One year follow-up of patients with refractory angina pectoris treated with enhanced external counterpulsation

Enhanced External Counterpulsation Outcomes Study: Retrospective Analyses of Data Obtained from Patients at a Single Medical Center in United States

The aim was to explore the effectiveness of enhanced external counterpulsation (EECP) therapy in patients with severe angina pectoris/ chronic heart failure symptoms, who were not suitable candidates for invasive treatment. This retrospective study employed a comprehensive methodology that includes individualized treatment, continuous monitoring, and thorough pre- and postprogram evaluations to assess the efficacy of EECP therapy. The standard protocol involved 35 one-hour treatments, with flexibility for extensions based on therapeutic progress. When pre- and posttreatment results were analyzed, EECP improved the original functional class compared with pretreatment. The mean difference in the functional class was 1.32 (0.92), p  < 0.0001. Six-minute walk (6MW) distance improved from 383.6 m (110.24) to 423.1 m (121.50) with mean difference of 37.1 (44.99), p  < 0.0001. Duke Activity Status Index (DASI) score improved from 3.9 (2.75) to 6.0 (4.17) with mean difference of 2.16 (3.8), p  < 0.0001. Training metabolic equivalents (METs) improved from 3.0 (0.74) to 4.0 (1.57) with mean difference of 1.04 (1.2), p  < 0.0001. Weekly anginal events decreased from 13.1 (13.19) to 3.2 (7.38) with mean difference of -9.78 (11.7), p  < 0.0001. EECP resulted in improvement of angina pectoris functional class, the 6MW distance, reduction in the number of hospitalizations in first year posttreatment, a significant decrease in sublingual nitroglycerin use, improvement of systolic and diastolic blood pressure, and improvement of DASI score.

Interventions for acute non-arteritic central retinal artery occlusion

BACKGROUND

Acute non-arteritic central retinal artery occlusion (CRAO) occurs as a sudden interruption of the blood supply to the retina and typically results in severe loss of vision in the affected eye. Although many therapeutic interventions have been proposed, there is no generally agreed upon treatment regimen.

OBJECTIVES

To assess the effects of treatments for acute non-arteritic CRAO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 15 February 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing any interventions with another treatment in participants with acute non-arteritic CRAO in one or both eyes.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology and graded the certainty of the body of evidence for primary (mean change in best-corrected visual acuity [BCVA]) and secondary (quality of life and adverse events) outcomes using the GRADE classification.

MAIN RESULTS

We included six RCTs with 223 total participants with acute non-arteritic CRAO; the studies ranged in size from 10 to 84 participants. The included studies varied geographically: one in Australia, one in Austria and Germany, two in China, one in Germany, and one in Italy. We were unable to conduct any meta-analyses due to study heterogeneity. None of the included studies compared the same pair of interventions: 1) tissue plasminogen activator (t-PA) versus intravenous saline; 2) t-PA versus isovolemic hemodilution, eyeball massage, intraocular pressure reduction, and anticoagulation; 3) nitroglycerin, methazolamide, mecobalamin tablets, vitamin B1 and B12 injections, puerarin and compound anisodine (also known as 654-2) along with oxygen inhalation, eyeball massage, tube expansion, and anticoagulation compared with and without intravenous recombinant tissue plasminogen activator (rt-PA); 4) transcorneal electrical stimulation (TES) with 0 mA versus with 66% of the participant's individual electrical phosphene threshold (EPT) at 20 Hz (66%) versus with 150% of the participant's individual EPT (150%) at 20 Hz; 5) ophthalmic artery branch retrograde thrombolysis versus superselective ophthalmic artery thrombolysis; and 6) pentoxifylline versus placebo. There was no evidence of an important difference in visual acuity between participants treated with t-PA versus intravenous saline (mean difference [MD] at 1 month -0.15 logMAR, 95% confidence interval [CI] -0.48 to 0.18; 1 study, 16 participants; low certainty evidence); t-PA versus isovolemic hemodilution, eyeball massage, intraocular pressure reduction, and anticoagulation (MD at 1 month -0.00 logMAR, 95% CI -0.24 to 0.23; 1 study, 82 participants; low certainty evidence); and TES with 0 mA versus TES with 66% of EPT at 20 Hz versus TES with 150% of EPT at 20 Hz. Participants treated with t-PA experienced higher rates of serious adverse effects. The other three comparisons did not report statistically significant differences. Other studies reported no data on secondary outcomes (quality of life or adverse events).  AUTHORS' CONCLUSIONS: The current research suggests that proposed interventions for acute non-arteritic CRAO may not be better than observation or treatments of any kind such as eyeball massage, oxygen inhalation, tube expansion, and anticoagulation, but the evidence is uncertain. Large, well-designed RCTs are necessary to determine the most effective treatment for acute non-arteritic CRAO.

