- Pulmonary hypertension (PH) and right heart failure are well-established risk factors for mortality in sickle cell disease (SCD).
- Observational studies have consistently shown that increased tricuspid regurgitant jet velocity (TRV) measured by Doppler echocardiography, an increased serum N-terminal pro–brain natriuretic peptide (NT-pro-BNP) level, and pulmonary hypertension measured by right heart catheterization are all independent risk factors for mortality in adults.
- To reduce the variability and to improve the quality of care that patients with SCD receive, the ATS developed clinical practice guidelines to advise hematologists, pulmonologists, cardiologists, pediatricians, and internists about how to identify and manage patients with SCD who are at increased risk for mortality.
Risk stratification guides clinical decision making in SCD:
- Mortality risk can be accurately determined by noninvasive measurement of the TRV via Doppler echocardiography. (Note: In children ≥8 yr old the TRV determines morbidity risk, rather than mortality risk, and provides a baseline for future comparisons.)
- Serum NT-pro-BNP measurement is a reasonable noninvasive alternative when Doppler echocardiography is either unavailable or cannot obtain adequate images.
Note: Measurements may be misleading in patients with renal insufficiency.
- Mortality risk can also be determined invasively by direct hemodynamic measurements via right heart catheterization (RHC).
An increased risk for mortality is defined as a TRV ≥2.5 m/second, an NT-pro-BNP level ≥160 pg/ml, or RHC-confirmed PH (a resting mean pulmonary arterial pressure ≥25 mm Hg). Hemodynamics in PH of SCD
may be consistent with pre- or postcapillary PH or have features of both.
Table 1. Sample Questions for Evaluation of Dyspnea
- Do you get short of breath at rest?
- Do you get short of breath with minimal exertion? (e.g., walking across
a room, doing light housework, putting on your shoes, talking on the telephone)
- How far can you walk before stopping due to shortness of breath?
- How far can you walk on an incline before stopping?
- How many flights of stairs can you climb before stopping?
- For how long have you felt short of breath?
- Do you have chest pain with exertion?
- Do you have any trouble breathing while you sleep or lie flat in bed?
- Have you ever passed out?
- Have you ever felt you were about to pass out?
- Do you have any dizziness or light-headedness at rest or with exertion?
- Do you have swelling in your legs?
- Do you have swelling in your abdomen?