Chronic therapeutically refractory angina pectoris

Novel Concepts in the Management of Angina in Coronary Artery Disease

Coronary artery disease remains a condition with high prevalence and detrimental effects on the quality of life of affected individuals. Its most frequent manifestation, stable angina pectoris, may be challenging to manage despite the available antianginal pharmacotherapy and adequate risk factor control, especially in subjects not amenable to revascularization. In the direction of refractory angina pectoris, several approaches have been developed over the years with varying degrees of success. Among the most recognized techniques in managing angina is enhanced external counterpulsation, which utilizes mechanical compression of the lower extremities to increase blood flow to the heart. Moving to coronary sinus reduction, it leads to an increase in coronary sinus backward pressure, ultimately augmenting myocardial blood flow redistribution to ischemic regions and ameliorating chronic angina. Clinical trial results of the above-mentioned techniques have been encouraging but are based on small sample sizes to justify their widespread application. Other interventional approaches, such as transmyocardial laser revascularization, extracorporeal shockwave myocardial revascularization, and spinal cord stimulation, have been met with either controversial or negative results, and their use is not recommended. Lastly, angiogenic therapy with targeted intramyocardial vascular endothelial growth factor injection or CD34+ cell therapy may be beneficial and warrants further investigation. In this review, we summarize the current knowledge in the field of angina management, highlighting the potential and the gaps in the existing evidence that ought to be addressed in future larger-scale, randomized studies before these techniques can be safely adapted in the clinical practice of patients with refractory angina pectoris.

Spinal Cord Stimulation for Refractory Angina Pectoris: A Systematic Review and Meta-analysis

Objectives:

Paresthesia-free stimulation such as high frequency and burst have been demonstrated as effective therapies for neuropathic pain. The aim of this meta-analysis was to evaluate the efficacy and safety of conventional spinal cord stimulation (SCS) in the treatment of refractory angina pectoris (RAP).

Materials and Methods:

Relevant randomized controlled trials that investigated SCS for patients with RAP were comprehensively searched in Medline, Pubmed, Embase, and Cochrane Library. Five meta-analyses were performed examining the changes in Canadian Cardiovascular Society classes, exercise time, Visual Analog Scale (VAS) scores of pain, Seattle Angina Questionnaire, and nitroglycerin use in RAP patients after SCS therapy. We analyzed standardized mean differences (MD) and 95% confidence intervals (CIs) for each outcome by Review Manager 5.0 and STATA 12.0.

Results:

A total of 12 randomized controlled trials involving 476 RAP patients were identified. A trend of reduction in the angina frequency (MD=−9.03, 95% CI, −15.70 to −2.36) and nitroglycerin consumption (MD=−0.64, 95% CI, −0.84 to −0.45) could be observed in the SCS group. Compared with the control group, SCS showed benefit on increasing exercise time (MD=0.49, 95% CI, 0.13-0.85) and treatment satisfaction (MD=6.87, 95% CI, 2.07-11.66) with decreased VAS scores of pain (MD=−0.50, 95% CI, −0.81 to −0.20) and disease perception (MD=−8.34, 95% CI, −14.45 to −2.23). However, the result did not reach the significance level in terms of physical limitation (95% CI, −8.75 to 3.38; P=0.39) or angina stability (95% CI, −7.55 to 3.67; P=0.50).

Discussion:

The current meta-analysis suggested that SCS was a potential alternative in the treatment of PAP patients. Further investigation for finding the appropriate intensity of stimulation is required before this treatment should be widely recommended and applied.

Cardiac shockwave therapy in patients with chronic refractory angina pectoris

Background

Cardiac shockwave therapy (CSWT) might improve symptoms and decrease ischaemia burden by stimulating collateral growth in chronic ischaemic myocardium. This prospective study was performed to evaluate the feasibility and safety of CSWT.

Methods

We included 33 patients (mean age 70 ± 7 years, mean left ventricular ejection fraction 55 ± 12 %) with end-stage coronary artery disease, chronic angina pectoris and reversible ischaemia on myocardial scintigraphy. CSWT was applied to the ischaemic zones (3–7 spots/session, 100 impulses/spot, 0.09 mJ/mm²) in an echocardiography-guided and ECG-triggered fashion. The protocol included a total of 9 treatment sessions (3 treatment sessions within 1 week at baseline, and after 1 and 2 months). Clinical assessment was performed using exercise testing, angina score (CCS class), nitrate use, myocardial scintigraphy, and cardiac magnetic resonance (CMR) 1 and 4 months after the last treatment session.

