Women with ATTR-CM face gaps in treatment, new study reports
Findings show differences in disease features and care, with similar survival
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Women with transthyretin amyloid cardiomyopathy (ATTR-CM) show differences in disease features and greater physical limitations than men, but are less likely to be given certain treatments, according to a study in Spain.
In addition, women had lower rates of hospitalization for heart failure. Despite these sex-specific differences, survival outcomes were similar in both men and women with ATTR-CM, data showed.
Sex differences in ATTR-CM highlight need for more research
These findings call for further studies to better characterize and address sex-specific differences in ATTR-CM features and care.
The study, “Clinical presentation and prognosis of transthyretin cardiac amyloidosis according to gender. Analysis of the Galician registry of cardiac amyloidosis (AMIGAL),” was published in Medicina Clínica.
ATTR-CM is a chronic disease in which toxic clumps of a protein called transthyretin build up in the heart. It can be caused by mutations in the TTR gene (hereditary) or occur with aging (wild-type).
Both of its forms are generally more common in men than women, and for many years, ATTR-CM was considered an almost exclusively male disease. More recent reports suggest women may account for up to 28% of cases.
“Recent research indicates that, similar to that observed in other cardiovascular diseases, there are notable differences in the clinical presentation and prognosis of this disease between the two sexes, although the evidence is scarce and contradictory,” the researchers wrote.
Study compares clinical features and outcomes in men and women
To learn more, scientists compared clinical features and outcomes from 290 men and 95 women with ATTR-CM who were followed as part of an ongoing registry study tracking the condition in a region of Spain.
Most participants had wild-type ATTR-CM and were in their 80s when they entered the registry, with no significant differences between women and men. Heart failure was the most common disease manifestation at diagnosis in both groups.
At the time of registry entry, women were significantly more likely than men to have a history of high blood pressure (83.2% vs. 69.3%) and high cholesterol levels (69.5% vs. 57.9%). In contrast, rates of smoking history were significantly higher among men (33.1% vs. 3.2%).
A significantly higher proportion of women showed greater limitations in physical activity than men, as evidenced by higher rates of New York Heart Association functional class III or IV (36.8% vs. 25.2%).
At the same time, women had a significantly greater thickening of the wall of the heart’s main pumping chamber, a sign of chronic heart stress.
Female patients also had significantly higher left ventricular ejection fraction, a measure of how efficiently the heart pumps oxygen-rich blood to the body. However, average values in both men and women remained within the normal range.
Heart rhythm measures and key biomarkers similar in both sexes
No significant differences were observed between the two sexes in terms of the heart’s electrical function and blood levels of NT-proBNP, a marker of heart stress.
The team believes that the observed differences in heart parameters “are not related to women being at a different stage of disease progression than men and that [they] may simply be due to a tendency to present different [features].” Factors such as differences in sex-related hormones may help explain these variations, they added.
There were also significant differences in treatments between men and women. Some of these variations were expected, including the fact that women were more likely to receive thiazide diuretics (18.9% vs. 10.3%), which the researchers suggested may be related to their higher rates of high blood pressure.
However, women were also significantly less likely than men to be on Vyndamax (tafamidis), an approved ATTR-CM treatment.
“These results corroborate published data showing that women with cardiovascular disease continue to receive the recommended therapies less frequently than men, with ATTR-CM being no exception,” the researchers wrote.
Over a median follow-up time of nearly two years (until heart transplant, death, or Dec. 31, 2023), there were 462 hospitalizations, and nearly a third of participants died. Data showed that women had significantly lower rates of hospitalization for heart failure than men. Rates of other clinical events were comparable in men and women.
Survival similar in women and men despite differences in care
Survival outcomes were also similar, with both women and men living for a mean of 4.1 years since entry in the registry.
The researchers speculated that the lower rates of heart failure hospitalizations among women may be related to social factors affecting access to care.
“Women experience more social stressors, which may make it difficult for them to be available for hospitalisation (e.g., family responsibilities that prevent them from leaving their homes), or the greater obstacles women face in accessing the resources offered by the healthcare system compared to men,” the team wrote.
Based on their findings, the researchers called for efforts to improve care for women with ATTR-CM and close sex-based gaps in treatment access.
This study was funded in part by an independent research grant from Pfizer, which markets Vyndamax.
