Background: This study was designed to determine the diagnostic value of adenosine cardiac magnetic resonance (CMR) in low to moderate total number cardiac risk factor (TLCRF) patients presenting with chest pain in outpatient clinic. We hypothesized that adenosine CMR has a high negative predictive value in development of CAD or future adverse cardiac events.
Methods: Adenosine stress CMR was performed on 315 pts who presented initially to outpatient clinics with chest pain. Ten patients confirmed to have previous myocardial infarction defined by delay CMR were excluded. Three patients were excluded due to suboptimal image quality. Patients were followed up during outpatient visits or contacted through telephone interview to determine the incidence of significant CAD defined as coronary artery stenosis >50% on angiography, new myocardial infarction (MI), or cardiovascular death.
Results: Totally 302 patients (M: F = 242:60; mean age= 58±12; mean baseline TLCRF= 2.5 ± 1) underwent rest and adenosine stress CMR. With a follow up period of 29 ± 6 months, there were 32 adverse event (30 patients underwent coronary percutaneous angioplasty due to unstable angina and 2 new MI) and 3 cardiovascular deaths. Adenosine perfusion abnormalities had 100% sensitivity and 89% specificity in detecting subsequent CAD and the most accurate component of the CMR examination in predicting events. Despite TLCRF and abnormal CMR can significantly predicting the prognostic outcome (p=0.04 Vs p=0.001 respectively), multivariate analysis showed that the abnormal CMR was the strongest predictor of the event rate (adjusted hazard ratio 1.45 per 10% increase, p=0.02). Three patients with normal adenosine study had a subsequent diagnosis of CAD and underwent successful angioplasty.
Conclusions: Among the low to moderate cardiac risk patients who presented with chest pain in outpatient clinics, adenosine CMR examination has a high sensitivity and specificity in predicting the future development of significant CAD. It implies the potential application of CMR in CAD screening in general population.
Prognosis of Negative Adenosine Stress Magnetic Resonance in Patients Presenting to an Emergency Department With Chest Pain
