Preoperative atrial fibrillation linked to adverse outcomes after noncardiac surgery

The pre-existence of atrial fibrillation (AF) contributes to postoperative adverse outcomes in patients undergoing noncardiac surgery (NCS), suggests a recent study.

A team of investigators identified Medicare beneficiaries admitted for noncardiac surgery from 2015 to 2019 and divided them into two cohorts: individuals with AF and those without. They also classified NCS as follows: vascular, thoracic, general, genitourinary, gynaecological, orthopaedics and neurosurgery, breast, head and neck, and transplant.

Propensity score matching on exact age, sex, race, urgency and type of surgery, revised cardiac risk index (RCRI) and CHA₂DS₂-VASc score, and tight caliper on other comorbidities was used. Outcomes assessed were 30-day mortality, stroke, myocardial infarction, and heart failure. The investigators also assessed the incremental use of AF in addition to RCRI to predict adverse events after NCS.

A total of 8,635,758 patients who underwent NCS were included, of which 16.4 percent had AF. Patients with AF were older, more likely to be men, and had more comorbidities.

After propensity score matching, AF correlated with an increased risk of mortality (odds ratio [OR], 1.31, 95 percent confidence interval [CI], 1.30‒1.32), heart failure (OR, 1.31, 95 percent CI, 1.30‒1.33), and stroke (OR, 1.40, 95 percent CI, 1.37‒1.43) and a reduced risk of myocardial infarction (OR, 0.81, 95 percent CI, 0.79‒0.82).

These findings persisted in subgroup analyses by sex, race, type of surgery, and all strata of RCRI and CHA₂DS₂-VASc score. Notably, AF improved the discriminative ability of RCRI (C-statistic 0.73 to 0.76), the investigators said.