Acute atrial fibrillation in type 2 myocardial infarction: A national analysis of incidence and in-hospital outcomes

Q: What are the key findings of this study?

Acute atrial fibrillation occurred in 31.3% of type 2 myocardial infarction hospitalizations and was independently associated with higher in-hospital mortality (aOR 1.17, 95% CI 1.14–1.20).

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Type 2 Myocardial Infarction (n=2016429). Intervention: Acute atrial fibrillation vs. No acute atrial fibrillation. Primary outcome: In-hospital mortality (OR 1.17, 95% CI 1.14–1.20, p=<0.01).

Q: What does this research mean for the field?

Acute atrial fibrillation occurs in 31.3% of type 2 myocardial infarction hospitalizations and is independently associated with increased in-hospital mortality and cardiogenic shock. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

Q: What question did this study set out to answer?

To evaluate the incidence of acute atrial fibrillation in patients hospitalized with type 2 myocardial infarction and determine its impact on in-hospital clinical outcomes.

Ben Thiravetyan; Napat Suriyathumrongkul; Sireethorn Wonghanchai; Varote Shotelersuk; Nisha Wanichwecharungruang; Nattanicha Chaisrimaneepan; Panat Yanpiset; Chanokporn Puchongmart

doi:10.12746/swjm.v14i61.1627

October 20, 2026The Southwest Journal of MedicineOpen Access

Acute atrial fibrillation in type 2 myocardial infarction: A national analysis of incidence and in-hospital outcomes

View Full Paper

Ask AI

Bookmark

Share

Key result

Acute AF linked to ~17% higher in-hospital mortality in type 2 MI.

OR 1.17
95% CI 1.14–1.20
P<0.01
n=2,016,429

Why the study?

Although atrial fibrillation is linked to worse outcomes, data on the incidence of acute AF and its association with in-hospital outcomes in patients with type 2 myocardial infarction are limited.

What is the incidence of acute atrial fibrillation and is it associated with worse in-hospital outcomes (such as mortality and cardiogenic shock) in adults hospitalized with type 2 myocardial infarction?

Key Points

To evaluate the incidence of acute atrial fibrillation in patients hospitalized with type 2 myocardial infarction and determine its impact on in-hospital clinical outcomes.
Retrospective cohort study of 2,016,429 adult hospitalizations with type 2 myocardial infarction from the National Inpatient Sample (2017–2022), excluding patients with chronic atrial fibrillation.
Survey-weighted analyses and multivariable logistic regression evaluated the primary outcome of acute atrial fibrillation incidence and secondary outcomes including mortality, cardiogenic shock, acute kidney injury, and bleeding.
Acute atrial fibrillation occurred in 31.3% of patients hospitalized with type 2 myocardial infarction (630,869 of 2,016,429).
Unadjusted in-hospital outcomes were higher in the acute atrial fibrillation group compared to the non-AF group for mortality (10.9% vs. 9.3%, p < 0.01), cardiogenic shock (4.3% vs. 2.9%, p < 0.01), and acute kidney injury (47.5% vs. 45.6%, p < 0.01), with no significant difference in bleeding complications (12.8% vs. 12.7%, p = 0.14).
After multivariable adjustment, acute atrial fibrillation remained an independent predictor of in-hospital mortality (aOR 1.17, 95% CI: 1.14–1.20, p < 0.01) and cardiogenic shock (aOR 1.46, 95% CI: 1.40–1.51, p < 0.01).

Study Design

Type

Cohort (n=2,016,429)

Multicenter

Yes

Structured PICO

What is the incidence of acute atrial fibrillation and is it associated with worse in-hospital outcomes (such as mortality and cardiogenic shock) in adults hospitalized with type 2 myocardial infarction?

P

Population

2,016,429 hospitalized adult patients in the United States with type 2 myocardial infarction and no history of chronic atrial fibrillation, evaluated during index hospitalization from 2017 to 2022.