Results

One and 4 months after CSWT, sublingual nitrate use decreased from 10/week to 2/week (p < 0.01) and the angina symptoms diminished from CCS class III to CCS class II (p < 0.01). This clinical improvement was accompanied by an improved myocardial uptake on stress myocardial scintigraphy (54.2 ± 7.7 % to 56.4 ± 9.4 %, p = 0.016) and by increased exercise tolerance at 4-month follow-up (from 7.4 ± 2.8 to 8.8 ± 3.6 min p = 0.015). No clinically relevant side effects were observed.

Conclusion

CSWT improved symptoms and reduced ischaemia burden in patients with end-stage coronary artery disease without relevant side effects. The study provides a solid basis for a randomised multicentre trial to establish CSWT as a new treatment option in end-stage coronary artery disease.

The Effectiveness and Cost-Effectiveness of Spinal Cord Stimulation for Refractory Angina (RASCAL Study): A Pilot Randomized Controlled Trial

Background

Patients with “refractory angina” (RA) unsuitable for coronary revascularization experience high levels of hospitalization and poor health‐related quality of life. Randomized trials have shown spinal cord stimulation (SCS) to be a promising treatment for chronic stable angina and RA; however, none has compared SCS with usual care (UC). The aim of this pilot study was to address the key uncertainties of conducting a definitive multicenter trial to assess the clinical and cost‐effectiveness of SCS in RA patients, i.e., recruitment and retention of patients, burden of outcome measures, our ability to standardize UC in a UK NHS setting.

Methods

RA patients deemed suitable were randomized in a 1:1 ratio to SCS plus UC (SCS group) or UC alone (UC group). We sought to assess: recruitment, uptake, and retention of patients; feasibility and acceptability of SCS treatment; the feasibility and acceptability of standardizing UC; and the feasibility and acceptability of the proposed trial outcome measures. Patient outcomes were assessed at baseline (prerandomization) and three and six months postrandomization.

Results

We failed to meet our planned recruitment target (45 patients) and randomized 29 patients (15 SCS group, 14 UC group) over a 42‐month period across four sites. None of the study participants chose to withdraw following consent and randomization. With exception of two deaths, all completed evaluation at baseline and follow‐up. Although the study was not formally powered to compare outcomes between groups, we saw a trend toward larger improvements in both primary and secondary outcomes in the SCS group.

Conclusions

While patient recruitment was found to be challenging, levels of participant retention, outcome completion, and acceptability of SCS therapy were high. A number of lessons are presented in order to take forward a future definitive pragmatic randomized trial.

High prevalence of raised lipoprotein(a) in patients with refractory angina

Background: Angina that is refractory to conventional medical therapy and revascularisation, remains challenging to manage and poses significant burden to patients. Elevated lipoprotein(a) [Lp(a)] has emerged as an important independent cardiovascular risk factor and predictor of adverse outcomes in atherosclerotic disease. The prevalence of raised Lp(a) amongst patients with refractory angina has not yet been defined. Objective: To establish the prevalence of raised [Lp(a)] >500 mg/L in patients with refractory angina. Methods: We conducted an epidemiological screening pilot study in 75 patients with refractory angina from a UK tertiary cardiac centre. We determined the proportion of the cohort with raised Lp(a) >500 mg/L using an isoform-insensitive method. In addition, a full fasting lipid profile (including: LDL cholesterol, HDL cholesterol, total cholesterol to HDL ratio and triglycerides) was obtained. Patients were also asked about the presence of conventional cardiovascular risk factors. Results: Our study demonstrated that 60% of the 75 patients with refractory angina had raised Lp(a) levels of >500 mg/L. The median and inter-quartile range of Lp(a) values were 771 mg/L (162 mg/L,1260 mg/L) respectively. Conclusions: This high prevalence of raised Lp(a) detected in our cohort with refractory angina may suggest a causal role. Further research is necessary to confirm this association and prospective studies are needed to explore the potential therapeutic benefit of Lp(a) reduction in patients with refractory angina.

