Objectives: The purpose of this study was to determine the role of adenosine stress cardiac magnetic resonance (CMR) for risk stratification in patients with coronary artery stenoses of intermediate angiographic severity.
Background: Coronary angiography only provides a morphological description of coronary lesions. As the patient's prognosis is closely related to the functional significance of angiographically detected coronary lesions, a functional assessment is desirable in patients with coronary artery stenoses of intermediate severity.
Methods: Myocardial perfusion measurements at rest and adenosine stress were performed on 81 patients (75.6% male, mean age 64.2 years) with stable angina pectoris (AP) and coronary artery stenoses of intermediate angiographic severity (50% to 75%). Regardless of the CMR result, all patients were treated conservatively with an intensified medical treatment, and a follow-up was performed after 18 +/- 8 months and 30 +/- 8 months. The primary end point was defined as a major adverse cardiac event (MACE): all-cause death, stroke, acute coronary syndrome; the secondary end point was defined as target vessel revascularization. Furthermore, AP and dyspnea were evaluated.
Results: After the follow-up period of 30 +/- 8 months, 9 patients with perfusion deficit (PD) suffered from MACE, whereas no MACE occurred among the 36 patients without PD (p = 0.014). Among patients who had MACE, the number of ischemic segments (2.3 +/- 1.6 vs. 1.4 +/- 1.6, p = 0.0025) was significantly higher, whereas the number of delayed enhancement segments did not differ (1.4 +/- 1.6 vs. 1.6 +/- 2.3, p = 0.4). Target vessel revascularization was required in 38% of patients with PD and 6% of patients without PD (p = 0.005). In addition, the percentage of freedom from AP and dyspnea at the follow-up after 18 +/- 8 months was significantly lower among patients without perfusion deficit (69.4% vs. 15.6%; p = 0.0001). After a follow-up period of 30 +/- 8 months, the rate of AP (11.1% vs. 8.3%, p = 0.33) as well as the percentage of patients free of symptoms was similar in both groups (77.8% vs. 88.9%, p = 0.82).
Conclusions: Adenosine stress CMR may help to identify patients at risk who benefit from intensified medical treatment and close follow-up.