A Systematic Review on the Economic Evaluations Evidence of Enhanced External Counter-Pulsation (EECP) for Managing Chronic Stable Angina

Background: Chronic Stable Angina (CSA) does not respond to clinical interventions always. Therefore, enhanced external counter pulsation (EECP) has been approved by the Food and Administration Drug (FDA) as an effective technology. This study aimed to synthesize evidence on the economic evaluation of EECP in managing CSA through a systematic approach. Methods: In this systematic review study, PubMed/Medline, Cochrane Library, Web of Sciences, Scopus, National Institute for Health Research Journals Library, and the University of York Centre for Review and Dissemination (CRD) were searched. The targeted population was people who suffered from CSA, and the main therapeutic intervention was EECP. The comparators were not limited to any particular ones. Outcomes were changes in the Canadian Cardiovascular Society grading of angina pectoris, quality of life, and any other investigated relevant outcomes in the retrieved studies. The quality of studies was assessed through Philips et al and Joanna Briggs Institute Critical Appraisal tools. We synthesized data through a narrative approach. Results: We retrieved 7821 studies; among which 3 studies were included in the final phase. Two studies were systematic reviews and the Markov model economic evaluation. Another study was a partial economic evaluation. Conclusion: All studies only considered direct costs. EECP is a cost-effective technology in managing CSA, however, the sensitivity analysis of the studies showed the cost-effectiveness ratio is varied considerably and further studies are needed to extrapolate its economic value.

Safety and effectiveness of enhanced external counterpulsation (EECP) in refractory angina patients: A systematic reviews and meta-analysis

Enhanced external counterpulsation (EECP) is believed to be a non-invasive treatment for coronary artery disease and angina. The aim of this study was to determine the safety and effectiveness of EECP in refractory angina patients through a systematic reviews and meta-analysis. We conducted a comprehensive search of the literature published on PubMed, Cochrane library, Scopus, ScienceDirect, Trip Database and Google Scholar databases using appropriate keywords and specific strategy with no time limit. Having selected and screened the studies based on the defined inclusion and exclusion criteria and evaluating their quality based on the Cochrane checklist. For the meta-analysis,the Mantel-Haenszel method or the generic Inverse Variance was used. Analyses were done with Review Manager 5.2 software. A number of 299 studies were initially reviewed and finally, seventeen studies were included in the meta-analysis based on the inclusion and exclusion criteria. Also, thirteen outcomes were analyzed and the results of meta-analysis in twelve outcomes including (Systolic Blood Pressure (7 studies), Diastolic Blood Pressure (7 studies), Pulse Pressure (4 studies), Mean Arterial Pressures (4 studies), Heart Rate (6 studies), Angina episodes (7 studies), Walking distance (2 studies),Canadian Cardiovascular Society classification (6 studies), Flow-Mediated Dilation (3 studies), Daily Nitrate Usage (4 studies), Exercise Treadmill Test-Time (2 studies), ST-segment depression (2 studies)demonstrated a significant clinical advantage in the EECP treatment effectiveness in patients with angina. No significant difference was observed regarding EECP usefulness (P = 0.18) in the outcome of brachial artery diameter (2 studies). Based on the meta-analysis, the results indicate the safety and effectiveness of EECP in patients with angina pectoris and indicate the usefulness of this treatment in these patients. In general, the authors believe that the general conclusion in this regard requires some studies with a large sample size and a control group assignment.

