Pulmonary embolism in sickle cell disease: a case-control study

A pulmonary embolism (PE) is a leading cause of mortality in hospitalized patients, yet the prevalence of PE in sickle cell disease (SCD) and its relation to disease severity or intrinsic hypercoagulability are not established.

We estimated inpatient PE incidence and prevalence among SCD and non-SCD populations in Pennsylvania, and compared severity of illness and mortality, using Pennsylvania Health Care Cost Containment Council (PHC4) discharge data, 2001-2006. Risk factors for PE were assessed in a case-control study of discharges from the University of Pittsburgh Medical Archival Records System (MARS).

The incidence of inpatient PE was higher in the SCD PA population than in the non-SCD Pennsylvania population, 2001-2006. The PE prevalence among SCD discharges ≤ 50 years of age, 0.57%, was similar to that in non-SCD Pennsylvania discharges, 0.60%, and unchanged after adjustment for race. Among SCD discharges, those developing PE were significantly older, with a longer length of stay, greater severity of illness and higher mortality, P < 0.001, than SCD without a PE. Among PE discharges, SCD had a similar severity of illness, P = 0.77, and mortality, P = 0.39, but underwent fewer computerized tomographic scans, P = 0.006, than non-SCD with PE. In the local case-control study, no clinical or laboratory feature was associated with PE.

The incidence of PE is higher and chest computed tomography (CT) utilization is lower in SCD than non-SCD inpatients, suggesting that PE may be under-diagnosed.