For patients with transthyretin amyloid cardiomyopathy (ATTR-CM), the need for increased diuretic doses over time may indicate worsening disease, according to a study recently published in the journal Clinical Research in Cardiology.
Diuretics (also called “water tablets”) are drugs that help the body remove excess fluid, and are used to treat ATTR-CM symptoms like heart congestion and shortness of breath. The study found that needing a higher dose of diuretic — called diuretic intensification (ODI) — and the amount by which the dose is increased both serve as useful markers for tracking disease progression.
Currently, experts recommend routine assessments of clinical parameters, biomarkers, and cardiac imaging to track disease progression after diagnosis. However, interpreting these results can be challenging due to uncertainty in cut-off values and interference from other health conditions. Some tests also require significant time and resources. Because of this, doctors are seeking simpler, more practical ways to monitor disease progression and guide treatment decisions for patients with ATTR-CM.
Read more about ATTR-CM prognosis and staging
The authors hypothesized that ODI might help predict the course of the disease. They aimed to investigate the frequency, predictors and clinical significance of ODI in patients with ATTR-CM.
The study included data from 182 patients with a confirmed ATTR-CM diagnosis. The researchers focused on the use of loop diuretics and defined ODI as an increase in the dose of these medications within six months after a patient’s first visit for the study. They analyzed the impact of ODI on all-cause mortality and hospitalization for heart failure (HF).
In the study, 25% of patients needed to increase their diuretic dose within six months. The median increase in diuretic dose was 10 mg.
The factors that predicted this ODI were more severe heart failure and polyneuropathy (nerve damage).
Results showed that ODI and the amount by which the diuretic dose is increased were linked to a higher risk of death and hospitalization for heart failure.
Even after adjusting for the severity of heart failure and disease stage, patients with ODI had a risk of death that was 2.38 times higher compared to that of patients who did not require an increase in their diuretic dose. The risk of hospitalization for heart failure was 3.27 times higher for patients with ODI.
The prognostic value of ODI was consistent across different groups of patients, regardless of factors such as age, the specific subtype of ATTR-CM, whether they had experienced previous heart failure, their biomarkers, their heart function or whether they were treated with tafamidis.
“ODI is a common, readily available clinical parameter associated with an increased risk of HF hospitalization and mortality, independent of established clinical risk factors such as NYHA class and UK-NAC stage. These findings provide evidence in support of the integration of ODI in the 6 months monitoring assessments of ATTR-CM patients,” the authors said.
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