Exercise as a therapeutic intervention in patients with stable ischemic heart disease: an underfilled prescription

Treatment for stable ischemic heart disease may include guideline-directed pharmacologic therapy, coronary revascularization, and lifestyle and behavioral changes, including structured exercise. Of these, regular exercise is arguably one of the most cost-effective yet underused interventions. Most patients with stable ischemic heart disease are eligible for secondary prevention programs, which should include exercise training regimens, but participation in such programs remains suboptimal. This review emphasizes the importance of education for both patients and providers to enhance participation in lifestyle physical activity, structured exercise, or both.

Interventional treatment of pain in refractory angina. A review

BACKGROUND

Refractory angina is characterized by repeated attacks of chest pain in patients on maximal anti-anginal pharmacotherapy, with a professional conscensus that further surgical or radiological revascularization would be futile. Refractory angina is a serious but relatively uncommon health problem, with a reported incidence of approximately 30 patients per million people/year. In this condition simply treating the associated pain alone is important as this can improve exercise tolerance and quality of life.

METHODS

An extensive literature search using five different medical databases was performed and from this, eighty-three papers were considered appropriate to include within this review.

RESULTS AND CONCLUSION

Available literature highlights several methods of interventional pain treatment, including spinal cord stimulation and video-assisted upper thoracic sympathectomy which can provide good analgesia whilst improving physical activities and quality of life. The positive effect of spinal cord stimulation on the intensity of pain and quality of life has been confirmed in nine randomized controlled trials. Other potential treatment methods include stellate ganglion blocks, insertion of thoracic epidural or spinal catheters and transcutaneous electrical nerve stimulation. These approaches however appear more useful for diagnostic purposes and perhaps as short-term treatment measures.

The expanding role of lipoprotein apheresis in the treatment of raised lipoprotein(a) in ischaemic heart disease and refractory angina

It is increasingly recognised that lipoprotein(a) [Lp(a)], an inherited, genetically-determined form of LDL-cholesterol, is an independent cardiovascular risk factor and predictor of adverse cardiovascular outcomes. Lp(a) is felt to increase cardiovascular risk via its pro-thrombotic effect and by enhancing intimal lipoprotein deposition. Lipoprotein apheresis is currently the most effective treatment for raised Lp(a). There is a growing body of evidence suggesting that aggressively lowering raised Lp(a) may improve cardiovascular and clinical outcomes, although much more research is required in this field.

Angina which is refractory to conventional medical therapy and revascularisation, is extremely challenging to manage. Treatment options for such patients remain very limited. We describe the case of a patient with refractory angina and raised lipoprotein(a) in whom aggressive reduction of Lp(a) with lipoprotein apheresis successfully ameliorated the progression of coronary stenosis and provided effective and durable relief of angina symptoms. In our centre, we are currently conducting a prospective, randomised controlled cross-over study of patients with refractory angina and raised Lp(a), randomised to undergoing lipoprotein apheresis or ‘sham’ apheresis with assessment of myocardial perfusion, carotid atherosclerosis, endothelial vascular function, thrombogenesis, oxidised phospholipids and their antibodies, exercise capacity, angina symptoms and quality of life at the beginning and end of treatment.

Spinal cord stimulation for long-term treatment of severe angina pectoris: what does the evidence say?

Patients who continue to suffer from severe and disabling angina pectoris, despite optimum treatment in terms of conventional pharmacological therapy and/or revascularization procedures, have been termed as having refractory angina pectoris. The future group of patients with refractory angina pectoris will be different from today’s patients and represent a ‘moving target’ as risk factors, efficacy of treatment and indications continue to change. Spinal cord stimulation (SCS) is today considered as first-line treatment of refractory angina pectoris, by the European Society of Cardiology, with an anti-ischemic effect. There is strong evidence for SCS giving symptomatic benefits (decrease in anginal attacks), improved quality of life and improvement of functional status. In addition, SCS seems to be cost effective with a ‘break-even’ after approximately 15–16 months.

The quality of pain management in German hospitals

BACKGROUND

The Pain-Free Hospital Project was initiated in 2003 with the aim of improving pain management throughout Germany. We assessed the current state of pain management in German hospitals.

