Mid-term outcomes of off-pump versus on-pump coronary artery bypass graft surgery; statistical challenges in comparison

Ali Sheikhy,Aida Fallahzadeh,Khalil Forouzannia,Kaveh Hosseini,Mina Pashang,Masih Tajdini,Abbas Salehi-Omran,Jamshid Bagheri,Saeed Sadeghian,Arash Jalali

doi:10.1186/s12872-021-02213-0

Ali Sheikhy, Aida Fallahzadeh + Show 8 more

Open Access

https://doi.org/10.1186/s12872-021-02213-0

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Abstract

BackgroundDespite several studies comparing off- and on-pump coronary artery bypass grafting (CABG), the effectiveness and outcomes of off-pump CABG still remain uncertain.MethodsIn this registry-based study, we assessed 8163 patients who underwent isolated CABG between 2014 and 2016. Propensity score matching (PSM), inverse probability of weighting (IPW) and covariate adjustment were performed to correct for and minimize selection bias.ResultsThe overall mean age of the patients was 62 years, and 25.7% were women. Patients who underwent off-pump CABG had shorter length of hospitalization (p < 0.001), intubation time (p = 0.003) and length of ICU admission (p < 0.001). Off-pump CABG was associated with higher risk of 30-days mortality (OR: 1.7; 95% CI 1.09–2.65; p = 0.019) in unadjusted analysis. After covariate adjustment and matching (PSM and IPW), this difference was not statistically significant. After an average of 36.1 months follow-up, risk of MACCE and all-cause mortality didn’t have significant differences in both surgical methods by adjusting with IPW (HR: 1.03; 95% CI 0.87–1.24; p = 0.714; HR: 0.91; 95% CI 0.73–1.14; p = 578, respectively).ConclusionOff-pump and on-pump techniques have similar 30-day mortality (adjusted, PSM and IPW). Off-pump surgery is probably more cost-effective in short term; however, mid-term survival and MACCE trends in both surgical methods are comparable.

Highlights

Despite several studies comparing off- and on-pump coronary artery bypass grafting (CABG), the effectiveness and outcomes of off-pump CABG still remain uncertain
Sheikhy et al BMC Cardiovasc Disord (2021) 21:412 of off-pump CABG (OPCABG) remains controversial, studies have shown that OPCABG reduces the operation time, the duration of intensive care unit (ICU) admission, the rate of blood transfusion, and early morbidity [4, 8]
After applying exclusion criteria; including complete loss to follow up (78 patients) and incomplete data registry (332 patients), 6574 patients who underwent on-pump CABG and 1589 patients who underwent OPCABG were included in the analysis

Summary

Methods

Study design This is a registry-based prospective data analysis study conducted in Tehran Heart Center (THC) [15] clinical registry, which includes patients with coronary artery disease who underwent on-pump or OPCABG between 2014 and 2016. This study didn’t meet criteria for informed consent whereas patients name kept anonymous except for corresponding author and data base chief, “informed consent waiver” obtained from the Tehran Heart Center ethical board. The adjusted and unadjusted effects of off-pump surgery on all-cause mortality and MACCE were obtained using Cox’s proportional hazards (PH) model. We conducted a one-to-one nearest neighborhood propensity score matching (PSM) technique (considering caliper as 0.01) without replacement to compute the effect of off-pump surgery on the abovementioned outcomes (Additional file 1, Table S1). All statistical analyses were conducted applying IBM SPSS Statistics for Windows, version 22.0 (Armonk, NY: IBM Corp.) and Stata Statistical Software, release 14 (College Station, TX: StataCorp LP)

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