Abstract 3092: Long-term Prognostic Value of Vasodilator Stress Cardiac Magnetic Resonance Myocardial Perfusion Imaging in Patients with Suspicion for Obstructive Coronary Artery Disease
Background The clinical use of vasodilator stress CMR myocardial perfusion (CMRMP) is increasing for the assessment of patients with chest pain syndrome. While reports have demonstrated high sensitivity and specificity in detecting flow-limiting coronary stenosis in select clinical settings, the long-term prognostic impact of CMRMP in a typical outpatient clinical cohort remains limited.
Methods CMRMP was performed on patients referred for myocardial ischemic evaluation. Rest and vasodilator (adenosine or dipyridamole) stress first-pass CMRMP images were obtained and followed by late gadolinium enhancement sequences. All images were qualitatively interpreted for reversible perfusion defects (REVDEF) using the accepted 16-segment nomenclature and a summed difference score (SDS) was derived. The readers were blinded to any clinical outcome. The presence of REVDEF was considered as evidence for flow-limiting coronary stenosis. We used Cox proportional hazards regression to model the association and extent of REVDEF to MACE and all-cause mortality.
Results The study cohort consisted of 254 patients (149 males, mean age 56 years) with intermediate cardiovascular risk. REVDEF was demonstrated in 74 patients (29%). At a median follow up of 1 year, 18 fatal and 20 nonfatal events occurred. Event-free survival was significantly reduced in patients with REVDEF. Presence of REVDEF was associated with a significant increase in hazard to MACE (HR 8.5, CI 4.1–17.6, p<0.0001) and, on average, MACE hazards increased by 6% for every SDS gained (HR 1.06, CI 1.03–1.07, p<0.0001). When adjusted for age, left ventricular ejection fraction, abnormal resting ECG, number of coronary risk factors, and infarct size the presence of REVDEF maintained a strong association with MACE (adjusted HR 20.5, 95% CI: 8.0 –52.4, P<0.0001). Absence of REVDEF was associated with a favorable outcome at 12 months after CMRMP (OR=0.24, 95% CI: 0.11– 0.53, p=0.0002).
Conclusion The presence or extent of reversible perfusion defects on vasodilator stress CMR provides strong long-term prognostic value for MACE and mortality in patients suspected of significant coronary stenosis, incremental to both infarct size by CMR and clinical risk assessment.