Risk-stratified evaluation of amiodarone to prevent atrial fibrillation after cardiac surgery.
BACKGROUND
Amiodarone prophylaxis (AMP) reduces the prevalence of postoperative atrial fibrillation (POAF) after cardiac surgery. We investigated the impact of AMP on the frequency and duration of POAF, the intensive care unit and hospital length of stay, and its cost-effectiveness in a risk-stratified cohort.


METHODS
A retrospective, observational analysis of 509 patients who underwent cardiac surgery in 2003 was performed. Data sources included The Society of Thoracic Surgeons national database; medical and medication administration records; and the activity-based cost data from our institution. Risk stratification for POAF was determined using a validated risk index. Cost-effectiveness was determined from the hospital's perspective.


RESULTS
The mean patient age was 63 years, 27% were female, 80% underwent coronary artery bypass grafting, and 29% underwent valve surgery. When a risk-stratified evaluation was made, 50% of patients were at an elevated risk for having POAF develop. When compared with nonprophylaxed patients, those receiving AMP (59%) experienced less POAF (31% vs 22%; p = 0.027) and shorter durations of POAF (4.7 vs 2.7 days; p = 0.025). In the elevated-risk group, AMP clinically (but not significantly) reduced length of stay in the intensive care unit (101 vs 68 hours; p > 0.05) and post-procedural hospital length of stay (9.7 vs. 7.9 days, p > 0.05). In the elevated-risk group, AMP was robustly cost-effective in reducing POAF.


CONCLUSIONS
Amiodarone prophylaxis reduced the prevalence and duration of POAF. Baseline risk for POAF was a major determinant of the overall cost-effectiveness of AMP. The greatest cost savings with AMP was seen in patients at an elevated risk for POAF. These findings suggest the need for risk stratification when prescribing AMP.
Barnes
Brian J
BJ
Department of Pharmacy Practice, School of Pharmacy, The University of Kansas Medical Center, Kansas City, Kansas 66160-7231, USA. bbarnes@kumc.edu
Kirkland
Erin A
EA
Howard
Patricia A
PA
Grauer
Dennis W
DW
Gorton
Michael E
ME
Kramer
Jeffrey B
JB
Muehlebach
Gregory F
GF
Reed
William A
WA
D000638:Amiodarone / Q000191:economics / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000191:economics / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003362:Cost-Benefit Analysis; D005260:Female; D006760:Hospitalization; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment
D000889:Anti-Arrhythmia Agents; D000638:Amiodarone