Cardiac shock wave therapy for chronic refractory angina pectoris. A prospective placebo-controlled randomized trial

Observation of the effectiveness of clinical indicators of cardiac shock wave therapy in patients with ischemic heart disease: A systematic review and meta-analysis

Objective

Ischemic heart disease (IHD) has a high prevalence and mortality rate, imposing a heavy burden on patients and society, and there is still a need to optimize treatment options for IHD patients. Cardiac shock wave therapy (CSWT) is gaining popularity as a new treatment for IHD patients. The objective of this meta-analysis is to reassess the effects of CSWT on IHD patients in light of the limited number of clinical studies included in previously published reviews, inconsistent methodological quality, and unclear outcomes.

Methods

From database creation until September 1, 2022, 4 English databases and 3 Chinese databases were rigorously searched for any current controlled trials of CSWT for IHD. The Cochrane Risk of Bias Assessment Tool was used for methodological quality assessment. Review Manager v.5.4 software was used for meta-analysis.

Results

Nineteen published controlled trials totaling 1,254 subjects were included. Results showed that CSWT could enhance left ventricular function and myocardial viability, improve cardiac function and alleviate angina pectoris symptoms. The effects of CSWT and control groups on SAQ scores and exercise time were not statistically significant.

Conclusion

According to this systematic review and meta-analysis, CSWT may be beneficial for a number of IHD clinical indications. To verify these findings, more RCT studies with bigger sample numbers and higher methodological standards are required in the future.

Efficacy and safety of cardiac shock wave therapy for patients with severe coronary artery disease: A randomized, double-blind control study

BACKGROUND

Previous studies proved the efficacy of cardiac shock wave therapy (CSWT) for coronary artery disease (CAD) patients who are not candidate for reperfusion therapy. Randomized control trials are limited. We try to explore the efficacy and safety of CSWT for patients with severe CAD.

METHODS

Thirty patients with severe CAD who had obvious ischemia on myocardial perfusion imaging (MPI) were enrolled and randomly assigned to the CSWT group or the control group. They had received optimal medication treatment for at least three months. Nine sessions of shock wave therapy were conducted over 3 months. CSWT group received the real treatment, while the control group received the pseudo-treatment. Clinical symptom, imaging outcomes and safety parameters were compared between two groups.

RESULTS

After treatment, regional stress score (P = .023), improvement rate (IR) of ischemic area (IA) stress (P < .001) and IR of IA difference (P < .001) were significantly favor CSWT group. The interaction of summed rest score (P < .001), summed stress score (P = .004), summed difference score (P = .036) were significantly improved in the CSWT group compared to the control group. Seattle angina questionnaire, quality of life (QOL) and the distance of six-minute walking test (6MWT) were improved in both groups without significant difference between them. Hemodynamic parameters were stable during procedure. Myocardial injury markers showed no changes in two groups.

CONCLUSIONS

Our study demonstrated CSWT could effectively and safely improve myocardial perfusion in patients with severe CAD. Clinical symptom, QOL and 6MWT were all improved after treatment, but no significant difference between two groups.

Cardiac Shock Wave Therapy in Coronary Artery Disease: A Systematic Review and Meta-Analysis

Objective

Coronary artery disease (CAD) has been one of the leading causes of morbidity and mortality worldwide. Cardiac shock wave therapy (CSWT) is a novel and non-invasive therapy for CAD. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy of CSWT on CAD.

Methods and results

We performed a comprehensive search of electronic databases such as PubMed, Embase, the Cochrane Library, and Wanfang Data in October 2021. The results were reported as weighted mean difference (WMD) with a 95% confidence interval (CI). Statistical heterogeneity scores were assessed with the standard Cochran's Q test and the I 2 statistic. A total of 8 randomized trials and 2 prospective cohort studies, together involving 643 patients (n = 336 CSWT and n = 307 control), were included in our study. Eight studies with 371 patients showed significantly improved rest left ventricular ejection fraction (LVEF) with CSWT as compared to that of the control group (WMD 3.88, 95% CI 1.53-6.23, p = 0.001, I 2 = 51.2%). Seven studies with 312 patients reported left ventricular internal diameter in diastole (LVIDd) were markedly decreased in the CSWT group compared to the control group (WMD -1.81, 95% CI -3.23 to -0.39, p = 0.012, I 2 = 20.3%). The summed stress score significantly favored the CSWT group (WMD -3.76, 95% CI -6.15 to -1.37, p = 0.002, I 2 = 56.8%), but there was no significant difference for the summed rest score. Our data were acquired from studies without a perceived high risk of bias, so plausible bias is unlikely to seriously affect the main findings of the current study.