E

Exposure

Diagnosis of acute atrial fibrillation (AF) or atrial flutter (exposure identified via ICD-10-CM codes I479, I480, I481, I4811, I4819, I4821, I483, I484, I4891, I4892)

C

Comparator

Patients hospitalized with type 2 myocardial infarction without acute atrial fibrillation

O

Outcome

Incidence of acute atrial fibrillation during hospitalizationhard clinical

Main Result

Odds Ratio: 1.17 (95% CI 1.14–1.2)

Absolute Event Rate: 10.9% vs 9.3%

p-value: p=<0.01

This nationally representative analysis demonstrates that acute atrial fibrillation occurs in nearly one-third of type 2 myocardial infarction hospitalizations and is independently associated with increased risks of in-hospital mortality and cardiogenic shock.

Limitations

Relies on administrative data from the National Inpatient Sample, which is subject to coding errors and misclassification
Use of ICD-10-CM codes does not allow confirmation of clinical diagnoses through chart review or biomarkers, nor AF chronicity beyond known chronic AF exclusion
Lacks granular clinical data such as case severity, do-not-resuscitate status, intensive care unit admission, or treatment protocols
Hospitalization-level dataset may count repeat admissions of the same patient multiple times
Observational nature precludes establishing causality between AF and adverse outcomes in T2MI
Relies on administrative data from the NIS, which is subject to coding errors and misclassification
Use of ICD-10-CM codes does not allow confirmation of clinical diagnoses through chart review or biomarkers, nor does it provide information on AF chronicity beyond exclusion of known chronic AF cases
Lacks granular clinical data, such as severity of cases, do-not-resuscitate status, intensive care unit admission, or treatment protocol
Hospitalization-level dataset means repeat admissions of the same patient may have been counted multiple times

Ask about this paper

Answers are grounded in this paper and cite their sources.

Implication

Acute AF in T2MI was associated with higher mortality; leaves open whether targeted management improves outcomes.

Abstract

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia linked to worse outcomes. However, data on AF in type 2 myocardial infarction (T2MI), characterized by oxygen supply-demand mismatch without coronary occlusion, are limited. Objective: To evaluate the incidence of acute AF in patients hospitalized with T2MI and its association with in-hospital outcomes. Methods: We conducted a retrospective cohort study using the National Inpatient Sample from 2017 to 2022. Adult patients hospitalized with T2MI were included, excluding those with chronic AF. The primary outcome was the incidence of acute AF. Secondary outcomes were in-hospital mortality, cardiogenic shock, acute kidney injury (AKI), and bleeding. Survey-weighted analyses and multivariable logistic regression were used to calculate adjusted odds ratios. Results: Among patients with T2MI, acute AF occurred in 31.3%. Patients with AF were older and had more comorbidities. In-hospital mortality, cardiogenic shock, and AKI were higher in the AF group compared to non-AF group. After adjustment, acute AF was independently associated with in-hospital mortality (aOR 1.17, 95% CI: 1.14–1.20) and cardiogenic shock (aOR 1.46, 95% CI: 1.40–1.51). Conclusions: Acute AF is common in T2MI hospitalizations and is associated with mortality and cardiogenic shock.

Discussion

No takes yet. Share an insight, caveat, or question.

Cite This Study

Thiravetyan et al. (2026) conducted a cohort in Type 2 Myocardial Infarction (n=2,016,429). Acute atrial fibrillation vs. No acute atrial fibrillation was evaluated on In-hospital mortality (OR 1.17, 95% CI 1.14–1.20, p=<0.01). Acute atrial fibrillation occurred in 31.3% of type 2 myocardial infarction hospitalizations and was independently associated with higher in-hospital mortality (aOR 1.17, 95% CI 1.14–1.20).

synapsesocial.com/papers/6ae28e94cbadf70daf6c4359 https://doi.org/10.12746/swjm.v14i61.1627

View Full Paper

Ask AI

Bookmark

Share

Acute atrial fibrillation in type 2 myocardial infarction: A national analysis of incidence and in-hospital outcomes

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Acute atrial fibrillation in type 2 myocardial infarction: A national analysis of incidence and in-hospital outcomes

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Keep reading

Keep reading