The systematic review included 14 studies involving a total of 1,367 patients, of whom 91.9% underwent cardiac MRI. The studies were heterogeneous in terms of design, patient demographics, and imaging protocols, which posed challenges for direct comparisons or meta-analysis. Despite these limitations, several key findings emerged:

1. Diagnostic Value of Cardiac MRI: Cardiac MRI provided significant diagnostic insights in cases where initial imaging modalities were inconclusive. Across studies, cardiac MRI led to new or alternative diagnoses in 13% to 50% of cases. In one study, Rodrigues et al. (3) reported that cardiac MRI was crucial in establishing a diagnosis in 30% of patients. Swoboda et al. (4) found that cardiac MRI enabled correct diagnoses in 36.4% of cases where other imaging methods failed. These findings underscore the potential of cardiac MRI to detect pathologies such as myocardial edema, arrhythmogenic substrates, and late gadolinium enhancement (LGE).

2. Prognostic Relevance: Prognostic markers identified through cardiac MRI included LGE, ventricular dimensions, and functional metrics. LGE was observed in 66.4% of patients across the included studies. Neilan et al. (5) highlighted that the presence and extent of LGE were strong predictors of major adverse cardiovascular events, including all-cause mortality and implantable cardioverter-defibrillator interventions. Similarly, Rodrigues et al. (3) associated LGE and ventricular function metrics with a higher risk of adverse outcomes, emphasizing the prognostic significance of these parameters.

3. Challenges in Implementation: Despite its potential, the diagnostic and prognostic efficacy of cardiac MRI was inconsistently reported. Some studies, such as those by Zaremba et al. (6), highlighted scenarios where cardiac MRI did not yield new diagnostic information, while others noted its decisive role in treatment planning. Additionally, the lack of comparator groups and reference standards in most studies limited the ability to draw definitive conclusions about its diagnostic accuracy. Patient selection biases further complicated the generalizability of findings.

4. Insights into Specific Conditions: Cardiac MRI was particularly effective in diagnosing non-ischemic CMPs, such as dilated CMP, hypertrophic CMP, and myocarditis. In a developing country context, Marçal et al. (7) demonstrated that cardiac MRI significantly improved etiologic diagnosis by identifying conditions like Chagas disease, which were less prevalent in studies from high-income countries. This highlights the modality’s adaptability to diverse clinical settings and patient populations.