In-hospital Outcomes and Characteristics of Heart Failure in Sickle Cell Disease

Abstract

Sickle cell disease (SCD) predominantly affects African-Americans (AAs) in the United States (US). Due to increasing life expectancy in developed countries, SCD-associated cardiomyopathy is typically seen in adults. The aim of this study was to distinguish hospitalization for this phenotype from traditional heart failure (HF) in AAs. We used the National Inpatient Sample (NIS) database to identify HF hospitalizations in AAs between 2005 and 2014 and stratified them according to SCD status. We compared the characteristics and outcomes before and after matching in a 1:3 ratio for age, gender, insurance, smoking status and admission year. Amongst the 1,195,718 HF admissions in AAs, SCD accounted for 7835. The age (mean ± SD) in the SCD cohort was significantly younger (45.66 ± 13.2) vs non-SCD (64.8 ± 15.2), p<0.001. SCD adults had significantly higher rates of pulmonary hypertension (PH), deep vein thrombosis, and pulmonary embolism while non-SCD adults had higher rates of cardiogenic shock and respiratory failure requiring intubation. The national hospitalization rate for HF in AAs increased from 151 to 257 per million between 2005 and 2011 before declining to 241 per million in 2014. There was a decrease in in-hospital mortality in AAs from 4.8% in 2005 to 3.6% in 2014. We also identified independent predictors of in-hospital mortality in SCD with HF. In conclusion, we described hospitalizations for an emerging heart failure phenotype in AAs. Although there is a national decreasing rate of HF hospitalizations in the US, this may not be reflective of the AA population.

Cardiomyopathy in Sickle Cell Disease

“…In the recent study, the pattern of heart failure in Afro-Americans (AA) with SCD versus heart failure in AA without SCD was studied with the help of the National Inpatient Sample Database (NIS), which represents more than 97% of the US population. While it is known that heart failure occurs at an earlier age in African-American (AA), but this study observed that the chances of getting heart failure increase even further in AA patients with SCD [1].…”

“…SCD, which originated from Sub-Saharan Africa, Southeast Asia and India, has been known to be the most common inherited hemoglobinopathy worldwide due to increasing migration in the modern world. Prolonged exposure to high cardiac output state from chronic anemia in SCD leads to significant dilatation of LV which, over time, adapts to increased wall stress by developing eccentric LV hypertrophy, as shown in Figure 1 [1,7,8]. Myocardial remodeling can be well tolerated for a long time; however, myocardial damage can occur from chronic volume overload leading to exercise intolerance and heart failure.…”

“…Complications of sickle cell disease (SCD) represent the significant health care burden in developed countries and cardiovascular (CV) complications being the highest causes of mortality [1]. SCD is an inherited blood disorder in which point mutation in the beta-globin gene results in the production of hemoglobin S that polymerizes within the erythrocyte during deoxygenation, making red blood cells (RBCs) rigid and sickle-shaped.…”

“…This hemoglobin S creates a state of chronic hemolytic anemia due to splenic sequestration of abnormal erythrocytes. Chronic anemia in SCD results in prolonged exposure to a high cardiac output state that causes compensatory eccentric myocardial remodeling, resulting in left ventricular (LV) hypertrophy, dilation, and atrial distension [1]. This chronic anemia is treated with frequent blood transfusions, which in turn leads to iron overload.…”