PAH Incidence in Systemic Sclerosis: Does Algorithm Use Affect Reported Incidence?

Use of the DETECT algorithm — a tool developed to screen patients with systemic sclerosis (SSc) for pulmonary arterial hypertension (PAH) — has not led to a change in incidence of PAH in a cohort of patients with SSc, according to study results published in Rheumatology.

A total of 161 patients with SSc from Oslo University Hospital in Norway who had undergone an incident right heart catheterization were divided into 2 cohorts: an “early” cohort (n=77) and the DETECT cohort (n=84). Enrollment in a particular cohort was based on whether the catheterization had been performed prior to (2009 to 2013) or following (2014 to 2017) the introduction of the DETECT algorithm. A diagnosis of PAH and patient risk stratification (low, intermediate, or high risk) were conducted based on European Society of Cardiology guidelines.

The mean patient age at study enrollment was 61±11.8 years; 78.8% of all patients were women. Demographic characteristics did not differ significantly in either of the two groups, except that the observation period (4.2±2.2 years in the early cohort) was significantly longer than that in the DETECT cohort (1.2±0.8 years; P <.001).

At the time of catheterization, the frequency of PAH was similar in both the DETECT and the early cohorts (18% vs 21%). However, more patients exhibited borderline PH in the DETECT cohort than in the early cohort (31% vs 17%). In addition, levels of PAH risk were distributed differently in the two arms. In the Early cohort, 19% and 44% of participants were at low and high risk, respectively, at the time of PAH diagnosis. In contrast, in the DETECT cohort, 27% and 27% of participants were at low and high risk, respectively.

A follow-up right heart catheterization performed after a mean of 2.4±1.8 years revealed that 39% of patients with borderline PH in the early cohort had gone on to develop PAH.

The investigators concluded that although “[t]he DETECT algorithm did not alter the incidence of PAH in this unselected SSc population,” the risk profiles and functional classes at the time of PAH diagnosis did appear to improve. An increase in the frequency of borderline PH cases was also noted. The results of this study may pave the way for novel opportunities for earlier treatment and prevention of PAH.

Reference

Hoffmann-Vold A-M, Fretheim H, Midtvedt Ø, et al. Frequencies of borderline pulmonary hypertension before and after the DETECT algorithm: results from a prospective systemic sclerosis cohort [published online December 11, 2017]. Rheumatology (Oxford). doi:10.1093/rheumatology/kex435