Although women diagnosed with transthyretin amyloid cardiomyopathy (ATTR-CM) tend to present at a later National Amyloidosis Centre (NAC) stage than men, their mortality rates are similar, according to results published in Frontiers in Cardiovascular Medicine.
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These findings could suggest that the NAC staging system might overestimate disease severity among women compared with men. Alternatively, the data may indicate that there are certain biological mechanisms that mean women have a less aggressive disease course despite being diagnosed at an advanced stage.
Read more about ATTR-CM prognosis and staging
The study included 268 men and 66 women with ATTR-CM who presented at Northwestern Memorial Hospital in Chicago, Illinois. At diagnosis, 21.4% of women presented at NAC stage 3, the second-most severe stage; in comparison, only 7.5% of men were diagnosed at the same stage. At diagnosis, women also had a lower estimated glomerular filtration rate, indicating reduced kidney function, and higher N-terminal pro-B-type natriuretic peptide levels, signaling increased stress on the heart.
Across NAC stages, however, no significant relationship between sex and mortality was observed. The ability to draw definitive conclusions is limited by the small sample size, though, especially at greater NAC stages.
In a statistical model adjusting for factors including age at diagnosis and race, NAC stage 3 was significantly associated with increased mortality. In this model, too, there was no significant relationship between sex and mortality.
In a separate model evaluating hospitalization, NAC stage 2 and the presence of atrial fibrillation, but not sex, were statistically significantly associated with all-cause hospitalization.
“The mechanisms underlying later-stage presentation in female patients remain incompletely understood, although current literature has begun to explore why female patients are diagnosed at later stages,” the authors wrote. “Diagnostic barriers may lead to delayed referral and evaluation, resulting in a later stage at diagnosis.”
The fact that ATTR-CM is often thought of as a disease impacting men may contribute to these disparities. In the future, more standardized referral pathways and diagnostic evaluations may help to improve the diagnosis of women at earlier stages of disease.