Conclusion

Based on data from our present meta-analysis, CSWT was shown to moderately improve myocardial perfusion and cardiac function among patients with CAD, which would provide the clinicians with a meaningful and valuable option.

Systematic Review Registration

The meta-analysis was registered on the Open Science Framework (OSF) (https://osf.io/r2xf9).

Contemporary Management of Refractory Angina

Refractory angina (RA) is defined as chest pain caused by coronary ischemia in patients on maximal medical therapy and is not amenable to revascularization despite advanced coronary artery disease (CAD). The long-term prognosis has improved with optimal medical therapy including risk factor modification. Still, patients are left with major impairment in quality of life and have high resource utilization with limited treatment options. We review the novel invasive and noninvasive therapies under investigation for RA.

Case Series: Extracorporeal Shockwave Myocardial Revascularization Therapy Improves Ischemic Response, Functional Capacity, and Quality of Life in Indicated CABG-Stable Angina Pectoris Patients

Introduction

Extracorporeal shockwave myocardial revascularization (ESMR) is included in the guidelines only for patients with refractory angina pectoris having no option for invasive revascularization. We intend to report a case series with ESMR therapy is indicated patients with coronary artery bypass grafting-stable angina pectoris (CABG-SAP) who refuse the surgery, irrespective of angina symptoms.

Methods

We review medical records of patients with SAP admitted to ESMR therapy in Dr. Hasan Sadikin General Hospital, Bandung, Indonesia from January 2018 to December 2019. Recorded variables at baseline and after therapy extracted, namely, (1) ischemic response, double product, and (2) functional capacity measured as metabolic equivalent (MET) using treadmill test; (3) six-minute walking test distance achieved; and (4) quality of life using SF-36 Questionnaire.

Results

A total of four indicated patients with CABG-SAP from 50 to 75 years old were included in this study. At baseline, one patient is CCS class I and two patients are CCS class II with SDS ranging from 3 to 17. Ischemic response improved in all the patients. The double product improved in patient 1 9,600–14,872 mm Hg × bpm, patient 2 9,460–10,640 mm Hg × bpm, and patient 4 17,220–20,480 mm Hg × bpm. The functional capacity improved in Patient 1 8.07–8.91 METs, patient 2 1.91–4.01 METs, patient 3 3.45–6.39 METs, and patient 4 3.9–4.43 METs. The 6-min walking distance improved in patient 1 540–570 m and patient 2 345–405 m. The CCS class, bodily pain, and general health domain scores improved in all patients.

Conclusion

ESMR therapy might be beneficial for indicated patients with CABG-SAP to improve ischemic response, functional capacity, and physical component of quality of life.

Management of refractory angina: an update

Despite the use of anti-anginal drugs and/or percutaneous coronary interventions (PCI) or coronary artery bypass grafting, the proportion of patients with coronary artery disease who have daily or weekly angina ranges from 2% to 24%. Refractory angina refers to long-lasting symptoms (for >3 months) due to established reversible ischaemia, which cannot be controlled by escalating medical therapy with the use of 2nd- and 3rd-line pharmacological agents, bypass grafting, or stenting. While there is uncertain prognostic benefit, the treatment of refractory angina is important to improve the quality of life of the patients affected. This review focuses on conventional pharmacological approaches to treating refractory angina, including guideline directed drug combination and dosages. The symptomatic and prognostic impact of advanced and novel revascularization strategies such as chronic total occlusion PCI, transmyocardial laser revascularization, coronary sinus occlusion, radiation therapy for recurrent restenosis, and spinal cord stimulation are also covered and recommendations of the 2019 ESC Guidelines on the Diagnosis and Management of Chronic Coronary Syndromes discussed. Finally, the potential clinical use of current angiogenetic and stem cell therapies in reducing ischaemia and/or pain is evaluated.

