Cardiac findings at necropsy in patients with chronic kidney disease maintained on chronic hemodialysis

The Detrimental Impact of End-Stage Kidney Disease Is Not Reflected in Autopsy Reports

CONTEXT.—

End-stage kidney disease (ESKD) is defined as renal impairment requiring renal replacement therapy to sustain life. With a 1-year mortality of ∼20% to 30%, many die of complications related to this disease.

OBJECTIVE.—

To determine the percentage of autopsy cases of decedents with ESKD in which the contribution of ESKD to death is accurately reflected in the final report.

DESIGN.—

Autopsy case records were retrospectively reviewed at 4 institutions (Yale New Haven Hospital, University of Chicago Medical Center, University of Illinois at Chicago Hospital, University of Iowa Hospital). Clinical, macroscopic, and microscopic autopsy findings were reviewed, with attention to renal disease findings.

RESULTS.—

One hundred sixty decedents with documented ESKD and premortem dialysis who underwent autopsy assessment were identified. ESKD was implicated as a cause of death (CoD) or significant contributing factor in 44 cases (28%), but not in the remaining 116 cases (72%). Cardiovascular disease was the most common CoD in ESKD. There was significant interpathologist variation in the inclusion of ESKD as a CoD across institutions. These rates ranged from 85% correlation (23 of 27 cases), to 13% (4 of 31 and 8 of 62 cases at 2 institutions), and 22.5% (9 of 40 cases) across the 4 participating institutions.

CONCLUSIONS.—

The recognition at autopsy of ESKD as a CoD or contributing CoD at autopsy in patients undergoing dialysis remains low (28%). The detrimental impact of ESKD is not reflected in hospital autopsy reports, which carries implications for collection of vital statistics and allocation of research funding for kidney diseases.

Cardiovascular Alterations and Structural Changes in the Setting of Chronic Kidney Disease: a Review of Cardiorenal Syndrome Type 4

Cardiovascular and renal physiology are interrelated. More than a decade ago this was codified in guidelines defining the five subtypes of the cardiorenal syndrome. Morbidity and mortality for those with the cardiorenal syndrome is high compared to demographically matched individuals without cardiorenal disease, acute or chronic. The focus of this review will be the epidemiology, the impact of chronic kidney disease on cardiac structure and function, and associated clinical symptoms, outcomes, and potential treatments for patients with chronic reno-cardiac syndrome, or cardiorenal syndrome type 4. Cardiac structural changes can be profound and are described in detail both at a cellular and physiologic level. Integrating therapies for the treatment of causative or resulting comorbidities may ultimately slow progression of both cardiac and renal disease as well as minimize symptoms and death.

Virtually All Complications of Active Infective Endocarditis Occurring in a Single Patient

Described herein is a 49-year-old black man with advanced polycystic renal disease, on hemodialysis for 6 years, who during his last 12 days of life had his vegetations on the aortic valve extend to the mitral and tricuspid valves, through the aortic wall to produce diffuse pericarditis, to the atrioventricular node to produce complete heart block, and embolize to cerebral arteries producing multiple brain infarcts, to a branch on the left circumflex coronary artery producing acute myocardial infarction, and to mesenteric arteries producing bowel infarction.

A Rat Model with Multivalve Calcification Induced by Subtotal Nephrectomy and High-Phosphorus Diet

Background

Chronic kidney disease (CKD) with known valve calcification (VC) places individuals at high risk of cardiovascular disease. The study of VC in CKD is challenging due to the lack of a suitable research model. Here, we established a rat model of multivalve calcification induced by subtotal nephrectomy and a high-phosphate (HP) diet and analyzed the valve characteristics.

Methods

We established a CKD model in Sprague-Dawley rats by performing 5/6 nephrectomy (5/6Nx) followed by feeding with chow containing different phosphate concentrations for 8, 12, or 16 weeks. The rats were divided into 4 groups: sham+normal phosphate (NP, 0.9% P), sham+high phosphate (HP, 2.0% P), 5/6Nx+NP, and 5/6Nx+HP. Serum creatinine (Scr), blood urea nitrogen (BUN), parathyroid hormone (PTH), calcium, phosphorus, and 24-h urine protein levels were investigated. Pathological examinations included histological characterization, safranin staining, Alcian blue staining, and von Kossa staining at different time points. Using nanoanalytical electron microscopy, we examined valves from rats in the 5/6Nx+HP and sham+HP groups and detected spherical particles using energy-dispersive spectroscopy (EDS) to observe microscopic changes in the valves. In addition, the calcified tissues were analyzed for phase and crystallization properties using an X-ray powder diffractometer.

