International Enhanced External Counterpulsation Patient Registry Research Articles

Enhanced External Counterpulsation Is Cost-Effective in Reducing Hospital Costs in Refractory Angina Patients.

Enhanced external counterpulsation (EECP) is effective in the treatment of refractory angina, a condition suffered by 1.7 million Americans. Declining cardiovascular mortality and appropriate use criteria may further increase this number. EECP is hypothesized to be cost-effective in reducing hospitalizations in refractory angina patients. The data used in this analysis were collected in phase II of the International EECP Patient Registry (IEPR-II). Data were collected on changes in Canadian Cardiovascular Society functional class, Duke Activity Status Index, and number of hospitalizations in the 6 months prior to EECP and in the 6- and 12-month intervals following EECP. Estimates of the changes in annual cost of all-cause hospitalization before and after EECP therapy were calculated by the product of the differences in hospitalization rates in the 6-month interval before and after EECP treatment and estimated hospitalization and physician charges after subtracting the average cost of EECP. Data for 1015 patients were analyzed. Hospitalization occurred in 55.2% of patients, an average of 1.7 ± 1.4 hospitalizations/patient, in the 6-month period before 35 hours of EECP; and in 24.4%, an average of 1.4 ± 1.0 hospitalizations/patient, during the 6- to 12-month period after EECP. The average hospitalization and physician charge in the US was $17,995, and the average EECP cost was $4880, yielding an annual cost savings/patient of $17,074. Treatment of refractory angina patients with EECP resulted in improvement in angina and functional class accompanied by a sustained reduction in health care costs over 1 year of follow-up.

Comparison of Long Term Clinical Outcomes, Event Free Survival Rates of Patients Undergoing Enhanced External Counterpulsation (EECP) for Coronary Artery Disease in the United States and Turkey

This study assessed the long-term efficacy of EECP (Enhanced External Counterpulsation) in Turkish (TR) patients initially and compared these results with the United States (US) in a real world setting. In this study, 2072 patients were treated and followed in the US and 82 patients were treated and followed in TR. The International EECP Patient Registry Phase I and II was initiated and coordinated at the University of Pittsburgh. The aim of the "registry" was to assess the outcomes of clinical trials in a real world setting. Another unique feature of this study was to enroll patients not only from university hospitals but also from private hospitals, educational hospitals, and treatment centers. TR patients had less diabetes, hypertension, and hyperlipidemia than US patients (p<0.01). TR patients also had a higher proportion of diastolic augmentation (p<0.001). Both groups showed a significant reduction in the severity of angina after a 35 h EECP course (p<0.001). Major Adverse Cardiac Events (MACE) rate (death, coronary artery bypass graft, percutaneous coronary intervention, myocardial infarction) was low in both groups during treatment (2.5% vs. 2.7%). At 1 year follow up, 84% of TR and 76% of US patients had maintained the improvement of angina. Patients presenting for EECP treatment from TR had different baseline profiles from US patients. However, despite the high risk baseline characteristics, both cohorts achieved similar reduction in angina. In the long term follow-up, the MACE rate was low and the improvement after EECP was sustained in most of the patients.

Passive tobacco exposure may impair symptomatic improvement in patients with chronic angina undergoing enhanced external counterpulsation

BackgroundThe adverse effects of tobacco abuse on cardiovascular outcomes are well-known. However, the impact of passive smoke exposure on angina status and therapeutic response is less well-established. We examined the impact of second-hand smoke (SHS) exposure on symptomatic improvement in patients with chronic ischemic coronary disease undergoing enhanced external counterpulsation (EECP).MethodsThis observational study included 1,026 non-smokers (108 exposed and 918 not-exposed to SHS) from the Second International EECP Patient Registry. We also assessed angina response in 363 current smokers. Patient demographics, symptomatic improvement and quality of life assessment were determined by self-report prior and after EECP treatment.ResultsNon-smoking SHS subjects had a lower prevalence of prior revascularization (85% vs 90%), and had an increased prevalence of stroke (13% vs 7%) and prior smoking (72% vs 61%; all p < 0.05) compared to non-smokers without SHS exposure. Despite comparable degrees of coronary disease, baseline angina class, medical regimens and side effects during EECP, fewer SHS non-smokers completed a full 35-hour treatment course (77% vs 85%, p = 0.020) compared to non-smokers without SHS. Compared to non-smokers without SHS, non-smoking SHS subjects had less angina relief after EECP (angina class decreased ≥ 1 class: 68% vs 79%; p = 0.0082), both higher than that achieved in current smokers (66%). By multivariable logistic regression, SHS exposure was an independent predictor of failure to symptomatic improvement after EECP among non-smokers (OR 1.81, 95% confidence intervals 1.16–2.83).ConclusionNon-smokers with SHS exposure had an attenuated improvement in anginal symptoms compared to those without SHS following EECP.

