Background: Approximately 50% of patients with angina pectoris undergoing coronary angiography have unobstructed coronary arteries. Coronary vasomotor abnormalities (coronary spasm, microvascular dysfunction) can be diagnosed using intracoronary acetylcholine testing in approx. 60% of such cases. Women are more prone to this scenario than men but the underlying causes are still not properly understood. Genetic polymorphisms for coronary vasomotor disorders have not yet been investigated/identified in European patients systematically. However, frequently a positive family history is found in these patients.
Purpose: The aim of this study was to assess whether a positive family history for cardiovascular disease is significantly more often found in patients with coronary vasomotor disorders.
Methods: Over a period of 3 years a total number of 415 consecutive patients (mean age 62±10 years, 62% female) with stable angina and unobstructed coronary arteries (no stenosis >50%) was recruited. All patients underwent intracoronary acetylcholine testing (ACh-test) according to a standardised protocol. The ACh-test revealed epicardial coronary spasm in 33% and coronary microvascular dysfunction in 30% of patients. In the remaining 37% no relevant coronary vasomotor disorder could be found. The following cardiovascular risk factors were systematically analysed: hypertension, hypercholesterolemia, diabetes mellitus, active cigarette smoking and a positive family history for cardiovascular disease. The latter was defined as a first degree relative with myocardial infarction or stroke.
Results: Women were more likely to have an abnormal ACh-test than men (72% vs. 49%, p<0.0005) and women with an abnormal ACh-test had significantly more often a microvascular than epicardial disorder (57% vs. 43%, p<0.0005). In contrast, male patients with abnormal ACh-test had more often an epicardial than a microvascular disorder (74% vs. 26%, p<0.0005). A positive family history was found in 55% of all patients with a significant preponderance among women compared to men (p=0.001, 61% vs. 45%). Moreover, among the patients with epicardial spasm, women had significantly more often a positive family history compared to men (p=0.006, 66% vs. 42%).
Conclusion: Patients with angina pectoris and unobstructed coronary arteries are often female and frequently suffer from a coronary vasomotor disorder diagnosed by acetylcholine testing. Epicardial coronary spasm in women is linked with a positive family history pointing towards a genetic background of this disease.