Intravascular ultrasound study and evidence of pathological coronary flow reserve in patients with isolated coronary artery aneurysms.

OBJECTIVES

Isolated coronary artery aneurysms (CA) are defined as non-obstructive lesions with luminal dilation > or =2-fold of normal coronary diameters.

METHODS

A coronary sinus study with incremental atrial pacing was performed in 19 patients with bilateral fusiform CA to investigate myocardial ischemia. Intravascular ultrasound was performed to characterize the lesions morphology. The average peak velocity in the aneurysmatic segment of the left anterior descending artery was simultaneously measured by a Doppler flow wire. Coronary flow volumes, vascular resistances and flow reserve after administration of papaverin were calculated. Ten patients without heart disease served as a control group (CG).

RESULTS

Intravascular ultrasound revealed large true CA with a cross-sectional area of 34.2 +/- 4.1 mm(2) and only slight atherosclerosis. Exercise-induced myocardial ischemia was found in CA presenting with a cardiac lactate production and an only 1.6-fold increase in coronary blood flow. A significant smaller coronary flow reserve of 1.51 was revealed in CA when compared with CG (2.86, P < 0.02) corresponding to a coronary vascular resistance of 0.59 versus 0.35 (P < 0.03) mmHg (ml/min) after papaverin.

CONCLUSIONS

Coronary artery aneurysms were unequivocally identified as an entity of ischemic non-obstructive coronary artery disease with a markedly reduced flow reserve.