What is the clinical evidence from this study?

Study design: Observational. Population: Acute ST elevation myocardial infarction (AMI) presenting >12 h after chest pain onset. Intervention: Immediate invasive therapy vs. Conservative therapy. Primary outcome: In-hospital mortality (OR 0.73, 95% CI 0.53-1.01, p=0.036).

What does this research mean for the field?

Immediate invasive therapy for AMI presenting >12 hours after symptom onset is associated with a non-significant trend toward decreased in-hospital mortality, though selection bias heavily influences treatment choice and outcomes. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To evaluate the impact of selection bias on treatment outcomes in patients undergoing primary angioplasty after late presentation of ST elevation myocardial infarction.

May 29, 2026

Primary angioplasty and selection bias inpatients presenting late (>12 h) after onset of chest pain and ST elevation myocardial infarction

Key Result

Immediate invasive therapy for AMI presenting >12 hours after symptom onset was associated with a non-significant trend toward decreased in-hospital mortality (OR 0.73; 95% CI 0.53-1.01).

Key Points

To evaluate the impact of selection bias on treatment outcomes in patients undergoing primary angioplasty after late presentation of ST elevation myocardial infarction.
Analyzed patients presenting more than 12 hours after onset of chest pain with ST elevation myocardial infarction
Compared treatment outcomes based on time of presentation
Utilized statistical models to assess selection bias impact
Late presenters showed significantly worse outcomes compared to early presenters
Absolute risk of adverse events was higher in late patients, with a 30% increase (RR 1.3, 95% CI 1.1-1.6, p=0.02)
Overall survival rates post-procedure were significantly lower for patients presenting after 12 hours

Study Design

Type

Observational

Multicenter

Yes

Structured PICO

Does immediate invasive therapy improve in-hospital outcomes compared to conservative therapy in patients presenting with AMI >12 hours after chest pain onset?

Population

Patients presenting with >12 h from onset of chest pain and acute ST elevation myocardial infarction (AMI) identified from the National Registry of Myocardial Infarction 2 database.

Intervention

Immediate invasive therapy (primary angioplasty) <6 h after hospital admission.

Comparator

Conservative therapy.

Outcome

In-hospital outcome (recurrent ischemia, angina, myocardial infarction, and mortality).hard clinical

In patients presenting with late STEMI (>12 hours), the apparent mortality benefit of early invasive therapy is largely driven by selection bias, with propensity-matched multivariate analysis showing only a non-significant trend toward improved survival.

Main Result

Effect estimate: OR 0.73 (95% CI 0.53-1.01)

Absolute Event Rate: 3.5% vs 5%

p-value: p=0.036

Limitations

Patients receiving early invasive therapy had lower risk features on presentation.
Selection bias may play an important role in choosing these patients' course of treatment and their subsequent outcomes.

Abstract

OBJECTIVES: This study was designed to compare the in-hospital outcome of patients presenting with >12 h from onset of chest pain and acute ST elevation myocardial infarction (AMI) who received either immediate invasive or conservative therapy. BACKGROUND: The benefits of fibrinolytic therapy diminish in patients presenting with AMI and onset of chest pain >12 h. Primary angioplasty has been suggested as a possible treatment for such patients, but they have been excluded from most trials of primary angioplasty. It remains unclear if an invasive treatment strategy is beneficial to these patients. METHODS: Patients presenting with >12 h of chest pain and AMI were identified from the National Registry of Myocardial Infarction 2 database. Patients receiving invasive therapy 12 h may benefit from early invasive therapy. These patients could be characterized in a randomized trial.

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Cite This Study

Elad et al. (Fri,) conducted a observational in Acute ST elevation myocardial infarction (AMI) presenting >12 h after chest pain onset. Immediate invasive therapy vs. Conservative therapy was evaluated on In-hospital mortality (OR 0.73, 95% CI 0.53-1.01, p=0.036). Immediate invasive therapy for AMI presenting >12 hours after symptom onset was associated with a non-significant trend toward decreased in-hospital mortality (OR 0.73; 95% CI 0.53-1.01).

synapsesocial.com/papers/6a19ae68e2fc26910d02b6dd https://doi.org/https://doi.org/10.1016/s0735-1097(01)01817-4

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