Higher Risk of Kidney Damage After Heart Surgery Not Restricted to Women

Acute kidney injury is the decline in kidney function which can arise following major cardiac surgery because the kidneys are deprived of normal blood flow.

Highlights:

Patients who undergo cardiac or heart surgery experience postoperative renal function deterioration mainly associated with acute renal injury.
Commonly held notion that women are at greater risk for acute kidney injury after cardiovascular surgery is now disputed.
Though previous studies have mentioned that women are at more risk of acute renal failure, the association is not linked with parameters which indicate kidney function deterioration.

Cardiac or heart surgery is one of the treatment options for heart disease such as coronary artery blockage or valve replacement. However this surgery can have side effects including acute kidney injury (AKI) or renal damage. Studies have shown that postoperative kidney function deterioration in cardiac surgery patients increases in-hospital mortality and can adversely affects long-term survival.

Studies have previously shown that women are more likely than men to develop kidney damage following cardiac surgery. Interestingly it was also believed that women are less likely to develop AKI associated with non-cardiac surgical procedures than men.

Acute Renal (Kidney) Failure- Causes, Symptoms, Diagnosis, Treatment and Complications
Acute renal failure is the sudden cessation of the functioning of kidneys, that can be due to reduced renal blood flow, damage to renal tissues.

‘Acute kidney injury is the decline in kidney function which can arise following major cardiac surgery because the kidneys are deprived of normal blood flow.’

The current study examined in greater detail the evidence as to why being a woman might be protective for ischemic AKI after general surgery but deleterious in patients undergoing heart surgery.

What is Acute Kidney Injury (AKI)?

AKI, an abrupt decline in kidney function can arise following any major surgery, often because the kidneys are deprived of normal blood flow during the procedure. It is characterized by a deterioration of kidney function over a period of hours or days following surgery, with symptoms including reduced urine output (less than 400ml/day) or oliguria. Decrease urine output usually results in volume overload, elevated levels of serum blood urea nitrogen and creatinine, and the development of serious electrolyte and acid-base disorders.

Chronic Renal Failure - Symptoms, Diagnosis, Complications, Treatment, Prevention
Chronic renal failure or chronic kidney disease is progressive loss in kidney function. The change is irreversible and is due to loss of nephrons of the kidney.

Current Evidence that Contradicts the Popular Belief that being a Woman is a Risk factor for the development of Acute Kidney Injury after Cardiac Surgery

Joel Neugarten, MD, Albert Einstein College of Medicine and his colleagues performed a systematic review and meta-analysis of relevant studies published between January 1978 and December 2015 to find out if women are at a higher risk after cardiac surgery. The analysis included 64 studies with 1,057,412 participants.

Recent Advancements in Cardiac Surgery
Cardiac surgery is a formidable field in treating congenital heart diseases, valve replacements, atrial fibrillation, and coronary heart disease.

The understanding of the pathophysiology of AKI is both clinically and experimentally complicated as AKI develops under different clinical scenarios. Few vital risk factors to consider are –

Age,
Gender,
Race,
Pre-existing chronic kidney disease,
Type and duration of cardiac surgery.

The link between the risk was true as far as gender-specific data was considered but was not seen in studies in which certain stringent classification methods called Risk, Injury, Failure, Loss, End-Stage (RIFLE) and Acute Kidney Injury Network (AKIN) criteria were used to define and AKI based on serum creatinine and urine output. When the investigators focused solely on studies that took patient characteristics and other factors into account there was also no association between sex and AKI risk.

“We have disputed the commonly held notion that women are at greater risk for acute kidney injury after cardiovascular surgery,” said Dr. Neugarten.

Aggressive early intervention by identifying individuals at risk for developing AKI is important to optimize outcomes.

References:

Acute Kidney Injury after Cardiovascular Surgery: An Overview - (http://cjasn.asnjournals.org/content/early/2016/10/19/CJN.03340316.abstract)
Sex and the Risk of AKI Following Cardio-thoracic Surgery: A Meta-Analysis - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3487575/)

Source-Medindia