Prevalence and factors associated with dyspnea in adult patients with Hemoglobin SC disease: a study of 221 cases

Abstract

Sickle cell disease is the most frequent genetic hemoglobinopathy worldwide and early childhood mortality has dramatically decreased in high-income countries. However, in the aging sickle cell disease population, the morbidity related to chronic organ damage, especially kidney and heart, has become a major concern. The disease is well characterized in homozygous SS patients, but the complications associated with Haemoglobin SC disease (HbSC) are mostly unknown. Dyspnea is frequent in SS patients and associated with poor quality of life, this symptom was not investigated in HbSC patients. Our objective is to investigate the prevalence and the factors associated with dyspnea in HbSC patients. A total of 221 HbSC patients (mean age 35 years, 47% men) were prospectively investigated. Clinical and biological data were collected, and 109 (49%) patients underwent an echocardiography. A dyspnea was observed in 28 (13%) patients. Compared to the rest of the cohort, these patients were older and had a lower hemoglobin level ( P < 0,001). In the subgroup with echocardiographic examination, the left ventricular (LV) ejection fraction was preserved in all the patients. An LV diastolic dysfunction was diagnosed in 25 (23%) patients, 10 had dyspnea and 15 were asymptomatic ( P = 0.06). In multivariable analysis, age (Odds ratio 0,94 [0,91–0,97]) and hemoglobin level (1,74 [1,17–2,58]) were independently associated with dyspnea ( Fig. 1 ). Dyspnea is relatively uncommon in adult HbSC patients and related to age and hemoglobin level. Cardiac involvement seems not to be a major factor associated to dyspnea in HbSC patients.