P1514: MULTI-PARAMETRIC CARDIAC MAGNETIC RESONANCE FOR RISK PREDICTION OF HEART FAILURE DEATH IN THALASSEMIA MAJOR

Abstract

Background: Iron-induced heart failure (HF) is the main cause of mortality in patients with thalassemia major (TM). Cardiovascular Magnetic Resonance (CMR) plays a key role in the management of these patients, assessing myocardial iron overload (MIO), biventricular function, and myocardial fibrosis. Aims: We evaluated the prognostic value of CMR parameters in predicting death for HF. Methods: We followed prospectively 1681 white TM patients who performed a baseline CMR exam within the Myocardial Iron Overload in Thalassemia (MIOT) network. All prognostic variables associated with the outcome at the univariate Cox model were placed in the multivariate model and were ruled out if they did not significantly improve the adjustment. Results: At baseline the mean age was 31.11±9.01 years and 874 (52.0%) patients were females. During a mean follow-up of 4.76±2.07 years, 47.3% of the patients changed at least once the chelation regimen, that is switched to a different type of chelator or underwent dose/frequency modification. Sixteen (1.0%) patients died for heart failure. No association was detected between age or gender and HF mortality. Patients who died for HF had significantly lower baseline global heart T2* values (19.45±15.11 ms vs 29.52±12.02 ms, P=0.006) and significantly higher baseline MR liver iron concentration (LIC) values (19.17±15.95 mg/g dw vs 8.72±10.63 mg/g dw, P=0.005) than patients still alive or died for a different cause, but the presence of a pathologic MRI LIC (>3 mg/g dw) was not associated with an increased risk of HF mortality. Heart iron, ventricular dysfunction, and ventricular dilatation were significant univariate prognosticators. In the multivariate analysis the independent predictive factors were a global heart T2*<10 ms (compared to a global heart T2*≥20 ms) (hazard ratio-HR=5.38, 95%CI=1.79-16.22, P=0.003) and ventricular dilatation (HR=4.59, 95%CI=1.55-13.59, P=0.006). The Figure shows the Kaplan–Meier survival curves. The log-rank test revealed a significant difference in the curves for each predictor (severe MIO: P<0.0001 and ventricular dilatation: P<0.0001). Image:Summary/Conclusion: We detected few HF deaths thanks to a MR-guided patient-specific adjustment of the chelation therapy. Severe MIO and ventricular dilatation identified TM patients at high risk for heart failure death. So, a widespread program using CMR exploiting its multi-parametric potential can have considerable power for further opening the prognosis of TM patients.