Prognostic significance of myocardial ischaemia during exercise echocardiography in the absence of angiographic evidence of obstructive coronary disease.

Aims: We studied the prognostic significance of myocardial ischaemia during exercise stress echocardiography (ExE) in the absence of angiographic evidence of obstructive coronary artery disease (CAD) in a contemporary cohort of patients.

Methods and results: We retrospectively enrolled 84 patients who underwent ExE and had exercise-induced myocardial ischaemia followed by angiographic coronary evaluation. Fifty-one (61%) patients had non-obstructive CAD (iNOCAD), and 33 (39%) had normal coronaries (iNC). iNC and NOCAD patients were propensity matched to 99 and 153 patients with non-ischaemic ExE, respectively. Compared to iNOCAD, iNC patients were younger (60.9 ± 10.4 vs. 68 ± 8.9 years, P = 0.002) and predominantly women (76% vs. 47%, P = 0.009). Ejection fraction (57 ± 9.4 vs. 56.4 ± 6, P = 0.776) as well as other clinical and demographic variables were similar. During median follow-up of 3.2 years, there were 27 composite adverse cardiovascular events (1 death, 10 acute chest pain events, 2 strokes, and 21 cardiac hospitalizations). iNC was associated with a higher risk of acute chest pain (HR: 19.0, 95% CI: 3.7-93) and the composite adverse outcome (HR: 3.3, 95% CI: 1.7-6.6), compared to matched patients. Similarly, iNOCAD was associated with a higher risk of the composite outcome (HR: 2.2, 95% CI: 1.2-4.2).

Conclusion: Ischaemic ExE in the absence of angiographically obstructive CAD carries an elevated risk of adverse cardiovascular events necessitating medical optimization and close follow-up for progression.