Enhanced External Counterpulsation in the Treatment of Chronic Refractory Angina: A Long‐term Follow‐up Outcome from the International Enhanced External Counterpulsation Patient Registry

The management of patients who suffer from medically refractory angina and are unsuitable for conventional revascularization therapy is often unsatisfactory. Enhanced external counterpulsation (EECP) is a noninvasive treatment that is safe and effective immediately after a course of treatment. However, the duration of benefit is less certain. To evaluate the 3-year outcome of EECP treatment. One thousand four hundred and twenty seven patients from 36 centers registered in the International EECP Patient Registry (IEPR)-Phase 1 was prospectively followed for a median of 37 months. Two hundred and twenty patients (15.4%) died, while 1,061 patients (74.4%) completed their follow-up. The mean age was 66+/-11 years and 72% were men. Seventy-six percent had multivessel coronary disease for 11+/-8 years. Eighty-eight percent had a prior percutaneous or surgical revascularization and 82% were unsuitable for further coronary intervention. Immediately post-EECP, the proportion of patients with severe angina (Canadian Cardiovascular Angina Classification [CCS] III/IV) were reduced from 89% to 25%, p<0.001. The CCS class was improved by at least 1 class in 78% of the patients and by at least 2 classes in 38%. This was sustained in 74% of the patients during follow-up.Thirty-six percent of the patients had CCS II or less angina, which was better than pre-EECP state without a major adverse cardiovascular event during follow-up. More severe baseline angina and a history of heart failure or diabetes were independent predictors of unfavorable outcome. An EECP improves angina and quality of life immediately after a course of treatment. For most of the patients, these beneficial effects are sustained for 3 years.

Effect of enhanced external counterpulsation on medically refractory angina patients with erectile dysfunction

Patients with refractory angina often suffer from erectile dysfunction. Enhanced external counterpulsation (EECP) decreases symptoms of angina, and increases nitric oxide release. This study evaluated the effect of EECP on sexual function in men with severe angina. The International Index of Erectile Function (IIEF) was used to assess erectile function of severe angina patients enroled in the International EECP Patient Registry. Their symptom status, medication use, adverse clinical events and quality of life were also recorded before and after completing a course of EECP. A cohort of 120 men (mean age 65.0+/-9.7) was enroled. The men had severe coronary disease with 69% having a prior myocardial infarction, 90% prior coronary artery bypass graft or percutaneous coronary intervention, 49% with three vessel coronary artery disease, 86% were not candidates for further revascularisation, 71% hypertensive, 83% dyslipidaemia, 42% diabetes mellitus, 75% smoking and 68% using nitrates. Functional status was low with a mean Duke Activity Status Inventory score of 16.6+/-14.8. After 35 h of EECP anginal status improved in 89%, and functional status in 63%. A comparison of the IIEF scores pre- and post-EECP therapy demonstrated a significant improvement in erectile function from 10.0+/-1.0 to 11.8+/-1.0 (p=0.003), intercourse satisfaction (4.2+/-0.5 to 5.0+/-0.5, p=0.009) and overall satisfaction (4.7+/-0.3 to 5.3+/-0.3, p=0.001). However, there were no significant changes in orgasmic function (4.2+/-0.4 to 4.6+/-0.4, p=0.19) or sexual desire (5.3+/-0.2 to 5.5+/-0.2). The findings suggest that EECP therapy is associated with improvement in erectile function in men with refractory angina.

