What does this research mean for the field?

The combination of microvascular obstruction > 1.06% LV and intramyocardial hemorrhage > 0.47% LV strongly predicts MACE in STEMI patients, and a novel risk score integrating these metrics with LVEF and the GRACE score outperforms established prognostic tools. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To evaluate the prognostic value of combining quantitative microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) extent assessed by cardiac magnetic resonance for predicting major adverse cardiovascular events (MACE) in STEMI patients.

August 29, 2026Insights into ImagingOpen Access

Combined MVO and IMH on CMR strongly predicts ~865% higher MACE risk.

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: ST-segment elevation myocardial infarction (STEMI) (n=568). Intervention: Extensive microvascular injury (MVO > 1.06% LV and IMH > 0.47% LV) vs. Limited microvascular injury (MVO ≤ 1.06% LV and IMH ≤ 0.47% LV). Primary outcome: Major adverse cardiovascular events (MACE), defined as heart failure, all-cause death, reinfarction, and revascularization (HR 9.646, 95% CI 6.327-14.705, p=<0.001).

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Why the study?

Current prognostic tools for STEMI patients lack quantitative combined assessment of microvascular obstruction and intramyocardial hemorrhage, limiting precise risk stratification after reperfusion.

Does a CMR-based risk score integrating quantitative microvascular obstruction and intramyocardial hemorrhage improve prognostic evaluation for MACE in STEMI patients compared to established risk scores?

Population

568 STEMI patients

Comparison

Novel score integrating quantitative MVO and IMH extent vs GRACE score, Score 1, and Score 2

Design

Retrospective multicenter study

Follow-up

Median 3.1 years

Key result

The combination of microvascular obstruction > 1.06% LV and intramyocardial hemorrhage > 0.47% LV strongly predicted MACE (HR 9.646), and a risk score integrating these metrics achieved an AUC of 0.853.

Authors

XGXuefan Gu TYTing-Xuan Yin LYLing-Yi Yu

Discussion

Member takes

Overview

MVO extent plus IMH may refine post-STEMI MACE risk stratification in observational data; leaves open prospective validation before guiding practice.

Key Points

To evaluate the prognostic value of combining quantitative microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) extent assessed by cardiac magnetic resonance for predicting major adverse cardiovascular events (MACE) in STEMI patients.
Analyzed 568 STEMI patients in a retrospective multicenter study with a median follow-up of 3.1 years (IQR: 1.7–5.0 years).
Visualized MVO using late gadolinium enhancement and IMH using T2* mapping and T2-weighted CMR imaging.
Developed a prognostic risk score (Score 3) combining LVEF ≤ 45%, MVO > 1.06% LV, IMH > 0.47% LV, and the GRACE score, comparing it to established risk models.
Over the follow-up period, 108 patients (19%) developed MACE, with event rates rising progressively across risk categories from 8.8% to 58.3%.
The combination of MVO > 1.06% LV and IMH > 0.47% LV served as the strongest independent predictor of MACE (HR: 9.646, 95% CI: 6.327–14.705, p < 0.001).
Score 3 demonstrated superior predictive performance (AUC: 0.853) compared to the GRACE score (AUC: 0.748), Score 1 (AUC: 0.825), and Score 2 (AUC: 0.802).

Study Design

Type

Cohort (n=568)

Multicenter

Yes

Structured PICO

Population

568 STEMI patients who underwent percutaneous coronary intervention within 12 hours of symptom onset and had a cardiac magnetic resonance scan within 7 days, followed for a median of 3.1 years.

Exposure

Prognostic evaluation using a novel CMR-based risk score (Score 3) integrating GRACE score, LVEF ≤ 45%, quantitative microvascular obstruction (MVO > 1.06% LV), and intramyocardial hemorrhage (IMH > 0.47% LV).

Comparator

Established risk scores: GRACE score, Eitel CMR risk score (Score 1: GRACE, LVEF ≤47%, infarct size ≥19% LV, MVO > 1.4% LV), and Glasgow CMR risk score (Score 2: GRACE, LVEF ≤45%, presence of IMH).

Outcome

Major adverse cardiovascular events (MACE), defined as a composite of heart failure, all-cause death, reinfarction, and revascularization, at a median follow-up of 3.1 years.composite

Main Result

Hazard Ratio: 9.646 (95% CI 6.327–14.705)

Absolute Event Rate: 58.3% vs 8.8%

p-value: p=<0.001

Integrating quantitative CMR measurements of microvascular obstruction and intramyocardial hemorrhage into a clinical risk score significantly improves prognostic accuracy for MACE in STEMI patients following primary PCI.

