The utility of a 'non-significant' coronary angiogram

Coronary angiography is the gold standard for assessing coronary artery disease (CAD). In many patients with chest pain, no or mild CAD (< 50% stenosis) is found. It is uncertain whether this 'non-significant' result influences management and outcomes. We reviewed characteristics and outcomes in a contemporary cohort of chest pain referrals who had mild or absent CAD on coronary angiography.

All patients undergoing coronary angiography at Auckland City Hospital during July 2010-October 2011 were reviewed (n = 2983). Of these, 12.3% (n = 366) underwent coronary angiography for evaluation of chest pain and were found to have absent or mild CAD. These patients were followed up for 2.3 ± 0.6 years.

Mean age was 60.0 ± 12.3 years, 56.1% were female. The ECG was abnormal in 55.0% of patients. Stress testing for inducible ischaemia was undertaken in 40.7% of patients and was abnormal in 57.7%. Following angiography, 43.2% had no changes to cardiac medications. Additional drug therapy (aspirin, statin, beta-blockers, ACE-inhibitor) was commenced in around 14.2-22.1% of cases. These drugs were discontinued in 4.1-8.2% of patients. Rates of major adverse cardiovascular events and readmissions with chest pain were 0.3% (1) and 1.9% (7) respectively at 30 days, and 1.9% (7) and 6.0% (22) at 1 year.

Although even non-obstructive atheroma may justify medical therapy to limit disease progression, our findings may suggest that in these cases, invasive coronary angiography, may not lead to the patient/physician reassurance justified by historical data.