Two-Year Clinical Outcomes After Enhanced External Counterpulsation (EECP) Therapy in Patients With Refractory Angina Pectoris and Left Ventricular Dysfunction (Report from the International EECP Patient Registry)

Two-Year Clinical Outcomes After Enhanced External Counterpulsation (EECP) Therapy in Patients With Refractory Angina Pectoris and Left Ventricular Dysfunction (Report from the International EECP Patient Registry)

Effectiveness of Repeat Enhanced External Counterpulsation for Refractory Angina in Patients Failing to Complete an Initial Course of Therapy

Aims: This study examined the causes and results of retreatment of patients who failed to complete an initial 35-hour Enhanced External Counterpulsation (EECP) course. Methods and Results:Data of 2,311 successive angina patients from the International EECP Patient Registry were analyzed, 86.5% completed their EECP course (Complete cohort). Of the 13.5% patients failing to complete the initial course (Incomplete cohort), 28.3% had repeat EECP within 1 year vs. 10.1% of the Complete group. The predictors of failure to complete the initial course of EECP were: female gender, heart failure, use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and use of nitroglycerin. For the Complete group, 83.4% had a reduction of at least one Canadian Cardiovascular Society (CCS) class after their initial EECP course, vs. 21.7% in the Incomplete group (p < 0.001). After repeat treatment, 66.2% of the Incomplete group achieved at least one CCS class reduction vs. 69.4% of the Complete group (p = NS) undergoing retreatment. The independent predictors for those who return to successfully complete their second course were patients who stopped their first course because of clinical events, and candidacy for coronary artery bypass grafting at the time of initial treatment. Conclusion: The results of retreatment of those who failed to complete their initial EECP course were comparable to those who completed their initial treatment, with similar reductions of CCS angina class.

Primer: practical approach to the selection of patients for and application of EECP

Over the past decade, the frequency of use of enhanced external counterpulsation (EECP) has increased in patients with angina, irrespective of medical therapy and coronary revascularization status. Many patients referred for EECP have one or more comorbidities that could affect this treatment's efficacy, safety, or both. By use of data from more than 8,000 patients enrolled in the International EECP Patient Registry, we provide practical guidelines for the selection and treatment of patients. We have focused on considerations for patients who have one or more of the following characteristics: age older than 75 years, diabetes, obesity, heart failure, and peripheral vascular disease. We have also reviewed outcomes and treatment recommendations for individuals with poor diastolic augmentation during treatment, for those with atrial fibrillation or pacemakers, and for those receiving anticoagulation therapy. Lastly, we examined relevant data regarding extended courses of EECP, repeat therapy, or both. While clinical studies have demonstrated the usefulness of EECP in selected patients, these guidelines permit recommendations for the extended application of this important treatment to subsets of patients excluded from clinical trials.

Enhanced External Counterpulsation in the Treatment of Angina Patients with Heart Failure and Diabetes

