In-hospital mortality decreased after CABG, but not PCI from 2003 to 2016 in the US
Trends in Characteristics and Outcomes of Patients Undergoing Coronary Revascularization in the United States, 2003-2016
Introduction and methods
The annual number of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) has decreased in recent years, possibly due to advances in medical therapy, the emergence of data questioning the benefit of PCI in stable CAD, and an increase in implementation of appropriate use criteria [1-4]. It remains unknown whether this change in procedural numbers is associated with changes in risk profiles of patients and with outcomes of the procedures.
This retrospective cohort study used the Nationwide Inpatient Sample (NIS) database to investigate temporal changes in baseline characteristics of patients undergoing PCI or CABG in the US from 2003 to 2016 and assessed in-hospital mortality after the procedures stratified by clinical indication. Data from 8,687,338 PCIs (72.0%, mean age 66.0 [SD=10.8] years, 66.2% was male) and 3,374,743 CABGs (28.0%, mean age was 64.5 [SD=12.4] years, 72.1% was male) were analyzed. PCIs were further classified into those performed for ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), or unstable angina or stable ischemic heart disease (UA-SIHD). CABG procedures were classified into those performed in the context of acute myocardial infarction (AMI), or UA-SIHD. Clinical risk profile trends were investigated in 3 eras (2003-2007, 2008-2012, and 2012-2016).
- The annual PCI volume decreased from 777,780 in 2003 to 440,505 in 2016, this corresponds with a decrease in PCI rate from 366 to 180 per 100,000 US adults between 200 and 2016. The annual CABG volume decreased from 337,444 in 2003 to 201,840 in 2016, corresponding with a decrease in CABG rate from 159 to 82 per 100,000 US adults between 2003 and 2016.
- In both PCI and CABG groups, a temporal increase was observed in the proportion of male, elderly and nonwhite patients, and patients with lower socioeconomic status.
- The percentage of patients with an Elixhauser comorbidity index score ≥3 increased in the PCI group from 24.7% in 2003-2007 to 52.3% in 2012-2016. In the CABG group was this 29.8% and 52.2%, respectively.
- The proportion of PCI for AMI among all PCIs increased from 22.8% in 2003-2007 to 53.1% in 2012-2016. The percentage of CABG for AMI increased from 19.5% to 28.2% and CABG for cardiogenic shock increased from 2.8% to 6.1%.
- In-hospital mortality modestly increased between 2003 and 2016 after PCI from STEMI (4.9% to 5.3%, P<0.001 for trend) or UA-SIHD (0.8% to 1.0%, P<0.001) and remained stable after PCI for NSTEMI (1.6% to 1.6%, P=0.18) after risk adjustment for patient- and hospital-level characteristics.
- In-hospital mortality decreased between 2003 and 2016 after CABG in the context of AMI (5.6% to 3.4%, P<0.001 for trend) or for UA-SIHD (2.8% to 1.7%, P<0.001 for trend) after risk adjustment for patient- and hospital-level characteristics.
The number of PCI and CABG procedures decreased in the US between 2003 and 2016. This was accompanied by changes in the demographic characteristics. In both groups, a temporal increase was observed in the proportion of male, elderly and nonwhite patients and patients with lower socioeconomic status. Changes in risk profile and clinical presentation of patients undergoing these procedures were also observed. Risk adjusted in-hospital mortality after PCI did not improve over time between 2003 and 2016, but decreased over time after CABG.