In developed countries, most CKD patients die of cardiovascular causes
Because renal replacement therapies have limited access in countries of low and middle income, most patients worldwide with chronic kidney disease (CKD) will die from kidney failure without receiving dialysis or transplantation. In developed countries, many more people will die from cardiovascular disease rather than progress to kidney failure requiring renal replacement, based on a global report published April 8 in the Lancet.

However, early recognition and prevention of CKD is “vital” in all settings, according to Marcello Tonelli, MD, from the division of nephrology at the University of Alberta in Edmonton, Alberta, and colleagues.

The aging of populations along with the growing global prevalence of diabetes and other chronic non-communicable diseases has led to corresponding worldwide increases in prevalence of CKD and kidney failure. When defined by a glomerular filtration rate (GFR) of 60 or less in standard GFR units (mL min–¹ 1.73 m), approximate CKD prevalence across Europe, Asia, North America and Australia is 2 to 11 percent of the population. Poorer countries have the same causes as high-income nations but with the added burden of extra CKD cases due to bacterial and viral infections and heavy metal poisoning (Asia, Africa and Middle East).

According to the authors, cardiovascular disease is the leading cause of mortality in CKD, and even mild reductions in GFR are associated with excess cardiovascular risk. At any given level of kidney function, raised amounts of proteinuria are associated with increased cardiovascular morbidity and mortality. In patients with cardiovascular disease, diabetes or hypertension, the presence of CKD (especially with proteinuria) is a risk multiplier that identifies the subset of individuals who are most likely to have adverse outcomes.

The authors said that the early identification of patients with CKD is “desirable” because interventions can then be implemented to reduce risk of cardiovascular events or progression to kidney failure. They advised that high prevalence of CKD, absence of symptoms until disease is advanced, accessibility of laboratory tests for diagnosis and prognostication and the availability of treatments that prevent complications suggest that screening for CKD could be worthwhile.

However, Tonelli and colleagues also noted that the role of population-based screening remains controversial. “Screening for proteinuria is appealing because it is easy to undertake, predicts cardiovascular morbidity and mortality and might be a better predictor of future decline in GFR than a reduction in estimated GFR,” they wrote.

The researchers advocate for CKD diagnostic testing for CKD for several patient groups who seek medical attention for other reasons, especially those with diabetes, hypertension, cardiovascular disease, structural renal-tract disease, autoimmune diseases with potential for kidney involvement, and a family history of CKD or hereditary kidney disease.

Irrespective of underlying cause, the authors said that the typical goals of management for all patients with CKD include prevention of cardiovascular events and reduction of the rate of progression of the disorder (thereby delaying or preventing kidney failure and other complications). Reduction of high blood pressure using an ACE inhibitor is a treatment frequently given to patients with non-diabetic or diabetic CKD. Statins and aspirin could also be of benefit, but their role is “less clearly defined,” they wrote.

Adherence to treatment for CKD can be poor, according to the researchers. In the U.K., only one-fifth of patients with diabetes and CKD had a blood pressure of 130/80 mm Hg or less, and fewer than half were receiving an ACE inhibitor or angiotensin-receptor blocker.

"Furthermore, only 50 percent of those with stage three chronic kidney disease were prescribed an antiplatelet agent or a lipid-lowering treatment, suggesting that the management of these patients in primary-care settings could be enhanced considerably," Tonelli and colleagues added.

Despite the availability of drugs to slow CKD progression, many patients do develop kidney failure—the authors called for more research into new drugs and treatments.

"Further research on the merits of novel methods for case-identification and care delivery in diverse settings is needed because of the high and growing global prevalence of chronic kidney disease,” they concluded. “In view of the severely restricted availability of dialysis in countries of low and middle incomes, such research is especially urgent outside the developed world. For all health systems (irrespective of resources), multi-intervention clinics and programs that enhance care of patients in primary practice settings are attractive alternatives to conventional models that merit further study."