-ECG indices (MST/QRS ratios) was evaluated on CMR-derived extracellular volume (ECV) as a continuous variable (p=<0.001). Integrated echo-ECG indices based on the ratio of maximum septal thickness to QRS voltage in leads I and/or aVR were independently associated with CMR-derived extracellular volume (p < 0.001).