Refractory angina frequencies during 7 weeks treatment by enhanced external counterpulsation in coronary artery disease patients with and without diabetes

Background:

Refractory angina is a clinical diagnosis which implies to chronic pain due to coronary artery insufficiency and it is often resistant to routine cardiac treatment. The present study conducted to compare changes in refractory angina frequencies during 7 weeks treatment by enhanced external counterpulsation (EECP) in coronary artery disease (CAD) patients with and without diabetes.

Methods:

In this retrospective study, 94 CAD patients (30 diabetics vs. 64 nondiabetics) who referred to cardiac rehabilitation department of Imam Ali Hospital of Kermanshah, Iran, during January 2006–2014 were assessed. The interventional method was EECP and medical records and frequencies of self-reported chest pain were research instruments. Data were analyzed through Chi-square test, mixed repeated measures, and Bonferroni test.

Results:

Frequencies of pain in both diabetic and nondiabetic groups during 7 weeks had linear reduction, but this reduction was significant only among nondiabetic patients (P < 0.0005). Furthermore, the significant reduction in frequencies of pain among this group begins after the 5^th week.

Discussion:

Diabetes is one of the obstacles to the successful control of pain frequencies by the EECP in patients with CAD. Future studies may pay attention to the confounding role of diabetes in improving the severity of chest pain.

Alternative therapy for medically refractory angina: enhanced external counterpulsation and transmyocardial laser revascularization

Medically refractory angina pectoris (RAP) is defined by presence of severe angina with objective evidence of ischemia and failure to relieve symptoms with coronary revascularization. Medication and invasive revascularization are the most common approaches for treating coronary artery disease (CAD). Although symptoms are eliminated or alleviated by these invasive approaches, the disease and its causes are present after treatment. New treatment approaches are needed to prevent the disease from progressing and symptoms from recurring. External enhanced counterpulsation therapy provides a treatment modality in the management of CAD and can complement invasive revascularization procedures. Data support that it should be considered a first-line treatment of RAP.

Effect of Enhanced External Counterpulsation (EECP) on Exercise Time Duration and Functional Capacity in Patients with Refractory Angina Pectoris

BACKGROUND

Enhanced external counterpulsation (EECP) is a noninvasive technique used for patients with refractory angina pectoris. There are controversial data on the effectiveness of EECP in improving patients with refractory stable angina. The aim of the present study was to evaluate the effectiveness and safety of EECP for the treatment of patients with refractory angina pectoris.

METHODS

Twenty consecutive patients with refractory angina pectoris were treated with EECP, and their symptoms, echocardiographic measures, treadmill exercise test parameters, and Canadian Cardiovascular Society Class were evaluated before and immediately after EECP. The patients were followed up for 6months post treatment.

RESULTS

There were significant differences regarding total exercise time before and after treatment (p value < 0.001). The patients showed a significant reduction in angina classes III and IV immediately after EECP (p value < 0.001); for most of the patients, these beneficial effects were sustained for 6 months (p value = 0.010). There was no significant improvement in the echocardiographic parameters.

CONCLUSION

EECP decreased symptoms and increased total exercise time in our study population. These beneficial effects were sustained for 6 months.

The safety and efficacy of enhanced external counterpulsation as a treatment for angina in patients with aortic stenosis

BACKGROUND

Comorbid aortic stenosis (AS) has been considered a precaution when applying enhanced external counterpulsation (EECP) to individuals with angina due to concerns about treatment-related hemodynamic changes.

HYPOTHESIS

The aim of this study was to determine whether EECP safely reduces symptoms of myocardial ischemia and improves hemodynamics in individuals with AS.

METHODS

Forty-three patients with AS (average age, 73 years; 86% male) and 43 comparison patients without AS were chosen from a database of 1327 EECP patients. Canadian Cardiovascular Society (CCS) Functional Angina Classification, diastolic augmentation ratio, and blood pressure were measured at baseline and on completion of the course of EECP.

RESULTS

Thirty-five of the 43 patients with AS (81%, 95% CI: 66.6% to 91.6%) and 38 of the 43 without AS (88%, 95% CI: 74.9% to 96.1%) improved in angina class (P < 0.0001). There was no statistical difference between the percentages in patients with and without AS (P = 0.54). CCS angina class outcome was not associated with AS severity (P = 0.55). The percentage of patients with diastolic augmentation ratio ≥1.0 was 16.3% in both groups at baseline and improved to 39.5% in AS patients and 37.2% in non-AS patients after EECP (both P = 0.002). The average decreases in systolic blood pressure in subjects with AS (-15 mm Hg, 95% CI: 11 to 20, P < 0.0001) and without AS (-18 mm Hg, 95% CI: 14 to 22, P < 0.0001) were similar (P = 0.31). No major adverse cardiac events were reported.

