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Page 2 of 7 Quin et al. Vessel Plus 2022;6:41 https://dx.doi.org/10.20517/2574-1209.2021.119

Results: Of the 2203 ROOBY veterans enrolled at 18 VA medical centers from 2002 to 2008, 100 patients with
preoperative AF (n = 93) or unknown post-CABG POAF status (n = 7) were excluded. The POAF rate was 26.2%
(n = 551/2103). The POAF patients were older and had more co-morbidities than the non-POAF patients (n =
1552). The AF rate among 10-year ROOBY POAF survivors was 18.9% (n = 64/338) compared to 5.8% (n =
61/1048) for non-POAF patients; P < 0.001. Compared to non-POAF patients’ 10-year survival of 70%, the ROOBY
POAF veterans’ 10-year survival rate was 63%. Baseline risks inversely associated with 10-year survival included
age, chronic obstructive pulmonary disease, serum creatinine > 1.5, peripheral vascular disease, and smoking.
Holding these factors constant, POAF was not independently associated with 10-year survival.

Conclusion: Post-CABG, ROOBY POAF veterans had higher rates of 10-year AF, which was negatively associated
with 10-year survival; however, this association was not significant. Given that POAF may adversely impact 10-year
AF rates, additional investigation appears warranted to improve future POAF patients’ care.

Keywords: Coronary artery bypass grafting, atrial fibrillation, long-term outcomes, veterans

INTRODUCTION
Patients recovering from coronary artery bypass grafting (CABG) surgery who develop new-onset
postoperative atrial fibrillation (POAF) often require an extended hospital stay and increased resource
[1-3]
utilization . The association of POAF with worse immediate and intermediate-term outcomes is known.
As was previously shown, the Randomized On-/Off-Bypass (ROOBY) trial’s patients who developed new-
onset POAF had worse short-term outcomes than those without POAF. Complications associated with
POAF included reintubation and prolonged ventilation, renal failure, the need for mechanical
hemodynamic support, and, ultimately, worse one-year survival and higher costs . For ROOBY patients,
[1]
[3]
POAF was also associated with higher 1-year post-CABG costs, although 5-year costs were comparable .
While it is anticipated that most patients who develop POAF after CABG with no underlying history of
arrhythmia will revert back to sinus rhythm over time, the actual long-term atrial fibrillation (AF) rates of
this post-CABG POAF patient population are not well known. Additionally, the factors associated with
long-term AF and long-term survival rates in the POAF population have not been extensively examined. As
a ROOBY-FS sub-study, this follow-up investigation builds on prior ROOBY trial reports by examining
POAF versus non-POAF patients’ 10-year AF and survival rates with the purpose of determining if POAF
impacts these longer-term rates.

METHODS
[4]
Briefly summarizing details of the ROOBY trial , 2203 veterans were enrolled at 18 VA medical centers
between February 2002 and May 2008. These patients were randomized to undergo off-pump vs. on-pump
CABG. Evaluated at one year and five years, the clinical endpoints included death, myocardial infarction,
and repeat revascularization . For the ROOBY Follow-up Study (ROOBY-FS), the clinical endpoints of
[5]
death or repeat revascularization were also assessed at 10-years.

As a ROOBY trial approved sub-analysis, patients were examined for the development of new-onset POAF.
At one year and five years post-CABG follow-up, clinical outcomes were compared between patients who
developed POAF vs. those who did not .
[1-3]

For these sub-analyses, POAF was defined as any new-onset irregular atrial rhythm lasting longer than 30
minutes, which was similar to the Society of Thoracic Surgeons’ definition of atrial fibrillation. Patients with
shorter episodes of atrial fibrillation were excluded, given that the clinical significance of isolated, self-