TOPLINE

Right ventricular (RV) dysfunction measured by free-wall strain (FWS) was common and independently predicted worse outcomes in patients with transthyretin amyloidosis with cardiomyopathy (ATTR-CM), whereas conventional measures were less predictive. Treatment with vutrisiran was linked to stabilized RV function.

METHODOLOGY

• HELIOS‑B was a double‑blind randomized trial that originally assessed clinical outcomes of vutrisiran in patients with ATTR-CM. Researchers conducted a post hoc analysis of the trial to examine RV function and how the drug affected it.
• The analysis included 548 patients with usable echocardiograms (mean age, 75 years; 92% men); 88% of patients had wild-type ATTR.
• Patients were randomly assigned to receive either 25 mg vutrisiran subcutaneously every 12 weeks or a matching placebo for up to 36 months.
• Researchers evaluated RVFWS, which measured strain of the heart muscle, and RVFWS indexed to pulmonary artery systolic pressure (RVFWS/PASP). Conventional measures included tricuspid annular systolic myocardial velocity and RV fractional area change.
• The primary outcome was a composite of all-cause mortality and recurrent cardiovascular events. The median duration of follow-up was 36 months.

TAKEAWAY

• Overall, 85.2% of patients had abnormal RVFWS (≤ 20%). Tricuspid annular systolic myocardial velocity was abnormal (≤ 9.5 cm/sec) in 56.0% of patients, and RV fractional area change was abnormal (≤ 35%) in 30.5% of patients.
• Lower RVFWS and RVFWS/PASP were independently associated with a higher risk for all-cause mortality and recurrent cardiovascular events (P < .05 for both).
• Associations between the conventional measures of RV function and outcomes were not statistically significant after multivariable adjustment.
• At 30 months, patients who received vutrisiran vs placebo had stabilized RVFWS (between-group difference, 1.6%; P < .001) and improved RVFWS/PASP (between-group difference, 0.08%/mm Hg; P = .002).

IN PRACTICE

"RV dysfunction assessed by RVFWS was highly prevalent among patients with ATTR-CM enrolled in HELIOS-B and may be underrecognized using conventional, nondeformation-based echocardiographic measures," the researchers wrote.

SOURCE

The study was led by Karola S. Jering, MD, of Brigham and Women's Hospital, and Harvard Medical School in Boston. It was published online on August 26 in JAMA Cardiology.

LIMITATIONS

The inclusion and exclusion criteria of the trial may have limited the generalizability of findings. Only 84% of patients had echocardiograms with image quality adequate to measure RVFWS. Researchers did not have data on other measures of RV function such as tricuspid annular plane systolic excursion or resistance in the lung circulation.

DISCLOSURES

The study received funding from Alnylam Pharmaceuticals. Several authors reported receiving grants, consulting fees, or research support from Alnylam Pharmaceuticals and other pharmaceutical, biotechnology, and healthcare companies. Some reported being employees, equity owners, or shareholders of the funder. Detailed author disclosures are reported in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.