Background: Neurohormonal activation affects the pathophysiology of insulin resistance, diabetes, cardiovascular events, and heart failure (HF). Enhanced External Counterpulsation (EECP) improves endothelial dysfunction, increases nitric oxide and reduces angiotensin II. This study tested the hypothesis that EECP is equally effective in treating diabetics (D) and non-diabetics (non-D) with angina and heart failure (HF). Methods: Patients with angina and HF in the International EECP Patient Registry (IEPR) were analyzed. Outcomes included: change pre- to post-EECP therapy in NYHA and CCS classes, NTG use, quality of Life (QOL) and major adverse cardiovascular events (Death, MI, CABG, PCI). Results: There were 277 (147 D; 130 non-D) patients with HF and angina in the IEPR. The D cohort was significantly heavier (90.4 vs 80.9 kg, p < 0.001), had more hypertension (87% vs 74%, p < 0.01), hyperlipidemia (92% vs 85%, p < 0.05), prior PCI (77% vs 63%, p < 0.05), and chronic renal insufficiency (32% vs 19%, p < 0.05). At baseline, there were no differences in D vs non-D in NYHA class II and III (81% vs 82%), CCS class III and IV (92% in both group), LVEF (37% vs 35%), multivessel CAD (93%), revascularization candidacy (6%), Ntg use/wk (8 vs 10), with similar medications and angina episodes/wk (12; both groups). D graded functional status by DASI as significantly worse (6.9 vs 9.1, p < 0.01). 72% of D and 82% of non-D completed EECP therapy (mean 32 hrs). During therapy there was a significant difference in MACE (6.1% D vs 0% non-D, p < 0.01) and higher CHF exacerbation (6.3% D vs 3.2% non-D, p = ns). Post EECP, D and non-D reported a comparable ≥ one class reduction in NYHA class (42% D vs 30% non-D), CCS ≥ one class reduction (76% D vs 78% non-D), mean decrease in angina episodes/week (8.7; both groups), and Ntg use (7.4 vs 5.6, p = ns). However, post EECP, even though D demonstrated significant improvements in physical functioning score compared with pre-EECP (p < 0.001), the mean DASI score was still significantly less than non-D (11.3 vs. 14.7 p < 0.05). Conclusions: EECP effectively relieves angina and heart failure symptoms in refractory patients with or without diabetes, although D have a significantly higher rate of events during the treatment period.

Two-year outcomes in patients with mild refractory angina treated with enhanced external counterpulsation.

In the International Enhanced External Counterpulsation Patient Registry (IEPR), approximately 85% of the patients treated are in Canadian Cardiovascular Society (CCS) class III-IV with no option for further invasive coronary revascularization procedures. This study sought to determine whether it is clinically important to establish whether the observed durable reduction in disabling severe angina with enhanced external counterpulsation (EECP) treatment can be extended to those with less severe CCS class II angina, who also have no option for further revascularization. This study evaluated the immediate response, durability and clinical events over a 2-year period after EECP treatment in 112 patients with Canadian Cardiovascular Society (CCS) class II angina versus 1346 patients with class III-IV angina using data from the International EECP Patient Registry (IEPR). Treatment with EECP significantly (by at least one CCS class) reduced angina frequency, nitroglycerin use, and improved quality of life in both groups. At 2-year follow-up, 74% of class II and 70% of class III-IV patients remained free of major adverse cardiovascular events (MACE) and continued to demonstrate a durable CCS class improvement over baseline. The robust effectiveness of EECP as a noninvasive device, together with its relatively low start-up and recurrent costs, makes it an attractive consideration for treating patients with milder refractory angina in addition to the patient with severely disabling angina treated in current practice.

Two-Year Clinical Outcomes After Enhanced External Counterpulsation (EECP) Therapy in Patients With Refractory Angina Pectoris and Left Ventricular Dysfunction (Report from the International EECP Patient Registry)

Enhanced external counterpulsation (EECP) is a noninvasive circulatory assist device that has recently emerged as a treatment option for refractory angina in left ventricular (LV) dysfunction. This 2-year cohort study describes the long-term follow-up of patients who had severe LV dysfunction that was treated with EECP for angina pectoris and reports clinical outcomes, event-free survival rates, and the incidence of repeat EECP. This study included 363 patients who had refractory angina and LV ejection fraction < or =35%. Most patients reported quality of life as poor. After completion of treatment, there was a significant decrease in severity of angina class (p < 0.001), and 72% improved from severe angina to no angina or mild angina. Fifty-two percent of patients discontinued nitroglycerin use. Quality of life improved substantially. At 2 years this decrease in angina was maintained in 55% of patients. The 2-year survival rate was 83%, and the major adverse cardiovascular event-free survival rate was 70%. Forty-three percent had no reported cardiac hospitalization; 81% had no reported congestive heart failure events. Repeat EECP was performed in 20% of these patients. The only significant independent predictor of repeat EECP in a proportional hazard model was failure to complete the first EECP treatment course (hazard ratio 2.9, 95% confidence interval 1.7 to 4.9). Improvements in angina symptoms and quality of life were maintained at 2 years. In conclusion, for patients who have high-risk LV dysfunction, EECP offers an effective, durable therapeutic approach for refractory angina. Decreased angina and improvement in quality of life were maintained at 2 years, with modest repeat EECP and low major cardiovascular event rates.