Results

The rats in the 5/6Nx+HP and 5/6Nx+NP groups presented with increased levels of Scr, BUN, and 24-h urine protein compared with those of the rats in the sham+HP and sham+NP groups. High levels of PTH were observed, and hematoxylin and eosin staining and immunohistochemistry for proliferating cell nuclear antigen showed parathyroid hyperplasia in rats in the 5/6Nx+HP group but not in the 5/6Nx+NP group. In rats in the 5/6Nx+HP group, extracellular matrix glycosylation was observed in the aortic valve in the 12th week and the mitral valve in the 16th week. In the 16th week, chondrocytes appeared in the aortic valve, as confirmed by immunofluorescence and Western blotting. Calcified particles mainly composed of phosphorus and calcium were observed in both the aortic and mitral valves by transmission electron microscopy and scanning electron microscopy (SEM). The main mineral component of the calcified aortic valve particles was hydroxyapatite [Ca₅(PO₄)₃(OH)], as shown by X-ray diffraction. However, there were no obvious differences in heart function between rats in the 5/6Nx+HP and sham+HP groups.

Conclusions

Our findings demonstrate that multivalve calcification is involved in CKD following 16-week HP and that hydroxyapatite [Ca₅(PO₄)₃(OH)] is the main component of the calcified aortic valve particles of rats in the 5/6Nx+HP group.

End-Stage Kidney Disease Is Overlooked as a Proximate Cause of Death at Autopsy

OBJECTIVES

To determine how often end-stage kidney disease (ESKD) is implicated as a cause of death (COD) at autopsy.

METHODS

We searched our autopsy database (2007-2017) using queries "end-stage renal disease," "end-stage kidney disease," "ESRD," "chronic renal disease," and "chronic kidney disease." Final diagnosis and summaries were reviewed to determine if ESKD was appropriately correlated with the COD. Cases in which the COD was unrelated to kidney function were excluded.

RESULTS

Eighty-five patients with a history of ESKD and histologic confirmation thereof were identified. Their CODs were cardiovascular (36%), infection/sepsis (41%), pulmonary (6%), gastrointestinal/hepatic (2%), central nervous system (3%), other systemic disease (7%), and unspecified (5%). ESKD was implicated as a contributing COD in 24 (28%) cases.

CONCLUSIONS

ESKD is often overlooked at autopsy, particularly in patients with cardiovascular or infectious disease. Accurate documentation of ESKD contributing to mortality is important for education, counseling, record maintenance, and directing research efforts.

The Cardiorenal Axis: Myocardial Perfusion, Metabolism, and Innervation

PURPOSE OF THE REVIEW

Cardiorenal syndrome (CRS), defined as concomitant heart and kidney disease, has been a focus of attention for nearly a decade. As more patients survive severe acute and chronic heart and kidney diseases, CRS has emerged as an "epidemic" of modern medicine. Significant advances have been made in unraveling the complex mechanisms that underlie CRS based on classification of the condition into five pathophysiologic subtypes. In types 1 and 2, acute or chronic heart disease results in renal dysfunction, while in types 3 and 4, acute or chronic kidney diseases are the inciting factors for heart disease. Type 5 CRS is defined as concomitant heart and kidney dysfunction as part of a systemic condition such as sepsis or autoimmune disease.

RECENT FINDINGS

There are ongoing efforts to better define subtypes of CRS based on historical information, clinical manifestations, laboratory data (including biomarkers), and imaging characteristics. Systematic evaluation of CRS by advanced cardiac imaging, however, has been limited in scope and mostly focused on type 4 CRS. This is in part related to lack of clinical trials applying advanced cardiac imaging in the acute setting and exclusion of patients with significant renal disease from studies of such techniques in chronic HF. Advanced cardiac nuclear imaging is well poised for assessment of the pathophysiology of CRS by offering a myriad of molecular probes without the need for nephrotoxic contrast agents. In this review, we examine the current or potential future application of advanced cardiac imaging to evaluation of myocardial perfusion, metabolism, and innervation in patients with CRS.

Hazards of Mitral Valve Replacement for Mitral Stenosis Caused by Massive Mitral Annular Calcium With or Without Aortic Valve Replacement for Aortic Stenosis

Mitral annular calcium (MAC) is common in older adults in the Western World and if extensive may cause mitral stenosis . The purpose of this report is to describe outcomes of 12 patients having mitral valve replacement for mitral stenosis secondary to massive MAC. Operatively excised deposits of calcium removed from the mitral annular area and the accompanying stenotic mitral valves were examined and then the patients' medical records were examined to confirm the diagnosis and the degree of valvular dysfunction. A total of 12 patients with massive MAC causing mitral stenosis and receiving mitral valve replacement with or without aortic valve replacement for aortic stenosis were observed in 2013 to 2015. Of the 12 patients, 7 died from 5 to 44 days (mean 19) after the valve operation and all had "stormy" postoperative courses; one survived 150 days and another, 600 days; the remaining 3 were improved by the operation and are alive 22, 27, and 59 months postoperatively. In conclusion, the high mortality in these patients suggests that mitral valve replacement in the setting of massive MAC be considered with caution.

