Impact of Prior Coronary Artery Bypass Grafting in Patients ≥75 Years Old Presenting With Acute Myocardial Infarction (From the National Readmission Database)

Patients ≥75 years old presenting with acute myocardial infarction (AMI) have complex coronary anatomy in part due to prior coronary artery bypass grafting (CABG), percutaneous coronary interventions (PCI), calcific and valvular disease. Using the National Readmission Database from January 2016 to November 2017, we identified hospital admissions for acute myocardial infarction in patients ≥75 years old and divided them based on a history of CABG. We evaluated in-hospital outcomes, 30-day mortality, 30-day readmission and predictors of PCI in cohorts. Out of a total of 296,062 patients ≥75 years old presenting with an AMI, 42,147 (14%) had history of previous CABG. Most presented with a non-ST segment elevation myocardial infarction, and those with previous CABG had higher burden of co-morbidities and were more commonly man. The in-hospital mortality was significantly lower in those with previous CABG (6.7% vs 8.8%, adjusted odds ratio, 0.88, 95% confidence interval, 0.82 to 0.94). Medical therapy was more common in those with previous CABG and 30-day readmission rates were seen more frequently in those with prior CABG. Predictors of not undergoing PCI included previous PCI, female, older ager groups, heart failure, dementia, malignancy, and higher number of co-morbidities. In conclusion, in patients ≥75 years old with AMI the presence of prior CABG was associated with lower odds of in-hospital and 30-day mortality, as well as lower complications rates, and a decreased use of invasive strategies (PCI, CABG, and MCS). However, 30-day MACE readmission was higher in those with previous CABG.