African-American women have the highest mortality rate for idiopathic pulmonary arterial hypertension (IPAH), according to new research. The study, presented at CHEST 2006 , the 72nd annual international scientific assembly of the American College of Chest Physicians (ACCP), revealed that racial disparities exist in pulmonary hypertension mortality and morbidity, with African-American women exhibiting the highest mortality rate when compared with all other groups.
"Idiopathic pulmonary arterial hypertension, by definition, means that there is no clear attributable cause for this disease," said study author Kala Davis, MD, Stanford University School of Medicine, Stanford, CA. "What has become apparent from this and other studies is that we have been operating with a very limited understanding of the epidemiology of IPAH, and that understanding is now changing."
Dr. Davis and colleagues reviewed data from the United States National Center for Health Statistics from the years 1994 to 1998 for deaths, in which the underlying cause was IPAH. The age, gender, race, and state of residence of the deceased were abstracted, and state-age-gender-race-specific tabulations of deaths, as a result of IPAH, were aggregated into nine geographic regions of the United States, as defined by the Census Bureau. Average, annual, age-adjusted, region-race-gender-specific rates were then calculated.
According to the United States National Center for Health Statistics, a total of 10,053 IPAH-related deaths were reported from 1994 to 1998. Researchers found that, although more Caucasian women reported having the disease, African-American women had the highest mortality rate among all IPAH-related deaths. In addition, researchers found that the highest mortality rates in IPAH were also observed at the extremes of the age spectrum.
"Women overall have higher mortality rates for IPAH, but the substantial difference shown in mortality rates between African-American women and Caucasian women, of all ages, was surprising," said Dr. Davis. "Further analysis of IPAH mortality data from 1999 to 2002 confirms that this trend is continuing." While the reasons for this disparity remain unclear, researchers suggest that under-recognized comorbidities, access to care, insurance, and race-specific genetic factors, are now being recognized as potential causes.
"Race, gender, and age have become defining factors in assessing the risk of death in IPAH," Dr. Davis concluded. "Clinicians must therefore be cognizant of this emerging demographic profile, which contrasts with the classic description of the condition as being a disease of middle aged, Caucasian women."
Pulmonary arterial hypertension is a rare disorder that affects the blood vessels within the lungs and leads to an increase in the pressure within the pulmonary arteries. This can lead to symptoms, such as unexplained shortness of breath on exertion, chest pain, fainting, and death. In the United States, an estimated 500 to 1,000 new cases of idiopathic pulmonary hypertension are diagnosed each year.
"Idiopathic pulmonary hypertension is a serious illness that is difficult to diagnose and manage," said Mark J. Rosen, MD, FCCP, President of the American College of Chest Physicians. "The results of this study provide a new outlook in terms of race and gender as risk factors for increased mortality in IPAH and may provide further insight into the management of IPAH in specific populations."