Abstract P100: Enhanced External Counterpulsation Reduces Central Blood Pressure In Stable Angina Patients: A Meta Analysis

Abstract

Introduction: Emerging evidence suggests central systolic blood pressure (cSBP) and augmentation index are superior predictors of adverse cardiovascular outcomes as compared to peripheral systolic blood pressure (pSBP). Enhanced external counterpulsation (EECP) is a non-invasive treatment modality approved for the management of refractory angina. The degree of benefit from EECP on central hemodynamics and arterial stiffness remains unknown. This meta-analysis evaluated the effect of EECP on peripheral (office) blood pressure and central hemodynamic parameters. Methods: A comprehensive literature search was conducted in Pubmed, CINAHL, and Cochrane Library databases. All prospective clinical trials assessing the impact of EECP in patients with stable angina and CAD were included. Studies were excluded for not completing a full course of EECP, having a baseline peripheral systolic blood pressure &lt100 mmHg, or not reporting adequate data for analysis. The primary endpoint was the change in cSBP before and after EECP. The change in pSBP, pDBP, cDBP, and augmentation index before and after EECP were also assessed. The weighted mean difference using the DerSimonian and Laird random-effect model was utilized for determining the change in each parameter before and after EECP. Statistical heterogeneity was evaluated using the Egger’s bias statistic. Results: Five studies containing 137 unique patients were included for the cSBP analysis. cSBP was reduced significantly by -7.56 mmHg (95% CI -11.83 to -3.28; Cochrane Q=1.81) post-EECP. In the same set of studies, pSBP was reduced significantly by -9.65 mmHg (95% CI -14.32 to -4.98) post-EECP. pDBP [-4.67 mmHg (95% CI -8.56 to -0.77)] was reduced post-EECP, while no changes were evident in cDBP. Augmentation index was reduced by -3.74% (95% CI -7.05 to -0.43) post-EECP. Two studies included a sham-EECP intervention arm and demonstrated no significant changes in cSBP [0.67 mmHg (95% CI -5.66 to 7.01)] or other parameters. Conclusion: EECP significantly reduced cSBP and pSBP by approximately 8 mmHg and 10 mmHg respectively. EECP also demonstrated a mild improvement in arterial stiffness, which translates to reduced wasted left ventricular energy and myocardial oxygen demand. In patients with stable angina and CAD, EECP exerts beneficial effects in both peripheral and central hemodynamics but whether these benefits are sustained over a longer duration need further exploration.