Effectiveness and Safety of Extracorporeal Shockwave Myocardial Revascularization in Patients With Refractory Angina Pectoris and Heart Failure

Extracorporeal shockwave myocardial revascularization (ESMR) is a therapy for refractory angina pectoris. Our aim was to assess the efficacy and safety of ESMR in the management of patients with stable coronary artery disease (CAD) and heart failure as well as its effects on inflammation and angiogenesis. In this single-arm prospective trial, we included 48 patients with CAD, myocardial ischemia assessed by radionuclide imaging, echocardiographic evidence of left ventricular systolic dysfunction and without revascularization options. Changes in angina grading score, myocardial perfusion, left ventricular ejection fraction, and six-minute walk test after ESMR therapy were used for efficacy assessment. Changes of inflammation and angiogenesis biomarkers were also evaluated. ESMR therapy was performed using a commercially available cardiac shockwave generator system (Cardiospec; Medispec). After 9 weeks of ESMR therapy, a significant improvement was found regarding the initial angina class, severity of ischemia, left ventricular ejection fraction, and six-minute walk test in most patients. No deleterious side effects after treatment were detected. Regarding biomarkers, endothelial progenitor cells and angiopoietin-3 were significantly increased whereas IL-18 and TGF-β were significantly decreased after ESMR in the total group. Notably, VEGF, IL-1ß, and lipoxin A4 levels were significantly increased only in patients with myocardial ischemia improvement. In conclusion, ESMR therapy is safe and effective in most but not all patients with CAD and heart failure. ESMR is associated with increased markers of angiogenesis and decreased markers of inflammation. Myocardial ischemia improvement after ESMR is associated with increased markers of angiogenesis and pro-resolving mediators.

Refractory Angina: From Pathophysiology to New Therapeutic Nonpharmacological Technologies

Despite optimal combination of guideline-directed anti-ischemic therapies and myocardial revascularization, a substantial proportion of patients with stable coronary artery disease continues to experience disabling symptoms and is often referred as "no-option." The appraisal of the pathways linking ischemia to symptom perception indicates a complex model of heart-brain interactions in the generation of the subjective anginal experience and inspired novel approaches that may be clinically effective in alleviating the angina burden of this population. Conversely, the prevailing ischemia-centered view of angina, with the focus on traditional myocardial revascularization as the sole option to address ischemia on top of medical therapy, hinders the experimental characterization and broad-scale clinical implementation of strongly needed therapeutic options. The interventionist, often the first physician to establish the diagnosis of refractory angina pectoris (RAP) following coronary angiography, should be aware of the numerous emerging technologies with the potential to improve quality of life in the growing population of RAP patients. This review describes the current landscape and the future perspectives on nonpharmacological treatment technologies for patients with RAP, with a view on the underlying physiopathological rationale and current clinical evidence.

Cardiac Shock Wave Therapy for Coronary Heart Disease: an Updated Meta-analysis

Introduction

The aim of this article is to study the efficacy and safety of cardiac shock wave therapy (CSWT) in the treatment of coronary heart disease (CAD).

Methods

A comprehensive search of electronic databases and a manual search of conference papers and abstracts were performed until September 30, 2018. The studies using RevMan 5.3 and STATA 14.0 softwares were reviewed, and meta-analyses were performed on 13 indicators, such as a six-min walking distance test (6MWT), New York Heart Association (NYHA) functional class, Seattle Angina Questionnaire (SAQ) score, angina class (Canadian Cardiology Society [CCS]), etc.

Results

A total of 26 articles were included. The total patient population was 855, of which 781 patients were treated with CSWT. Meta-analyses indicated that 6MWT (mean difference [MD] 75.64, 95% confidence interval [CI] 49.03, 102.25, P<0.00001) and NYHA (MD -0.70, 95% CI -0.92) in the CSWT group were comparable to those in the conventional revascularization group (MD -0.70, 95% CI -0.92, -0.49, P<0.00001). SAQ (MD 10.75, 95% CI 6.66, 14.83, P<0.00001), CCS (MD -0.99, 95% CI -1.13, -0.84, P<0.00001), nitrate dosage (MD -1.84, 95% CI -2.77, -1.12, P<0.00001), LVEF (MD 3.77, 95% CI 2.17, 5.37, P<0.00001), and SSS (MD -4.29, 95% CI -5.61, -2.96, P<0.00001), SRS (MD -2.90, 95% CI -4.85, -0.95, P=0.004), and the exercise test (standard mean difference 0.57, 95% CI 0.12, 1.02, P=0.01) all showed significant differences.