Predictors of Benefit in Angina Patients One Year after Completing Enhanced External Counterpulsation: Initial Responders to Treatment versus Nonresponders

Enhanced external counterpulsation (EECP) has been shown to reduce Canadian Cardiovascular Society angina class. This study examines the factors that affect the reduction at 1 year, especially in patients who do not demonstrate an initial response. The data of 2,007 consecutive patients enrolled in the International EECP Patient Registry were analyzed. After 36.6 ± 4.9 h of EECP, angina was reduced by at least one class in 82.7%. At 1 year, 35.4% of initial nonresponders and 70.6% of responders remained improved by at least one angina class and free of major adverse cardiovascular events. Multivariate predictors of 1-year benefit are initial response to treatment (odds ratio 4.5, 95% CI 3.5–5.8), baseline angina class compared with class IV (odds ratios: class I 2.1, CI 0.93–4.81; class II 0.62, CI 0.43–0.87; class III 0.80, CI 0.62–1.01) and no history of congestive heart failure (odds ratio 1.41, CI 1.14–1.74).

Frequency and efficacy of repeat enhanced external counterpulsation for stable angina pectoris (from the International EECP Patient Registry)

We assessed the frequency, efficacy, predictors, and long-term success of repeat enhanced external counterpulsation (EECP) therapy in relieving angina in a large cohort of patients who had chronic angina pectoris and had undergone a full course of EECP. Within 2 years of the initial course of EECP, the rate of repeat EECP was 18%, which occurred at a mean interval of 378 days after initial EECP. Of those who underwent repeat EECP, 70% had a decrease of >/=1 angina class at the end of repeat EECP with similar decreases in nitroglycerin use.

Effectiveness of enhanced external counterpulsation in patients with left main disease and angina

Enhanced external counterpulsation (EECP) is a noninvasive device that uses three pairs of sequentially inflated pneumatic cuffs applied to the lower extremities and synchronized with the heart beat to provide diastolic augmentation, increase coronary blood pressure and flow, venous return and cardiac output, and decrease afterload. This study examines the safety and effectiveness of EECP therapy in patients with significant left main coronary artery disease (LMD). In all, 2,861 patients enrolled in the International EECP Patient Registry (IEPR) were divided into three groups, those without LMD (n = 2,377), those with LMD and prior CABG (n = 431), and those with unbypassed LMD (n = 53). Patients with LMD, with or without prior CABG, were significantly more likely to have triple-vessel disease (98.1 and 88.7%, respectively) than patients without LMD (41.9%). Post-EECP, 74% without LMD, 75% with LMD with prior CABG, and 65% with unbypassed LMD improved their Canadian Cardiovascular Society (CCS) angina by at least one class (p = NS). There were no differences in the mean decrease in weekly angina episodes (7.1 vs. 8.0 vs. 7.6) and in the mean frequency of weekly nitroglycerin use (6.6 vs. 8.1 vs. 8.9). At 6-month follow-up, the CCS class improved further in all three groups, and there was a further reduction in mean weekly angina episodes (4.7 vs. 4.6 vs. 5.3) and nitroglycerin use (6.5 vs. 6.8 vs. 8.2). Kaplan-Meier life table analysis 8 months after starting EECP demonstrated a major cardiovascular event rate of 11.2% in patients without LMD, 15.6% in LMD with CABG, and 24.3% in LMD without prior CABG. Late mortality in unbypassed LMD was 13.2% (confidence interval [CI] 3.3-23.1) versus 4.8% (CI 2.7-7.1) in LMD with CABG, and 2.8% (CI 2.1-3.5) without LMD (p = 0.0039 by log-rank test). Enhanced external counterpulsation is equally effective in relieving angina in patients with or without LMD. However, the significantly increased late mortality in patients with LMD without prior CABG suggests that early revascularization should be considered in these patients.

