Diagnosis of microvascular disease a priority

New programs are looking for ways to diagnose and treat the condition that is four times more common in women than in men.

Women can receive a two-step diagnostic test for microvascular disease as part of the new Women’s Heart Program at Cedars-Sinai Medical Center.

“Only in recent years have physicians become aware of microvascular disease, a dysfunction of the heart’s small arteries, as a significant problem for women. Now the challenge is to integrate into medical practice systematic ways to diagnose and treat the condition,” said C. Noel Bairey Merz, MD, director of the Women’s Heart Program and Preventive and Rehabilitative Cardiac Center at Cedars-Sinai Medical Center.

Merz, an editorial board member of Cardiology Today’s Preventive Cardiology section, said that the Mayo Clinic in Rochester and other sites that participated in the Women’s Ischemia Syndrome Evaluation (WISE) study have instituted similar programs.

Microvascular disease affects four times as many women as men, but most evaluation methods test for dysfunction in the large arteries.

Clinicians at Cedars-Sinai and elsewhere use a pharmacological stress test that combines an assessment of acetylcholine endothelial function and adenosine coronary flow reserve. During the two-step test, adenosine is injected into one of the coronary arteries, and the amount of blood flow is measured. Acetylcholine is then injected, followed by another measurement of blood flow. If either test shows decreased blood flow to the myocardium, a diagnosis of microvascular disease can be made.

Treatment options

A recent report from the WISE study concluded that women are much more likely to have persistent signs and symptoms of ischemic heart disease in the setting of nonobstructive coronary disease than men.

In a recent clinical review in the Journal of the American Medical Association, researchers estimated the rate at 10% in women compared with 6% in men. “The prognosis of patients with unstable angina and nonobstructive atherosclerotic coronary artery disease is not benign and includes a 2% risk of myocardial infarction at 30 days of follow-up,” they said.

Randomized placebo-controlled trials have demonstrated that tricyclic antidepressants, beta-blockers, ACE inhibitors, statins and exercise may relieve symptoms of microvascular disease. However, longer-term studies evaluating cardiac event rates should be conducted, they said.

Accurately diagnosing microvascular disease is the first step, Merz said. Continued research is needed to identify the best course of treatment.

“Currently, we have several small studies that indicate the efficacy of different treatments but we don’t have any good, large randomized trials yet to look at how treating this condition may lead to reductions in heart attack, stroke and heart failure,” Merz said. “We need to explore this further, so we can develop therapies that are specific to this type of disease.” – by Jeremy Moore

For more information:

• Merz CNB, Shaw L, Reis SE, et al. Insights from the NHLBI-sponsored Women’s Ischemia Syndrome Evaluation (WISE) study: Part II: gender differences in presentation, diagnosis, and outcome with regard to gender-based pathophysiology of atherosclerosis and macrovascular and microvascular coronary disease. J Am Coll Cardiol. 2006;47:21S-29S.
• Bugiardini R, Merz CNB. Angina with “normal” coronary arteries: a changing philosophy. JAMA.2005;293:477-484.