Limitations

Retrospective design may introduce potential selection bias and unmeasured confounders
Cohort comprised only patients without contraindications to CMR and with complete clinical data for GRACE score calculation
Temporal differences in CMR image acquisition and variability in image quality across multiple centers may influence diagnostic accuracy
Lack of external validation in independent cohorts
T2* and T2WI sequences were limited to three-layer imaging, which may result in the underestimation of overall IMH measurements
Retrospective nature may introduce selection bias and unmeasured confounders
Cohort limited to patients without CMR contraindications and with complete GRACE data, which may limit generalizability
Temporal differences in CMR image acquisition and variability in image quality across multiple centers
Internal validation only; requires external validation in independent cohorts
T2* and T2WI sequences limited to three-layer imaging, potentially underestimating overall IMH measurements

Cite This Study

Gu et al. (2026) conducted a cohort in ST-segment elevation myocardial infarction (STEMI) (n=568). Extensive microvascular injury (MVO > 1.06% LV and IMH > 0.47% LV) vs. Limited microvascular injury (MVO ≤ 1.06% LV and IMH ≤ 0.47% LV) was evaluated on Major adverse cardiovascular events (MACE), defined as heart failure, all-cause death, reinfarction, and revascularization (HR 9.646, 95% CI 6.327-14.705, p=<0.001). The combination of microvascular obstruction > 1.06% LV and intramyocardial hemorrhage > 0.47% LV strongly predicted MACE (HR 9.646), and a risk score integrating these metrics achieved an AUC of 0.853.

synapsesocial.com/papers/6a92995f8e5d7d1fc0c114ef https://doi.org/10.1186/s13244-026-02386-2

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August 29, 2026Insights into ImagingOpen Access

Combined MVO and IMH on CMR strongly predicts ~865% higher MACE risk.

View Full Paper

Ask AI

Bookmark

Why the study?

Current prognostic tools for STEMI patients lack quantitative combined assessment of microvascular obstruction and intramyocardial hemorrhage, limiting precise risk stratification after reperfusion.

Population

568 STEMI patients

Comparison

Novel score integrating quantitative MVO and IMH extent vs GRACE score, Score 1, and Score 2

Design

Retrospective multicenter study

Follow-up

Median 3.1 years

Key result

Authors

XGXuefan Gu TYTing-Xuan Yin LYLing-Yi Yu

Discussion

Member takes

Overview

MVO extent plus IMH may refine post-STEMI MACE risk stratification in observational data; leaves open prospective validation before guiding practice.

Key Points

To evaluate the prognostic value of combining quantitative microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH) extent assessed by cardiac magnetic resonance for predicting major adverse cardiovascular events (MACE) in STEMI patients.
Analyzed 568 STEMI patients in a retrospective multicenter study with a median follow-up of 3.1 years (IQR: 1.7–5.0 years).
Visualized MVO using late gadolinium enhancement and IMH using T2* mapping and T2-weighted CMR imaging.
Developed a prognostic risk score (Score 3) combining LVEF ≤ 45%, MVO > 1.06% LV, IMH > 0.47% LV, and the GRACE score, comparing it to established risk models.
Over the follow-up period, 108 patients (19%) developed MACE, with event rates rising progressively across risk categories from 8.8% to 58.3%.
The combination of MVO > 1.06% LV and IMH > 0.47% LV served as the strongest independent predictor of MACE (HR: 9.646, 95% CI: 6.327–14.705, p < 0.001).
Score 3 demonstrated superior predictive performance (AUC: 0.853) compared to the GRACE score (AUC: 0.748), Score 1 (AUC: 0.825), and Score 2 (AUC: 0.802).

Study Design

Type

Cohort (n=568)

Multicenter

Yes

Structured PICO

Population

568 STEMI patients who underwent percutaneous coronary intervention within 12 hours of symptom onset and had a cardiac magnetic resonance scan within 7 days, followed for a median of 3.1 years.

Exposure

Comparator

Outcome

Major adverse cardiovascular events (MACE), defined as a composite of heart failure, all-cause death, reinfarction, and revascularization, at a median follow-up of 3.1 years.composite

Main Result

Hazard Ratio: 9.646 (95% CI 6.327–14.705)

Absolute Event Rate: 58.3% vs 8.8%

p-value: p=<0.001

Limitations

Retrospective design may introduce potential selection bias and unmeasured confounders
Cohort comprised only patients without contraindications to CMR and with complete clinical data for GRACE score calculation
Temporal differences in CMR image acquisition and variability in image quality across multiple centers may influence diagnostic accuracy
Lack of external validation in independent cohorts
T2* and T2WI sequences were limited to three-layer imaging, which may result in the underestimation of overall IMH measurements
Retrospective nature may introduce selection bias and unmeasured confounders
Cohort limited to patients without CMR contraindications and with complete GRACE data, which may limit generalizability
Temporal differences in CMR image acquisition and variability in image quality across multiple centers
Internal validation only; requires external validation in independent cohorts
T2* and T2WI sequences limited to three-layer imaging, potentially underestimating overall IMH measurements

Cite This Study

synapsesocial.com/papers/6a92995f8e5d7d1fc0c114ef https://doi.org/10.1186/s13244-026-02386-2

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