Incidence and In-Hospital Outcomes of Bradycardia or Atrioventricular Conduction Disorder in Patients With Type 2...

Type 2 myocardial infarction (T2MI), caused by an imbalance between oxygen supply and demand without significant coronary obstruction, is increasingly recognized yet remains underexplored, particularly regarding conduction abnormalities.

We conducted a retrospective cohort study using the National Inpatient Sample from 2017 to 2022. Adult patients hospitalized with T2MI were identified by ICD-10-CM code. Bradycardia or atrioventricular (AV) conduction delay was defined using diagnostic codes for bradycardia and all degrees of AV block. We compared baseline characteristics, comorbidities, and causes of T2MI, and used multivariable logistic regression to evaluate associations with in-hospital mortality and cardiogenic shock.

Among 1 960 410 patients with T2MI, 118 025 (6.0%) had bradycardia or AV conduction delay. These patients were older, more often male, and had higher rates of hypertension, heart failure, chronic kidney disease, and diabetes. The pacemaker implantation was significantly more prevalent (8.7% vs. 0.3%, p < 0.01). They also showed an increase in in-hospital mortality (10.4% vs. 9.8%, p < 0.01), cardiogenic shock (5.1% vs. 3.2%, p < 0.01), and AKI (47.9% vs. 46.3%, p < 0.01). After adjustment, conduction disorders remained associated with higher odds of mortality (aOR 1.09, 95% CI 1.04-1.14) and cardiogenic shock (aOR 1.71, 95% CI 1.61-1.83).

Bradycardia or AV conduction delay occurred in 6% of T2MI hospitalizations and was independently linked to worse in-hospital outcomes, underscoring the need for close monitoring in this population.