Treating Microvascular Angina (Cardiac Syndrome X)

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Cardiac Syndrome X (CSX) is diagnosed when a person has angina, with evidence of cardiac ischemia on stress testing, but with normal-looking coronary arteries on cardiac catheterization. In most cases, CSX is caused by a disorder of the small branches of the coronary arteries in which these tiny vessels fail to dilate normally, thus producing a lack of blood flow to the heart muscle. Since the problem is localized to the small arteries, this condition is referred to as microvascular angina.

Microvascular angina is much more common in women (typically, postmenopausal women) than in men. There are several possible causes of the small artery dysfunction that occurs in microvascular angina, including insulin resistance, inflammation, increased adrenalin activity, estrogen deficiency, and dysautonomia. It is likely that different patients with microvascular angina may have different underlying causes.

While most people with microvascular angina have a favorable prognosis - in that the risk of acute coronary syndrome caused by microvascular angina is low - it is not uncommon for the chest pain produced by this condition to be a significant, and sometimes disabling, problem.

Treating Microvascular Angina

Whenever you see a long list of possible treatments for some medical condition, it’s a sign that treating that condition may be difficult.

(Likely, that’s why so many treatments have been tried in the first place.) Such is the case with microvascular angina.

Many medications have been found helpful in at least some patients with microvascular angina. However, in finding the “best” treatment for any given individual, a trial-and-error approach is often required.

This means that the both sufferer of microvascular angina and the doctor will need to be patient and persistent in order to find the optimal therapy.

Here is a list of treatments often used in treating microvascular angina:

Traditional Angina Drugs -

Non-traditional Angina Drugs -

  • Ranolazine - quite effective in small clinical trials
  • ACE inhibitors, especially in patients with hypertension
  • Ivabradine - also effective in clinical trials, but not yet available in the US
  • Statins, especially in patients with high cholesterol levels
  • Estrogens, in post-menopausal women
  • Nicorandil - another angina drug not available in the US
  • Imipramine - not an angina drug, but can be effective with pain control

Non-Drug Therapy -

  • EECP - shown in one small study to be effective for microvascular angina
  • Spinal cord stimulation - shown to be helpful in some patients in whom drug treatment has failed.
  • Exercise training has been quite helpful, especially in patients who are deconditioned.

A General Approach to the Treatment of Microvascular Angina

Given all these possibilities, most cardiologists will attempt to optimize the treatment of microvascular angina using a step-wise approach. If adequate control of symptoms is not obtained with any given step, the doctor and patient will move on to the next step.

  • Step 1 is usually to use either a beta blocker or a calcium channel blocker.
  • Step 2 is usually to treat with a combination of a beta blocker and a calcium channel blocker.
  • Step 3 is usually to try ranolazine, either alone or with the beta blocker and calcium blocker.
  • Step 4 is to consider non-drug therapy, with spinal cord stimulation or EECP.

In addition to taking steps like these, an ACE inhibitor also should be strongly considered if hypertension is present, and a statin should be strongly considered if risk factors for typical coronary artery disease are also present. In women who are recently menopausal, estrogen therapy might be worth considering as well. Exercise training ought to be recommended in most patients with microvascular angina. Sublingual nitroglycerin can be used to treat acute episodes of angina while more effective preventive therapy is being sought.

With patience - often a good deal of patience - adequate control of symptoms eventually can be achieved in the large majority of people who have microvascular angina.

Sources:

Kaski JC. Pathophysiology and management of patients with chest pain and normal coronary arteriograms (cardiac syndrome X). Circulation 2004; 109:568.

Mehta PK, Goykhman P, Thomson LE, et al. Ranolazine improves angina in women with evidence of myocardial ischemia but no obstructive coronary artery disease. JACC Cardiovasc Imaging 2011; 4:514.

Eriksson BE, Tyni-Lennè R, Svedenhag J, et al. Physical training in Syndrome X: physical training counteracts deconditioning and pain in Syndrome X. J Am Coll Cardiol 2000; 36:1619.

Lanza GA, Sestito A, Sgueglia GA, et al. Effect of spinal cord stimulation on spontaneous and stress-induced angina and ‘ischemia-like’ ST-segment depression in patients with cardiac syndrome X. Eur Heart J 2005; 26:983.

Kayikcioglu M, Payzin S, Yavuzgil O, et al. Benefits of statin treatment in cardiac syndrome-X1. Eur Heart J 2003; 24:1999.

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