Frequency of 30-day readmission and its causes after percutaneous coronary intervention in acute myocardial infarction complicated by cardiogenic shock

Background Survival after percutaneous coronary intervention (PCI) in acute myocardial infarction complicated by cardiogenic shock (AMI-CS) has increased over the years. Short-term readmission rates in this high-risk population remain unknown. Methods We queried the United States (U.S.) Nationwide Readmission Database (NRD) from January 2010 to November 2014 using the International Classification of Diseases-Ninth edition, Clinical Modification (ICD-9 CM) codes to identify all patients >= 18 years readmitted within 30 days after surviving an index hospitalization for PCI in AMI-CS. Incidence, etiologies, and predictors of 30-day readmission were analyzed. Results Among 46,435 patients who survived to discharge after PCI in AMI-CS, 9,020 (19.4%) were readmitted within 30 days. Median time to 30-day readmission was 11 days. Cardiac conditions were the most common causes of readmission (57.8%). Heart failure was the leading readmission diagnosis (24.8%). Private insurance including HMO and self-pay were predictive of lower 30-day readmission. Among other covariates, female sex, comorbidities such as heart failure, atrial fibrillation, in-hospital complications such as major bleeding, sepsis, respiratory complications, AKI requiring dialysis, utilization of mechanical circulatory support (IABP and ECMO) were independently predictive of 30-day readmission. Trend analysis showed decline in 30-day readmission rates from 21.9% in 2010 to 17.9% in 2014 (p(trend) < 0.001). Conclusion In this large real-world database, one in five patients receiving PCI in AMI-CS was readmitted within 30 days after discharge. Cardiac conditions were the most common causes of readmission. Insurance type had significant influence on 30-day readmission.