P1309RIGHT VENTRICULAR-PULMONARY ARTERIAL UNCOUPLING IN PATIENTS ON CHRONIC HEMODIALYSIS WITH SEVERE RIGHT VENTRICULAR REMODELING

Background and Aims

Patients on chronic hemodialysis (HD) may present right ventricular (RV) dysfunction and increased pulmonary artery pressure (PA). The aim of the current study is to describe the RV-PA coupling in chronic patients on HD.

Method

This study explored the adequacy of RV-PA coupling in 41 patients on HD. They underwent a comprehensive transthoracic Doppler echocardiography, and were stratified in accordance with the severity of RV remodeling defined by the presence of RV dilation (tricuspid annulus ≥40 mm) and RV systolic dysfunction (tricuspid annulus systolic excursion plane [TAPSE] <17 mm). RV-PA coupling was estimated by the TAPSE to PA systolic pressure (TAPSE:PASP) ratio.

Results

Three groups of patients were identified: No RV remodeling (Group 1, n=26), mild-to-moderate RV remodeling (Group 2, n=11) and severe RV remodeling (Group 3, n=4). Compared to patients from Groups 1 and 2, patients from Group 3 exhibited significant lower TAPSE values (p<0.001), a tendency to higher PASP values (p=0.054) and significant lower TAPSE:PASP ratio values (p=0.012). C-reactive protein levels and were directly correlated with PASP (r=0.405, p=0.017) and inversely with TAPSE (r=-0.311, p=0.041) and the TAPSE:PASP ratio (r= -0.392, p=0.015) in all patients. These echocardiographic parameters were not correlated with other biochemical, hemodynamic or anthropometric parameters.

Conclusion

These findings suggest that RV-PA coupling is markedly decreased in HD patients with severe RV remodeling. The role of systemic inflammation in RV remodeling and RV-PA uncoupling in HD patients warrants further studies.

Renal autotransplant for subsequent endovascular exclusion of the thoracoabdominal aorta

In the last 20 years, endovascular procedures have radically altered the treatment of diseases of the aorta. The objective of endovascular treatment of dissections is to close the entry point to redirect blood flow toward the true lumen, thereby achieving thrombosis of the false lumen. In extensive chronic dissections that have evolved with the formation of a large aneurysm, the dissection is maintained from the end of the endoprosthesis due to multiple orifices, or reentries, that communicate with the lumens. In addition, one of the primary limitations of this technique is when the visceral arteries have disease involvement. In this report we present a case where, despite having treated the entire length of the descending thoracic aorta, the dissection was maintained distally, leading to progression of the diameter of the aneurysm. After reviewing the literature, and to the best of our knowledge, we describe the first case in which renal autotransplant was performed to allow for subsequent exclusion of the aorta at the thoracoabdominal level using a fenestrated endoprosthesis for the celiac trunk and the superior mesenteric artery.

[Acute kidney injury]

Acute kidney injury (AKI) is defined as an abrupt decline in the glomerular filtration rate with accumulation of nitrogenous waste products and the inability to maintain fluid and electrolyte homeostasis. Occurring in 7% of all hospitalized patients and 28% to 35% of those in intensive care units, AKI increases hospital mortality. Early evaluation should include differentiating prerenal and postrenal components from intrinsic renal disease. Biological markers can give early warning of AKI and assist with differential diagnosis and assessment of prognosis. The most effective preventive measure is to maintain adequate circulation and cardiac output, avoiding ischemia- or nephrotoxin-induced injury. To that end, patients and situations of risk must be identified, hemodynamics and diuresis monitored, hypovolemia reversed, and nephrotoxins avoided. Protective agents such as sodium bicarbonate, mannitol, prostagiandins, calcium channel blockers, N-acetyl-L-cysteine, sodium deoxycholate, allopurinol, and pentoxifylline should be used. Treatment includes the elimination of prerenal and postrenal causes of AKI; adjustment of doses according to renal function; avoidance of both overhydration and low arterial pressure; maintenance of electrolytic balance, avoiding hyperkalemia and correcting hyperglycemia; and nutritional support, assuring adequate protein intake. For severe AKI, several modalities of renal replacement therapy, differentiated by mechanism and duration, are available. Timing--neither the best moment to start dialysis nor the optimal duration--has been not established. Early detection of AKI is necessary for preventing progression and starting renal replacement therapy at adjusted doses that reflect metabolic requirements.

Timing of renal replacement therapy after cardiac surgery: a retrospective multicenter Spanish cohort study

BACKGROUND

The optimal time to initiate renal replacement therapy (RRT) in cardiac surgery-associated acute kidney injury (CSA-AKI) is unknown. Evidence suggests that the early use of RRT in critically ill patients is associated with improved outcomes. We studied the effects of time to initiation of RRT on outcome in patients with CSA-AKI.

