Correlation of ECG left ventricular strain pattern with late gadolinium enhancement on cardiac magnetic resonance and impact on mortality in cardiac amyloidosis: a multimodality-imaging study
N Saeed, A I Andreas Ingebrigtsen, S S Sahrai Saeed, H R Haakon Reikvam, T H L Terje H. LarsenAbstract
Background
Electrocardiographic (ECG) abnormalities, including low voltage and pseudo-infarct pattern, have been studied in patients with cardiac amyloidosis. However, the clinical significance and prognostic value of left ventricular (LV) strain pattern on ECG (LVS-ECG) and its correlation with late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) remain inadequately investigated.
Purpose
How does LVS-ECG correlate with LGE on CMR and what is the prognostic value for mortality?
Method
Eighty-four patients with laboratory- and imaging-verified amyloidosis (AL 65 [77.4%], ATTR 19 [22.6%]) were included. LVS-ECG was defined as down-sloping, convex ST-segment depression with asymmetric T-wave inversion in leads V5-V6 (Figure 1). Survival was analysed by Cox proportional hazards regression for association of LVS-ECG with all-cause mortality.
Results
Mean age was 67.5±13.5 years, and 70.2% (n=59) were male. Cardiac involvement was seen in 75% of patients (68.0% in AL, 100.0% in ATTR amyloidosis, p=0.004) (Table 1). LVS-ECG prevalence was 34.5% (n=29), low voltage ECG 66.7% (n=56) and pseudo-infarct pattern 44.0% (n=37). LGE on CMR was found in 94.0% of patients with LVS-ECG and 63.0% without. Patients with LVS-ECG were more likely to be male, have higher creatinine, elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), and left atrial and LV remodelling (all p<0.005). During median follow-up of 28 months (range 0-143), 42 deaths occurred (23/55 [42%] in those without LVS-ECG, 19/29 [66%] with LVS-ECG, p=0.039). LVS-ECG was associated with a 2.5-fold increased risk of all-cause mortality (HR 2.49; 95% CI 1.32-4.67, p=0.005) in univariate and 2.7-fold risk (HR 2.66; 95% CI 1.26-5.62, p=0.011) in multivariate Cox analysis after adjusting for age, gender, atrial fibrillation, serum creatinine, cTnT and LV ejection fraction. After substituting cTnT with NT-proBNP, LVS-ECG remained a strong predictor of all-cause mortality (HR 2.58 95% CI 1.18-5.62, p=0.017).
Conclusion
In cardiac amyloidosis, LV strain on ECG was common and strongly correlated with LGE on cardiac MR, reflecting myocardial fibrosis. LVS-ECG was an independent and powerful predictor of mortality and may indicate advanced cardiac damage from extensive amyloid infiltration.