Age, Certain Comorbidities Predict Outcomes in Idiopathic PAH Patients, Study Shows

Age, ischemic heart disease, and kidney dysfunction are important predictors of outcomes in patients with idiopathic pulmonary arterial hypertension (IPAH), a Swedish study shows.

The research, “Impact of age and comorbidity on risk stratification in idiopathic pulmonary arterial hypertension,” was published recently in the European Respiratory Journal.

The first large registry of patients with IPAH was initiated 40 years ago in the U.S. It included 194 patients (68 percent women) with a mean age of 36 years and a median survival time of 2.8 years.

The development of more effective treatments improved patients’ quality of life and survival, and worldwide registries indicate that the IPAH patient group is now different. The prevalence in the elderly is increasing, with a mean age of 50 to 65 years at diagnosis.

While there are no conclusive answers for this shift, scientists hypothesize that left ventricular diastolic dysfunction, which occurs when the heart is unable to fill up with blood before pumping it out, may play a key role.

An important factor limiting the understanding of IPAH in the elderly is the exclusion of patients with multiple comorbidities from clinical trials. Another issue is that current risk assessment measurements do not include age and/or comorbidities as possible prognostic markers.

Recent work by the research team validated the feasibility of the new European Society of Cardiology/European Respiratory Society guidelines’ instrument for risk assessment in 530 patients with associated or familial/idiopathic PAH enrolled in the Swedish Pulmonary Arterial Hypertension Register (SPAHR).

The investigators aimed to further assess whether the risk assessment instrument could be used in different age categories and associated comorbidities in an IPAH patient group.

Data from 264 patients also recorded in SPAHR were divided in four age groups: 18-45, 46-64, 65-74, and 75 or older. The team assessed change in risk and survival in each group from study start to follow-up (median of five months).

Results showed that a significant number of patients improved risk category in the two youngest groups, but no improvements were found in older patients. The data further revealed that the five-year survival rate was highest in patients with 18-45 years (88%), and decreased gradually along the age range —  63%, 56%, and 36% for patients in the groups 46-64, 65-74 and 75 or older, respectively.

Also, ischemic heart disease and kidney dysfunction were associated with poor prognosis. These two comorbidities were more frequent in patients older than 75.

“The main findings of the present study illustrate that improvement in risk category at follow-up is a strong predictor of survival across all age groups,” the researchers wrote.

“The present study highlights the importance of age and specific comorbidity as prognostic markers of outcome, suggesting the usefulness of adding these parameters to previously established risk assessment algorithms,” they concluded.