METHODS

From 2004 to 2006, data were obtained anonymously from 2252 patients who had undergone surgery, and 999 who had been treated non-surgically, in a total of 25 hospitals. They were interviewed about the intensity of pain they had experienced and about the effectiveness of its treatment.

RESULTS

No pain at all was reported by 12.4% of patients who had undergone surgery and by 16.7% of the non-surgically treated patients. Moderate to severe pain at rest was reported by 29.5% of the surgical group and 36.8% of the non-surgical group. More than 50% of the overall group reported pain on movement. 55% of the surgical group, and 57% of the non-surgical group, were dissatisfied with their pain management. Peak pain tended to occur outside normal working hours. No analgesic treatment at all was given to 39% of patients in the non-surgical group, even though they were in pain; the corresponding figure for the surgical group was 15% (a significant difference, p<0.001). Inadequately effective pain management was reported by 45.6% of patients in the non-surgical group and 29.6% in the operative group (again, a significant difference. Cancer patients were treated more often with potent opioids.

CONCLUSION

Severe postoperative pain is still too common among hospitalized patients, particularly pain that is induced by movement. Patients being treated on non-surgical wards also often suffer severe pain needlessly. Pain management seems to be worse for non-surgical patients (cancer patients excepted) than for surgical patients: waiting times for medication are longer, and ineffective medications are given more often. On the other hand, a number of hospitals provide positive examples of the potential effectiveness of pain management for both surgical and non-surgical patients.

Spinal cord stimulation in the treatment of refractory angina: systematic review and meta-analysis of randomised controlled trials

Background

The aim of this paper was undertake a systematic review and meta-analysis of the use of spinal cord stimulation (SCS) in the management of refractory angina.

Methods

We searched a number of electronic databases including Medline, Embase and Cochrane Library up to February 2008 to identify randomised controlled trials (RCTs) reporting exercise capacity, ischemic burden, functional class, quality of life, usage of anti-anginal medication, costs and adverse events including mortality. Results were reported both descriptively for each study and using random effects meta-analysis. Given the variety in outcomes reported, some outcome results were pooled as standardised mean differences (SMD) and reported in standard deviation units.

Results

Seven RCTs were identified in a total of 270 refractory angina patients. The outcomes of SCS were found to be similar when directly compared to coronary artery bypass grafting (CABG) and percutaneous myocardial laser revascularisation (PMR). Compared to a 'no stimulation' control, there was some evidence of improvement in all outcomes following SCS implantation with significant gains observed in pooled exercise capacity (SMD: 0.76, 0.07 to 1.46, p = 0.03) and health-related quality of life (SMD: 0.83, 95% CI: 0.32 to 1.34, p = 0.001). Trials were small and were judged to range considerably in their quality. The healthcare costs of SCS appeared to be lower than CABG at 2-years follow up.

Conclusion

SCS appears to be an effective and safe treatment option in the management of refractory angina patients and of similar efficacy and safety to PMR, a potential alternative treatment. Further high quality RCT and cost effectiveness evidence is needed before SCS can be accepted as a routine treatment for refractory angina.

Putative mechanisms behind effects of spinal cord stimulation on vascular diseases: a review of experimental studies

Spinal cord stimulation (SCS) is a widely used clinical technique to treat ischemic pain in peripheral, cardiac and cerebral vascular diseases. The use of this treatment advanced rapidly during the late 80's and 90's, particularly in Europe. Although the clinical benefits of SCS are clear and the success rate remains high, the mechanisms are not yet completely understood. SCS at lumbar spinal segments (L2-L3) produces vasodilation in the lower limbs and feet which is mediated by antidromic activation of sensory fibers and decreased sympathetic outflow. SCS at thoracic spinal segments (T1-T2) induces several benefits including pain relief, reduction in both frequency and severity of angina attacks, and reduced short-acting nitrate intake. The benefits to the heart are not likely due to an increase, or redistribution of local blood flow, rather, they are associated with SCS-induced myocardial protection and normalization of the intrinsic cardiac nervous system. At somewhat lower cervical levels (C3-C6), SCS induces increased blood flow in the upper extremities. SCS at the upper cervical spinal segments (C1-C2) increased cerebral blood flow, which is associated with a decrease in sympathetic activity, an increase in vasomotor center activity and a release of neurohumoral factors. This review will summarize the basic science studies that have contributed to our understanding about mechanisms through which SCS produces beneficial effects when used in the treatment of vascular diseases. Furthermore, this review will particularly focus on the antidromic mechanisms of SCS-induced vasodilation in the lower limbs and feet.

