Preexisting atrial fibrillation (AF) is independently associated with postoperative mortality, hospitalizations for heart failure (HF), and stroke within 30 days following noncardiac procedures, according to the results of a study published in the Journal of the American College of Cardiology.
Researchers sought to evaluate the effect of AF on the risk for adverse outcomes after noncardiac procedures in a nationwide cohort of Medicare beneficiaries. Individuals from the Medicare Provider Analysis and Review File who had undergone a noncardiac procedure between January 1, 2015, and October 1, 2019, were identified. The analysis included the following surgical categories: vascular, thoracic, head and neck, noncardiac transplant, breast, genitourinary, gynecologic, orthopedic, neurologic, and general. If a patient received more than 1 procedure in the study period only the first procedure was included in the evaluation.
The urgency of the procedure was established from a variable used to classify the inpatient admission as elective, urgent, or emergent. Individuals aged younger than 40 years, those with less than 3 years of fee-for-service Medicare coverage prior to the noncardiac procedure, and patients who had a history of mitral stenosis were excluded.
For each patient, the CHA2DS2-VASc risk score and the Revised Cardiac Risk Index (RCRI) were calculated. The primary study outcome was 30-day all-cause mortality. Secondary study outcomes included 30-day ischemic stroke, myocardial infarction (MI), HF hospitalization, major bleeding, and length of hospital stay. All of the study outcomes were calculated from the date of procedure. All of the participants had available follow-up data for 30 days after the index procedure date.
A total of 8,635,758 patients who had received a noncardiac procedure (16.4% with AF) were included in the study cohort. The participants with AF were more likely to be men, were older, and had a higher prevalence of comorbidities. Following the use of propensity matching, AF was associated with a higher risk for 30-day mortality (odds ratio [OR], 1.31; 95% CI, 1.30-1.32; P <.001), 30-day HF (OR, 1.31; 95% CI, 1.30-1.33; P <.001), and 30-day stroke (OR, 1.40; 95% CI, 1.37-1.43; P <.001), as well as a lower risk for 30-day MI (OR, 0.81; 95% CI, 0.79-0.82; P <.001).
Study results were consistent in a subgroup analysis that was performed according to sex, race, type of procedure, and all strata of CHA2DS2-VASc risk score and RCRI. The addition of preexisting AF to the RCRI improved the discriminative ability of the risk index (C-statistic from 0.73-0.76; P <.001) to predict 30-day adverse cardiovascular (CV) events. Further, preexisting AF was associated with a significant net reclassification improvement of 0.441 (95% CI, 0.438-0.443; P <.001) compared with the use of RCRI alone.
Several limitations of the study should be noted. This was a retrospective observational study, with inherent limitations of possible unmeasured confounding and without any prospective adjudication. Further, the investigators lacked information on the use of important medications, including antiarrhythmic prescriptions for patients while they were hospitalized, thus rendering the assessment of perioperative and postoperative periods on outcomes not feasible.
“Preexisting AF is independently associated with postoperative mortality, HF hospitalizations, and stroke within 30 days after noncardiac surgery,” the researchers wrote. “Adding preexisting AF to the RCRI can improve risk prediction of adverse cardiovascular events after noncardiac surgery.”
Disclosure: One of the study authors has declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the author’s disclosures.
Prasada S, Desai MY, Saad M, et al. Preoperative atrial fibrillation and cardiovascular outcomes after noncardiac surgery. J Am Coll Cardiol. Published online June 20, 2022. doi:10.1016/j.jacc.2022.04.021