Calvin Y. Choi

Enhanced External Counterpulsation Improves Peripheral Artery Flow-Mediated Dilation in Patients With Chronic Angina A Randomized Sham-Controlled Study

Background— Mechanisms responsible for anti-ischemic benefits of enhanced external counterpulsation (EECP) remain unknown. This was the first randomized sham-controlled study to investigate the extracardiac effects of EECP on peripheral artery flow-mediated dilation. Methods and Results— Forty-two symptomatic patients with coronary artery disease were randomized (2:1 ratio) to thirty-five 1-hour sessions of either EECP (n=28) or sham EECP (n=14). Flow-mediated dilation of the brachial and femoral arteries was performed with the use of ultrasound. Plasma levels of nitrate and nitrite, 6-keto-prostaglandin F1&agr;, endothelin-1, asymmetrical dimethylarginine, tumor necrosis factor-&agr;, monocyte chemoattractant protein-1, soluble vascular cell adhesion molecule, high-sensitivity C-reactive protein, and 8-isoprostane were measured. EECP increased brachial (+51% versus +2%) and femoral (+30% versus +3%) artery flow-mediated dilation, the nitric oxide turnover/production markers nitrate and nitrite (+36% versus +2%), and 6-keto-prostaglandin F1&agr; (+71% versus +1%), whereas it decreased endothelin-1 (−25% versus +5%) and the nitric oxide synthase inhibitor asymmetrical dimethylarginine (−28% versus +0.2%) in treatment versus sham groups, respectively (all P<0.05). EECP decreased the proinflammatory cytokines tumor necrosis factor-&agr; (−16% versus +12%), monocyte chemoattractant protein-1 (−13% versus +0.2%), soluble vascular cell adhesion molecule-1 (−6% versus +1%), high-sensitivity C-reactive protein (−32% versus +5%), and the lipid peroxidation marker 8-isoprostane (−21% versus +1.3%) in treatment versus sham groups, respectively (all P<0.05). EECP reduced angina classification (−62% versus 0%; P<0.001) in treatment versus sham groups, respectively. Conclusions— Our findings provide novel mechanistic evidence that EECP has a beneficial effect on peripheral artery flow-mediated dilation and endothelial-derived vasoactive agents in patients with symptomatic coronary artery disease.

Effects of enhanced external counterpulsation on arterial stiffness and myocardial oxygen demand in patients with chronic angina pectoris.

Enhanced external counterpulsation (EECP) is a noninvasive technique for treatment of symptomatic coronary artery disease in patients not amenable to revascularization procedures. However, the mechanisms underlying the benefits of EECP remain unknown. We hypothesized that decreases in arterial stiffness and aortic wave reflection are a therapeutic target for EECP. Patients with coronary artery disease and chronic angina pectoris were randomized (2:1 ratio) to 35 1-hour sessions of EECP (n = 28) or sham EECP (n = 14). Central and peripheral arterial pulse-wave velocity and aortic wave reflection (augmentation index) were measured using applanation tonometry before, and after 17 and 35 1-hour treatment sessions. Wasted left ventricular pressure energy and aortic systolic tension-time index, markers of left-ventricular myocardial oxygen demand, were derived from the synthesized aortic pressure wave. Exercise duration, anginal threshold, and peak oxygen consumption were measured using a graded treadmill test. Central arterial stiffness and augmentation index were decreased after 17 and 35 sessions in the treatment group. Measurements of peripheral arterial stiffness were decreased after 35 sessions in the treatment group. Changes in aortic pressure wave reflection resulted in decreased measurements of myocardial oxygen demand and wasted left ventricular energy. No changes in central or peripheral arterial stiffness were observed in the sham group. Furthermore, measurements of exercise capacity were improved in the EECP group but unchanged in the sham group. In conclusion, EECP therapy decreases central and peripheral arterial stiffness, which may explain improvements in myocardial oxygen demand in patients with chronic angina pectoris after treatment.

Effect of enhanced external counterpulsation on inflammatory cytokines and adhesion molecules in patients with angina pectoris and angiographic coronary artery disease.

Cardiovascular disease is associated with chronic low-level inflammation, as evidenced by elevated circulating proinflammatory cytokines. Experimental evidence suggests that inflammation can be suppressed under conditions of high shear stress. This study was conducted to examine the effects of enhanced external counterpulsation (EECP), a noninvasive therapy that increases endothelial shear stress, on circulating levels of inflammatory biomarkers and adhesion molecules in patients with angina pectoris. Twenty-one patients were randomly assigned to either 35 1-hour treatments at cuff pressures of 300 mm Hg (EECP; n=12) or 75 mm Hg (sham; n=9). Plasma tumor necrosis factor-alpha, monocyte chemoattractant protein-1, and soluble vascular cell adhesion molecule-1 were measured before and after 35 1-hour sessions of treatment or sham. Patients in the EECP group demonstrated reductions in tumor necrosis factor-alpha (6.9+/-2.7 vs 4.9+/-2.5 pg/ml, p<0.01; -29%) and monocyte chemoattractant protein-1 (254.9+/-55.9 vs 190.4+/-47.6 pg/ml, p<0.01; -19%) after treatment, whereas there was no change in the sham group. Changes in soluble vascular cell adhesion molecule-1 were not observed in either group. In conclusion, 35 sessions of EECP decreased circulating levels of proinflammatory biomarkers in patients with symptomatic coronary artery disease.

