Safety and efficacy of extracorporeal shock wave myocardial revascularization therapy for refractory angina pectoris.

OBJECTIVE: To assess the safety and efficacy of extracorporeal shockwave myocardial revascularization (ESMR) therapy in treating patients with refractory angina pectoris. PATIENTS AND METHODS: A single-arm multicenter prospective trial to assess safety and efficacy of the ESMR therapy in patients with refractory angina (class III/IV angina) was performed. Screening exercise treadmill tests and pharmacological single-photon emission computed tomography (SPECT) were performed for all patients to assess exercise capacity and ischemic burden. Patients were treated with 9 sessions of ESMR to ischemic areas over 9 weeks. Efficacy end points were exercise capacity by using treadmill test as well as ischemic burden on pharmacological SPECT at 4 months after the last ESMR treatment. Safety measures included electrocardiography, echocardiography, troponin, creatine kinase, and brain natriuretic peptide testing, and pain questionnaires. RESULTS: Fifteen patients with medically refractory angina and no revascularization options were enrolled. There was a statistically significant mean increase of 122.3±156.9 seconds (38% increase compared with baseline; P=.01) in exercise treadmill time from baseline (319.8±157.2 seconds) to last follow-up after the ESMR treatment (422.1±183.3 seconds). There was no improvement in the summed stress perfusion scores after pharmacologically induced stress SPECT at 4 months after the last ESMR treatment in comparison to that at screening; however, SPECT summed stress score revealed that untreated areas had greater progression in ischemic burden vs treated areas (3.69±6.2 vs 0.31±4.5; P=.03). There was no significant change in the mean summed echo score from baseline to posttreatment (0.4±5.1; P=.70). The ESMR therapy was performed safely without any adverse events in electrocardiography, echocardiography, troponins, creatine kinase, or brain natriuretic peptide. Pain during the ESMR treatment was minimal (a score of 0.5±1.2 to 1.1±1.2 out of 10). CONCLUSION: In this multicenter feasibility study, ESMR seems to be a safe and efficacious treatment for patients with refractory angina pectoris. However, larger sham-controlled trials will be required to confirm these findings.

Wearable defibrillator use in heart failure (WIF): results of a prospective registry.

BACKGROUND: Heart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD. METHODS: Ten enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality). RESULTS: Out of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75±58 days. Mean age was 56.8±13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD. CONCLUSIONS: In conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF.

Endothelial progenitor cells delivered into the pericardial space incorporate into areas of ischemic myocardium.

OBJECTIVE: Our objective was to determine whether autologous endothelial progenitor cells (EPCs) delivered into the pericardial space will migrate to and incorporate into ischemic myocardium in a porcine model. BACKGROUND: Use of EPCs to enhance neovascularization and preserve myocardial function in ischemic tissue is undergoing intense scrutiny as a potential therapy. Delivery into the pericardial sac may overcome some of the limitations of currently employed cell delivery techniques. METHODS: EPCs were immunopurified from peripheral blood of Yorkshire pigs by selecting for the CD31 surface antigen, and adherent cells were cultured for 3-5 days. After myocardial ischemia was induced in the left anterior descending (LAD) artery, either autologous DiI (1,1'-dioctadecyl-1-3,3,3',3'-tetramethylindocarbocyanine perchlorate)-labeled EPCs (n=10) or serum-free medium (SFM; n=8) was delivered into the pericardial space using a percutaneous transatrial approach. Animals were sacrificed on Day 7 or 21. Echocardiography was performed at baseline, during ischemia, and on Day 7 in six SFM group animals and six EPC group animals. RESULTS: On Day 7, EPCs were identified in the left ventricular (LV) anterior wall or anterior septum in all six EPC-treated animals (cell density of 626 ± 122/mm(2)). On Day 21, EPCs were identified in the LV anterior wall or anterior septum in three of four EPC-treated animals (cell density of 267 ± 167/mm(2)). These cells showed dual staining for DiI and Bandeiraea simplicifolia lectin I (a marker of both native and exogenous endothelial cells). At the Day 7 follow-up, echocardiography demonstrated that fractional shortening in the EPC-treated group was 30.6 ± 3.4, compared with 22.6 ± 2.8 in SFM controls (P=.05). CONCLUSIONS: EPCs can migrate from the pericardial space to incorporate exclusively into areas of ischemic myocardium and may have favorable effects on LV function.