Predictors of atherosclerotic events in patients on haemodialysis: post hoc analyses from the AURORA study

Background

Patients on haemodialysis (HD) are at high risk for cardiovascular events, but heart failure and sudden death are more common than atherosclerotic events. The A Study to Evaluate the Use of Rosuvastatinin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events (AURORA) trial was designed to assess the effect of rosuvastatin on myocardial infarction and death from any cardiac cause in 2773 HD patients. We studied predictors of the atherosclerotic cardiovascular events in AURORA.

Methods

We readjudicated all deaths and presumed myocardial infarctions according to the criteria used in the Study of Heart and Renal Protection (SHARP); these were specifically developed to separate atherosclerotic from non-atherosclerotic cardiovascular events. The readjudicated atherosclerotic end point included the first event of the following: non-fatal myocardial infarction, fatal coronary heart disease, non-fatal and fatal non-haemorrhagic stroke, coronary revascularization procedures and death from ischaemic limb disease. Stepwise Cox regression analysis was used to identify the predictors of such events.

Results

During a mean follow-up of 3.2 years, 506 patients experienced the new composite atherosclerotic outcome. Age, male sex, prevalent diabetes, prior cardiovascular disease, weekly dialysis duration, baseline albumin [hazard ratio (HR) 0.96; 95% confidence interval (CI) 0.94-0.99 per g/L increase], high-sensitivity C-reactive protein (HR 1.13; 95% CI 1.04-1.22 per mg/L increase) and oxidized low-density lipoprotein (LDL) cholesterol (HR 1.09; 95% CI 1.03-1.17 per 10 U/L increase) were selected as significant predictors in the model. Neither LDL cholesterol nor allocation to placebo/rosuvastatin therapy predicted the outcome.

Conclusions

Even with the use of strict criteria for end point definition, non-traditional risk factors, but not lipid disturbances, predicted atherosclerotic events in HD patients.

Trends and outcomes of infective endocarditis in patients on dialysis

Dialysis patients are at high risk for infective endocarditis (IE); however, no large contemporary data exist on this issue. We examined outcomes of 44 816 patients with IE on dialysis and 202 547 patients with IE not on dialysis from the Nationwide Inpatient Sample database from 2006 thorough 2011. Dialysis patients were younger (59 ± 15 years vs 62 ± 18 years) and more likely to be female (47% vs 40%) and African-American (47% vs 40%; all P < 0.001). Hospitalizations for IE in the dialysis group increased from 175 to 222 per 10 000 patients (P _trend  = 0.04). Staphylococcus aureus was the most common microorganism isolated in both dialysis (61%) and nondialysis (45%) groups. IE due to S aureus (adjusted odds ratio [aOR]: 1.79, 95% confidence interval [CI]: 1.73-1.84), non-aureus staphylococcus (aOR: 1.72, 95% CI: 1.64-1.80), and fungi (aOR: 1.4, 95% CI: 1.12-1.78) were more likely in the dialysis group, whereas infection due to gram-negative bacteria (aOR: 0.85, 95% CI: 0.81-0.89), streptococci (aOR: 0.38, 95% CI: 0.36-0.39), and enterococci (aOR: 0.78, 95% CI: 0.74-0.82) were less likely (all P < 0.001). Dialysis patients had higher in-hospital mortality (aOR: 2.13, 95% CI: 2.04-2.21), lower likelihood of valve-replacement surgery (aOR: 0.82, 95% CI: 0.76-0.86), and higher incidence of stroke (aOR: 1.08, 95% CI: 1.03-1.12; all P < 0.001). We demonstrate rising incidence of IE-related hospitalizations in dialysis patients, highlight significant differences in baseline comorbidities and microbiology of IE compared with the general population, and validate the association of long-term dialysis with worse in-hospital outcomes.

Infective endocarditis superimposed on a massively calcified severely stenotic congenitally bicuspid aortic valve

We describe a 55-year-old man who presented with a stroke resulting from active infective endocarditis (IE) involving a heavily calcified bicuspid aortic valve. The case highlights the infrequency of IE involving a heavily calcified valve, the inability of the infection to penetrate the calcific deposits, and the ability of the infection to spread to the adjacent soft tissues, leading to ring abscess and its multiple complications.