Premature coronary artery disease and early stage chronic kidney disease.

A 30 year old asymptomatic male with stage 3 chronic kidney disease (CKD) secondary to Focal Segmental Glomerulosclerosis was found to have features of CKD associated cardiomyopathy including left ventricular hypertrophy (LVH) and focal sub-endocardial scarring on cardiac magnetic resonance imaging. There was also a significantly raised CT coronary calcium score and evidence of non-flow limiting coronary artery disease (CAD) on a CT coronary angiogram. Early stage CKD is a major risk factor for cardiovascular risk causing myocardial hypertrophy and fibrosis and coronary artery atheroma. Cardiovascular risk begins to increase from an eGFR of around 75ml/min/1.73m2. The pathophysiology of cardiovascular disease in CKD is under investigation but to date, treatment options are limited. Blood pressure control and statins have the strongest supportive evidence.

Variability in cardiac MR measurement of left ventricular ejection fraction, volumes and mass in healthy adults: defining a significant change at 1 year.

OBJECTIVE: Variability in the measurement of left ventricular (LV) parameters in cardiovascular imaging has typically been assessed over a short time interval, but clinicians most commonly compare results from studies performed a year apart. To account for variation in technical, procedural and biological factors over this time frame, we quantified the within-subject changes in LV volumes, LV mass (LVM) and LV ejection fraction (EF) in a well-defined cohort of healthy adults at 12 months. METHODS: Cardiac MR (CMR) was performed in 42 healthy control subjects at baseline and at 1 year (1.5 T Magnetom® Avanto; Siemens Healthcare, Erlangen, Germany). Analysis of steady-state free precession images was performed manually offline (Argus software; Siemens Healthcare) for assessment of LV volumes, LVM and EF by a single blinded observer. A random subset of 10 participants also underwent repeat imaging within 7 days to determine short-term interstudy reproducibility. RESULTS: There were no significant changes in any LV parameter on repeat CMR at 12 months. The short-term interstudy biases were not significantly different from the long-term changes observed at 1 year. The smallest detectable change (SDC) for LVEF, end-diastolic volume, end-systolic volume and LVM that could be recognized with 95% confidence were 6%, 13 ml, 7 ml and 6 g, respectively. CONCLUSION: The variability in CMR-derived LV measures arising from technical, procedural and biological factors remains minimal at 12 months. Thus, for patients undergoing repeat annual assessment by CMR, even small differences in LV function, size and LVM (which are greater than the SDC) may be attributed to disease-related factors. ADVANCES IN KNOWLEDGE: The reproducibility and reliability of CMR data at 12 months is excellent allowing clinicians to be confident that even small changes in LV structure and function over this time frame are real.

Automated cardiopulmonary resuscitation using a load-distributing band external cardiac support device for in-hospital cardiac arrest: a single centre experience of AutoPulse-CPR.

BACKGROUND: Poor quality cardiopulmonary resuscitation (CPR) predicts adverse outcome. During invasive cardiac procedures automated-CPR (A-CPR) may help maintain effective resuscitation. The use of A-CPR following in-hospital cardiac arrest (IHCA) remains poorly described. AIMS & METHODS: Firstly, we aimed to assess the efficiency of healthcare staff using A-CPR in a cardiac arrest scenario at baseline, following re-training and over time (Scenario-based training). Secondly, we studied our clinical experience of A-CPR at our institution over a 2-year period, with particular emphasis on the details of invasive cardiac procedures performed, problems encountered, resuscitation rates and in-hospital outcome (AutoPulse-CPR Registry). RESULTS: Scenario-based training: Forty healthcare professionals were assessed. At baseline, time-to-position device was slow (mean 59 (±24) s (range 15-96s)), with the majority (57%) unable to mode-switch. Following re-training time-to-position reduced (28 (±9) s, p<0.01 vs baseline) with 95% able to mode-switch. This improvement was maintained over time. AutoPulse-CPR Registry: 285 patients suffered IHCA, 25 received A-CPR. Survival to hospital discharge following conventional CPR was 28/260 (11%) and 7/25 (28%) following A-CPR. A-CPR supported invasive procedures in 9 patients, 2 of whom had A-CPR dependant circulation during transfer to the catheter lab. CONCLUSION: A-CPR may provide excellent haemodynamic support and facilitate simultaneous invasive cardiac procedures. A significant learning curve exists when integrating A-CPR into clinical practice. Further studies are required to better define the role and effectiveness of A-CPR following IHCA.

