Quantitative stress perfusion cardiovascular magnetic resonance: clinical implications for patients with suspected myocardial ischemia.

Abstract

Introduction: Recent technical advances in stress perfusion cardiovascular magnetic resonance (CMR) allow for myocardial blood flow (MBF) quantification (quantitative perfusion CMR; QP CMR). However, clinical utility of QP CMR compared to conventional grey scale qualitative assessment (QA) is unknown.

Objectives: The study aimed to compare the clinical conclusions on ischemia detection derived from conventional grey-scale QA of stress perfusion CMR imaging and QP CMR in a real-world population of patients with suspected myocardial ischemia.

Patients and methods: This study retrospectively analyzed 101 patients with suspected myocardial ischemia referred for adenosine stress perfusion CMR imaging. QA of grey-scale first-pass perfusion CMR was performed by level 3 CMR experts. In QP, stress and rest MBF (ml/g/min) were calculated for automatically determined myocardial segments. Each patient and coronary territory was classified by both QA and QP, in a blinded manner, as either ischemic or non-ischemic.  Results: QP classified more coronary territories as ischemic compared to QA (46% vs. 17%, P <0.001). In the per-patient analysis, QP diagnosed myocardial ischemia in 64 patients (63%), and QA in 40 (40%) (P <0.001). Ischemia was diagnosed by QA but not QP in 7% of patients  (QA+/QP-). In 31% of patients, QP established a new diagnosis of myocardial ischemia (QA-/QP+).

Conclusion: QP CMR detects more ischemic coronary territories compared to QA and holds promise for identifying cases of myocardial ischemia that may be overlooked by QA alone in a real-world patient population.