Prognostic CMR parameters for heart failure and arrhythmias in large cohort of well treated thalssemia major patients

Abstract

Purpose: Cardiovascular Magnetic Resonance (CMR) plays a key role in the management of thalassemia major (TM), allowing to assess myocardial iron overload (MIO), biventricular function, atrial dimensions, and myocardial fibrosis. We determined the predictive value of CMR parameters for heart failure (HF) and arrhythmias in TM. Methods: We followed prospectively 537 patients enrolled in the MIOT network. Fifty patients were excluded because a cardiac complication was present at the time of the first CMR. All variables associated with the outcome at the univariate model were placed in the multivariate model and ruled out if they did not significantly improve the model's adjustment. Results: At baseline the mean age was 29.5±9.0 years and 222 were males. The mean follow-up time was 58±18 months. After the first CMR scan only the 37.8% of the patients did not change the chelator or the frequency/dosage. We recorded 19 episodes of HF. In the multivariate analysis the independent predictive factors were an homogeneous pattern of MIO (vs no MIO) (HR=5.81 P=0.014), global heart T2* 20 ms) (HR=6.19 P=0.003), myocardial fibrosis (HR=4.76 P=0.003; Kaplan–Meier curve in Figure) and ventricular dysfunction (HR=3.21 P=0.029). Arrhythmias (all supraventicular hyperhyperkinetic) occurred in 19 patients. In the multivariate analysis the independent predictive factors were male sex (HR=3.17 P=0.047) and atrial dilation (HR=3.07 P=0.026). ![Figure][1] Conclusion: We detected few cardiac events thanks to a CMR-guided, patient-specific adjustment of the chelation therapy. Severe and homogeneous MIO, myocardial fibrosis and ventricular dysfunction identify patients at high risk of HF. Heart T2* doesn't have any power in predicting arrhythmias while male sex and atrial dilation are independent prognosticators. [1]: pending:yes