CONCLUSIONS

Angina patients with AS who undergo EECP had clinically important symptomatic and hemodynamic improvements comparable to their non-AS counterparts.

Reduced peripheral vascular reactivity in refractory angina pectoris: Effect of enhanced external counterpulsation

AIMS

To examine if the skin microvascular bed is altered and can be modified by enhanced external counterpulsation (EECP) in patients with chronic refractory angina.

METHODS

Twenty patients diagnosed with refractory angina were divided into EECP (n = 10) or no EECP (n = 10) groups. The data were compared to matched healthy subjects (n = 20). The cutaneous forearm microvascular blood flow was measured by Laser-Doppler flowmetry. The vascular responsiveness to iontophoretic administration of acetylcholine (ACh), sodium nitroprusside (SNP) and local skin warming were studied. Measurements of Canadian Cardiovascular Society (CCS)-class, blood pressure and plasma samples were registered.

RESULTS

EECP patients showed reduced CCS-class compared to no EECP (P < 0.05). Both EECP and no EECP (P < 0.05) groups had decreased systolic blood pressure (SBP) as compared to SBP at baseline (P < 0.05). There was no difference in resting blood flow between the two refractory groups at baseline as well as after EECP and seven weeks of follow-up. Responses to heating, the responses to ACh and SNP in the cutaneous microcirculation were lower in both groups of refractory angina patients as compared to healthy subjects (P < 0.05). EECP patients corresponded positively to the treatment shown by reduced plasma level of soluble interleukin-2 receptor and CCS-class.

CONCLUSIONS

Refractory angina patients have reduced responsiveness in their cutaneous microcirculation to ACh, SNP and heat compared to healthy subjects. Although EECP reduced the CCS-class, this effect was not associated with improvements in responsiveness of the cutaneous microcirculation.

Therapeutic goals in patients with refractory chronic angina

Refractory angina presents a major clinical challenge for everyday medical practice. Despite the widespread use of statins and improvements in revascularization techniques, a substantial proportion of patients with preserved left ventricular function and no life-threatening arrhythmias remain symptomatic, with severe debilitating angina. Because the rate of major cardiac events in this population is relatively low, the major aim of therapy should be not only to prolong survival but also to improve quality of life. The cornerstone of therapy for all these patients should be the aggressive modification of risk factors using evidence-based treatment, with the aim of stabilizing the disease process and improving overall survival. No opportunity for revascularization should be overlooked. Complementary approaches should be implemented to raise the angina threshold by either reducing oxygen demand or improving hemodynamics to increase myocardial oxygen supply. This review provides an update on therapeutic techniques and goals, and reinforces the need for a multidisciplinary approach to the management of patients with refractory angina.

Enhanced external counterpulsation: an innovative physical therapy for refractory angina

The prevalence of refractory angina in the United States is 600,000 to 1.8 million. Improved pharmacological, invasive, and surgical therapies for cardiovascular diseases during the last few decades have led to an increase in life expectancy of such individuals. Despite treatment with multiple medications and invasive procedures, these patients remain symptomatic and functionally limited. Enhanced external counterpulsation (EECP) is a safe, noninvasive, well-tolerated, and clinically effective outpatient physical therapy for many patients with refractory angina. Numerous trials demonstrate positive clinical responses among at least 80% of patients undergoing EECP, including reductions in angina and nitrate use, increases in exercise tolerance, and enhanced quality of life. Several mechanisms, including the promotion of collateral blood flow, improvement in endothelial function, reduction in inflammation, and the production of peripheral training effects similar to exercise, are thought to be responsible for the clinical benefits of this therapy. Despite the marked success rates EECP achieves with appropriately selected patients who have end-stage coronary artery disease, the treatment remains largely unknown, particularly among physiatrists. This review will summarize the current evidence for the use of EECP and spark a better understanding of the potential role of this treatment in cardiac rehabilitation.