Coronary Sinus Reducer Stent for the Treatment of Chronic Refractory Angina Pectoris

OBJECTIVES

This study sought to evaluate the safety of the Coronary Sinus Reducer (Neovasc Medical, Inc., Or Yehuda, Israel) as a potential alternate therapy for patients with refractory angina who are not candidates for conventional revascularization procedures.

BACKGROUND

Increased coronary sinus (CS) pressure can reduce myocardial ischemia by redistribution of blood from nonischemic to ischemic territories. The Coronary Sinus Reducer is a percutaneous implantable device designed to establish CS narrowing and to elevate CS pressure. In preclinical experiments, implantation of the Reducer was safe and was associated with improved ischemic parameters. In the present study, the safety and feasibility of the Coronary Sinus Reducer was evaluated in patients with refractory angina who were not candidates for revascularization.

METHODS

Fifteen coronary artery disease patients with severe angina and reversible ischemia were electively treated with the Reducer. Clinical evaluation, dobutamine echocardiography, thallium single-photon emission computed tomography, and administration of an angina questionnaire were performed before and 6 months after implantation. Cardiac computed tomography was performed 2 days and 6 months after implantation.

RESULTS

All procedures were completed successfully. No procedure-related adverse events occurred during the periprocedural and the follow-up periods. Angina score improved in 12 of 14 patients. Average Canadian Cardiovascular Society score was 3.07 at baseline and 1.64 at follow-up (n = 14, p < 0.0001). Stress-induced ST-segment depression was reduced in 6 of 9 patients and was eliminated in 2 of these 6 (p = 0.047). The extent and severity of myocardial ischemia by dobutamine echocardiography and by thallium single-photon emission computed tomography was reduced (p = 0.004 [n = 13] and p = 0.042 [n = 10], respectively).

CONCLUSIONS

Implantation of the Coronary Sinus Reducer is feasible and safe. These findings, along with the clinical improvement observed, support further evaluation of the Reducer as an alternative treatment for patients with chronic refractory angina who are not candidates for coronary revascularization.

A brief cognitive-behavioral intervention reduces hospital admissions in refractory angina patients

Chronic refractory angina is an increasingly prevalent, complex chronic pain condition, which results in frequent hospitalization for chest pain. We have previously shown that a novel outpatient cognitive-behavioral chronic disease management program (CB-CDMP) improves angina status and quality of life in such patients. In the present study of 271 chronic refractory angina patients enrolled in our CB-CDMP, total hospital admissions were reduced from 2.40 admissions per patient per year to 1.78 admissions per patient per year (P<0.001). The rising trend of total hospital bed day occupancy prior to enrollment fell from 15.48 days per patient per year to a stable 10.34 days per patient per year (P<0.001). There were 32 recorded myocardial infarctions prior to enrollment compared to eight in the year following enrollment (14% vs. 2.3%, P<0.001) and overall mortality was lower that comparable groups treated with surgery. This study shows that educating patients and demystifying angina using a brief outpatient CB-CDMP produces an immediate and sustained reduction in hospital admission costs that represents a major potential health care saving. This benefit accrues in addition to the known effects of CB-CDMP on symptoms and quality of life. These data suggest that a CB-CDMP approach to symptom palliation represents a low cost alternative to palliative revascularization.

Enhanced External Counterpulsation (EECP): An Evidence-Based Analysis

OBJECTIVE

To assess the effectiveness, and cost effectiveness of EECP in patients with severe anginal symptoms, secondary to chronic coronary disease, who are unresponsive to exhaustive pharmacotherapy and not candidates for surgical/percutaneous revascularization procedures (e.g., angioplasty, coronary bypass surgery). To assess the effectiveness, and cost effectiveness of EECP in patients with heart failure.

