Myocardial ischaemia due to subclavian stenosis after coronary artery bypass graft: a case report.

INTRODUCTION: Subclavian artery stenosis occurs up to 4.6% in patients who are referred for a coronary artery bypass graft (CABG). Subclavian artery stenosis can compromise the blood flow in the ipsilateral mammary artery. CASE PRESENTATION: In this case report, we describe a patient with prior history of CABG and peripheral vascular disease, who presented with recurrent chest pain symptoms. Cardiac perfusion imaging using Rubidium-82 positron emission tomography showed extensive ischaemia in the anterior wall. Coronary angiography showed an ipsilateral (left) severe subclavian stenosis, while there was no significant stenosis in the bypass grafts. Patient's symptoms resolved after percutaneous intervention of the left subclavian artery. DISCUSSION: The presence of subclavian artery stenosis can result in myocardial ischaemia after prior CABG utilizing the internal mammary artery. A history of peripheral vascular disease and a blood pressure difference between the upper extremities greater than 15 mmHg are clinical predictors of subclavian artery stenosis. Percutaneous angioplasty and stenting is considered the first-line treatment for subclavian artery stenosis. Surgical management should be considered after failure of endovascular treatment in low-surgical-risk patients.

Bone suppressed images improve radiologists' detection performance for pulmonary nodules in chest radiographs.

OBJECTIVES: To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs. MATERIALS AND METHODS: Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis. RESULTS: ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03). CONCLUSION: Bone suppressed images improve radiologists' detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity.

Atherosclerotic renal artery stenosis is prevalent in cardiorenal patients but not associated with left ventricular function and myocardial fibrosis as assessed by cardiac magnetic resonance imaging.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is common in cardiovascular diseases and associated with hypertension, renal dysfunction and/or heart failure. There is a paucity of data about the prevalence and the role of ARAS in the pathophysiology of combined chronic heart failure (CHF) and chronic kidney disease (CKD). We investigated the prevalence in patients with combined CHF/CKD and its association with renal function, cardiac dysfunction and the presence and extent of myocardial fibrosis. METHODS: The EPOCARES study (ClinTrialsNCT00356733) investigates the role of erythropoietin in anaemic patients with combined CHF/CKD. Eligible subjects underwent combined cardiac magnetic resonance imaging (cMRI), including late gadolinium enhancement, with magnetic resonance angiography of the renal arteries (MRA). RESULTS: MR study was performed in 37 patients (median age 74 years, eGFR 37.4 ± 15.6 ml/min, left ventricular ejection fraction (LVEF) 43.3 ± 11.2%), of which 21 (56.8%) had ARAS (defined as stenosis >50%). Of these 21 subjects, 8 (21.6%) had more severe ARAS >70% and 8 (21.6%) had a bilateral ARAS >50% (or previous bilateral PTA). There were no differences in age, NT-proBNP levels and medication profile between patients with ARAS versus those without. Renal function declined with the severity of ARAS (p = 0.03), although this was not significantly different between patients with ARAS versus those without. Diabetes mellitus was more prevalent in patients without ARAS (56.3%) against those with ARAS (23.8%) (p = 0.04). The presence and extent of late gadolinium enhancement, depicting myocardial fibrosis, did not differ (p = 0.80), nor did end diastolic volume (p = 0.60), left ventricular mass index (p = 0.11) or LVEF (p = 0.15). Neither was there a difference in the presence of an ischemic pattern of late enhancement in patients with ARAS versus those without. CONCLUSIONS: ARAS is prevalent in combined CHF/CKD and its severity is associated with a decline in renal function. However, its presence does not correlate with a worse LVEF, a higher left ventricular mass or with the presence and extent of myocardial fibrosis. Further research is required for the role of ARAS in the pathophysiology of combined chronic heart and renal failure.

Erythropoietin treatment in patients with combined heart and renal failure: objectives and design of the EPOCARES study.

BACKGROUND: Anemia is common in patients with the combination of chronic heart failure and chronic kidney disease and is associated with increased mortality. Recent clinical studies suggest that recombinant human erythropoietin (EPO) treatment has desirable as well as undesirable effects, related to its hematopoietic or nonhematopoietic effects. Therefore a translational study is needed to elucidate mechanistic aspects of EPO treatment. METHODS: In this open-label randomized 12-month trial (the Mechanisms of Erythropoietin Action in the Cardiorenal Syndrome [EPOCARES]), patients with the combination of chronic heart failure and chronic kidney disease (glomerular filtration rate 20-70 ml/min) and mild anemia (hemoglobin 10.3-12.6 g/dL in men, and 10.3-11.9 g/dL in women) are being randomized into 3 groups: 1 group (n=25) receives a fixed dose of 50 IU/kg per week EPO to increase hemoglobin level to a maximum of 13.7 g/dL for men and 13.4 g/dL for women; another group (n=25) is treated with 50 IU/kg per week EPO maintaining baseline hemoglobin levels for the first 6 months by phlebotomy. The control group (n=25) receives standard care without EPO. RESULTS: Cardiac and renal function as well as a panel of biomarkers and iron parameters are being assessed. Furthermore, the effects of EPO on monocyte gene expression profiles and on endothelial progenitor cells are being evaluated. CONCLUSION: This translational study is designed primarily to discern hematopoietic from nonhematopoietic effects of EPO in cardiorenal patients. The study will add insights into the mechanisms that could explain the fragile balance between desirable and undesirable effects of EPO (Trial registration: ClinicalTrials.gov identifier NCT00356733).

Determinants of maximal exercise performance in chronic heart failure.

BACKGROUND: Chronic heart failure (CHF) is characterized by symptoms like fatigue, dyspnoea and limited exercise performance. It has been postulated that maximal exercise performance (Wmax) is predominantly limited by skeletal muscle function and less by heart function. AIM: To study the interrelation between most relevant muscle and anthropometrical variables and Wmax in CHF patients in order to develop a model that describes the impact of these variables for maximal exercise performance. DESIGN: In 77 patients with CHF Wmax was assessed by incremental cycle ergometry until exhaustion (20 Watt/3 min). Peak torque (strength) and total work (endurance) for the quadriceps and hamstrings were assessed by isokinetic dynamometry. Isometric strength was measured by hand dynamometry. Relevant muscle areas were calculated by computerized tomography scan. RESULTS: Significant correlations between Wmax and isokinetic muscle parameters (peak torque and total work) ranged from 0.41-0.65 (P<0.01). Other significant relationships (P<0.01) with Wmax were obtained for age (r=-0.22), gender (r=0.45), fat free mass (FFM) (r=0.51), quadriceps muscle area (r=0.73), hamstrings muscle area (r=0.50), upper leg muscle function (i.e., a combination of muscle strength and muscle endurance) (r=0.71) and isometric strength (r=0.63). Multiple regression analysis showed that upper leg muscle function and quadriceps muscle area could predict 57% of the variance in Wmax. CONCLUSION: Muscle strength and muscle endurance, combined with quadriceps muscle area are the main predictors of maximal exercise performance in patients with CHF.