The Diagnostic and Prognostic Impact of Cardiovascular Magnetic Resonance in Ischemic Heart Disease: A Systematic Review.

Background: Ischemic heart disease (IHD) diagnosis is complicated by anatomical-functional dissociation, where morphological stenosis severity fails to reliably predict hemodynamic significance. This diagnostic gap necessitates a shift toward integrated physiological and structural phenotyping, a role increasingly fulfilled by Cardiovascular Magnetic Resonance (CMR). Objective: To systematically evaluate the incremental diagnostic and prognostic value of CMR across the clinical spectrum of IHD, defining its evidence-based integration into multimodal pathways, particularly for diagnostically indeterminate cases. Methods: A systematic review was conducted in accordance with the PRISMA guidelines. A structured literature search of PubMed, Web of Science, and Scopus retrieved peer-reviewed articles published between January 2021 and April 2026. Methodological quality was appraised using the Newcastle-Ottawa Scale and AMSTAR 2, while evidence certainty was evaluated via the GRADE framework. Results: Thirty studies were included in the qualitative synthesis. Current evidence demonstrates that stress perfusion CMR provides superior diagnostic accuracy compared with traditional tests (e.g., SPECT, stress ECG), although it may be outperformed by advanced CT-derived fractional flow reserve in specific post-CCTA cohorts. In indeterminate presentations such as MINOCA, CMR accurately reclassified the underlying etiology in approximately 68% of cases. Furthermore, multiparametric assessment-integrating late gadolinium enhancement (LGE), microvascular obstruction (MVO), and global longitudinal strain (GLS)-refined post-infarction short- and medium-term risk stratification beyond LVEF alone, though the independent prognostic value of MVO attenuates in long-term follow-up (>6 years). Emerging data support the non-inferiority of accelerated stress-only protocols and the utility of artificial intelligence-driven analytics. Conclusions: CMR is a critical modality for resolving anatomical-functional mismatches and providing robust risk stratification. However, evidence does not support its use as a universal first-line test due to operational costs, scan duration, and patient contraindications. Expanding its clinical impact relies strictly on standardizing protocols and adopting AI-assisted, accelerated sequences to mitigate logistical barriers.