Central pulse pressure in patients with chronic kidney disease and in renal transplant recipients.

Patients with chronic kidney disease (CKD) and renal transplant recipients (RTR) have increased cardiovascular risk. The value of measuring central pulse pressure (cPP) over brachial pulse pressure (pPP) is not known. Central PP was measured in 597 patients (364 CKD:233 RTR). In multivariate analysis, age and female gender positively correlated with cPP; heart rate and estimated glomerular filtration rate negatively correlated with cPP. Associations for age, heart rate and gender persisted after additional adjustment for pPP and aortic wave reflection. This model accounted for 91% of the variability in cPP, with pPP alone accounting for 74%. Results were similar when both patient groups were analysed separately. A subset of patients with CKD had aortic pulse wave velocity (PWV) and left ventricular mass index (LVMI) measured. There were no differences in the univariate correlations between PWV (r=0.368 vs 0.315; P=0.4) or LVMI (r=0.125 vs 0.163; P=0.7); nor in the multivariate models created for PWV (P=0.1) or LVMI (P=0.1) when either cPP or pPP were used. This study demonstrates that in these patients most of the variability in cPP can be explained by pPP. Additionally, cPP does not appear to provide additional information beyond pPP in determining PWV and LVMI.

Understanding the effects of chronic kidney disease on cardiovascular risk: are there lessons to be learnt from healthy kidney donors?

Chronic kidney disease (CKD) is now a recognized global public health problem. It is highly prevalent and strongly associated with hypertension and cardiovascular disease (CVD); far more patients with a glomerular filtration rate below 60 ml min(-1) per 1.73 m(2) will die from cardiovascular causes than progress to end-stage renal disease. A better understanding of the complex mechanisms underlying the development of CVD among CKD patients is required if we are to begin devising therapy to prevent or reverse this process. Observational studies of CVD in CKD are difficult to interpret because renal impairment is almost always accompanied by confounding factors. These include the underlying disease process itself (for example, diabetes mellitus and systemic vasculitis) and the complications of CKD, such as hypertension, anaemia and inflammation. Kidney donors provide an ideal opportunity to study healthy subjects without manifest vascular disease who experience an acute change from having normal to modestly impaired renal function at the time of uninephrectomy. Prospectively examining the cardiovascular consequences of uninephrectomy using donors as a model of CKD may provide useful insight into the pathophysiology of CVD in CKD and, therefore, into how the CVD risk associated with renal impairment might eventually be reduced.

Is lowering phosphate exposure the key to preventing arterial stiffening with age?

Cardiovascular disease remains the leading cause of death world wide. Although atheroma is clearly important, the role of arteriosclerotic vascular disease is often overlooked. Arteriosclerosis causes increased arterial stiffness, with consequent systolic hypertension and left ventricular hypertrophy. Serum phosphate is increasingly being recognised as a cardiovascular risk factor and has been implicated in the development of arteriosclerosis and arterial calcification. Its determinants are unclear, but both diet and minor reductions in renal function may be important. Diets in affluent populations are high in phosphate because of increased consumption of animal protein and the use of phosphate-containing preservatives. This viewpoint suggests that the consumption of a phosphate-rich diet, exacerbated by the high prevalence of chronic kidney disease found in ageing populations, accelerates the development of arteriosclerosis. It is hypothesised that reducing phosphate intake will attenuate the progression of arterial stiffness with major beneficial effects upon cardiovascular mortality and morbidity.

Aortic distensibility and arterial-ventricular coupling in early chronic kidney disease: a pattern resembling heart failure with preserved ejection fraction.

