Ask the Doctors January 2011 Issue

Ask The Doctors: January 2011

I was diagnosed with coronary artery disease about a year ago and have since had one stent put in. I take my medications and try to live a healthy lifestyle with regular exercise and a good diet, but I frequently find myself worrying about my heart and my life expectancy. Any advice?

Your situation is not unusual for people who have been diagnosed with coronary artery disease (CAD). Although worrying about your heart is a normal response, shared by most of those afflicted, you should not let it take over your life. Remember that in countries such as the United States, CAD is a relatively common occurrence. Despite its seriousness, millions of people with CAD are productively coping with the physical and emotional stresses of CAD.

Another reassuring fact is that we have effective treatments for CAD, which is not the case for all medical problems. In multiple large clinical trials, these therapies have been shown to cut the risk of heart attack and prolong life.

As you mention in your letter, you are already doing the right things to reduce your risk of CAD progression and its adverse outcomes. Having frequent followup with your cardiologist, taking your medications as instructed, and being proactive on your own behalf are all very important aspects of lowering your chances of experiencing a heart attack.

I’d like to stress the last part, which you touch upon briefly in your note. Eating a heart-healthy diet (as described in the "Getting Healthy" section of the American Heart Association’s website, http://www.heart.org/HEARTORG/), engaging in regular aerobic exercise, quitting smoking, and losing weight are all practical, feasible goals, which cut your risk of cardiac events beyond the effects of medication alone.

Like many others with the same problem, you are already taking very positive measures to treat your CAD.

I’ve heard that heart disease and kidney disease are related, but how exactly? Is it that kidney problems can cause heart problems in a person with a relatively healthy heart, or is it that heart disease can lead to kidney disease in someone with healthy kidneys?

What you have heard is true, and the relationships between heart and kidney disease are complex. People with chronic kidney disease (CKD), including but not limited to those on hemodialysis, are at increased risk for developing atherosclerosis in multiple vascular territories supplying the heart, brain, extremities, and other areas. The mechanism for increased atherosclerosis may be related to higher levels of oxidation and free radicals in the bloodstream of patients with CKD, which can damage the walls of blood vessels. Individuals with CKD often suffer from other conditions that predispose to heart disease, especially diabetes and hypertension.

On the flipside of the coin, heart disease can increase the risk of kidney disease (both acute and chronic) in several ways. If a patient has heart failure–a situation where the cardiac pump does not circulate blood effectively–the kidneys tend not to filter the blood as well. This type of "cardiorenal syndrome" can lead to both short and long-term dysfunction of the kidneys. Another result of heart failure is that the kidneys interpret the lower blood pressure as a signal that the body needs to hold on to sodium and water. This leads to volume overload, manifested by swelling of the legs and shortness of breath due to fluid accumulation in the lungs ("congestive heart failure"). Several of our useful heart failure drugs, such as diuretics and ACE-inhibitors, can sometimes lead to dehydration, hypotension, and acute kidney failure. Patients who diligently record their own daily weights and blood pressures, and who receive close monitoring by a physician, are much less likely to experience these effects.