Ten-year trends of clinical outcomes after percutaneous coronary intervention: a Korean nationwide longitudinal cohort study

OBJECTIVES: Mortality following percutaneous coronary intervention (PCI) is a key quality measurement in clinical practice. This study investigated the 10-year trends of mortality following PCI in an unselected nationwide cohort. DESIGN: Retrospective cohort study. SETTING: A nationwide study in South Korea. PARTICIPANTS: PCI claim data from 2006 to 2015 of the National Health Insurance Service and the Statistics of Korea. MEASURES: 1-year cardiovascular or non-cardiovascular death. RESULTS: In total, 437 436 patients were included. The annual number of PCI cases increased from 32 098 to 51 990 over the decade studied (p<0.001). Patients were divided into quartile subgroups according to an estimated adjusted probability for predicting 1-year all-cause death. The proportion of patients in the high-risk quartiles increased whereas those in the low-risk quartiles decreased (p<0.001). The 1-year cumulative incidence rate of all-cause death did not change in the population with risk scores in the 1st (0.9% to 0.8%) and 2nd (1.3% to 1.3%) quartiles, whereas it increased in the population with risk scores in the 3rd (3.4% to 5.1%) and 4th (15.5% to 19.4%) quartiles (p<0.001). Compared with year 2006, the mean survival time in year 2015 was shorter by 0, 3.3 and 12.4 days in patients with risk scores in the 1st or 2nd, 3rd and 4th quartiles, respectively. These findings were also consistent for cardiovascular or non-cardiovascular deaths. CONCLUSION: The number, proportion and the overall risk of patients with a high risk for mortality after PCI increased over the decade in Korea.