CLINICAL NEED

ANGINA: Angina is a clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back or arm. Angina usually occurs in patients with coronary artery disease (CAD) involving ≥1 large epicardial artery. However it can also occur in people with valvular heart disease, hypertrophic cardiomyopathy, and uncontrolled hypertension. CONVENTIONAL APPROACHES TO RESTORING THE BALANCE BETWEEN OXYGEN SUPPLY AND DEMAND FOCUS ON THE DISRUPTION OF THE UNDERLYING DISEASE THROUGH: drug therapy (β blockers, calcium channel blockers, nitrates, antiplatelet agents, ACE inhibitors, statins); life-style modifications (smoking cessation, weight loss); or revascularization techniques such as coronary artery bypass graft surgery (CABG) or percutaneous coronary interventions (PCI). (1) Limitations of each of these approaches include: adverse drug effects, procedure-related mortality and morbidity, restenosis after PCI, and time dependent graft attrition after CABG. Furthermore, an increasing number of patients are not appropriate candidates for standard revascularization options, due to co-morbid conditions (HF, peripheral vascular disease), poor distal coronary artery targets, and patient preference. The morbidity and mortality associated with repeat surgical revascularization procedures are significantly higher, and often excludes these patients from consideration for further revascularizations. (2) Patients with CAD who have chronic ischemic symptoms that are unresponsive to both conventional medical therapy and revascularization techniques have refractory angina pectoris. It has been estimated that greater than 100,000 patients each year in the US may be diagnosed as having this condition. (3) Patients with refractory angina have marked limitation of ordinary physical activity or are unable to perform any ordinary physical activity without discomfort (CCS functional class III/IV). Also, there must be some objective evidence of ischemia as demonstrated by exercise treadmill testing, stress imaging studies or coronary physiologic studies. (1) Dejongste et al. (4)estimated that the prevalence of chronic refractory angina is about 100,000 patients in the United States. This would correspond to approximately 3,800 (100,000 x 3.8% [Ontario is approximately 3.8% of the population of the United States]) patients in Ontario having chronic refractory angina.

HEART FAILURE

Heart failure results from any structural or functional cardiac disorder that impairs the ability of the heart to act as a pump. A recent study (5) revealed 28,702 patients were hospitalized for first-time HF in Ontario between April 1994 and March 1997. Women comprised 51% of the cohort. Eighty-five percent were aged 65 years or older, and 58% were aged 75 years or older. Patients with chronic HF experience shortness of breath, a limited capacity for exercise, high rates of hospitalization and rehospitalization, and die prematurely. (6) The New York Heart Association (NYHA) has provided a commonly used functional classification for the severity of HF (7): CLASS I: No limitation of physical activity. No symptoms with ordinary exertion.CLASS II: Slight limitations of physical activity. Ordinary activity causes symptoms.CLASS III: Marked limitation of physical activity. Less than ordinary activity causes symptoms. Asymptomatic at rest.CLASS IV: Inability to carry out any physical activity without discomfort. Symptoms at rest.The National Heart, Lung, and Blood Institute (7) estimates that 35% of patients with HF are in functional NYHA class I; 35% are in class II; 25%, class III; and 5%, class IV. Surveys (8) suggest that from 5% to 15% of patients with HF have persistent severe symptoms, and that the remainder of patients with HF is evenly divided between those with mild and moderately severe symptoms. To date, the diagnosis and management of chronic HF has concentrated on patients with the clinical syndrome of HF accompanied by severe left ventricular systolic dysfunction. Major changes in treatment have resulted from a better understanding of the pathophysiology of HF and the results of large clinical trials. Treatment for chronic HF includes lifestyle management, drugs, cardiac surgery, or implantable pacemakers and defibrillators. Despite pharmacologic advances, which include diuretics, angiotensin-converting enzyme inhibitors, beta-blockers, spironolactone, and digoxin, many patients remain symptomatic on maximally tolerated doses. (6) THE TECHNOLOGY: Patients are typically treated by a trained technician in a medically supervised environment for 1 hour daily for a total of 35 hours over 7 weeks. The procedure involves sequential inflation and deflation of compressible cuffs wrapped around the patient's calves, lower thighs and upper thighs. In addition to 3 sets of cuffs, the patient has finger plethysmogram and electrocardiogram (ECG) attachments that are connected to a control and display console. External counterpulsation was used in the United States to treat cardiogenic shock after acute myocardial infarction. (9;10) More recently, an enhanced version namely "enhanced external counterpulsation" (EECP) was introduced as a noninvasive procedure for outpatient treatment of patients with severe, uncontrollable cardiac ischemia. EECP is said to increase coronary perfusion pressure and reduce the myocardial oxygen demand. Currently, EECP is not applicable for all patients with refractory angina pectoris. For example, many patients are considered ineligible for therapy due to co-morbidities, including those with severe pulmonary vascular disease, deep vein thrombosis, phlebitis and irregular heart rhythms, and heart failure. (1) Very recently, investigation began into EECP as an adjunctive treatment for patients with HF. Anecdotal reports suggested that EECP may benefit patients with coronary disease and left ventricular dysfunction. The safety and effectiveness of EECP in patients with symptomatic heart failure and coronary disease and its role in patients with nonischemic heart failure secondary to LV dysfunction is unclear. Furthermore, the safety and effectiveness of EECP in the different stages of HF and whether it is only for patients who are refractive to pharmacotherapy is unknown. 2003 HEALTH TECHNOLOGY ASSESSMENT BY THE MEDICAL ADVISORY SECRETARIAT: The Medical Advisory Secretariat health technology assessment (originally published in February 2003) reported on the effectiveness of EECP for patients with angina and HF. The report concluded that there was insufficient evidence to support the use of EECP in patients with refractory stable CCS III/IV angina as well as insufficient evidence to support the use of EECP in patients with HF.

