Little is known about cardiac adverse events among patients with nonobstructive coronary artery disease (CAD).
Among 37 674 patients, 8384 patients (22.3%) had nonobstructive CAD and 20 899 patients (55.4%) had obstructive CAD. Within 1 year, 845 patients died and 385 were rehospitalized for MI.
Among patients with no apparent CAD, the 1-year MI rate was 0.11% (n = 8, 95% CI, 0.10%-0.20%) and increased progressively by number of vessels involved.
1-vessel nonobstructive CAD had a hazard ratio for 1-year MI of 2.0
2-vessel nonobstructive HR, 4.6
3-vessel nonobstructive HR, 4.5
1-vessel obstructive HR, 9.0
2-vessel obstructive HR, 16.5
3-vessel or LM obstructive HR, 19.5
One-year mortality rates were associated with increasing CAD extent, ranging from 1.38% among patients without apparent CAD to 4.30% with 3-vessel or LM obstructive CAD.
Conclusions and Relevance In this cohort of patients undergoing elective coronary angiography, nonobstructive CAD, compared with no apparent CAD, was associated with a significantly greater 1-year risk of MI and all-cause mortality. These findings suggest clinical importance of nonobstructive CAD and warrant further investigation of interventions to improve outcomes among these patients.