Interventions for acute non-arteritic central retinal artery occlusion

BACKGROUND

Acute central retinal artery occlusion (CRAO) occurs as a sudden interruption of the blood supply to the retina and results in an almost complete loss of vision in the affected eye. There is no generally agreed treatment regimen although a number of therapeutic interventions have been proposed.

OBJECTIVES

The objective of this review was to examine the effects of treatments used for acute non-arteritic CRAO.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 3, 2008), MEDLINE (January 1966 to September 2008), EMBASE (January 1980 to September 2008) and the reference lists of relevant papers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) only in which one treatment aimed to re-establish blood supply to the retina in people with acute CRAO was compared to another treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results for relevant trials. Discrepancies were resolved by discussion.

MAIN RESULTS

We found two RCTs that met our inclusion criteria.

AUTHORS' CONCLUSIONS

The included studies in this review were small and from single centres. Neither study was completely clear about it's method of treatment allocation. One study described the use of pentoxifylline tablets (three 600 mg tablets daily) and the other the use of enhanced external counterpulsation (EECP) combined with haemodilution. Both studies indicated improved retinal perfusion in the non-control group but neither showed an improvement in vision. Large, well-designed RCTs are still required to establish the most effective treatment for acute CRAO. These studies should be looking at factors important to the patient i.e. improved vision with acceptable risk/side-effects.

Blood Flow Changes in Normal and Ischemic Myocardium During Topically Applied Negative Pressure

BACKGROUND

Topical negative pressure (TNP) therapy has been adopted as a first-line treatment for wound healing. One of the mechanisms by which TNP improves healing is by stimulating blood flow to the wound edge. Among patients with ischemic heart disease, it is of great importance to improve the microvascular blood flow in the myocardium during episodes of ischemia to protect the myocardium from infarction. The present study was designed to elucidate the effect of TNP on microvascular blood flow in the myocardium.

METHODS

Six pigs underwent median sternotomy. The microvascular blood flow in the myocardium was recorded, before and after the application of TNP, by using laser Doppler velocimetry. Analyses were performed before left anterior descending artery (LAD) occlusion (normal myocardium), after 20 minutes of LAD occlusion (ischemic myocardium), and after 20 minutes of reperfusion (reperfused myocardium).

RESULTS

TNP at -0 mm Hg increased microvascular blood flow in the normal myocardium from 14.7 +/- 3.9 perfusion units (PU) before to 25.8 +/- 6.1 PU after TNP application (p < 0.05), in the ischemic myocardium from 7.2 +/- 1.5 PU before to 13.8 +/- 2.6 PU after TNP application (p < 0.05), and in the reperfused myocardium from 10.8 +/- 2.0 PU before to 19.3 +/- 5.6 PU after TNP application (p < 0.05).

CONCLUSIONS

TNP increases the microvascular blood flow significantly in normal, ischemic, and reperfused myocardium and may provide a novel therapeutic tool in the treatment of ischemic myocardium.

Current strategies for the prevention of angina in patients with stable coronary artery disease

PURPOSE OF REVIEW

Angina pectoris affects at least 6.6 million people in the US and approximately 400,000 new cases of stable angina occur each year. Angina may be one of the first signs of ischemic heart disease, although it is likely not causally related to the likelihood of plaque rupture leading to an acute coronary syndrome. Modalities for treatment of angina should be used maximally to improve quality of life and decrease cardiovascular morbidity and mortality. The current recommended pharmacologic and invasive approaches, as well as novel therapies, are reviewed.

RECENT FINDINGS

Antiischemic agents, including beta-blockers, nitrates and calcium channel blockers, remain the mainstay in the prevention of angina. Revascularization via percutaneous interventions or coronary bypass surgery are appropriate in specific cases or when medical treatment fails. Noninvasive treatment options for refractory angina, metabolic agents, and vasodilator therapies are adding to the armamentarium to prevent and treat angina.

SUMMARY

A multifaceted approach is optimal to address the prevention of angina. Once angina is recognized, there are many modalities that lessen the incidence of daily life-induced and exercise-induced angina and ischemia. Angina management is best addressed by pharmacologic and lifestyle interventions.