The CMR GUIDE trial protocol outlines a precision approach to preventing sudden cardiac death by using cardiac magnetic resonance imaging to detect ventricular scar tissue as the primary criterion for implantable cardioverter defibrillator (ICD) placement in patients with mild-to-moderate left ventricular systolic dysfunction. The study targets a composite endpoint of sudden cardiac death or hemodynamically significant ventricular arrhythmia causing syncope or severe hypotension. This represents a potentially transformative shift from current ejection fraction-based ICD guidelines toward scar-guided therapy. Current practice relies heavily on left ventricular ejection fraction below 35% for ICD decisions, but emerging evidence suggests myocardial scarring may be a superior predictor of arrhythmic risk regardless of overall pump function. The approach could prevent unnecessary device implantations in low-risk patients while ensuring high-risk individuals receive appropriate protection. However, this document presents only the statistical analysis framework rather than actual trial results. The methodology appears robust with competing risk analysis and planned subgroup evaluations. As this is a preprint statistical analysis plan awaiting peer review, the actual trial outcomes and clinical validation of this scar-based strategy remain to be demonstrated through the completed study results.