Treatment of angina pectoris: associations with symptom severity

Objective: To evaluate whether the frequency of anginal attacks in medically treated patients with stable angina is related to the intensity of anti-anginal treatment, the clinical history and coronary anatomy. Methods: Analysis of baseline data from the A Coronary disease Trial Investigating Outcome with Nifedipine GITS (ACTION) study, an ongoing placebo-controlled trial in 7669 patients with stable angina pectoris who require anti-anginal treatment. Results: Prior to randomisation, 8% of 7669 patients had no anginal attacks, 63% had occasional, 22% had regular, 4% had frequent and 3% had daily attacks. Men (79% of all patients) and patients with a history of MI (51%) had less frequent anginal attacks (P<0.0001). The number of coronary angiograms ever performed (70% had at least one angiogram), the extent of angiographic coronary disease (32% of those who had angiography had more than two-vessel disease), a history of peripheral artery disease (12%), the number of anti-anginal drugs used (64% were prescribed two or more such medications) and a history of revascularisation (a history of coronary bypass surgery was present in 23% and of balloon dilatation in 26%) were each positively associated with anginal attack frequency. Conclusions: For the majority of patients with chronic stable angina not on a calcium-antagonist, medical treatment with other anti-anginal drugs is sufficient to control symptoms and only a minority of patients are refractory to medical treatment. Invasive treatments for chronic stable angina are only needed in a small proportion where symptoms persist.