OBJECTIVES: To examine arterial and left ventricular function and their interaction in patients with early-stage chronic kidney disease (CKD). DESIGN AND SETTING: Cross-sectional observational study in a university teaching hospital. PATIENTS: 117 patients with stage 2 (60-89 ml/min/1.73 m(2)) or stage 3 (30-59 ml/min/1.73 m(2)) non-diabetic CKD, without overt cardiovascular disease were compared with 40 controls. INTERVENTIONS: Aortic distensibility and left ventricular mass were assessed using cardiac magnetic resonance imaging. Systolic and diastolic ventricular function and arterial-ventricular elastance (stiffness) were assessed by transthoracic echocardiography. MAIN OUTCOME MEASURES: Arterial stiffness as measured by aortic distensibility and arterial elastance. Left ventricular mass, left ventricular systolic and diastolic function, including end-diastolic and end-systolic elastance and their relationship with arterial elastance. RESULTS: Compared with controls, patients with CKD 2 and CKD 3 had reduced aortic distensibility (4.12 (1.3) vs 2.94 (1.8) vs 2.18 (1.8)x10(-3) mm Hg, p<0.01), increased arterial elastance (1.4 (1.3) vs 1.65 (0.40) vs 1.74 0.48) mm Hg, p<0.05) and increased end-systolic (1.88 (0.48) vs 2.43 (0.83) vs 2.42(0.78) mm Hg/ml, p<0.05) and end diastolic elastances (0.07 (0.04) vs 0.11 (0.04) vs 0.12 (0.04, p<0.01). Aortic distensibility was positively correlated with estimated glomerular filtration rate (r = 0.349, p<0.01) and indices of elastance were inversely correlated (r = 0.284, p<0.05). Systolic function was not impaired in patients with early CKD compared with controls but diastolic filling velocities (Em) were reduced (8.1 (0.9) vs 7.9 (0.6) vs 7.5 (0.7) cm/s, p<0.01) while mean left atrial pressure (E/Em) was increased (5.6 (1.1), vs 7.4 (1.8) vs 8.0 (2.4), p<0.01) and end-diastolic elastance was increased. CONCLUSIONS: Early-stage CKD is characterised by reduced aortic distensibility and increases in arterial, ventricular systolic and diastolic stiffness; arterial-ventricular coupling is preserved. This pattern of pathophysiological abnormalities resembles that seen in heart failure with preserved ejection fraction and may account for the high levels of cardiovascular morbidity and mortality in patients at all stages of CKD. TRIAL REGISTRATION NUMBER: NCT00291720.

Management of patients taking antiplatelet or anticoagulant medication requiring invasive breast procedures: United Kingdom survey of radiologists' and surgeons' current practice.

AIM: To determine the current practice in the UK National Health Service Breast Screening Programme for invasive diagnostic procedures and surgery in patients taking anticoagulant and antiplatelet medication. MATERIALS AND METHODS: Lead radiologists and surgeons at each breast screening service were surveyed to determine current practice. One hundred and five respondents provided information regarding their services, protocols, and willingness to proceed with combinations of procedures and anti-haemostatic medications. RESULTS: Between units there was wide variation in practice. Within 21 services providing more than one response, 10 (48%) disagreed on whether protocols existed. Decisions to perform biopsies were unrelated to professional group. The taking of a drug history was variable. Surgeons reported more adverse effects than radiologists [21 (48%) versus 12 (26%)], but no difference in self-assessment of knowledge. CONCLUSION: Both radiologists and surgeons have expressed uncertainty about their understanding of anticoagulant and antiplatelet treatment. This is reflected in a wide range of practice. Guidance regarding the management of these patients is suggested.

The treatment of coronary artery disease in patients with chronic kidney disease.

Premature cardiovascular disease is the largest cause of mortality, and a major cause of morbidity, in patients with chronic kidney disease (CKD). Patients with end-stage kidney disease (ESKD) are at extreme risk, but cardiovascular event rates are increased even in early CKD. There is little controlled trial evidence on which to base treatment, as most therapeutic trials have excluded CKD patients. Current treatment strategies are therefore based upon small prospective studies or retrospective analyses of controlled trials and registry data. It is thus unclear whether CKD patients benefit from modern secondary preventive treatments in the same manner as patients with normal renal function. There is a need for randomized trials to identify effective drugs to prevent and treat coronary artery disease in CKD. Revascularization by CABG in CKD has been widely reported in registry data to provide better results than medical treatment or angioplasty. Recent angioplasty data in patients with CKD, however, show improving results, and the risks of CABG in CKD remain high. It is not clear which revascularization technique has a better outcome in patients 'equally suitable' on angiographic criteria for either procedure. The high rate of late adverse cardiovascular events after both CABG and angioplasty accentuates the need for effective secondary preventive therapy disease in these high-risk patients.