Original article
Adult cardiac
Hospital Variability Drives Inconsistency in Antiplatelet Use After Coronary Bypass

https://doi.org/10.1016/j.athoracsur.2019.12.064Get rights and content

Background

Continuation of dual antiplatelet therapy (DAPT) after coronary artery bypass grafting (CABG) after acute myocardial infarction is recommended by current guidelines. We sought to evaluate guideline adherence over time and factors associated with postoperative DAPT within a regional consortium.

Methods

Isolated CABG patients from 2011 to 2017 who had a myocardial infarction within 21 days prior to surgery were included. Patients were stratified by DAPT prescription at discharge and by time period, early (2011-2014) vs late (2015-2017). Hierarchical regressions were then performed to evaluate factors influencing DAPT use after CABG.

Results

A total of 7314 patients were included with an overall rate of DAPT utilization of 31.2% that increased from 29.6% in the early to 33.4% in the late era (P < .01). There was considerable variability in hospital rates of DAPT (range 9.5%-92.1%) and hospital level changes over time (26% increased, 11% decreased, and 63% remained stable). After adjustment for clinical factors, era was not associated with DAPT use but treating hospital remained significantly associated with DAPT use. Other clinical factors associated with increased DAPT utilization included off-pump surgery (odds ratio [OR] 4.48, P < .01) and prior percutaneous coronary intervention (OR 2.02, P < .01), and atrial fibrillation (OR 0.39, P < .01) was associated with decreased utilization.

Conclusions

Dual antiplatelet use has increased between 2011 and 2017, driven primarily by evolving patient demographics. Significant hospital-level variability drives inconsistency in DAPT utilization. Efforts to promote DAPT use for patients treated with CABG after myocardial infarction in concordance with current guidelines should be targeted at the hospital level.

Section snippets

Patient Data

The Virginia Cardiac Services Quality Initiative includes 19 hospitals and surgical groups in the region. Registry data includes 99% of all adult cardiac surgery in the region and methodologies for clinical data acquisition have been described previously.14 Standard Society of Thoracic Surgeons definitions were used for all variables.15 Institutional Society of Thoracic Surgeons data are voluntarily submitted by each center and compiled in a central database to be used for quality improvement.

Results

A total of 7314 patients who underwent isolated CABG in the setting of a recent AMI were included in the analysis, after excluding 167 (2.2%) patients with missing discharge medication data (Figure 1). Of these, 4164 (56.9%) underwent surgery in the early era and 3149 (43.1%) in the late era.1 In the late era, patients were more likely to have diabetes (50.5% vs 47.6%, P = .014), hypertension (86.8% vs 85.0, P = .031), and heart failure (31.2% vs 24.0%, P < .001) and were more likely to have

Comment

In this analysis of a regional quality database containing over 7000 patients who underwent CABG after AMI, we observed a relatively low rate of discharge on DAPT after CABG (31.2%). Although there was a significant increase in DAPT over time, this plateaued in 2014. This change appears to be in part affected by evolving patient demographics, with a surgical population at higher overall ischemic risk and more patients presenting for CABG after previous PCI. Moreover, there was significant

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