Outcomes of Coronary Artery Bypass Grafting With Bilateral Internal Mammary Artery in Obese Patients

Chikashi Nakai; Cheng Zhang; Hiroto Kitahara; Christian Shults; Ron Waksman; Ezequiel J Molina

doi:10.1016/j.atssr.2023.02.005

Outcomes of Coronary Artery Bypass Grafting With Bilateral Internal Mammary Artery in Obese Patients

Ann Thorac Surg Short Rep. 2023 Feb 21;1(2):298-301. doi: 10.1016/j.atssr.2023.02.005. eCollection 2023 Jun.

Authors

Chikashi Nakai¹, Cheng Zhang¹, Hiroto Kitahara¹, Christian Shults¹, Ron Waksman², Ezequiel J Molina¹

Affiliations

¹ Division of Cardiac Surgery, MedStar Washington Hospital Center, Washington DC.
² Division of Cardiology, MedStar Washington Hospital Center, Washington DC.

Abstract

Background: The purpose of this study was to evaluate postoperative outcomes with the use of bilateral internal mammary artery (BIMA) conduits in obese patients.

Methods: Between January 2003 and December 2018, 8109 patients underwent isolated coronary artery bypass grafting, including 7218 (89%) treated with single internal mammary artery (SIMA) and 891 (11%) treated with BIMA grafts. Patients were divided into 3 groups according to preoperative body mass index (BMI): normal, BMI <25 kg/m² (22.2%); overweight, BMI of 25 to <30 kg/m² (37.2%); and obese, BMI ≥30 kg/m² (40.6%). In each group, BIMA and SIMA patients were compared to investigate 30-day mortality and postoperative complications. Significant baseline differences were observed between the 3 BMI groups, and such differences were adjusted by inverse probability weighting matching.

Results: Thirty-day mortality, deep sternal wound infection (DSWI) rates, and length of hospital stay were 1.4%, 0.5%, and 6.0 ± 9.1 days for the normal group; 0.2%, 1.0%, and 5.5 ± 4.2 days for the overweight group; and 0.9%, 1.8%, and 5.5 ± 4.0 days for the obese group. There was no significant difference in 30-day mortality, incidence of DSWI, and hospital stay between BIMA and SIMA groups, except in the obese group, in which the rate of DSWI was significantly higher in the BIMA patients (3.4% vs 0%; P = .02).

Conclusions: BIMA grafts in obese patients can be used without an increase of the 30-day mortality and hospital stay. However, the use of BIMA grafts in obese patients may lead to an increase of postoperative DSWI.