Enhanced external counterpulsation for the relief of angina in patients with diabetes: safety, efficacy and 1-year clinical outcomes

Abstract Background Patients with diabetes are at greater risk for coronary events, yet they are less likely to benefit from revascularization than those without diabetes. Enhanced external counterpulsation has recently emerged as a treatment option for select patients with chronic stable angina. Methods We examined baseline characteristics, angina response, and cardiac outcomes of patients with diabetes mellitus treated with Enhanced External Counterpulsation (EECP) for chronic stable angina. Data were collected from patients enrolled in the International EECP Patient Registry (IEPR) before and after a course of EECP, and at 1 year after completion of treatment. Results Of 1532 IEPR patients studied, 43% had diabetes mellitus at baseline. Patients with diabetes were experiencing, on average, 11 episodes of angina per week. Most had been revascularized with prior percutaneous coronary intervention or coronary artery bypass graft surgery (86%) and most were considered unsuitable for either additional procedure (87%). Treatment was completed as prescribed in 79% of patients (mean, 32 hours). Immediately after EECP, 69% of patients with diabetes demonstrated a reduction in angina of ≥1 Canadian Cardiovascular Society angina class. After 1 year, maintenance of angina reduction was reported in 72% of patients with diabetes. Quality of life was significantly improved. Despite a high-risk profile among the diabetic group in this study, 1-year mortality was similar to coronary intervention registry populations. Conclusion This study suggests that in select patients with diabetes, EECP can be a safe, effective, well-tolerated treatment option for the relief of angina.

Enhanced External Counterpulsation as Initial Revascularization Treatment for Angina Refractory to Medical Therapy

Enhanced external counterpulsation (EECP) is effective in patients with angina refractory to medical therapy or revascularization. However, as a noninvasive treatment it should perhaps be considered the first-line treatment with invasive revascularization reserved for EECP failures or high-risk patients. The International EECP Patient Registry was used to analyze a cohort of patients with prior percutaneous coronary intervention (PCI) and/or coronary artery bypass graft (CABG) (n = 4,454) compared with a group of patients (PUMPERS) who were candidates for PCI and/or CABG and chose EECP as their initial revascularization treatment (n = 215). The PUMPERS responded to treatment with EECP with decreased anginal episodes and nitroglycerin use and with improvement in their Canadian Cardiovascular Society functional class, similarly to previously revascularized patients. Treatment with EECP resulted in sustained, and often progressive, reduction in angina over the succeeding 6 months. Given the findings of this study, it is interesting to speculate on the possibility of using EECP as the primary revascularization intervention after medical therapy proves unsatisfactory.

Enhanced external counterpulsation for the relief of angina in patients with diabetes: safety, efficacy and 1-year clinical outcomes

Background Patients with diabetes are at greater risk for coronary events, yet they are less likely to benefit from revascularization than those without diabetes. Enhanced external counterpulsation has recently emerged as a treatment option for select patients with chronic stable angina. Methods We examined baseline characteristics, angina response, and cardiac outcomes of patients with diabetes mellitus treated with Enhanced External Counterpulsation (EECP) for chronic stable angina. Data were collected from patients enrolled in the International EECP Patient Registry (IEPR) before and after a course of EECP, and at 1 year after completion of treatment. Results Of 1532 IEPR patients studied, 43% had diabetes mellitus at baseline. Patients with diabetes were experiencing, on average, 11 episodes of angina per week. Most had been revascularized with prior percutaneous coronary intervention or coronary artery bypass graft surgery (86%) and most were considered unsuitable for either additional procedure (87%). Treatment was completed as prescribed in 79% of patients (mean, 32 hours). Immediately after EECP, 69% of patients with diabetes demonstrated a reduction in angina of ≥1 Canadian Cardiovascular Society angina class. After 1 year, maintenance of angina reduction was reported in 72% of patients with diabetes. Quality of life was significantly improved. Despite a high-risk profile among the diabetic group in this study, 1-year mortality was similar to coronary intervention registry populations. Conclusion This study suggests that in select patients with diabetes, EECP can be a safe, effective, well-tolerated treatment option for the relief of angina.

