Introduction:
Patients with equivocal nuclear stress test (SPECT) results are at higher risk for cardiac events compared to those with normal studies. Cardiovascular magnetic resonance stress perfusion imaging (SCMR) identifies individuals with coronary artery disease (CAD) with high sensitivity and specificity, with excellent spatial resolution, and without ionizing radiation. The utility of SCMR testing is uncertain in individuals with prior equivocal stress results.
Hypothesis:
SCMR provides high prognostic capability to risk stratify patients after equivocal or uncertain SPECT studies.
Methods:
We retrospectively analyzed patients from 2011 to 2019 with equivocal or uncertain SPECT studies subsequently referred for SCMR within a 6 month window. Equivocal studies included qualifying wording such as significant artifact or technical difficulty. Uncertain studies included documented suspicion of false positive or false negative results. Adverse outcomes were defined as cardiovascular death or obstructive CAD found on unplanned coronary angiography (CA).
Results:
151 patients met inclusion criteria: mean age 58, male 88 (58%). At one year, the negative predictive value of SCMR was 0.97; 122 patients with negative SCMR had a total of 4 events including 1 cardiovascular death and 3 obstructive CAD on CA. 27 patients had positive SCMR for ischemia, of which 9 patients were referred for CA and all demonstrated obstructive CAD. 18 patients were medically managed without adverse events. 2 patients were noted to have non-diagnostic SCMR and subsequent CA showed no significant CAD.
Conclusion:
Following equivocal or uncertain SPECT, SCMR demonstrated high 1-year prognostic capability with negative predictive value of 0.97 for adverse outcomes and high positive predictive value for obstructive CAD. SCMR may represent a reasonable, noninvasive option should additional risk stratification be required in this clinical setting.
Heart rate adaptive maximal resolution cardiovascular magnetic resonance myocardial stress perfusion imaging at 3.0T