Conclusion

CSWT may offer beneficial effects to patients with CAD, but more large-scale clinical studies are needed to further verify its therapeutic effect.

Non-pharmacological Treatment of Refractory Angina and Microvascular Angina

Refractory angina (RA) is defined as debilitating anginal symptoms despite the optimal guideline-directed combination of medical, percutaneous, and surgical therapies. Often referred to as “no option”, these patients represent a significant unmet clinical need for healthcare institutions. Due to the ageing of the population, and increased survival from coronary artery disease, the number of patients with RA is expected to rise exponentially. Despite the developments of novel technologies for the treatment of RA, none of them found wide clinical application (to date). Microvascular dysfunction, alone or in combination with epicardial coronary disease, is thought to contribute significantly to refractory angina. However, most of the techniques developed to improve RA symptoms have not been tested specifically on patients with microvascular dysfunction. This review discusses the recent developments in the treatment of RA, and gives some perspectives on the future of these techniques.

Therapeutic Angiogenesis with Sound Waves

Along with the progress of global aging, the prognosis of severe ischemic heart disease (IHD) remains poor, and thus the development of effective angiogenic therapy remains an important clinical unmet need. We have developed low-energy extracorporeal cardiac shock wave therapy as an innovative minimally invasive angiogenic therapy and confirmed its efficacy in a porcine chronic myocardial ischemia model in animal experiments as well as in patients with refractory angina. Since ultrasound is more advantageous for clinical application than shock waves, we then aimed to develop ultrasound therapy for IHD. We demonstrated that specific conditions of low-intensity pulsed ultrasound (LIPUS) therapy improve myocardial ischemia in animal models through the enhancement of angiogenesis mediated by endothelial mechanotransduction. To examine the effectiveness of our LIPUS therapy in patients with severe angina pectoris, we are now conducting a prospective multicenter clinical trial in Japan. Furthermore, to overcome the current serious situation of dementia pandemic but with no effective treatments worldwide, we have recently demonstrated that our LIPUS therapy also improves cognitive impairment in mouse models of Alzheimer's disease and vascular dementia. Here, we summarize the progress in our studies to develop angiogenic therapies with sound waves.

The effect of cardiac shock wave therapy on myocardial function and perfusion in the randomized, triple-blind, sham-procedure controlled study

Background

Recent triple-blind sham procedure-controlled study revealed neutral effects of the cardiac shock wave therapy (CSWT) on exercise tolerance and symptoms in patients with stable angina. Current data about the effects of CSWT on global and regional myocardial contractility and perfusion is limited. Hereby we report the results of an imaging sub-study that evaluated the capacity of CSWT to ameliorate myocardial ischemia induced during dobutamine stress echocardiography (DSE) and cardiac single photon emission computed tomography (SPECT).

Methods

Prospective, randomized, triple-blind, sham procedure-controlled study enrolled 72 adult subjects who complied with defined inclusion criteria. The subjects were assigned to the OMT + CSWT and the OMT + sham procedure study groups with 1:1 ratio. Application of the CSWT covered all segments of the left ventricle. Imaging ischemia tests were performed in 59 study patients: DSE and SPECT before the CSWT treatment and after 6 months, with DSE carried out additionally at 3 months after randomization. Co-primary endpoints of the study were: change in wall motion score index (WMSI), representing the stress-induced impairment of regional myocardial function, and change in summed difference score (SDS), representing the amount of perfusion defect.

Results

OMT + CSWT and OMT + sham procedure study groups included 30 and 29 patients, respectively. Regional myocardial contractility during DSE significantly improved at 3 months follow-up in OMT + CSWT group compared to baseline as shown by WMSI at stress (1.4 ± 0.4 vs 1.6 ± 0.4, p = 0.001), but not in OMT + sham procedure group (1.5 ± 0.3 vs 1.6 ± 0.4, p = 0.136). The difference in stress DSE results between both study groups disappeared after 6 months. SPECT results demonstrated a significant reduction of inducible ischemia in OMT + CSWT group compared to OMT + sham procedure group at 6 months follow-up (SDS dropped from 5.4 ± 3.7 to 3.6 ± 3.8 vs 6.4 ± 5.9 to 6.2 ± 5 respectively, p = 0.034).