METHODS

This was a retrospective observational multicenter study (24 Spanish hospitals). We analyzed data on 203 patients who required RRT after cardiac surgery in 2007. The cohort was divided into 2 groups based on the time at which RRT was initiated: in the early RRT group, therapy was initiated within the first 3 days after cardiac surgery; in the late group, RRT was begun after the 3rd day. Multivariate nonconditional logistic and linear regression models were used to adjust for potential confounders.

RESULTS

In-hospital mortality was significantly higher in the late RRT group compared with early RRT patients (80.4 vs. 53.2%; p < 0.001; adjusted odds ratio of 4.1, 95% CI: 1.6-10.0). Also, patients in the late RRT group had longer adjusted hospital stays by 11.6 days (95% CI: 1.4-21.9) and higher adjusted percentage increases in creatinine at discharge compared with baseline by 67.7% (95% CI: 28.5-106.4).

CONCLUSIONS

Patients who undergo early initiation of RRT after CSA-AKI have improved survival rates and renal function at discharge and decreased lengths of hospital stay.

Autosomal-dominant polycystic kidney disease: high prevalence of graft loss for death-related malignancies and cardiovascular risk factors

Autosomal-dominant polycystic kidney disease (ADPKD) is a systemic disease with multiple extrarenal manifestations. It accounts for 7% to 11% of patients receiving dialysis or renal transplantation (RT) for end-stage renal disease (ESRD) in Europe. We analyzed retrospectively the causes of death, the prevalence of cardiovascular risk factors (CVRF) and the patient and graft survivals in 62 consecutive ADPKD patients who received 63 cadaveric grafts (29 men and 34 women), of the 600 RTs performed between 1980-2001. The diagnosis of ADPKD was established by family history and ultrasound techniques. At present, 50 patients (79.4%) have functioning grafts, with a mean follow-up of 84.7 months (range, 12-255), and 13 patients have lost their grafts. The main cause of failure was patient death with a functioning graft (9 cases). Malignancies occurred in 5 patients, including 2 lymphomas, 1 renal carcinoma, 1 pancreas sarcoma, and 1 lung cancer associated with infection. Three patients died of cardiocerebrovascular events, and 1 patient of pneumonia. One patient lost the graft after decreasing the immunosuppression for an obstructing colon cancer. Three additional patients now on dialysis lost their grafts due to chronic rejection in 2 cases and primary nonfunction in 1 case. The prevalence of cardiovascular risk factors among the 50 patients with functional grafts were: hypertension, 70%; hypercholesterolemia, 62%; hyperhomocysteinemia, 30%; hyperfibrinogenemia, 68%; increased lipoprotein (a), 18%; microalbuminuria, 22%; hyperuricemia, 48%; hyperparathyroidism, 24%; overweight status, 24%; and nonlethal myocardial infarction, 10%. We conclude that ADPKD patients have good graft and patient survivals, and that the presence of malignancy is the main cause of death and graft failure at our center.

Treatment of hyperhomocysteinemia after renal transplantation

INTRODUCTION

Several epidemiologic prospective studies have provided strong evidence that hyperhomocysteinemia (HHC) is a risk factor for cardiovascular disease (CVD) due to its role in producing endothelial damage due to oxidation stress. Several studies show that combined folic acid (FA) and vitamin B12 (B12) treatment decreases fasting total homocysteine (HC) levels in renal transplant recipients (RTR). The aim of the study was to determine the efficacy and safety during one year of combined FA and B12 treatment in 89 RTR, as well as the relationship between HHC with other known risk factors for CVD and the intrinsic characteristics of the transplantation.

METHODS

Among 193 RTR in whom we determined the baseline levels of HC, FA, B12, creatinine, and CV risk factors, 81 had normal (HC < 14 micromol/L) and 112 elevated (HC > or = 14 micromol/L) HC levels, 89 of whom were included in a treatment group (23 nontreated). Analytic measures were performed at baseline and 1, 3, and 12 months.

RESULTS

We observed a decrease in HC levels among the treatment group (P<.05) after 12 months without differences in the other groups. There were no differences in age, hypertension, hypercholesterolemia, smoking, presence of diabetes, or type of immunosuppression between the groups. There was a significant correlation between basal creatinine and HC level (P<.05). A higher prevalence of CVD was observed in the HHC group (P<.05).

CONCLUSION

HHC is associated with worse renal function and a higher prevalence of CVD. FA and B12 treatment normalize HC levels, representing a safe treatment that could improve the long-term vascular prognosis of RTR.