Risk stratification for survival and time to clinical worsening (TTCW) based on the 2015 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines was confirmed only in patients with pulmonary arterial hypertension (PAH) without comorbidities and not in patients with PAH and comorbidities, according to study results published in Respiratory Research.
Researchers conducted a retrospective analysis of medical records of 142 patients with invasively PAH from a single center in Germany. Of these, 52 patients had comorbidities (mean age, 70.8±8.7 years), whereas the other 90 had no significant comorbidities (mean age, 59±15.7 years). Patients with PAH who had comorbidities were more often obese (51.9% vs 24.4%; P =.001). All patients were treated with PAH therapy and had a follow-up of 3.3±2.4 years.
Patients with comorbidities at baseline had significantly lower exercise capacity based on 6-minute walking distance scores (6MWD; 271.8±122.3 m vs 372.6±115.5 m; P <.0001), lower diffusion capacity of carbon monoxide (40%±19.4% predicted vs 53.5%±21.7% predicted; P =.001), lower glomerular filtration rate (55.95±18.5 pg/mL vs 77.4±25.0 pg/mL; P <.0001), larger right atrial (RA) area (22.4±5.9 cm2 vs 19.2±6.3 cm2; P =.003), and were significantly more frequently in worse World Health Organization functional class (WHO FC; P =.021).
Approximately 27.7% (n=39) of patients died between the observation period. The mortality rate was 21.4% (n=19) of patients with PAH without comorbidities and 38.5% (n=20) for patients with PAH and comorbidities. Survival and TTCW in patients with PAH but without comorbidities were associated with reduced 6MWD (survival: P =.006; TTCW: P =.02), elevated N-terminal pro-brain natriuretic peptide (NT-proBNP; survival: P =.011), and WHO FC (survival: P =.001; TTCW: P <.0001).
The multivariate analysis revealed that the 6MWD was an independent predictor for survival (P =.002), whereas WHO FC was an independent predictor for TTCW (P =.001). In contrast, these variables held no significant association with survival and TTCW in patients with PAH and comorbidities. An average risk score that incorporated the 4 ESC/ERS risk parameters — 6MWD, WHO FC, NT-proBNP, and RA area — was significantly associated with survival (P =.001) and TTCW (P =.013) in patients with PAH with no comorbidities but not in patients with PAH and comorbidities.
Study limitations included its retrospective nature, the small sample size, as well as the inclusion of only noninvasive risk parameters in the analysis of predictive factors for survival and TTCW.
Since ESC/ERS risk stratification was only confirmed in patients without comorbidities, the investigators suggest that “different risk stratification and treatment recommendations need to be applied to PAH patients with comorbidities matched to age and concomitant diseases.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Xanthouli P, Koegler M, Marra AM, et al. Risk stratification and prognostic factors in patients with pulmonary arterial hypertension and comorbidities a cross-sectional cohort study with survival follow-up. Respir Res. 2020;21(1):127.