Effect of Tafamidis on Renal Function in Patients With Transthyretin Amyloid Cardiomyopathy in ATTR-ACT

Area of Science:

• Cardiology
• Nephrology
• Pharmacology

Background:

• Chronic kidney disease (CKD) is a common comorbidity in patients with amyloid cardiomyopathy.
• Tafamidis is approved for treating transthyretin amyloid cardiomyopathy (ATTR-CM), a condition often associated with renal impairment.
• The ATTR-ACT trial provided efficacy and safety data for tafamidis in ATTR-CM patients.

Purpose of the Study:

• To conduct a post hoc analysis of the ATTR-ACT trial to evaluate the impact of tafamidis on renal function in ATTR-CM patients.
• To assess changes in estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) staging over 30 months.
• To analyze the composite renal endpoint in patients treated with tafamidis versus placebo.

Main Methods:

• Patients with ATTR-CM were randomized to receive tafamidis (pooled 20 mg and 80 mg doses) or placebo for 30 months.
• Changes in eGFR from baseline were compared between treatment groups over the study duration.
• A composite renal endpoint (all-cause death, dialysis, kidney transplant, or ≥30% eGFR decline) was analyzed for time to first event.

Main Results:

• Tafamidis treatment was associated with a significantly smaller decline in eGFR compared to placebo (mean difference of 3.99 mL/min/1.73 m²; P=0.004).
• Improvement in CKD staging was observed more frequently in the tafamidis group (17.7%) versus the placebo group (7.2%; P=0.034).
• A lower proportion of patients receiving tafamidis reached the composite renal endpoint (34.5%) compared to placebo (44.1%; P=0.040).

Conclusions:

• Renal function naturally deteriorates in patients with ATTR-CM.
• Tafamidis treatment demonstrated a significant reduction in the decline of renal function over 30 months.
• Tafamidis therapy was associated with a higher incidence of improved eGFR and CKD staging compared to placebo in ATTR-CM patients.