Cardiac shockwave therapy in coronary artery disease: a novel adjunct to coronary artery bypass grafting—a narrative review

Abstract Background Despite improvements in revascularization, coronary artery disease continues to be a major source of morbidity and heart failure. Although coronary artery bypass grafting can restore epicardial flow, it cannot consistently repair established myocardial scarring or microvascular dysfunction. In order to improve perfusion and function in ischemic myocardium, cardiac shockwave therapy (CSWT), a low-intensity acoustic modality that encourages mechanotransductive signaling, angiogenic factor release, and progenitor-cell recruitment has been studied as a non-invasive regeneration adjuvant. Main body With a focus on its function as a supplement to bypass surgery, this review summarizes clinical and mechanistic findings on CSWT in coronary disease. Increases in circulating endothelial progenitor cells, activation of vascular endothelial growth factor (VEGF)-receptor signaling and downstream AKT/extracellular signal-regulated kinase (ERK) pathways, upregulation of vascular endothelial growth factor, and anti-inflammatory and anti-fibrotic effects that can result in increased capillary density and decreased scar are all indicated by mechanistic studies. According to clinical data from randomized trials, cohort series, and meta-analyses, increased left ventricular ejection fraction (LVEF), better myocardial perfusion metrics, decreased ischemic burden, enhanced exercise capacity, and improved angina scores are examples of surrogate and functional endpoints that have consistently improved. In the CAST-HF randomized, single-blind, sham-controlled surgical trial, adding epicardial shock-wave treatment following coronary artery bypass grafting (CABG) resulted in greater LVEF improvements and increased 6-min walk distance at 12 months. Stable cardiac biomarkers, a low frequency of transient minor symptoms, and no indication of significant adverse events connected to the device are all shown by safety data from several trials. Important technical features include image-guided targeting, electrocardiogram (ECG)/R-wave gating, sterile epicardial coupling, and standardized impulse counts per territory. Conclusions Current evidence supports CSWT as a promising, safe adjunct to improve microvascular perfusion and functional outcomes in selected patients with refractory ischemia, including intraoperative application during CABG. In order to define clinical indications and maximize translation into practice, there is a need for larger multicenter, sham-controlled trials, harmonized registries, standardized procedural training, and validation of imaging and biomarker endpoints. These limitations of the evidence include small single-center trials, protocol heterogeneity, and limited long-term hard-endpoint data.