Eye Exams Can Predict Heart Failure Risk

Summarized by Robert W. Griffith, MD
November 6, 2006

Summary

Retinal examinations can disclose changes that are associated with an increased risk of the development of congestive heart failure.

Introduction

Examination of the retina - the inner layer of tissue at the back of the eye - can tell an ophthalmologist a lot about your general health. For instance, early cases of diabetes or high blood pressure can be picked up by the eye doctor before the patient is aware of the problem. The risk for another condition can be added to this list: congestive heart failure (CHF). It's long been thought that microvascular disease involving the finer blood vessels, including the capillaries, of the coronary artery circulation is involved in the causation of CHF. The retinal circulation offers a non-invasive way of examining microvascular disease in the body. This led researchers to look for a possible link between changes in the retina and the risk for developing CHF. They published their findings in the Journal of the American Medical Association, and we summarize the main points here.

What was done

Over 15,750 people aged 45 to 64 were enrolled into a study called The Atherosclerosis Risk in Communities, which was conducted in four states in the USA: North Carolina, Mississippi, Minnesota, and Maryland. The participants attended for three extensive physical examinations, three years apart. At the third exam, retinal photographs were taken of over 11,500 of the subjects.

Trained graders used a standard protocol to evaluate the photographs for microvascular changes. Four categories were defined: retinopathy, arteriovenous nicking, focal arteriolar narrowing, and generalized arteriolar narrowing.¹

Participants were contacted by phone annually in order to identify all hospitalizations during the previous year. Medical records, including death certificates, were used to identify all cases of congestive heart failure.

What was found

Among the 11,612 participants there were 719 with retinopathy at baseline, and 492 who developed CHF during the 6-year follow-up period; 20 of the CHF cases had died.

The incidence of CHF was approximately three times higher in persons with retinal microvascular changes than in those without - 15.1% vs. 4.8%. This was after adjusting for the influence of age, gender, and race. When further adjustments were made for possible effects of existing coronary artery disease, raised blood pressure over 6 years, diabetes, cholesterol, smoking, and body mass index (BMI), the risk was decreased from about 3 times to approximately twice the risk of people without such retinal changes.

What the findings mean

This study shows that retinal examination can reveal microvascular changes that are associated with an increased risk of the development of CHF. The increased likelihood (three times) remains significant although slightly reduced (to two times) after correcting for the existence of coronary artery disease and/or high blood pressure. This shows that microvascular disease clearly has an independent role in the causation of CHF.

It's important to recognize that people without known cardiovascular disease may be at risk for developing CHF, so that people found to have retinal microvascular changes by their ophthalmologist should be referred promptly to a cardiologist, if they don't already have one. This should allow necessary lifestyle improvements to be made to reduce the risk considerably.

Source

• Retinopathy and risk of congestive heart failure. TY. Wong , W. Rosamond, PP. Chang,  et al., JAMA, 2006, vol. 293, pp. 63--69

Footnotes
1. In retinopathy, there can be bleeding, swelling of the tissue, microaneurisms (ballooning of the artery), and leakage of material from the blood vessel called exudates. "Arteriovenous nicking" means an artery crossing a vein compresses or "nicks" the vein. Focal or generalized arteriolar narrowing is self-explanatory; an arteriole is just a small artery.

Related Links
InteliHealth: Retinopathy
How Congestive Heart Failure Works
MedlinePus: Heart Failure

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