Revolutionizing Treatment: Cardiac Shockwave Therapy Enhances Myocardial Function in Ischemic Heart Failure

The findings from the CAST-HF trial indicate that direct cardiac SWT, in addition to coronary bypass surgery, improves left ventricular ejection fraction (LVEF) and physical capacity at one year in patients with ischaemic heart failure (HF). The findings were published online in the European Heart Journal on June 20, 2024.

Ischemic heart failure arises when the heart muscle receives insufficient blood flow due to narrowed or blocked coronary arteries. Traditional treatments like coronary bypass surgery aim to restore blood flow, but residual myocardial dysfunction often persists, limiting patients' quality of life and prognosis. Revascularisation strategies control symptoms but are less effective in improving LVEF.

Against the above background, Johannes Holfeld, Medical University of Innsbruck, Anichstrasse, Innsbruck, Austria, and colleagues aimed to investigate the safety of cardiac shockwave therapy as a novel treatment option and its efficacy in increasing cardiac function by inducing angiogenesis and regeneration in hibernating myocardium.

For this purpose, the researchers enrolled patients with LVEF ≤40% requiring surgical revascularization in a single-blind, parallel-group, sham-controlled trial.

Patients were randomly assigned to undergo direct cardiac shockwave therapy or sham treatment in addition to coronary bypass surgery. The main measure of effectiveness was the improvement in LVEF as assessed by cardiac magnetic resonance imaging from the start of the study to day 360.

The study led to the following findings:

• Sixty-three patients were randomized, of which 30 patients of the SWT group and 28 patients of the Sham group attained 1-year follow-up of the primary endpoint.
• There was greater improvement in LVEF in the SWT group (Δ from baseline to 360 days: SWT 11.3%, SD 8.8; Sham 6.3%).
• Secondary endpoints included the 6-minute walking test, where patients randomized in the SWT group showed a greater Δ from baseline to 360 days (127.5 m) than patients in the Sham group (43.6 m) and Minnesota Living with Heart Failure Questionnaire score on day 360, which was 11.0 points for the SWT group and 17.3 points for the Sham group.
• Two patients in the treatment group died for non-device-related reasons.

The study showed that SWT, in addition to CABG, is a promising novel therapeutic option for patients suffering from ischaemic cardiomyopathy.

"The results of the CAST-HF trial indicate that this therapeutic approach may address the significant clinical challenge of myocardial regeneration in individuals with ischemic heart failure," the researchers wrote.

"Additional studies with larger participant groups in this patient cohort are necessary to determine if the positive impacts of direct cardiac shockwave therapy on myocardial function lead to improved clinical outcomes, as observed in the current trial," they concluded.

Reference:

Holfeld, J., Nägele, F., Pölzl, L., Engler, C., Graber, M., Hirsch, J., Schmidt, S., Mayr, A., Troger, F., Pamminger, M., Theurl, M., Schreinlechner, M., Sappler, N., Schaden, W., Cooke, J. P., Ulmer, H., Bauer, A., & Grimm, M. Cardiac shockwave therapy in addition to coronary bypass surgery improves myocardial function in ischaemic heart failure: The CAST-HF trial. European Heart Journal. https://doi.org/10.1093/eurheartj/ehae341