Postoperative AFib Could Signal Increased Risk of Heart Failure Hospitalizations

Parag Goyal, MD

The development of arrhythmia following surgery could serve as a major red flag for the identification of patients at increased risk of hospitalization for heart failure following both cardiac and noncardiac surgery.

Results of a recent study, which included data from more than 76,537 patients undergoing cardiac surgery, demonstrate occurrence of postoperative atrial fibrillation (POAF) was associated with a 33% increase in risk of incident heart failure hospitalization in those undergoing cardiac surgery and a doubling in risk among those undergoing noncardiac surgery compared to their counterparts without POAF.

“Our study, which to our knowledge is the largest study to date, shows that post-operative atrial fibrillation is associated with future heart failure hospitalizations,” said Parag Goyal, MD, associate professor of medicine at Weill Cornell Medicine, in a statement. “This could mean that atrial fibrillation is an important indicator of underlying but not yet detected heart failure; or it could mean that atrial fibrillation itself contributes to the future development of heart failure. While this study could not specifically address which of these mechanisms are at play, our hope is that this study will inspire future work into exploring the underlying mechanism seen in our important findings.”

Although previous research has outlined the association between POAF with increased incidence of stroke and mortality, much less is known regarding occurrence of POAF and risk of heart failure hospitalization. Citing this lack of knowledge, investigators designed a retrospective cohort study using administrative claims data from all nonfederal emergency department visits from 11 states with the intent of assessing the association between POAF and incident heart failure hospitalizations among those undergoing cardiac and noncardiac surgeries.

Investigators obtained from all-payer claims data for all discharges from nonfederal emergency departments and acute care hospitals in Arkansas, Florida, Georgia, Iowa, Maryland, Massachusetts, Nebraska, New York, Utah, Vermont, and Wisconsin. Performing a search with as the period of interest, a total of 9,620,584 adults with any hospitalizations were identified by investigators.

After exclusion of those hospitalized without surgery, those with preexisting diagnosis of heart failure, and those who died during index hospitalizations, a cohort of 3,006,390 patients was identified for inclusion in the investigators’ analyses. The primary outcome of interest for the investigators’ analyses was the association between POAF and incident heart failure hospitalization after adjustment for sociodemographic factors and comorbidities, which was assessed using Cox proportional hazards regression models.

The study cohort had a mean age of 57.0±18.6 years, 59.9% were women, and the median follow-up time was 1.7 (IQR, 1.0-2.2) years. Of the 3,006,390 patients identified for inclusion, 76,536 had undergone cardiac surgery and the remaining 2,929,854 patients underwent noncardiac surgery. At baseline, 38,128 had incident POAF, 201,101 had previously diagnosed atrial fibrillation, and 2,767,161 had no atrial fibrillation. Investigators noted those with incident POAF were older than those without atrial fibrillation and slightly younger than those with previously diagnosed atrial fibrillation. Additionally, the cumulative rate of death at 3 years was 4.00% (95% CI 3.75-4.27%) in those with POAF, 4.64% (95% CI 4.51-4.76%) in those with previously diagnosed atrial fibrillation, and 1.56% (95% CI 1.53-1.58%) in those without atrial fibrillation (P <.001 for log-rank test).

Of the 76,536 patients who underwent cardiac surgery, 18.8% (n=14,365) developed incident POAF. In adjusted analyses, incidence of POAF was associated with an increased risk of incident heart failure hospitalization. In further analyses, which excluded heart failure within the first year of surgery, POAF remained associated with incident heart failure hospitalizations (HR, 1.15 [95% CI, 1.01-1.31]). Of the 2,929,854 patients who underwent noncardiac surgery, 0.8% (n=23,763) developed incident POAF. Similar to the analyses among those who underwent cardiac surgery, results suggested POAF was associated with an increased risk of incident heart failure hospitalization (HR, 2.02 [95% CI, 1.94-2.10]). In analyses excluding heart failure within 1 year of surgery, results also suggested POAF was associated with an increased risk of incident heart failure hospitalization (HR, 1.49 [95% CI, 1.38-1.61]).

In an accompanying editorial, Melissa Middeldorp, PhD, and Christine Albert, MD, MPH, both of the Smidt Heart Institute at Cedars-Sinai Medical Center, underlined the importance of the data from the current study but also recognize the need for further research to improve risk stratification and predictive models for these patient populations.

“What are the potential implications of these findings? The present study and other recent studies highlight the burden of POAF on morbidity, mortality, and the healthcare system,” wrote the duo. “Currently, preoperative evaluation and risk prediction models focus primarily on detection and optimal management of coronary artery disease, and these data suggest that a greater focus on heart failure and atrial fibrillation, particularly in non-cardiac patients, may improve postoperative outcomes.”

This study, “Post-operative atrial fibrillation and risk of heart failure hospitalization,” was published in the European Heart Journal.