A randomized, triple-blind trial of cardiac shock-wave therapy on exercise tolerance and symptoms in patients with stable angina pectoris.

BACKGROUND: Despite major advances in managing coronary artery disease and continuous research on alternative techniques to enhance myocardial perfusion and reduce symptoms, coronary artery disease is still one of the leading causes of adult disability worldwide. Cardiac shock-wave therapy (CSWT) has shown promising results in the amelioration of myocardial ischemia in experimental studies; however, clinical results are limited to single-center, mostly uncontrolled and underpowered trials. The current study aimed to evaluate whether CSWT can improve exercise tolerance and relieve angina symptoms in addition to optimal medical treatment in patients with stable angina. PARTICIPANTS AND METHODS: A prospective, randomized, triple blind, sham-procedure-controlled study was carried out. The primary endpoint was total exercise duration in the modified Bruce treadmill test at the 6-month follow-up. The secondary endpoints were changes in ST-segment depression during the treadmill test, angina symptoms during the treadmill test, number of angina attacks per week, number of sublingual nitroglycerin consumption per week, Canadian Cardiovascular Society angina functional class, and the Seattle Angina Questionnaire score at the 6-month follow-up. Patients were randomized at a 1 : 1 ratio to optimal medical plus cardiac shock-wave therapy (OMT+CSWT) and optimal medical therapy with sham procedure (OMT+placebo) groups. RESULTS: The mean exercise time improved in both study arms - CSWT and placebo treatment - at the 3- and 6-month follow-up, without a significant difference between groups. The magnitude and frequency of peak exercise ST-segment depression reduced significantly in the CSWT+OMT group compared with the OMT+placebo group at the 6-month follow-up (51.4 vs. 90.6%, P=0.001). Percentage of angina-free patients increased progressively in both groups throughout the study. The Seattle Angina Questionnaire scores improved significantly in both arms for four of five domains at the 3- and the 6-month follow-up. Numerically, although insignificant, the decrease in the number of angina episodes was more prominent in the OMT+CSWT group compared with the OMT+placebo group. CONCLUSION: The total exercise duration in the modified Bruce treadmill test at the 6-month follow-up did not differ significantly in patients treated with CSWT compared with optimal medical therapy alone. In addition, CSWT exerted a neutral effect on the quality of life and level of angina.

Efficacy of cardiac shock wave therapy in patients with stable angina: The design of randomized, triple blind, sham-procedure controlled study.

OBJECTIVE: Despite revascularization and optimal medical treatment (OMT), patients with angina often have a reduced quality of life due to inadequate relief from symptoms. Recent studies have shown that the application of shock waves may reduce angina symptoms and improve quality of life, exercise capacity, and myocardial perfusion due to the stimulation of angiogenesis. However, there is limited evidence due to small, single-arm, single-center studies of low to moderate quality. The purpose of this study is to evaluate the impact of cardiac shock wave therapy (CSWT) on exercise tolerance and angina symptoms in patients with coronary artery disease and objective evidence of myocardial ischemia who cannot undergo traditional revascularization and experience angina despite OMT in comparison to sham procedure. METHODS: We designed a randomized, triple-blind, placebo-controlled, multicentre trial (NCT02339454) to assess the efficacy of CSWT in addition to OMT in patients with stable angina and myocardial ischemia documented by exercise treadmill test (ETT). All patients were treated with stable doses of standard medical treatment 4 weeks before screening. An increase in the total exercise duration on ETT by ≥90 s from the baseline at the end of the study was set as the primary endpoint. Secondary endpoints included angina class, Seattle angina questionnaire scores, symptoms, and ECG changes during stress test. Patients underwent nine sessions of CSWT or corresponding sham procedure applied to all segments of the left ventricle, within 9 weeks. Endpoint assessments were performed at 6-month follow-up. The imaging substudies assessed the potential of CSWT to reduce stress-induced myocardial ischemia detected by dobutamine stress echocardiography, cardiac single-photon emission computed tomography, and cardiac magnetic resonance imaging. RESULTS: At two centers, 72 of the 323 screened patients were randomized in two groups (ratio 1:1): active treatment and placebo control. Study patients were predominantly males (70.8%); the mean age of the patients was 68.4±8.3 years. Of these, 44 patients had angina Canadian Cardiovascular Society class III, and 66.7% of the patients had a history of myocardial infarction. CONCLUSION: Using sham applicators, blinding study participants, investigators, and endpoints assessors to the study data as well as centralized randomization ensures rigorous methodology and low risk of bias in this large randomized controlled CSWT study.