Abstract 15405: Role of Noninvasive Assessment in Prediction of Preclinical Cardiac Affection in Multi-transfused Thalassaemia Major Patients
Background: Chronically transfused β-thalassemia major (β-TM) patients die from cardiac iron overload in their teens and twenties. Monitoring of iron status through cardiac magnetic resonance imaging (CMRI) has replaced the conventional methods of assessment, yet this modality is not readily available in centers where the disease distribution is maximal.
Objectives: To study the ability of some simple tools to predict preclinical cardiac affection (PCCA) reflecting cardiac iron deposition (CID) in β-TM patients taking the T2* CMRI as a gold standard reference test.
Methods: One hundred multi-transfused β-TM patients were included. Serum ferritin, hepcidin, and hs-CRP as well as echo-doppler and 24h Holter were used to predict CID, and consequently PCCA, in reference to CMRI results.
Results: According to CMRI results, patients were divided into group with detectable myocardial iron (DMI) (T*≤ 20ms) representing the PCCA (42 patients), and group with no DMI (T*>20ms). No differences in age, gender or splenectomy were observed between both groups. Patients with DMI received more transfusions per year (14.6±1.7 vs 12.5±1.7 transfusions; p<0.001) but with comparable levels of serum ferritin, hepcidin and hepcidin/ferritin ratio (p>0.05). CID was associated with lower heart rate (75±6.1 vs 80±6.9 bpm), lower left ventricular ejection fraction (LVEF) (60.1±3.2 vs 70.1±2.8%), and higher total number of premature ventricular contractions (PVCs) per day (median 78 vs 14 beats) P<0.001 in all. The group with DMI comprised more patients with left ventricular diastolic dysfunction (LVDD) (35.7 vs 5.2%); PVCs ≥10/h (31 vs 3.4%) P<0.001; episodes of Sinus pauses (14.3 vs 1.7%); and episodes of high grade AV Block (11.9 vs 1.7%) P<0.05. In presence of normal LVEF, detection of ten or more PVCs/hour was the most predictive of CID with a positive predictive value (PPV) of 86.7% and specificity of 96.6%, and the highest likelihood ratio (9.09). Detection of more than 22 PVCs/24 hours had the best sensitivity (81%) and the best negative predictive value (84%).
Conclusion: Our results support our hypothesis that simple non-invasive tools like Holter and ECHO can serve as a reasonable alternative to detect PCCA reflecting early CID in β-TM in centers lacking MRI facilities.
- © 2013 by American Heart Association, Inc.