Absence of long-term incremental prognostic value of inducible wall motion abnormalities on dipyridamole stress CMR in patients with suspected or known coronary artery disease

Objectives: This single-center retrospective study evaluated the long-term (~5 years) prognostic value of dipyridamole stress cardiac magnetic resonance (CMR) in patients with known or suspected coronary artery disease (CAD), assessing the impact of both key phases of the ischemic cascade (perfusion and wall motion).

Material and methods: We considered 322 consecutive patients who underwent dipyridamole stress CMR. Abnormal wall motion at rest and after dipyridamole, perfusion at stress and at rest, and late gadolinium enhancement (LGE) were analyzed. End-points were non-fatal myocardial infarction, unplanned late revascularization (60 days after CMR), and cardiac death.

Results: Forty-four patients were excluded because they underwent early revascularization (within 60 days after stress CMR), leading to a final population of 278 patients (73 females, 62.42 ± 10.50 years). A positive stress CMR was found in 78 (28.1%) patients; 50 patients had a reversible stress perfusion defect in at least one myocardial segment and 28 had a reversible stress perfusion defect plus worsening of stress wall motion in comparison with the rest. During a mean follow-up time of 59.34 ± 31.72 months, 37 (13.3%) cardiac events were recorded: 10 cardiac deaths, one non-fatal myocardial infarction, and 26 late revascularization after unstable angina or myocardial infarction. According to the Cox regression analysis, age, diabetes mellitus, previous revascularization, left ventricular ejection fraction (LVEF), reversible perfusion and perfusion + motion defect, and LGE were significant univariate prognosticators. The presence of associated wall motion abnormality (WMA) did not provide additional prognostic stratification in comparison to the only perfusion defect. In the multivariate Cox regression, the independent predictive factors were diabetes (hazard-ratio-HR = 5.64, p < 0.0001), reversible perfusion defect and reversible perfusion + motion defect vs normal stress CMR (HR = 6.43, p < 0.0001, and HR = 4.57, p = 0.004; respectively), and LVEF (HR = 0.96, p = 0.010).

Conclusion: A positive dipyridamole stress CMR predicted a higher long-term risk of cardiovascular events, but the presence of inducible WMA did not show any additional prognostic value over the reversible perfusion defect.

Key points: Question The long-term incremental prognostic value of inducible wall motion abnormalities by stress cardiac MR in patients with known or suspected CAD requires investigation. Findings The presence of inducible wall motion abnormalities did not offer additional prognostic value in comparison to the only reversible perfusion defect. Clinical relevance Independent from the presence of wall motion abnormalities, more aggressive management may be appropriate in patients with reversible perfusion defects to reduce the long-term risk of cardiovascular events.