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  • Open Access

Biventricular dimensions and function in pediatric sickle-cell disease and thalassemia major patients without cardiac iron

  • 1, 2,
  • 2,
  • 3,
  • 1,
  • 1,
  • 3 and
  • 1, 4
Journal of Cardiovascular Magnetic Resonance201315 (Suppl 1) :P111

https://doi.org/10.1186/1532-429X-15-S1-P111

  • Published:

Keywords

  • Right Ventricular
  • Cardiovascular Magnetic Resonance
  • Iron Overload
  • Thalassemia
  • Thalassemia Major

Background

Chronically anemic patients develop compensatory ventricular dilation, even when maintained on chronic transfusion regimens. Our primary goal was to compare right and left ventricular dimensions and function assessed by Cardiovascular Magnetic Resonance (CMR) in pediatric, chronically-transfused sickle-cell disease (SCD) and thalassemia major (TM) patients who lacked cardiac iron. Moreover we explored systematic sex differences in ventricular dimensions in both populations.

Methods

We reviewed all CMRs identifying 261 studies suitable for analysis from 64 SCD patients (34 females and 30 males) and 49 TM patients (29 males and 20 females). All demographic and CMR parameters were inversely weighted by the number of exams. Analysis of covariance (ANCOVA) models were used to evaluate the impact of potential covariates (variables unbalanced between groups and associated with the outcome) on group differences in CMR parameters.

Results

In both populations, males had larger left ventricular (LV) and right ventricular (RV) dimensions than females, with a more marked effect observed in SCD patients. The percentage difference for the RV was larger than that one seen in normal subjects (from 8 to 14%). Table 1 shows the comparison of LV parameters between SCD and TM with the differentiation by sex. All LV volumes as well as the LV mass were significantly higher in SCD than in TM patients, also adjusting for the covariates. Table 2 shows the comparison of RV parameters between SCD and TM, by sex. Overall findings are similar to those from the LV. All RV volumes remained significantly higher in SCD also after ANCOVA adjustments, except RV ESVI.
Table 1

LV parameters for and SCD and TM pediatric patient without cardiac iron overload, with differentiation for gender. All variables are expressed as mean ± SD with 95% confidence intervals in square brackets.

 

SCD

TM

P

P adjusted for systolic BP

P adjusted for cardiac R2*

P adjusted for both covariates

Males

LV EDVI (ml/m 2 )

104.7 ± 15.2 [99.5 - 109.9]

88.7 ± 11.0 [84.5 - 92.8]

<0.0001

<0.0001

<0.0001

<0.0001

LV ESVI (ml/m 2 )

38.1 ± 7.4 [35.6 - 40.7]

31.6 ± 5.5 [29.5 - 33.6]

<0.0001

<0.0001

0.0003

<0.0001

LV SVI (ml/m 2 )

66.6 ± 9.5 [63.3 - 69.8]

57.1 ± 6.5 [54.6 - 59.5]

<0.0001

<0.0001

<0.0001

<0.0001

LV EF (%)

63.8 ± 3.5 [62.6 - 65.0]

64.7 ± 2.8 [63.6 - 65.7]

0.286

   

LV MI (g/m 2 )

83.5 ± 11.4 [79.1 - 87.9] (27 pts; 45 MRIs)

66.9 ± 7.0 [64.0 - 69.8] (24 pts; 59 MRIs)

<0.0001

<0.0001

<0.0001

<0.0001

LV CI (l/min/m2)

4.8 ± 0.6 [4.6 - 5.1] (32 pts; 55 MRIs)

4.5 ± 0.5 [4.4 - 4.7] (29 pts; 74 MRIs)

0.017

   

Females

LV EDVI (ml/m 2 )

93.5 ± 9.6 [90.0 - 97.0]

81.4 ± 6.7 [78.4 - 84.4]

<0.0001

<0.0001

<0.0001

<0.0001

LV ESVI (ml/m 2 )

36.0 ± 5.3 [34.0 - 37.9]

29.4 ± 3.8 [27.6 - 31.1]

<0.0001

<0.0001

<0.0001

<0.0001

LV SVI (ml/m 2 )

57.5 ± 6.3 [55.2 - 59.8]

52.0 ± 4.2 [50.1 - 53.4]

0.0006

0.009

  

LV EF (%)

61.6 ± 3.5 [60.4 - 62.9]

64.1 ± 2.9 [62.8 - 65.4]

0.008

   

LV MI (g/m 2 )

72.9 ± 8.9 [69.6 - 79.3] (28 pts; 60 MRIs)

62.8 ± 7.5 [60.4 - 66.1] (18 pts; 40 MRIs)

0.0001

0.0002

  

LV CI (l/min/m 2 )

4.6 ± 0.6 [4.4 - 4.8] (72 MRIs)

4.2 ± 0.5 [3.9 - 4.4] (52 MRIs)

0.006

   
Table 2

RV parameters for and SCD and TM pediatric patient without cardiac iron overload, with differentiation for gender. All variables are expressed as mean ± SD with 95% confidence intervals in square brackets.

 

SCD

TM

P

P adjusted for systolic BP

P adjusted for cardiac R2*

P adjusted for both covariates

Males

RV EDVI (ml/m 2 )

103.3 ± 18.8 [96.8 - 109.8]

87.3 ± 11.5 [82.9 - 91.6]

<0.0001

<0.0001

0.0004

0.0002

RV ESVI (ml/m 2 )

37.9 ± 9.6 [34.7 - 41.2]

32.4 ± 5.7 [30.2 - 34.5]

0.0005

0.006

0.050

0.037

RV SVI (ml/m 2 )

65.4 ± 10.8 [61.6 - 69.1]

54.9 ± 6.9 [52.3 - 57.5]

<0.0001

0.016

<0.0001

<0.0001

RV EF (%)

63.8 ± 4.7 [62.2 - 65.4]

63.2 ± 3.4 [61.9 - 64.5]

0.620

   

Females

RV EDVI (ml/m 2 )

84.7 ± 10.3 [80.9 - 88.5]

76.5 ± 9.1 [72.4 - 80.6]

0.005

0.026

0.009

0.051

RV ESVI (ml/m 2 )

31.1 ± 5.8 [28.9 - 33.2]

27.7 ± 5.3 [25.3 - 30.1]

0.037

0.108

  

RV SVI (ml/m 2 )

53.6 ± 6.8 [51.1 - 56.1]

48.8 ± 5.1 [46.6 - 51.1]

0.006

0.047

  

RV EF (%)

63.6 ± 4.6 [61.9 - 65.2]

64.4 ± 3.7 [62.7 - 66.1]

0.477

   

Conclusions

Compared to TM patients, SCD patients showed significantly greater biventricular dilation and LV hypertrophy. This difference could not be explained by different hemoglobin levels, cardiac iron overload and systolic blood pressure. Our results represent important baseline findings that place changes introduced by iron overload as well as systemic and pulmonary vasculopathy in proper context.

Funding

This work was supported by the NHLBI (1 RO1 HL075592-01A1), General Clinical Research Center at the Children's Hospital Los Angeles (RR000043-43), Center for Disease Control (Thalassemia Center Grant U27/CCU922106), Novartis Pharma, and the Department of Pediatrics.

Authors’ Affiliations

(1)
CMR Unit, Fondazione G.Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy
(2)
Department of Pediatrics, Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, USA
(3)
Division of Hematology, Children's Hospital Los Angeles, Los Angeles, CA, USA
(4)
Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA, USA

Copyright

© Meloni et al; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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