African Americans Tend to Have More Severe Systemic Sclerosis-Associated PAH
More often than not, risk factors for and development rates of cardiovascular diseases vary according to race and ethnicity, and pulmonary arterial hypertension due to systemic sclerosis is no exception. A study from Johns Hopkins University, appearing in the journal European Respiratory Journal, identified the fact that African Americans tend to have more severe systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH).
The finding is based on right ventricular dysfunction measurements taken from nine African Americans and 66 Caucasians with SSc-PAH. Within the cohort, 41 patients (54.7%) were grouped in World Health Organization functional class III or IV, which is the most severe class of pulmonary hypertension (on a scale of I-IV). The two racial groups had no significant difference in mean age or disease duration, but it is known African Americans tend to develop systemic sclerosis younger than other ethnic groups.
Other measurements taken that showed worse results in African Americans were higher mean pulmonary artery pressure (MPAP), higher pulmonary vascular resistance (PVR), and lower stroke volume index (SVI). Pulmonary capillary wedge pressure (PCWP) was similar between the two groups. These measurements were taken via heart catheterization.
Interesting to note is that, despite the difference in severity, patient treatment plans were similar between the two groups. Median survival was not significantly different and neither was renal dysfunction.
When interpreting the results, it should be noted that the study sample size is mismatched between African Americans and Caucasians. However, the study demonstrates a potential need for clinicians to evaluate treatment of SSc-PAH in African Americans differently than they evaluate treatment of SSc-PAH in Caucasians.