The need for detailed institutional case analysis in assessing thirty-day unplanned readmission rate after Percutaneous Coronary Intervention (PCI): A quality assurance study

Author(s): Eric C. Wong, David A. Wood, Janarthanan Sathananthan, Simon W. Rabkin

Background: Thirty-day unplanned readmission following PCI is recognized as an important quality metric because it is associated with poor outcomes. A national health information data bank (Canadian Institute of Health Information (CIHI)) reported an overall mean risk-adjusted 30-day all-cause unplanned readmission rate for PCI of 7.2%. We sought to compare this national metrics with a detailed analysis of local institutional data. Methods: A retrospective study of 30-day readmissions following PCI at Vancouver General Hospital during a three-year period from April 2015 to July 2018 to coincide with the CIHI report. Inclusion criteria were patients readmitted to any one of 5 hospitals within the region-Vancouver Coastal Health Authority (VCHA) or 12 hospitals within the adjacent Fraser Health Authority (FHA). Planned staged PCI procedures were excluded. The proportion of VCHA readmissions potentially related to poor PCI outcomes, angina pectoris or arrhythmia were determined. Results: There were 4,478 patients with PCI, of who had a 108 unplanned hospital readmission to VCHA and 50 to FHA, for a cumulative 3.5% readmission rate across the two largest health authorities in the province. Among the VCHA readmissions, a minority 21% (23 cases) were related to unstable angina/myocardial ischemia or arrhythmias. The majority of those cases had PCI on an urgent basis with drug-eluting stents. Conclusion: Thirty-day unplanned readmission rate after discharge from PCI at our tertiary hospital was low. These data underscore the importance of detailed case analysis to define true readmission rates, and questions the use of readmission rates as a sole metric of quality of care independent of detailed case review.