Prognostic impact of persistent microvascular obstruction on cardiac magnetic resonance after STEMI: a systematic review and meta analysis

Background Microvascular obstruction after reperfused ST-elevated myocardial infarction (STEMI) predicts adverse prognosis on cardiac magnetic resonance (CMR). The incremental risk associated with persistent microvascular obstruction on late or follow up imaging is less well defined. Methods We searched the literature through January 2026 for cohort studies of adults with STEMI treated with primary PCI who underwent CMR and reported outcomes by persistent microvascular obstruction status. Persistent microvascular obstruction (MVO) was defined on late gadolinium enhancement or follow up scans and was compared with transient microvascular obstruction or no microvascular obstruction. Random effects models pooled risk ratios and mean differences, and heterogeneity was assessed using I². Results Seven cohort studies including 2,180 patients with follow up from 1 month to 5 years were included. Compared with transient MVO, persistent MVO was associated with higher MACE (RR 2.40, 95% CI 1.51–3.81, p=0.0002) (Figure A) and higher death (RR 3.51, 95% CI 1.69–7.29, p=0.0008), with lower LVEF (MD −5.81%, 95% CI −9.04 to −2.58, p=0.0004) and larger infarct size (MD 7.26%, 95% CI 2.98–11.53, p=0.0009). Compared with no MVO, persistent MVO was associated with higher MACE (RR 3.72, 95% CI 2.48–5.60, p<0.0001) (Figure B), higher death (RR 5.90, 95% CI 2.65–13.15, p<0.0001), and higher heart failure readmission (RR 4.80, 95% CI 2.66–8.66, p<0.0001), with lower LVEF (MD −11.33%, 95% CI −17.67 to −4.99, p=0.0005) and larger infarct size (MD 12.75%, 95% CI 6.34–19.17, p<0.0001). Recurrent MI was not significantly different in either comparison, and heart failure readmission did not differ versus transient MVO. Conclusion Persistent microvascular obstruction identifies a high-risk STEMI phenotype with worse long-term outcomes and adverse remodeling markers.