Risk of Bleeding in End-Stage Liver Disease Patients Undergoing Cardiac Catheterization

Patients with end-stage liver disease frequently have baseline coagulopathies. The international normalized ratio is in common use for the estimation of bleeding tendency in such patients, especially those undergoing an invasive procedure like cardiac catheterization. The practice of international normalized ratio measurement-followed by pharmacologic (for example, vitamin K or fresh frozen plasma) or nonpharmacologic intervention-is still debatable. The results of multiple randomized trials have shown the superiority of the radial approach over femoral access in reducing catheterization bleeding. This reduction in bleeding in turn decreases the risk and cost of blood-product transfusion. However, there is little evidence regarding the use of the radial approach in the end-stage liver disease patient population specifically. In this review, we summarize the studies that have dealt with cardiac catheterization in patients who have end-stage liver disease. We also discuss the role of the current measurements that are used to reduce the risk of bleeding in these same patients.

Perioperative Cardiovascular Evaluation for Orthotopic Liver Transplantation

Patients with advanced liver disease have a high prevalence of cardiovascular risk factors, but many of them are asymptomatic. Cardiovascular risk stratification prior to liver transplant can be done by dobutamine stress echocardiography, stress myocardial perfusion imaging, cardiac computer tomography, and coronary angiography, but there are no clear recommendations regarding what method should be used and who should be screened. Because of this and because of inherent risk profile in this population, the variations in practice are significant. Careful screening and rigorous management of cardiovascular risk factors are important to ensure optimal cardiovascular outcomes in the immediate post-transplantation period and in the long term as well.

Postgraduate Education in Quality Improvement Methods: Initial Results of the Fellows’ Applied Quality Training (faqt) Curriculum

OBJECTIVE Training in quality improvement (QI) is a pillar of the next accreditation system of the Accreditation Committee on Graduate Medical Education and a growing expectation of physicians for maintenance of certification. Despite this, many postgraduate medical trainees are not receiving training in QI methods. We created the Fellows Applied Quality Training (FAQT) curriculum for cardiology fellows using both didactic and applied components with the goal of increasing confidence to participate in future QI projects. METHODS AND RESULTS Fellows completed didactic training from the Institute for Healthcare Improvements Open School and then designed and completed a project to improve quality of care or patient safety. Self-assessments were completed by the fellows before, during, and after the first year of the curriculum. The primary outcome for our curriculum was the median score reported by the fellows regarding their self-confidence to complete QI activities. Self-assessments were completed by 23 fellows. The majority of fellows (15 of 23, 65.2%) reported no prior formal QI training. Median score on baseline self-assessment was 3.0 (range, 1.85-4), which was significantly increased to 3.27 (range, 2.23-4; P = 0.004) on the final assessment. The distribution of scores reported by the fellows indicates that 30% were slightly confident at conducting QI activities on their own, which was reduced to 5% after completing the FAQT curriculum. An interim assessment was conducted after the fellows completed didactic training only; median scores were not different from the baseline (mean, 3.0; P = 0.51). CONCLUSION After completion of the FAQT, cardiology fellows reported higher self-confidence to complete QI activities. The increase in self-confidence seemed to be limited to the applied component of the curriculum, with no significant change after the didactic component.

Coronary artery bypass graft pseudoaneurysm from saphenous vein graft stent fracture

Saphenous venous graft (SVG) pseudoaneurysms are a rare complication of coronary artery bypass grafting (CABG). An 85-year-old man with CABG and a distal SVG stent presented with dyspnea. Chest computed tomography (CT) revealed a large partially thrombosed pseudoaneurysm at the distal SVG with stent fracture. Endoluminal exclusion of the distal SVG pseudoaneurysm using a covered stent was performed. Follow-up chest CT and angiography showed persistent pseudoaneurysm filling and enlargement. The SVG proximal to the pseudoaneurysm was embolized with coils to reduce rupture risk. Following embolization, the patients left ventricular ejection fraction was moderately depressed but the patient remained stable and was discharged. <Learning objective: Saphenous venous graft pseudoaneurysms are a rare post-operative complication of coronary artery bypass graft procedures with a risk of impending rupture if left untreated. Fracture of a vein graft stent is an even further unique etiology of pseudoaneurysms. Covered stents are a practical therapeutic option for the treatment of vein graft pseudoaneurysms, especially in high risk patients who are not surgical candidates.>.

