medwireNews: Elderly men and patients with low baseline systolic blood pressure (SBP) are among those at a particularly high risk of death from pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc-APAH), a US study has found.
Patients with SSc-APAH are known to have higher mortality rates than those with PAH as a result of other connective tissue diseases, such as systemic lupus erythematosus.
Now, Lorinda Chung (Veterans Affairs Palo Alto Health Care System, California, USA) and colleagues have found predictors of mortality in patients with SSc-APAH that differentiate them from PAH patients with other connective tissue disorders.
“Identifying SSc-APAH patients who are at particularly high risk of death, including elderly males and patients with low baseline SBP or 6MWD [6-minute walk distance], or markedly elevated mRAP [mean right atrial pressure] or PVR [pulmonary vascular resistance], will enable clinicians to identify patients who may benefit from closer monitoring and more aggressive treatment,” they write in the journal Chest.
A group of 804 patients with PAH as a result of either SSc (n=500) or another connective tissue disease (n=304) and who did not have significant interstitial lung disease were selected from the multicentre, longitudinal, US-based REVEAL Registry. Patients with SSc were, on average, older than those in the non-SSc group (62 versus 40 years), and had more severe disease overall.
As expected, 3-year survival in the SSc group was significantly worse than in the non-SSc group, and this was true both in patients who had previously been diagnosed with the disease and those who were newly diagnosed (diagnostic right heart catheterisation occurring within 90 days of enrolment).
Survival rates were 61.4% versus 80.9% for previously diagnosed SSc-APAH patients compared with non-SSc-APAH patients and 51.2% versus 76.4%, respectively, for newly diagnosed patients SSC-APAH and non-SSC-APAH patients.
Using multivariate analyses, the researchers identified two variables that were predictive of mortality in both groups, namely New York Heart Association Functional Class III or IV status, and brain natriuretic peptide levels of more than 180 pg/mL.
However, some predictors of mortality were unique to the SSc group, including being male and aged over 60 years, a SBP of 110 mmHg or lower at baseline, 6MWD less than 165 m, mRAP of more than 20 mmHg within 1 year of diagnosis and PVR of more than 32 WU.
A 6MWD of 440 m or further was protective in the non-SSc group, but not in the SSc-APAH group.
“To our knowledge, this is the first study identifying low baseline SBP ≤110 mmHg as an independent predictor of death in patients with SSc-APAH,” Chung and colleagues say.
“Identifying SSc-APAH patients with high mortality risk based on the presence of these unique predictors of mortality will enable clinicians to monitor these patients more closely and escalate therapy when indicated,” they conclude.
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By Afsaneh Gray, medwireNews Reporter