Although heart and kidney are two different organs occupying different places in the body, they are interdependent on each other. Disease of one affects the other.
Having both heart and kidney disease can cause 20 times the risk of death from heart problems than either problem alone. A modest decline in kidney function can increase the death rate from heart disease by more than 50%.
Most patients with chronic kidney disease succumb to heart and vascular problems like heart attacks, heart failure and brain strokes rather than to kidney problem.
Involvement of heart and blood vessels happens very early in the course of kidney disease—so even just a small decline in kidney function should trigger efforts to help protect your heart.
Passage of albumin (protein) in the urine even in microscopic amounts is the earliest sign of kidney problem and is a more serious risk factor than very high levels of blood cholesterol as a cause of heart attacks and strokes.
Healthy kidneys contribute significantly for the control of blood pressure. A fall in blood pressure stimulates kidneys to trigger a process of releasing an enzyme renin, which signals the body to make the hormone angiotensin which produces constriction of blood vessels and increases the blood pressure. An over-activation of renin angiotensin system leads to both impairment to kidney and heart functioning.
High blood pressure (hypertension) is a very common problem in adults and its presence affects the kidneys by damaging its tiny blood vessels leading to leakage of protein in the urine. The damage is reflected by elevation of serum creatinine levels.
This is best measured as glomerular filtrations rate (GFR). Its calculation is simple using an equation or an application, using creatine level, age and sex. Normal GFR is more than 90ml/min. A GFR less than 60 ml/min means significant impairment and the lower it is the worse is the kidney function. Levels below 30 ml/min are very alarming and those below 15ml/min chronically, need dialysis or are candidates for kidney transplantation.
Diabetes mellitus which again is a very common problem in the community with around 11% adults suffering form it. Diabetes affects both the kidneys and the heart both directly because of injurious effects of high sugar levels and also by cholesterol deposition in blood vessels of the heart kidneys and the brain.
A combination of diabetes and hypertension (Deadly duo) is a serious combination leading to a very high occurrence of heart attacks, kidney involvement and strokes. A serious view and aggressive management of both is very important.
How to protect kidneys in vulnerable patients with declining GFR?
By aggressively controlling blood pressure to levels below 130/80 mms Hg. Diabetics need an effective sugar control and liberally using kidney protective sugar reducing agents like: SGLT2 inhibitors (Dapagliflozin or empagliflozin). Keeping blood cholesterol very low by using statins in adequate doses and finally Avoiding pain killers other than paracetamol.
Heart failure and Kidney involvement:
Heart failure and involvement of kidney go hand in hand. A failing heart or a failing kidney involves each other. It is called the Cardio – Renal syndrome. Early recognition of both these problems and starting evidence-based treatment is the key.
Fortunately, we have today 4 pillars in the management of heart failure with poorly functioning heart (Low Left ventricular ejection fraction). These pillars are 1. Drug group called ACE inhibitors or ARNI (enalapril, losartan or sacubitril valsartan combination) , 2. Beta blockers (metoprolol , bisoprolol etc.), 3. SGLT2 inhibitors (dapagliflozin, empagliflozin),4.aldosterone antagonists (spironolactone and eplerenone).
All patients of heart failure should be on these agents unless there is a valid reason not to administer. An additional drug called Vericiguat has recently been introduced.
Likewise patients with declining GFR should be on SGLT2 inhibitors, strict BP and blood sugar control. Coexistence of anemia is very common and should be treated with iron therapy if iron deficiency is proven. Drugs like erythropoietin and darbepoetin are important adjuncts in case of bone marrow depression which is a frequent accompaniment.
Improvement of heart failure and vice versa leads to better functioning of the other organ and often reversal of the problem. It again indicates the inter dependence of kidney and heart in our body.
Take home Message:
Heart and kidney are dependent on each other. High blood pressure, diabetes and high cholesterol need to be taken seriously.
A meticulous management with early recognition of these maladies is important. Passage of albumin or protein in urine is the earliest sign of kidney involvement and can be detected by simple urine testing.
There are important drugs to minimize damage to kidneys and heart once the earliest signs of heart or kidney failure have been recognized. A healthy life style is the best way of protection.
Prof Upendra Kaul, Founder Director Gauri Kaul foundation, Recipient of Padma Shri and Dr B C Roy Award
DISCLAIMER: The views and opinions expressed in this article are the personal opinions of the author.
The facts, analysis, assumptions and perspective appearing in the article do not reflect the views of GK.