Lack of correlation between noninvasive stress tests and invasive coronary vasomotor dysfunction in patients with nonobstructive coronary artery disease

Abstract

Background: Despite a nonobstructive coronary angiogram, many patients may still have an abnormal coronary vasomotor response to provocation and to myocardial demand during stress. The ability of noninvasive stress tests to predict coronary vasomotor dysfunction in patients with nonobstructive coronary artery disease is unknown.

Methods and results: All patients with nonobstructive coronary artery disease who had invasive coronary vasomotor assessment and a noninvasive stress test (exercise ECG, stress echocardiography, or stress nuclear imaging) within 6 months of the cardiac catheterization with provocation at our institution were identified (n=376). Coronary vasomotor dysfunction was defined as a percentage increase in coronary blood flow of <or=50% to intracoronary acetylcholine (endothelium-dependent dysfunction) and/or a coronary flow reserve ratio of <or=2.5 to intracoronary adenosine (endothelium-independent dysfunction). We determined the sensitivity and specificity of various noninvasive stress tests to predict coronary vasomotor dysfunction in these patients. On invasive testing, 233 patients (63%) had coronary vasomotor dysfunction, of which 187 patients (51%) had endothelium-dependent dysfunction, 109 patients (29%) had endothelium-independent dysfunction, and 63 patients (17%) had both. On noninvasive stress testing, 157 (42%) had a positive imaging study and 56 (15%) a positive ECG stress test. The noninvasive stress tests had limited diagnostic accuracy for predicting coronary vasomotor dysfunction (41% sensitivity [95% CI, 34 to 47] and 57% specificity [95% CI, 49 to 66]), endothelium-dependent dysfunction (41% sensitivity [95% CI, 34 to 49] and 58% specificity [95% CI, 50 to 65]), or endothelium-independent dysfunction (46% sensitivity [95% CI, 37 to 56] and 61% specificity [95% CI, 54 to 67]). The exercise ECG test was more specific but less sensitive than the imaging tests.

Conclusions: This study suggests that a negative noninvasive stress test does not rule out coronary vasomotor dysfunction in symptomatic patients with nonobstructive coronary artery disease. This underscores the need for invasive assessment or novel more sensitive noninvasive imaging for these patients.

Conflict of interest statement

Disclosures: No conflicts of interest.

Figures

Fig. 1. Study Cohort Profile

CVD = Coronary Vasomotor Dysfunction, CFR = Coronary Flow Reserve, CBF = Coronary Blood Flow. Exercise SPECT = Exercise Sestamibi (n=114) + Exercise Thallium (n=20); Vasodilator SPECT = Adenosine Sestamibi (n=55) + Adenosine Thallium (n=9) + Dipyridamole Thallium (n=2); Vasodilator PET = Adenosine PET (n=32) + Dipyridamole PET (n=1); Others = Exercise MUGA (n=10) + Dobutamine PET (n=4) + Dobutamine Sestamibi (n=2) + Exercise ECG only (n=2) + Dobutamine Thallium (n=1).

Fig. 2. Mean Percentage Change in CBF and Mean CFR Ratio in all Patients with Positive Imaging compared to all Patients with Negative Imaging Stress Tests

No significant difference (p=0.30 for mean percentage change CBF and p=0.45 for mean CFR ratio) by T-test.