Conclusions

Cardiac shock wave treatment showed the ability to reduce stress-induced myocardial ischemia, as assessed by wall motion abnormalities and perfusion defects, compared to sham procedure.

Trial registration

Clinicaltrials.gov (NCT02339454). The trial was registered retrospectively on 12 January 2015.

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.

A multicenter trial of extracorporeal cardiac shock wave therapy for refractory angina pectoris: report of the highly advanced medical treatment in Japan

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.9 ± 12.6 (SD) years, M/F 38/12] without the indications of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were enrolled in 4 institutes in Japan. Ischemic myocardial regions in the left ventricle (LV) were identified by drug-induced stress myocardial perfusion imaging (MPI). Shock waves (200 shots/spot at 0.09 mJ/mm²) were applied to 40-60 spots in the ischemic myocardium 3 times in the first week. The patients were followed up for 3 months thereafter. Forty-one patients underwent CSWT and completed the follow-up at 3 months. CSWT markedly improved weekly nitroglycerin use [from 3.5 (IQR 2 to 6) to 0 (IQR 0 to 1)] and the symptoms [Canadian Cardiovascular Society functional class score, from 2 (IQR 2 to 3) to 1 (IQR 1 to 2)] (both P < 0.001). CSWT also significantly improved 6-min walking distance (from 384 ± 91 to 435 ± 122 m, P < 0.05). There were no significant changes in LV ejection fraction evaluated by echocardiography and LV stroke volume evaluated by cardiac magnetic resonance imaging (from 56.3 ± 14.7 to 58.8 ± 12.8%, P = 0.10, and from 52.3 ± 17.4 to 55.6 ± 15.7 mL, P = 0.15, respectively). Percent myocardium ischemia assessed by drug-induced stress MPI tended to be improved only in the treated segments (from 16.0 ± 11.1 to 12.1 ± 16.2%, P = 0.06), although no change was noted in the whole LV. No procedural complications or adverse effects related to the CSWT were noted. These results of the multicenter trial further indicate that CSWT is a useful and safe non-invasive strategy for patients with refractory AP with no options of PCI or CABG.

Extracorporeal myocardial shockwave therapy; a precious blast for refractory angina patients

INTRODUCTION

Refractory Angina Pectoris (RAP) dramatically affects patients' life quality and medical costs. External Shockwave Myocardial Revascularization (ESMR) improves the cardiac blood flow thanks to its pro-angiogenetic action on ischaemic tissues. We hereby describe our experience of ESMR in RAP patients.

MATERIALS AND METHODS

This is a retrospective study encompassing all patients referred to OSR for RAP treatment. Efficacy of ESMR was assessed considering the difference between pre and post therapy data in SAQ score and CCS, stress test performance, 24h ECG monitoring, NT-proBNP and echocardiographic measures.

RESULTS

From a total of 97 patients with RAP, 19 patients underwent ESMR, whereas 4 were considered as control group. After the end of the treatment, ESWT group showed a significant improvement in CCS class (-1.32±0.58; p<0.001) and in each of the five variables of the SAQ score (p<0.05). Patients also improved their exercise duration (50,74±29.40 seconds; p<0,001) and double product (1340,53±1321,77; p<0,001) and reduced the number of daily ST segment depression (-1,16±1,01; p<0,01). Ejection Fraction (2,05±1,84%; p<0,01) and Cardiac Output (0,20±0,28L, p<0,01) improved too. No changes were documented in the control group.

CONCLUSION

ESMR is an efficient therapy for refractory angina capable to improve both symptoms and instrumental tests.