REVIEW STRATEGY

The aim of this literature review was to assess the effectiveness, safety, and cost effectiveness of EECP for the treatment of refractory stable CCS III/IV angina or HF. The standard search strategy used by the Medical Advisory Secretariat was used. This included a search of all international health technology assessments as well as a search of the medical literature from December 2002 to March 2006. A modification of the GRADE approach (11) was used to make judgments about the quality of evidence and strength of recommendations systematically and explicitly. GRADE provides a framework for structured reflection and can help to ensure that appropriate judgments are made. GRADE takes into account a study's design, quality, consistency, and directness in judging the quality of evidence for each outcome. The balance between benefits and harms, quality of evidence, applicability, and the certainty of the baseline risks are considered in judgments about the strength of recommendations.

SUMMARY OF FINDINGS

The Cochrane and INAHTA databases yielded 3 HTAs or systematic reviews on EECP treatment (Blue Cross Blue Shield Technology Evaluation Center [BCBS TEC], ECRI, and the Centers for Medicare and Medicaid Services [CMS]). A search of Medline and Embase December 2005 - March 2006 (after the literature search cutoff from the most recent HTA) was conducted using key words enhanced external counterpulsation, EECP, angina, myocardial ischemia, congestive heart failure. This search produced 1 study which met the inclusion criteria. This level 4a study was inferior in quality to the RCT which formed the basis of the 2003 Medical Advisory Secretariat recommendation. BCBS reviewed the evidence through November 2005 to determine if EECP improves health outcomes for refractory chronic stable angina pectoris or chronic stable HF. (12) BCBS concluded that the available evidence is not sufficient to permit conclusions of the effect of EECP on health outcomes. Both controlled trials had methodologic flaws (MUST EECP and MUST EECP quality of life studies). The case series and observational studies for both indications while suggestive of a treatment benefit from EECP have shortcomings as well. On March 20 2006, CMS posted their proposed coverage decision memorandum for external counterpulsation therapy. (ABSTRACT TRUNCATED)

Refractory myocardial ischemic syndromes: patients’ characterization and treatment goals

Experimental strategies such as gene transfer and/or cell transplantation have been explored to enrich collateral perfusion and improve contractility in severely ischemic cardiac patients. Nonetheless, the criteria used to define those patients are not uniform and need to be standardized. The authors propose herein standardized definitions in order to characterize the ‘no option’ ischemic cardiac patients as follows: lack of revascularization options; angina symptoms; limited exercise capacity; perfusion defects; an identifiable target myocardial region. In order to define a favorable clinical effect, the following end points should be the aim of treatment: improved exercise; reduced perfusion defects; improved angina or equivalent symptoms; augmented myocardial stress response; better quality of life parameters following treatment; improved collateral-dependent perfusion. The authors propose that such a systematic approach for patient evaluation should be considered to allow an accurate assessment of treatment efficacy and the comparison of results between alternative myocardial revascularization trials.