An observational evaluation of 30-day unplanned readmissions after percutaneous coronary intervention in the United States

Abstract

Percutaneous coronary intervention (PCI) has become one of the most commonly performed procedures in hospital used to treat coronary heart disease. As PCI has evolved into a safe procedure with low mortality rates, however, there is now a growing population of patients who undergo PCI and are at risk of complications and readmissions. With the constant aim to improve patient care, reducing unplanned readmissions are of interest because they can be considered an adverse outcome for patients and potentially requiring unnecessary cost. There is limited literature from national cohorts that were designed to evaluate unplanned readmissions from all payers in the United States.
The aim of this thesis is to evaluate 30-day unplanned readmissions after PCI in a nationally representative, all-payer cohort in the United States. In particular, this thesis will determine 1) The overall rate of 30-day unplanned readmissions and trends in readmission rates will be explored to determine how rates have changed over time 2) Who are the patients at risk of 30-day unplanned readmissions? 3) How do age group, sex, comorbidity and discharge against medical advice impact unplanned readmissions? 4) Why do patients return for 30-day unplanned readmission? 5) How do the rates of unplanned readmissions after PCI change over time after the procedure? 6) What are the costs of 30-day unplanned readmissions after PCI?
This thesis addresses the aforementioned aims in multiple chapters. Chapter 5 evaluates the 30-day unplanned readmission rate in the entire cohort, trends in readmission rates, predictors of readmissions and cause of readmission in the entire PCI cohort. Chapter 6, 7, 8 and 9 evaluated how 30-day unplanned readmissions differ depending on age group, sex, comorbidity burden and discharge against medical advice. Chapter 10 highlights the impact of 30-day unplanned readmissions on cost while Chapter 11 discusses how readmission rates, predictors and causes of readmission differ depending on the timing of evaluation of readmissions up to 180 days.
Overall, this thesis demonstrates that 30-day unplanned readmissions are common affecting nearly 1 in 10 patients who undergo PCI. Older patients, female patients, comorbid patients and patients who discharge against medical advice have a greater propensity for unplanned readmissions and measures should be taken to reduce readmissions in these patients. The financial burden of readmissions is significant and the cost of coronary syndromes treated with PCI and 30-day unplanned readmissions in the United States is estimated to be $10.8 billion. Important causes of unplanned readmissions include non-specific chest pain, infection, gastrointestinal disease, coronary artery disease including angina, acute myocardial infarction and heart failure and these causes should be targeted by interventions to reduce readmissions. Hospitals where patients undergo PCI should evaluate if rates of readmission are a problem and clinicians should implement interventions to reduce the burden of unplanned readmissions after PCI. In particular, patient care should be tailored to the individual with risk reduction and optimization of the management of both cardiac and co-morbid conditions and the appropriate arrangement of community care once discharged.