Study of the Safety of Extracorporeal Cardiac Shock Wave Therapy: Observation of the Ultrastructures in Myocardial Cells by Transmission Electron Microscopy

Extracorporeal cardiac shock wave therapy (CSWT) has been used to treat patients with severe coronary heart disease and cardiac failure with good results; however, the safety of this treatment is still controversial. Its safety in clinical setting and on microstructures has been confirmed, but the influence of shock wave on the ultrastructures of myocardial cells is not clear. In this study, 12 Sprague-Dawley rats were randomly divided into control (NC) and CSWT therapy (NC+SW) groups. The heart rate, blood pressure, serum troponin I (TNI), and cardiac ultrasound were evaluated, and the myocardial inflammatory responses and fibrosis changes were compared. The samples were observed by transmission electron microscopy to evaluate the changes in myocardial tissue ultrastructure. The CSWT had no significant influence on rat hemodynamics indices and serum TNI, did not affect left ventricular function, and did not cause myocardial inflammatory response and fibrosis changes. The scores of myocardial ultrastructure damage in the NC and NC+SW groups were 1.39 ± 0.982 and 2.42 ± 1.009, respectively ( P = .103). The CSWT did not cause significant additional damage to myocardial ultrastructures. The safety of CWST has been preliminarily proved at the clinical, microstructure, and ultrastructure levels, but its long-term safety needs further exploration.

Cardiac shock-wave therapy in the treatment of coronary artery disease: systematic review and meta-analysis

AIM

To systematically review currently available cardiac shock-wave therapy (CSWT) studies in humans and perform meta-analysis regarding anti-anginal efficacy of CSWT.

METHODS

The Cochrane Controlled Trials Register, Medline, Medscape, Research Gate, Science Direct, and Web of Science databases were explored. In total 39 studies evaluating the efficacy of CSWT in patients with stable angina were identified including single arm, non- and randomized trials. Information on study design, subject's characteristics, clinical data and endpoints were obtained. Assessment of publication risk of bias was performed and heterogeneity across the studies was calculated by using random effects model.

RESULTS

Totally, 1189 patients were included in 39 reviewed studies, with 1006 patients treated with CSWT. The largest patient sample of single arm study consisted of 111 patients. All selected studies demonstrated significant improvement in subjective measures of angina symptoms and/or quality of life, in the majority of studies left ventricular function and myocardial perfusion improved. In 12 controlled studies with 483 patients included (183 controls) angina class, Seattle Angina Questionnaire (SAQ) score, nitrates consumption were significantly improved after the treatment. In 593 participants across 22 studies the exercise capacity was significantly improved after CSWT, as compared with the baseline values (in meta-analysis standardized mean difference SMD = -0.74; 95% CI, -0.97 to -0.5; p < 0.001).

CONCLUSIONS

Systematic review of CSWT studies in stable coronary artery disease (CAD) demonstrated consistent improvement of clinical variables. Meta-analysis showed a moderate improvement of exercise capacity. Overall, CSWT is a promising non-invasive option for patients with end-stage CAD, but evidence is limited to small sample single-center studies. Multi-center adequately powered randomised double blind studies are warranted.

Feasibility of Extracorporeal Shock Wave Myocardial Revascularization Therapy for Post-Acute Myocardial Infarction Patients and Refractory Angina Pectoris Patients

Extracorporeal shockwave myocardial revascularization (ESMR) is one of the new treatment options for refractory angina pectoris (RAP), and some studies have indicated its effectiveness. A single-arm prospective trial to assess the feasibility of ESMR using Cardiospec for patients with post-acute myocardial infarction (AMI) and RAP was designed and performed. The patients were treated with 9 sessions of ESMR to the ischemic areas for 9 weeks. The feasibility measures included echocardiography; cardiac magnetic resonance imaging; troponin T, creatine kinase-MB (CK-MB), and brain natriuretic peptide testing; and a Seattle Angina Questionnaire (SAQ) survey. Three post-AMI patients and 3 RAP patients were enrolled. The post-AMI patients had already undergone revascularization with percutaneous coronary intervention (PCI) in the acute phase. In two patients, adverse events requiring admission occurred: one a lumbar disc hernia in a post-AMI patient and the other congestive heart failure resulting in death in an RAP patient. No apparent elevations in CK-MB and troponin T levels during the trial were observed. Echocardiography revealed no remarkable changes of ejection fraction; however, septal E/E' tended to decrease after treatments (11.6 ± 4.8 versus 9.2 ± 2.8, P = 0.08). Concerning the available SAQ scores for two RAP patients, one patient reported improvements in angina frequency and treatment satisfaction and the other reported improvements in physical limitations and angina stability. In this feasibility study, ESMR seems to be a safe treatment for both post-AMI patients and RAP patients. The efficacy of ESMR for post-AMI patients remains to be evaluated with additional studies.

