Swedish Men and Women with IPAH Have Similar Survival Rates, Study Says

Joana Carvalho, PhD avatar

by Joana Carvalho, PhD |

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Survival rates

Swedish men and women who have been diagnosed with idiopathic pulmonary arterial hypertension (IPAH) in recent years have similar survival rates, study says.

The study, “Sex-specific differences and survival in patients with idiopathic pulmonary arterial hypertension 2008–2016,” was published in the journal ERJ Open Research.

IPAH, a form of the disease whose specific root cause is difficult to identify, affects mostly women. Studies have also suggested that women with IPAH “have a worse haemodynamic status at diagnosis, but better survival than men,” the researchers wrote.

However, in older people, reports indicate that PAH affects women and men equally.

Because previous studies were based on younger patient populations and might not reflect the advancements in PAH therapies seen in recent years, researchers from the Karolinska Institutet in Sweden and collaborators set out to explore the possible impact of patients’ gender on their clinical features and disease outcomes.

The study involved 271 IPAH patients (151 women and 120 men) with a median age of 68. They had been diagnosed with IPAH between 2008 and 2016; their medical records had been stored at the Swedish Pulmonary Arterial Hypertension Register (SPAHR).

Study participants were divided into two groups based on sex. Patients’ clinical features at the time of diagnosis were analyzed and compared between the two groups. Patients’ survival was assessed in both groups using statistical analyses.

Results showed that women tended to be younger, had lower pulmonary vascular resistance, and fewer comorbidities — particularly atrial fibrillation (irregular and fast heartbeat) and ischemic heart disease (low blood supply to the heart) — compared to men at the time of diagnosis.

In addition, researchers found that women tended to be prescribed more often combinations of PAH-targeted therapies than men. However, the proportion of women and men treated with an endothelin receptor antagonist (ERA; 53% women versus 53% men) or a phosphodiesterase inhibitor (PDEi; 40% women versus 37% men), two different classes of vasodilators, were virtually identical.

Vasodilators are agents that induce blood vessels’ widening and relaxation, lowering blood pressure in the lungs.

Importantly, the team found that men had worse survival rates than women at one year (78% men versus 88% women), three years (62% men versus 74% women) and five years (55% men versus 68% women) after receiving a diagnosis of IPAH.

Although statistical analyses indicated that men had significantly lower survival rates than women (approximately 1.49 times lower), these differences were no longer significant once investigators normalized the data for participants’ age.

“In the present study, men with incident IPAH had worse crude survival rates than women, but after adjusting for age, the difference in survival between the sexes disappeared. This may be explained by men being on average 5 years older, and having a higher comorbidity burden than women at time of IPAH diagnosis,” the researchers said.

“Thus, in patients diagnosed with IPAH between 2008 and 2016, the survival rates for men and women were similar when considering natural confounders such as age and comorbidity,” they concluded.