Cardiorenal syndrome and heart failure

Biomarkers and echocardiography for evaluating the improvement of the ventricular diastolic function after surgical relief of hydronephrosis

The pathophysiology of cardio-renal syndrome (CRS) is complex. Hydronephrosis caused by urolithiasis may cause cytokine release and lead to cardiac dysfunction. The aim of this study was to evaluate cardiac function changes observed in patients who received double J placement using feasible biomarkers and echocardiography. This was a prospective, single-center study. Eighty-seven patients who presented with acute unilateral hydronephrosis and received ureteroscope stone manipulation were enrolled. Echocardiography and cytokines were measured on the day of the operation and 24 hours after the procedure. Changes before and after surgery were assessed by the paired t-test and Wilcoxon test. Correlation analyses between echocardiographic diastolic indices and cytokine levels were performed using Pearson’s correlation coefficients. Patients with hydronephrosis showed a higher left atrium volume index (LAVI), decreased E', and increased E/ E' ratio, which indicated diastolic dysfunction. Patients with hydronephrosis also exhibited decreased global strain rates during isovolumetric relaxation (SR_IVR) and E/ SR_IVR, which confirmed the diastolic dysfunction. Significant reductions in LAVI, increases in SR_IVR and decreases in E/ SR_IVR were observed after the operation. Biomarkers, such as TGF-β and serum NT-proBNP, were significantly decreased after surgery. In addition, a significant correlation was observed between the post-surgical decrease in TGF-β1 and increase in SR_IVR. Unilateral hydronephrosis causes cardiac diastolic dysfunction, and relieving hydronephrosis could improve diastolic function. Improvements in cardiac dysfunction can be evaluated by echocardiography and measuring cytokine levels. The results of this study will inform efforts to improve the early diagnosis of CRS and prevent further deterioration of cardiac function when treating patients with hydronephrosis.

Predictors of suboptimal and crash initiation of dialysis at two tertiary care centers

Many end-stage renal disease patients do not have an optimal start to dialysis. Many patients have suboptimal initiation, while others "crash" start on dialysis without prior care from a nephrologist. We examined factors associated with suboptimal or crash starts. We conducted a retrospective cohort study of 377 incident dialysis patients at two tertiary care centers from January 2006 to April 2011. Logistic regression was used to identify factors associated with suboptimal and crash starts to dialysis. Out of 377 patients, 102 (27%) had optimal starts, 221 (59%) had suboptimal starts, and 54 (14%) had crash starts. Three hundred thirty-four patients (89%) began with hemodialysis, while 11% started with peritoneal dialysis. Factors independently associated with a suboptimal start as opposed to an optimal start included nephrology care more than 12 months prior to initiation of dialysis (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.12-0.58), Charlson Comorbidity Index (OR, 1.25 per 1 point; 95% CI, 1.09-1.43), and age (OR, 1.02 per 1 year; 95% CI, 1.00-1.04). In comparison, diabetic nephropathy (OR, 0.25; 95% CI, 0.12-0.54), a history of pulmonary edema within 6 months prior to initiation of dialysis (OR, 3.70; 95% CI, 1.77-7.75), and a diagnosis of chronic obstructive lung disease (OR, 0.07; 95% CI, 0.01-0.52) were independently associated with a crash start. There was a low incidence of optimal dialysis starts in our tertiary care dialysis population. Our study highlights that suboptimal and crash start patients are distinct populations. Modifying factors that predict nonoptimal dialysis starts will need to consider these distinctions.

Cardiorenal syndrome caused by heart failure with preserved ejection fraction

Since cardiorenal dysfunction is usually secondary to multiple factors acting in concert (and not only reduced cardiac output) in the present paper we are going to focus on the interrelationship between heart failure with normal ejection fraction and the development of cardiorenal syndrome. The coexistence of renal impairment in heart failure with preserved ejection fraction (CRS type 2 and 4) is common especially in older females with hypertension and/or diabetes. It can be hypothesized that the incidence of this disease association is growing, while clinical trials enrolling these patients are still lacking. The main mechanisms thought to be involved in the pathophysiology of this condition are represented by the increase of intra-abdominal and central venous pressure and the activation of the renin-angiotensin system. Differently from CRS in heart failure with reduced ejection fraction, the involvement of the kidney may be under-diagnosed in patients with heart failure and preserved ejection fraction and the optimal therapeutic strategy in this condition, though challenging, is far to be completely elucidated. Further studies are needed to assess the best therapeutic regimen in patients with renal dysfunction (and worsening) and heart failure and preserved ejection fraction.