The role of CMR in the timing of aortic valve interventions and risk stratification in aortic regurgitation: a systematic review and meta-analysis

AIMS: Aortic regurgitation (AR) is a prevalent valvular disease. Cardiovascular magnetic resonance (CMR) imaging is emerging as an accurate and precise method for assessing AR. However, its role in guiding interventions and risk stratification for outcomes remains to be fully defined.

OBJECTIVE: This systematic review and meta-analysis evaluate the predictive utility of CMR-derived AR fraction (ARF) in determining intervention timing and clinical outcomes.

METHODS AND RESULTS: A systematic search identified observational studies assessing CMR-derived ARF in AR prognostication. Hazard ratios (HRs) for intervention timing, mortality, and heart failure were pooled using a random-effects model. Study heterogeneity (I² statistic) was assessed, and publication bias was evaluated using a funnel plot. A total of 1235 studies were screened, with 12 meeting the inclusion criteria. Eight studies (n = 1996 patients) were included in the meta-analysis. ARF severity thresholds ranged from 30 to 43% (mean 33.7%). Follow-up ranged from 2 to 5.1 years. The pooled HR for clinic outcomes with an ARF > 33% was 4.12 (95% CI: 2.31-7.34, P value < 0.01). The highest reported HR was 24.59, while the lowest was 1.04. Studies demonstrated that a higher ARF correlates with an increased risk of adverse outcomes, supporting CMR as a key tool for risk stratification and intervention timing.

CONCLUSION: CMR-derived ARF is strongly predictive of clinical outcomes. ARF > 33% is associated with significantly increased risk, warranting its integration into clinical decision-making frameworks.