Conivaptan: promise of treatment in heart failure.

Conivaptan, the first vasopressin receptor antagonist approved by the FDA, is available for the treatment of hyponatremia in euvolemic and hypervolemic patients. The renin-angiotensin-aldosterone system is activated in heart failure (HF) causing clinical worsening. Arginine vasopressin levels are also elevated in HF. Conivaptan is an effective and FDA approved for the treatment of euvolemic and hypervolemic hyponatremia and may offer an extra treatment option in HF by targeting V(1a) and V(2) receptors. In this article we review the physiology, preclinical studies as well as the human clinical studies on the use of conivaptan and its potential and promise in the treatment of HF.

Echocardiographic evidence of left atrial abnormality in young patients with lone paroxysmal atrial fibrillation.

Usual assessment of left atrial size by 2-dimensional echocardiography in the anteroposterior dimension often underestimates the true atrial size. We compared 15 young patients (< or =50 years old) with lone paroxysmal atrial fibrillation to age-matched controls, and measured atrial size in the inferosuperior and mediolateral dimensions. These additional measurements and atrial volumes were significantly increased compared with control patients, revealing that patients with apparent "lone" paroxysmal atrial fibrillation may have subtle structural abnormalities of the left atrium.

Intraoperative epicardial coronary artery imaging: rationale, methods, and applications.

Epicardial coronary imaging using high frequency (7-12 MHz) ultrasound probes could aid the surgeon performing coronary artery bypass procedures by localizing the coronary artery segments underneath epicardial fat, identifying the site of coronary stenosis to be bypassed, evaluating the integrity of distal coronary artery, assessing the efficacy of anastomosis, and detecting anastomotic complications. While an ideal coronary imaging probe is yet to be developed, early clinical experience with vascular imaging probes applied on the coronary vessels suggests that epicardial coronary artery imaging could enhance the optimum performance of coronary interventions. Fabrication of a flexible high frequency probe that could be applied not only on the arteries on the anterior surface of the heart but also on the lateral and posterior surfaces could facilitate development of newer surgical procedures as well.

Therapeutic ultrasound in cardiology.

Ultrasound can be exploited to derive therapeutic results by using its bioeffects such as creation of mechanical vibrations, localized cavitations, microstream formation, physicochemical changes and thermal energy. Extensive in vitro and animal investigations during the last 2 decades have laid a foundation for ultrasound energy to be used for treatment purposes in various medical specialties. In the area of cardiovascular diseases, ultrasound could be used for thrombolysis, adjunct to coronary interventions, drug delivery, local gene transfer, and creating therapeutic lesions. The dispensation approaches to therapeutic ultrasound are varied, from the use of low- to medium-range frequency, low to focused high intensity, and catheter-based to external devices. Catheter-based ultrasound could be useful for intracoronary thrombolysis, and external ultrasound instrument with transcutaneous delivery could be of use in applications such as creation of myocardial lesions, peripheral vessel thrombolysis, and drug and gene delivery. Adjunct administration of microbubbles has been found to enhance thrombolysis, and drug and gene therapy. Ongoing studies strongly suggest that therapeutic ultrasound could have an important role in cardiovascular disorders associated with thrombosis, inflammation, atherosclerotic disease, and arrhythmias.

Recent role of imaging in the diagnosis of pericardial disease.

Noninvasive cardiac imaging techniques have made a striking impact on the evaluation and management of pericardial disorders. Two-dimensional and Doppler echocardiography are the methods of choice in the evaluation of pericardial effusion and cardiac tamponade. Magnetic resonance imaging, computed tomography, and transesophageal echocardiography are valuable in the assessment of pericardial thickness in suspected cases of constrictive pericarditis. Filling dysfunction associated with constrictive pericarditis is well demonstrated by Doppler flow velocity recordings of intracardiac flow jets, and pulmonary and hepatic venous flow streams. Tissue Doppler echocardiography, by which tissue velocity of myocardial regions and mitral annulus are analyzed, offers additional information in the differentiation of constrictive pericarditis and restrictive cardiomyopathy. Magnetic resonance imaging and computed tomography are the techniques of choice in the recognition of unusual disorders such as pericardial cysts, tumors invading the pericardium, and congenital absence of pericardium. Noninvasive imaging aids not only in the diagnosis of pericardial diseases, but also in the guidance of optimal therapy.