Katsuhiko Morimoto

Suppressed soluble Fms–like tyrosine kinase-1 production aggravates atherosclerosis in chronic kidney disease

Patients with chronic kidney disease (CKD) die of cardiovascular diseases for unknown reasons. Blood vessel formation in plaques and its relationship with plaque stability could be involved with signaling through the Flt-1 receptor and its ligands, vascular endothelial growth factor, and the closely related placental growth factor (PlGF). Flt-1 also exists as a circulating regulatory splice variant short-inhibitory form (sFlt-1) that serves as a decoy receptor, thereby inactivating PlGF. Heparin releases sFlt-1 by displacing the sFlt-1 heparin-binding site from heparin sulfate proteoglycans. Heparin could provide diagnostic inference or could also induce an antiangiogenic state. In the present study, postheparin sFlt-1 levels were lower in CKD patients than in control subjects. More importantly, sFlt-1 levels were inversely related to atherosclerosis in CKD patients, and this correlation was more robust after heparin injection, as verified by subsequent cardiovascular events. Knockout of apolipoprotein E (ApoE) and/or sFlt-1 showed that the absence of sFlt-1 worsened atherogenesis in ApoE-deficient mice. Thus, the relationship between atherosclerosis and PlGF signaling, as regulated by sFlt-1, underscores the underappreciated role of heparin in sFlt-1 release. These clinical and experimental data suggest that novel avenues into CKD-dependent atherosclerosis and its detection are warranted.

Heart Failure Associated with Metastatic Myocardial Calcification in a Hemodialysis Patient with Progressive Calcification of the Hand

Metastatic myocardial calcification is a frequent cause of heart failure in hemodialysis patients. However, early detection is difficult, often resulting in a poor prognosis. A 47-year-old man with hemodialysis-dependent end-stage renal disease presented with progressive dyspnea. Levels of serum phosphate, calcium, and intact parathyroid hormone were poorly controlled. He developed pain in his right thumb 1 year before presentation, and the pain gradually increased and extended to the entire right hand. Hand radiography 1 month earlier had revealed significant progressive calcification. Echocardiography showed severe, diffuse hypokinesis and pericardial effusion as well as possible anterior myocardial calcification with high echogenicity. Chest computed tomography revealed a severely dilated heart with anterior massive myocardial calcification and a large amount of pericardial effusion, which was not detected on computed tomography performed 20 months earlier. The patient was diagnosed with heart failure associated with metastatic myocardial calcification and died suddenly 2 weeks later. This experience suggests that progressive metastatic calcification of the skin and subcutaneous tissue is useful for predicting myocardial calcification.

Therapeutic Benefits of Tocilizumab Vary in Different Organs of a Patient with AA Amyloidosis.

Systemic reactive AA amyloidosis is a life-threatening complication of chronic inflammatory diseases. Anti-interleukin-6 receptor, tocilizumab (TCZ), has been shown to improve clinical symptoms of patients with AA amyloidosis, accompanied with regression of the amyloid deposition. We report a case of AA amyloidosis evaluated by histology of multiple organs before and after TCZ treatment. A woman in her 60s with rheumatoid arthritis was referred to our hospital because of cardiac and renal dysfunction. A gastric and renal biopsy revealed the deposition of AA amyloid, and echocardiography revealed concentric left ventricular hypertrophy. Her estimated glomerular filtration rate was decreased to 8.6 mL/min/1.73 m2, and B-type natriuretic peptide, C-reactive protein, and serum amyloid A protein were significantly elevated. TCZ treatments markedly decreased her serum amyloid A protein and C-reactive protein levels, but hemodialysis was required 1 year later. Endoscopic gastric rebiopsy 3 years after initiation of TCZ treatments revealed the regression of amyloid deposition and echocardiography revealed improvement of her left ventricular hypertrophy. However, a renal rebiopsy revealed that the amyloid deposition had not regressed. In conclusion, these observations suggest that the therapeutic effects of TCZ can vary among organs in patients with AA amyloidosis.

Placental Growth Factor as a Predictor of Cardiovascular Events in Patients with CKD from the NARA-CKD Study

Placental growth factor (PlGF) contributes to atherogenesis through vascular inflammation and plaque destabilization. High levels of PlGF may be associated with mortality and cardiovascular disease, but the relationship between PlGF level and adverse outcomes in patients with CKD is unclear. We conducted a prospective cohort study of 1351 consecutive participants with CKD enrolled in the Novel Assessment of Risk management for Atherosclerotic diseases in CKD (NARA-CKD) study between April 1, 2004, and December 31, 2011. During a median follow-up of 3 years, 199 participants died and 383 had cardiovascular events, defined as atherosclerotic disease or heart failure requiring hospitalization. In adjusted analyses, mortality and cardiovascular risk increased in each successive quartile of serum PlGF level; hazard ratios (HRs) (95% confidence intervals [95% CIs]) for mortality and cardiovascular risk, respectively, were 1.59 (0.83 to 3.16) and 1.55 (0.92 to 2.66) for the second quartile, 2.97 (1.67 to 5.59) and 3.39 (2.20 to 5.41) for the third quartile, and 3.87 (2.24 to 7.08) and 8.42 (5.54 to 13.3) for the fourth quartile. The composite end point of mortality and cardiovascular events occurred during the study period in 76.4% of patients in both the highest PlGF quartile (≥19.6 pg/ml) and the lowest eGFR tertile (<30 ml/min per 1.73 m(2)). The association between PlGF and mortality or cardiovascular events was not attenuated when participants were stratified by age, sex, traditional risk factors, and eGFR. These data suggest elevated PlGF is an independent risk factor for all-cause mortality and cardiovascular events in patients with CKD.

