Preeclampsia: a gestational cardiorenal syndrome

To determine whether venous congestion, rather than impairment of cardiac output, is primarily associated with the development of worsening renal function (WRF) in patients with advanced decompensated heart failure (ADHF). Reduced cardiac output is traditionally believed to be the main determinant of WRF in patients with ADHF. A total of 145 consecutive patients admitted with ADHF treated with intensive medical therapy guided by pulmonary artery catheter were studied. We defined WRF as an increase of serum creatinine >/=0.3 mg/dl during hospitalization. In the study cohort (age 57 +/- 14 years, cardiac index 1.9 +/- 0.6 l/min/m(2), left ventricular ejection fraction 20 +/- 8%, serum creatinine 1.7 +/- 0.9 mg/dl), 58 patients (40%) developed WRF. Patients who developed WRF had a greater central venous pressure (CVP) on admission (18 +/- 7 mm Hg vs. 12 +/- 6 mm Hg, p < 0.001) and after intensive medical therapy (11 +/- 8 mm Hg vs. 8 +/- 5 mm Hg, p = 0.04). The development of WRF occurred less frequently in patients who achieved a CVP <8 mm Hg (p = 0.01). Furthermore, the ability of CVP to stratify risk for development of WRF was apparent across the spectrum of systemic blood pressure, pulmonary capillary wedge pressure, cardiac index, and estimated glomerular filtration rates. Venous congestion is the most important hemodynamic factor driving WRF in decompensated patients with advanced heart failure.

Improved mechanistic understanding of renal cell death in acute kidney injury (AKI) has generated new therapeutic targets. Clearly, the classic lesion of acute tubular necrosis is not adequate to describe the consequences of renal ischemia, nephrotoxin exposure, or sepsis on glomerular filtration rate. Experimental evidence supports a pathogenic role for apoptosis in AKI. Interestingly, proximal tubule epithelial cells are highly susceptible to apoptosis, and injury at this site contributes to organ failure. During apoptosis, well-orchestrated events converge at the mitochondrion, the organelle that integrates life and death signals generated by the BCL2 (B-cell lymphoma 2) protein family. Death requires the 'perfect storm' for outer mitochondrial membrane injury to release its cellular 'executioners'. The complexity of this process affords new targets for effective interventions, both before and after renal insults. Inhibiting apoptosis appears to be critical, because circulating factors released by the injured kidney induce apoptosis and inflammation in distant organs including the heart, lung, liver, and brain, potentially contributing to the high morbidity and mortality associated with AKI. Manipulation of known stress kinases upstream of mitochondrial injury, induction of endogenous, anti-apoptotic proteins, and improved understanding of the timing and consequences of renal cell apoptosis will inevitably improve the outcome of human AKI.

We sought to investigate the relationship between increased central venous pressure (CVP), renal function, and mortality in a broad spectrum of cardiovascular patients. The pathophysiology of impaired renal function in cardiovascular disease is multifactorial. The relative importance of increased CVP has not been addressed previously. A total of 2,557 patients who underwent right heart catheterization in the University Medical Center Groningen, the Netherlands, between January 1, 1989, and December 31, 2006, were identified, and their data were extracted from electronic databases. Estimated glomerular filtration rate (eGFR) was assessed with the simplified modification of diet in renal disease formula. Mean age was 59 +/- 15 years, and 57% were men. Mean eGFR was 65 +/- 24 ml/min/1.73 m(2), with a cardiac index of 2.9 +/- 0.8 l/min/m(2) and CVP of 5.9 +/- 4.3 mm Hg. We found that CVP was associated with cardiac index (r = -0.259, p < 0.0001) and eGFR (r = -0.147, p < 0.0001). Also, cardiac index was associated with eGFR (r = 0.123, p < 0.0001). In multivariate analysis CVP remained associated with eGFR (r = -0.108, p < 0.0001). In a median follow-up time of 10.7 years, 741 (29%) patients died. We found that CVP was an independent predictor of reduced survival (hazard ratio: 1.03 per mm Hg increase, 95% confidence interval: 1.01 to 1.05, p = 0.0032). Increased CVP is associated with impaired renal function and independently related to all-cause mortality in a broad spectrum of patients with cardiovascular disease.