A review of enhanced external counterpulsation clinical trials.

A variety of clinical trials of enhanced external counterpulsation (EECP) have been conducted since the 1960s. The vast majority of these studies have investigated the use of EECP in patients with angina pectoris. Only one of these trials was randomized. These clinical trials have demonstrated the benefits of EECP in terms of reduction in anginal episodes, increased exercise times, and improvement in health-related quality of life scores. The International EECP Patient Registry, through its phase I and II enrollment, is expanding the data set on outcomes after EECP treatment.

Relation of the pattern of diastolic augmentation during a course of enhanced external counterpulsation (EECP) to clinical benefit (from the International EECP Patient Registry [IEPR

E external counterpulsation (EECP) is a noninvasive counterpulsation technique that reduces angina and extends time to exercise-induced ischemia in patients with symptomatic stable angina. In addition to relieving myocardial ischemia, EECP is associated with improved quality of life. It uses a sequential inflation of 3 sets of pneumatic cuffs wrapped around the lower extremities. The cuffs are inflated sequentially at the onset of diastole, producing aortic counterpulsation, diastolic augmentation (DA), and increased venous return. At the onset of systole, external pressure in the cuffs is released, producing a decrease in systolic pressure (systolic unloading). These hemodynamic effects are monitored noninvasively by assessing the finger plethysmographic waveforms. A typical course of EECP involves 1 to 2 hours/day for a total of 35 hours of therapy. It has been hypothesized that the sustained benefits of EECP result from effective DA, which promotes coronary collateral formation or recruitment. A previous study has demonstrated that patients who are younger, male, nonsmoking, and without multivessel coronary or noncardiac vascular disease are most likely to have higher DA at the end of an EECP treatment course. Patients with higher DA ratios at the end of EECP tended to have a greater reduction in angina class than those with lower DA ratios, suggesting that clinical benefit from EECP is associated with the magnitude of DA. That initial study was limited by assessing the DA ratios on the final day of EECP therapy. This present analysis further investigates the role of DA in EECP by assessing the impact of DA levels both at the first and last treatment session with EECP.

Comparison of patients undergoing enhanced external counterpulsation and percutaneous coronary intervention for stable angina pectoris

Enhanced external counterpulsation (EECP) has recently emerged as a treatment option for angina in selected patients suitable for revascularization with percutaneous coronary intervention (PCI). We compared baseline characteristics and 1-year outcome in 2 cohorts of PCI candidates presenting with stable symptoms: 323 patients treated with EECP in the International EECP Patient Registry (IEPR), and 448 NHLBI Dynamic Registry patients treated with elective PCI. Compared with patients receiving PCI, IEPR patients had a higher prevalence of many risk factors including prior PCI (53.0% vs 33.3%, p <0.001), prior coronary artery bypass grafting (42.1% vs 18.6%, p <0.001), prior myocardial infarction (56.4% vs 27.8%, p <0.001), history of congestive heart failure (16.8% vs 9.2%, p <0.01), and history of diabetes (37.9% vs 23.5%, p <0.001). Left ventricular ejection fraction was lower among IEPR patients (mean 50.3% vs 59.2%, p <0.001). At 1 year, survival was comparable in the 2 cohorts (98.7% IEPR vs 96.8% PCI, p = NS), as were rates of coronary artery bypass grafting during follow-up (4.5% IEPR vs 5.7% PCI, p = NS). At 1 year, 43.7% of IEPR patients reported no anginal symptoms compared with 73.4% of Dynamic Registry patients (p <0.001). Rates of severe symptoms (Canadian Cardiovascular Society class III, IV, or unstable) at 1 year were 15.5% among IEPR patients and 9.5% in the Dynamic Registry (p = 0.02). PCI candidates suitable for and treated with EECP had 1-year major event rates comparable to patients receiving elective PCI. Although PCI was associated with substantially lower rates of 1-year symptoms, EECP may be a safe treatment option for selected patients with obstructive coronary disease.