Economic trends from 2003 to 2010 for perioperative myocardial infarction: a retrospective, cohort study

Perioperative myocardial infarction (PMI) is a major surgical complication that is costly and causes much morbidity and mortality. Diagnosis and treatment of PMIs have evolved over time. Many treatments are expensive but may reduce ancillary expenses including the duration of hospital stay. The time-dependent economic impact of novel treatments for PMI remains unexplored. The authors thus evaluated absolute and incremental costs of PMI over time and discharge patterns.

Approximately 31 million inpatient discharges were analyzed between 2003 and 2010 from the California State Inpatient Database. PMI was defined using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Propensity matching generated 21,637 pairs of comparable patients. Quantile regression modeled incremental charges as the response variable and year of discharge as the main predictor. Time trends of incremental charges adjusted to 2012 dollars, mortality, and discharge destination was evaluated.

Median incremental charges decreased annually by $1,940 (95% CI, $620 to $3,250); P < 0.001. Compared with non-PMI patients, the median length of stay of patients who experienced PMI decreased significantly over time: yearly decrease was 0.16 (0.10 to 0.23) days; P < 0.001. No mortality differences were seen; but over time, PMI patients were increasingly likely to be transferred to another facility.

Reduced incremental cost and unchanged mortality may reflect improving efficiency in the standard management of PMI. An increasing fraction of discharges to skilled nursing facilities seems likely a result from hospitals striving to reduce readmissions. It remains unclear whether this trend represents a transfer of cost and risk or improves patient care.