A Systematic Review of Extracorporeal Shockwave Therapy as a Novel Treatment for Intermittent Claudication

BACKGROUND

Extracorporeal shockwave therapy (ESWT) is emerging as a potential new treatment option for a variety of clinical scenarios including promotion of wound healing and symptom control in end-stage ischemic heart disease. A number of small trials have investigated ESWT in the management of peripheral arterial disease (PAD). A systematic review of the literature was performed investigating the efficacy and potential mechanism of action of ESWT for PAD.

METHODS

A systematic review was conducted using MEDLINE and PubMed databases in keeping with the standard reporting guidelines set by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis group to identify any publications relating to the use of ESWT in PAD.

RESULTS

Systematic literature review identified 5 studies in 4 articles investigating ESWT in the treatment of symptomatic PAD. Although participant numbers within the identified studies were small, significant improvements in pain-free walking distance and maximum walking distance were demonstrated. The mechanism of action is thought to be due to mechanotransduction and subsequent angiogenesis.

CONCLUSIONS

ESWT shows promise as a potentially efficacious novel treatment for symptomatic PAD. However, studies to date are small and record heterogeneous outcomes. Appropriately powered, randomized, sham-controlled data including objective clinical outcomes to comprehensively assess the efficacy of this novel treatment modality is still required before determining if ESWT should be brought into routine clinical practice.

Evaluation of extracorporeal shock wave therapy for refractory angina pectoris with quantitative analysis using cardiac magnetic resonance imaging: a short communication

Aims

There is a continuing search for new treatment options in patients who suffer from refractory angina pectoris to improve quality of life. Several studies have recently demonstrated promising results by stimulating angiogenesis using extracorporeal shockwave therapy in these patients. The purpose of this study is to quantitatively analyse the effect of extracorporeal shockwave therapy on myocardial perfusion in patients with refractory angina pectoris.

Methods

We included 15 patients with NYHA class 3–4 of whom 8 patients underwent baseline and follow-up cardiac magnetic resonance imaging (CMR). All patients received 9 shockwave treatments of their ischaemic zone over a period of 3 months.

Results

Quantitative analysis of myocardial perfusion using CMR revealed no significant improvement of myocardial perfusion after treatment (0.80 ± 0.22 vs 0.76 ± 0.31; p = 0.42). However, the total group of 15 patients did experience a significant improvement in NYHA class (p = 0.034) and reduction of nitroglycerin use (p = 0.012).

Conclusion

Although treatment with extracorporeal shockwave was associated with an improvement in NYHA class, we could not observe an improvement in myocardial ischaemic zone and perfusion with CMR. To unravel the exact mechanisms of shockwave treatment, more in vitro and animal studies as well as larger (placebo-controlled) studies are required.

Cardiac shock wave therapy and myocardial perfusion in severe coronary artery disease

BACKGROUND

Ultrasound guided cardiac shock wave therapy (CSWT) is a noninvasive therapeutic option in the treatment of chronic-refractory angina. Clinical trials have shown that CSWT reduces angina symptoms, improves regional systolic function, LV ejection fraction, myocardial perfusion and quality of life parameters. Absolute measurements of myocardial perfusion before and after CSWT have not been performed so far.

METHODS AND RESULTS

We studied a total of 21 CCS III patients with history of CAD and multiple interventions who suffered from disabling angina despite individually optimized medical therapy. An N-13 NH3 PET perfusion scan under adenosine was performed before and after CSWT treatment. CSWT was well tolerated in all patients. Absolute perfusion under adenosine of the global left-ventricular myocardium did not change under therapy or minimal coronary resistance. The treated segments, however, showed in terms of both perfusion and resistance a mild but significant improvement, by 11 and 15 %, respectively, whereas no change could be observed in the remote segments. Considering a threshold of increased perfusion of 5 %, 10 (77 %) out of 13 patients with a better target perfusion improved in their CCS class, whereas 3 (43 %) out of 7 patients without improved target perfusion improved in their CCS class too.

CONCLUSION

Standard CSWT has the potential to improve myocardial perfusion of the therapy zone and clinical CAD symptomatology without affecting global myocardial perfusion. As a noninvasive and well tolerated therapeutic option, these data suggest the use of CSWT in patients with end-stage CAD.