1. There was no significant difference in the primary composite endpoint between the interatrial shunt and sham procedure groups.
2. The frequency of cardiovascular death, non-fatal ischemic events, and heart failure events were similar between both groups.
Evidence Rating Level: 1 (Excellent)
Study Rundown: Patients with heart failure often have an elevated left atrial pressure, leading to dyspnea and reduced ejection fraction. Prior research suggests that placing an interatrial shunt device may help reduce left atrial pressures, allowing for preserved or mildly reduced ejection fraction. This randomized controlled trial aimed to assess the efficacy and safety of interatrial shunts in patients with symptomatic heart failure. Patients were randomly assigned to the intervention (interatrial shunt) or sham (no shunt) group, and followed up at 1, 3, 6, 12, and 24 months. The primary outcome was a combination of cardiovascular death or ischemic stroke at 12 months, change in Kansas City Cardiomyopathy Questionnaire score at 12 months, and total heart failure events at 24 months. According to study results, the primary composite endpoint remained comparable in the atrial shunt group and sham procedure group. No significant differences were noted for the composite safety endpoint. A major limitation of this study was that it only included patients aged 40 and older. It is unclear whether placement of an atrial shunt device yields greater benefits in patients below the age of 40.
Click to read the study in The Lancet
In-depth [randomized-controlled trial]: Between May 25, 2017, and July 24, 2020, 1072 patients were screened for eligibility across 89 healthcare centers in the USA. Included were those ≥ 40 years of age with symptomatic heart failure, ≥ 40% ejection fraction, and pulmonary capillary wedge pressure (PCWP) ≥ 25 mmHg. Altogether, 626 patients (314 to intervention and 312 to sham) were included in the intention-to-treat analysis. The primary composite outcome was similar in the interatrial shunt group compared to sham procedure (win ratio 1.0, 95% confidence interval [CI] 0.8-1.2, p=0.85). At 12 months, cardiovascular death and non-fatal ischemic events were comparable between the groups (n=4 in atrial shunt vs. n=2 in sham procedure). At 24 months, the frequency of heart failure events was similar between both groups (0.28 events per patient-year in atrial shunt vs. 0.25 events per patient-year in sham procedure). Overall, findings from this study suggest that insertion of an interatrial shunt in symptomatic heart failure patients did not decrease the total rate of heart failure events or improve overall health status.
Image: PD
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