Pulmonary Haemodynamics in Sickle Cell Disease Are Driven Predominantly by a High-Output State Rather Than Elevated Pulmonary Vascular Resistance: A Prospective 3-Dimensional Echocardiography/Doppler Study.
OBJECTIVE
Patients with sickle cell disease have significant morbidity and mortality. Pulmonary hypertension is suggested to be an important contributor but its nature and severity in these patients and how best to non-invasively assess it are controversial. We hypothesised that a high-output state rather than primary pulmonary vascular pathology may be the major abnormality in sickle cell disease. This study aimed to evaluate the characteristics and severity of pulmonary hypertension in patients with sickle cell disease using detailed echocardiography.


RESULTS
We undertook a prospective study in 122 consecutive stable outpatients with sickle cell disease and 30 age, gender and ethnicity-matched healthy controls. Echocardiographic evaluation included 3D ventricular volumes, sphericity, tissue Doppler, and non-invasive estimation of pulmonary vascular resistance. 36% of patients had a tricuspid regurgitant velocity ≥2.5 m.s(-1) but only 2% had elevated pulmonary vascular resistance and the prevalence of right ventricular dysfunction was very low. Patients with raised tricuspid regurgitant velocity had significantly elevated biventricular volumes and globular left ventricular remodelling, related primarily to anaemia. In a subgroup of patients who underwent cardiac catheterization, invasive pulmonary haemodynamics confirmed the echocardiographic findings.


CONCLUSIONS
Elevated cardiac output and left ventricular volume overload secondary to chronic anaemia may be the dominant factor responsible for abnormal cardiopulmonary haemodynamics in patients with sickle cell disease. 3D echocardiography with non-invasive estimation of pulmonary vascular resistance represents a valuable approach for initial evaluation of cardiopulmonary haemodynamics in sickle cell disease.
King's College London British Heart Foundation Centre, Cardiovascular Division, London, United Kingdom; Department of Cardiology, King's College Hospital, Denmark Hill, London, United Kingdom.
Sitali
S
Mushemi-Blake
King's College London British Heart Foundation Centre, Cardiovascular Division, London, United Kingdom; Department of Cardiology, King's College Hospital, Denmark Hill, London, United Kingdom.
Narbeh
N
Melikian
Department of Haematological Medicine, King's College Hospital, Denmark Hill, London, United Kingdom.
Emma
E
Drasar
Department of Cardiology, King's College Hospital, Denmark Hill, London, United Kingdom.
Amit
A
Bhan
Department of Paediatrics, King's College Hospital, Denmark Hill, London, United Kingdom.
Alan
A
Lunt
Department of Radiology, King's College Hospital, Denmark Hill, London, United Kingdom.
Sujal R
SR
Desai
Department of Paediatrics, King's College Hospital, Denmark Hill, London, United Kingdom.
Anne
A
Greenough
King's College London British Heart Foundation Centre, Cardiovascular Division, London, United Kingdom; Department of Cardiology, King's College Hospital, Denmark Hill, London, United Kingdom.
Mark J
MJ
Monaghan
Department of Haematological Medicine, King's College Hospital, Denmark Hill, London, United Kingdom; NIH / National Institute of Heart, Lung and Blood Diseases, Sickle Cell Branch, Bethesda, Maryland, United States of America.
Swee Lay
SL
Thein
King's College London British Heart Foundation Centre, Cardiovascular Division, London, United Kingdom; Department of Cardiology, King's College Hospital, Denmark Hill, London, United Kingdom.
Ajay M
AM
Shah
D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002302:Cardiac Output / Q000502:physiology; D015150:Echocardiography, Doppler / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D014261:Tricuspid Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014655:Vascular Resistance / Q000502:physiology; D055815:Young Adult