Right ventricular volumes and function in thalassemia major patients in the absence of myocardial iron overload.
OBJECTIVE
We aimed to define reference ranges for right ventricular (RV) volumes, ejection fraction (EF) in thalassemia major patients (TM) without myocardial iron overload.


RESULTS
RV volumes, EF and mass were measured in 80 TM patients who had no myocardial iron overload (myocardial T2* > 20 ms by cardiovascular magnetic resonance). All patients were receiving deferoxamine chelation and none had evidence of pulmonary hypertension or other cardiovascular comorbidity. Forty age and sex matched healthy non-anemic volunteers acted as controls. The mean RV EF was higher in TM patients than controls (males 66.2 +/- 4.1% vs 61.6 +/- 6%, p = 0.0009; females 66.3 +/- 5.1% vs 62.6 +/- 6.4%, p = 0.017), which yielded a raised lower threshold of normality for RV EF in TM patients (males 58.0% vs 50.0% and females 56.4% vs 50.1%). RV end-diastolic volume index was higher in male TM patients (mean 98.1 +/- 17.3 mL vs 88.4 +/- 11.2 mL/m2, p = 0.027), with a higher upper limit (132 vs 110 mL/m2) but this difference was of borderline significance for females (mean 86.5 +/- 13.6 mL vs 80.3 +/- 12.8 mL/m2, p = 0.09, with upper limit of 113 vs 105 mL/m2). The cardiac index was raised in TM patients (males 4.8 +/- 1.0 L/min vs 3.4 +/- 0.7 L/min, p < 0.0001; females 4.5 +/- 0.8 L/min vs 3.2 +/- 0.8 L/min, p < 0.0001). No differences in RV mass index were identified.


CONCLUSIONS
The normal ranges for functional RV parameters in TM patients with no evidence of myocardial iron overload differ from healthy non-anemic controls. The new reference RV ranges are important for determining the functional effects of myocardial iron overload in TM patients.
Carpenter
John-Paul
JP
Cardiovascular MR Unit, Royal Brompton Hospital, London, London, UK.
Alpendurada
Francisco
F
Deac
Monica
M
Maceira
Alicia
A
Garbowski
Maciej
M
Kirk
Paul
P
Walker
J Malcolm
JM
Porter
John B
JB
Shah
Farrukh
F
Banya
Winston
W
He
Taigang
T
Smith
Gillian C
GC
Pennell
Dudley J
DJ
D000328:Adult; D001803:Blood Transfusion; D016022:Case-Control Studies; D003676:Deferoxamine / Q000627:therapeutic use; D005260:Female; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism; D007502:Iron Chelating Agents / Q000627:therapeutic use; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D011237:Predictive Value of Tests; D012016:Reference Values; D012189:Retrospective Studies; D013318:Stroke Volume; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016278:Ventricular Function, Right; D055815:Young Adult; D017086:beta-Thalassemia / Q000150:complications* / Q000378:metabolism / Q000628:therapy
D006454:Hemoglobins; D007502:Iron Chelating Agents; D007501:Iron; D003676:Deferoxamine