Erratum to: Improvement of Subjective Well-Being by Ranolazine in Patients with Chronic Angina and Known Myocardial Ischemia (IMWELL Study)

The paper contains an incorrect funding statement within the Acknowledgements section. The statement currently reads: Sponsorship for this study was funded by Gilead. No funding or sponsorship was received for publication of this article. The statement should read: Sponsorship for this study and article processing charges for the manuscript were funded by Gilead. Open Access. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/ by-nc/4.0/), which permits any noncommercial use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Enhanced External Counterpulsation Improves Peripheral Artery Flow-Mediated Dilation in Patients With Chronic AnginaClinical Perspective

Background— Mechanisms responsible for anti-ischemic benefits of enhanced external counterpulsation (EECP) remain unknown. This was the first randomized sham-controlled study to investigate the extracardiac effects of EECP on peripheral artery flow-mediated dilation. Methods and Results— Forty-two symptomatic patients with coronary artery disease were randomized (2:1 ratio) to thirty-five 1-hour sessions of either EECP (n=28) or sham EECP (n=14). Flow-mediated dilation of the brachial and femoral arteries was performed with the use of ultrasound. Plasma levels of nitrate and nitrite, 6-keto-prostaglandin F1&agr;, endothelin-1, asymmetrical dimethylarginine, tumor necrosis factor-&agr;, monocyte chemoattractant protein-1, soluble vascular cell adhesion molecule, high-sensitivity C-reactive protein, and 8-isoprostane were measured. EECP increased brachial (+51% versus +2%) and femoral (+30% versus +3%) artery flow-mediated dilation, the nitric oxide turnover/production markers nitrate and nitrite (+36% versus +2%), and 6-keto-prostaglandin F1&agr; (+71% versus +1%), whereas it decreased endothelin-1 (−25% versus +5%) and the nitric oxide synthase inhibitor asymmetrical dimethylarginine (−28% versus +0.2%) in treatment versus sham groups, respectively (all P<0.05). EECP decreased the proinflammatory cytokines tumor necrosis factor-&agr; (−16% versus +12%), monocyte chemoattractant protein-1 (−13% versus +0.2%), soluble vascular cell adhesion molecule-1 (−6% versus +1%), high-sensitivity C-reactive protein (−32% versus +5%), and the lipid peroxidation marker 8-isoprostane (−21% versus +1.3%) in treatment versus sham groups, respectively (all P<0.05). EECP reduced angina classification (−62% versus 0%; P<0.001) in treatment versus sham groups, respectively. Conclusions— Our findings provide novel mechanistic evidence that EECP has a beneficial effect on peripheral artery flow-mediated dilation and endothelial-derived vasoactive agents in patients with symptomatic coronary artery disease.

Enhanced External Counterpulsation Improves Peripheral Artery Flow-Mediated Dilation in Patients With Chronic AnginaClinical Perspective: A Randomized Sham-Controlled Study

Background— Mechanisms responsible for anti-ischemic benefits of enhanced external counterpulsation (EECP) remain unknown. This was the first randomized sham-controlled study to investigate the extracardiac effects of EECP on peripheral artery flow-mediated dilation. Methods and Results— Forty-two symptomatic patients with coronary artery disease were randomized (2:1 ratio) to thirty-five 1-hour sessions of either EECP (n=28) or sham EECP (n=14). Flow-mediated dilation of the brachial and femoral arteries was performed with the use of ultrasound. Plasma levels of nitrate and nitrite, 6-keto-prostaglandin F1&agr;, endothelin-1, asymmetrical dimethylarginine, tumor necrosis factor-&agr;, monocyte chemoattractant protein-1, soluble vascular cell adhesion molecule, high-sensitivity C-reactive protein, and 8-isoprostane were measured. EECP increased brachial (+51% versus +2%) and femoral (+30% versus +3%) artery flow-mediated dilation, the nitric oxide turnover/production markers nitrate and nitrite (+36% versus +2%), and 6-keto-prostaglandin F1&agr; (+71% versus +1%), whereas it decreased endothelin-1 (−25% versus +5%) and the nitric oxide synthase inhibitor asymmetrical dimethylarginine (−28% versus +0.2%) in treatment versus sham groups, respectively (all P<0.05). EECP decreased the proinflammatory cytokines tumor necrosis factor-&agr; (−16% versus +12%), monocyte chemoattractant protein-1 (−13% versus +0.2%), soluble vascular cell adhesion molecule-1 (−6% versus +1%), high-sensitivity C-reactive protein (−32% versus +5%), and the lipid peroxidation marker 8-isoprostane (−21% versus +1.3%) in treatment versus sham groups, respectively (all P<0.05). EECP reduced angina classification (−62% versus 0%; P<0.001) in treatment versus sham groups, respectively. Conclusions— Our findings provide novel mechanistic evidence that EECP has a beneficial effect on peripheral artery flow-mediated dilation and endothelial-derived vasoactive agents in patients with symptomatic coronary artery disease.