Prognostic Impact of Placental Growth Factor on Mortality and Cardiovascular Events in Dialysis Patients

Background: Placental growth factor (PlGF), a member of the vascular endothelial growth factor (VEGF) family, has recently emerged as a predictor of survival and cardiovascular risk. Along with others, we have shown an independent association between PlGF and cardiovascular events in CKD patients, but not much is known about patients receiving dialysis. Methods: We studied 205 dialysis patients undergoing cardiac catheterization at the Nara Medical University between April 1, 2004, and December 31, 2012. Serum levels of PlGF and VEGF were measured with ELISA in all the patients. Results: During a median follow-up of 20 months, 121 participants died from any cause or experienced a cardiovascular event. In the fully adjusted analysis, having an above-median PlGF or VEGF level was associated with a hazards ratio for adverse outcomes of 2.55 (1.72-3.83) and 1.39 (0.95-2.04), respectively. Using a multimarker strategy in a model with age, serum albumin, history of coronary artery disease, brain natriuretic peptide and PlGF, patients with 2, 3 and 4 positive markers had a 3.82-, 5.77- and 6.59-fold higher risk of mortality or a cardiovascular event, respectively, compared to those with no positive markers. The model with PlGF had a significantly higher c-statistic, integrated discrimination improvement index and category-free net reclassification improvement index than the model without PlGF. Conclusion: PlGF is independently associated with mortality and cardiovascular events, but the association between VEGF and adverse events was attenuated with covariate adjustment. The addition of PlGF to models with established clinical predictors provides additional useful prognostic information in patients receiving dialysis.

Prognostic Value of Predialysis Indices for Technique Failure and Mortality in Peritoneal Dialysis Patients

Technique failure remains a frequent cause of peritoneal dialysis (PD) withdrawal. Many post‐commencement predictors of PD technique failure have been identified, while predialysis predictors have remained unclear. The aim of this study was to identify predialysis indices for technique failure in PD patients. We recruited 206 consecutive PD patients who were treated at Nara Medical University Hospital between 1 April 1997 and 31 December 2012. Forty‐eight patients were excluded because of transition from hemodialysis (HD) or withdrawal from PD within 3 months, leaving 158 patients for analysis. Clinical characteristics and laboratory data from within 3 months preceding PD commencement were analyzed. The primary outcome was the composite of time to combined use of HD, transition to HD, and all‐cause mortality within 2 years after PD commencement. During the study period, the primary outcome was observed in 50 patients. Using multivariate analysis, greater age (odds ratios (ORs) [95%CI], 3.08 [1.72–5.61]), anemia (ORs [95%CI], 2.12 [1.08–4.43]), overweight/obesity (ORs [95%CI], 2.09 [1.16–3.72]), and hypocalcemia (ORs [95%CI], 1.86 [1.04–3.35]) were independently associated with technique failure. Adding corrected calcium to the model incorporating age, body mass index, and hemoglobin significantly increased the c‐statistic from 0.678 to 0.755 (P = 0.048) relative to the model incorporating age alone. The integrated discrimination improvement was 0.085 (95% CI 0.036–0.134, P < 0.001) and the continuous net reclassification improvement was 0.395 (95% CI 0.066–0.724, P = 0.02). In conclusion, the combination of predialysis indices comprising age, overweight/obesity, anemia, and corrected calcium could provide a significant predictive value for technique failure of PD.

Angiogenic Factors and Risks of Technique Failure and Cardiovascular Events in Patients Receiving Peritoneal Dialysis.

Background: Placental growth factor (PlGF) is a member of the vascular endothelial growth factor family that acts as a pleiotropic cytokine capable of stimulating angiogenesis and accelerating atherogenesis. Soluble fms-like tyrosine kinase-1 (sFlt-1) antagonizes PlGF action. Higher levels of PlGF and sFlt-1 have been associated with cardiovascular events in patients with chronic kidney disease, yet little is known about their relationship with adverse outcomes in patients on peritoneal dialysis (PD). The aim of this study was to investigate the association of PlGF and sFlt-1 with technique survival and cardiovascular events. Methods: We measured serum levels of PlGF and plasma levels of sFlt-1 in 40 PD patients at Nara Medical University. Results: PlGF and sFlt-1 levels were significantly correlated with the dialysate-to-plasma ratio of creatinine (r = 0.342, p = 0.04 and r = 0.554, p < 0.001) although PlGF and sFlt-1 levels were not correlated with total creatinine clearance and total Kt/V. Additionally, both PlGF and sFlt-1 levels were significantly higher in patients with high transport membranes compared to those without (p = 0.039 and p < 0.001, respectively). Patients with PlGF levels above the median had lower technique survival and higher incidence of cardiovascular events than patients with levels below the median, with hazard ratios of 11.9 and 7.7, respectively, in univariate Cox regression analysis. However, sFlt-1 levels were not associated with technique survival or cardiovascular events (p = 0.11 and p = 0.10, respectively). Conclusion: Elevated PlGF and sFlt-1 are significantly associated with high transport membrane status. PlGF may be a useful predictor of technique survival and cardiovascular events in PD patients.