In the Abnormal COronary VAsomotion in patients with stable angina and unobstructed coronary arteries study, we showed that 62% of patients with stable angina and unobstructed coronary arteries had coronary spasm. In this study, we sought to assess the 5-year prognosis in these patients.
Data regarding the following endpoints were obtained: death, non-fatal myocardial infarction, coronary event (=cardiac death or non-fatal myocardial infarction), persistent angina and repeated coronary angiography. Quality of life was assessed using the Seattle Angina Questionnaire.
Among patients with unobstructed coronary arteries there were three deaths (2.9%) and no non-fatal myocardial infarction. Among those with obstructive CAD 15 died (13.8%) and three had a non-fatal myocardial infarction (2.8%). Patients with obstructive CAD had a higher rate of all-cause death and coronary events compared to those without (P = 0.004). Persistent angina was more prevalent in patients with unobstructed coronaries (P = 0.042). Prognosis of patients with unobstructed coronaries regarding hard clinical events, persistent angina and repeated coronary angiography was independent of the presence of coronary spasm (all P > 0.05). However, spasm patients were more likely to take nitrate medication at follow-up (P = 0.029).
Patients with stable angina and unobstructed coronary arteries have a favorable prognosis regarding mortality and non-fatal myocardial infarction after 5 years compared to patients with obstructive CAD irrespective of the presence of coronary artery spasm. However, persistent angina remains a common issue in patients with unobstructed coronary arteries leading to a similar frequency of repeated invasive procedures as in patients with obstructive CAD.