Preventive Cardiology Fellow Brigham and Women's Hospital, United States
Background: Heart failure remains highly prevalent, with many patients experiencing elevated filling pressures and dyspnea. Interatrial shunts offer a potential therapy to reduce left atrial pressure, improving exercise tolerance, quality of life, and hospitalization risk. This study evaluates the hemodynamic and health outcomes of interatrial shunting in HFrEF and HFpEF patients.
Methods: This systematic review and meta-analysis was conducted in accordance with the PRISMA guidelines. Two reviewers independently performed a systematic search of all databases from inception through December 2024 to identify studies that evaluated hemodynamic and QoL metrics in patients with interatrial shunt devices. Any discrepancy in study inclusion or data extraction was resolved by consensus with a senior author. Random-effects meta-analysis with inverse variance weighting method was performed to calculate relative risk and 95% confidence interval (CI) for binary outcomes. Similarly, mean difference (MD) and 95% CI was calculated for continuous variables using RevMan 5.3 software. I2 values of ≥25%- < 50%, ≥50%- < 75%, and 75% represented mild, moderate, and severe interstudy heterogeneity, respectively. P value < 0.05 indicated statistical significance. The primary objective of the study was to assess the impact of IASD on mean PCWP, and its associated effect on CO, pHTN (mean right atrial pressure [mRAP], mean pulmonary artery pressure [mPAP], pulmonary vascular resistance [PVR]) and RV function (Tricuspid annular plane systolic excursion [TAPSE]). Secondary outcomes included measures of QoL in individuals as outlined by KCCQ scores, change from baseline in 6-minute walk distance (6MWD), NYHA functional class, and The Minnesota Living with Heart Failure (MLWHF) scores.
Outcome: Following an initial search yielding 275 unique citations, 10 studies met the inclusion criteria, encompassing 293 patients. Pooled analysis of 8 studies demonstrated a significant reduction in mean PCWP (MD −3.26; 95% CI −4.83 to −1.69; P < 0.0001), which was associated with a significant increase in the pulmonary-to-systemic blood flow ratio (Qp/Qs; MD 0.18; 95% CI 0.10 to 0.21; P < 0.0001) and right-sided cardiac output (MD 0.77; 95% CI 0.02 to 1.52; P < 0.04). However, there were no significant changes in pulmonary hypertension—mRAP (MD 0.39; 95% CI −0.14 to 0.93; P = 0.15), mPAP (MD −0.37; 95% CI −2.03 to 1.3; P = 0.67), PVR (MD −0.22; 95% CI −0.79 to 0.34; P = 0.44)—or right ventricular function (TAPSE; MD 0.02; 95% CI −0.08 to 0.12; P = 0.73). Quality-of-life metrics improved significantly, as evidenced by increased 6MWD (MD 49.4; 95% CI 16.6 to 82.2; P < 0.001), enhanced KCCQ scores (MD 21.8; 95% CI 8.8 to 34.4; P < 0.001), reduced MLWHF scores (MD −26.7; 95% CI −39 to −14.4; P < 0.001), and decrease in patients with NYHA Class > III from 90.8% to 28.7% (RR 0.31; 95% CI 0.20 to 0.49; P < 0.001).
Conclusion: Interatrial shunting reduced PCWP, increased CO, and improved quality of life, including NYHA class, KCCQ scores, 6MWD, and MLWHF scores.Further research involving larger sample sizes and longer follow-up durations is necessary to ensure the long-term safety and efficacy of these devices.
