Troponin Levels at Presentation Before Coronary Angiogram and Their Association With Cost, Mortality, and Readmission

Background and objective In patients undergoing coronary angiogram, the degree of cardiac enzyme elevation at presentation has been thought of as a strong and independent predictor of in-hospital mortality and readmission. Recent studies, however, have suggested a lack of clarity regarding this speculation, particularly with regard to troponin elevations. Additionally, the impact of troponin levels (TnI) at presentations on cost is poorly understood. In this study, we aimed to evaluate the association of Tnl at initial presentation with 30-day all-cause readmission and all-cause mortality as well as admission costs. Methods This study was a retrospective analysis of 7,388 patients who underwent coronary angiogram at our facility from 2015 to 2017. Patients were identified from a local CathPCI Registry^® registry, and a subsequent chart review was performed for readmission and mortality data. Cost data were provided by our in-facility finance department. We excluded patients with incomplete records and those who required coronary artery bypass grafting (CABG). After the exclusion of patients deemed ineligible, the final sample size eligible for analysis was 1,163. Patients were divided into two groups based on Tnl at presentation with a cut-off value of 0.04 ng/ml. Adjusted regression and multivariate analysis were used for clinical outcomes. Primary outcomes were 30-day readmission and mortality. The secondary outcome was the admission cost. Results Within our cohort, the average participant age was 64.6 years (SD: 12.7), and the majority of them were male (70.7%). Of these patients, 207 had lower TnI (<0.04 ng/ml), while 956 had higher TnI at presentation. The high TnI (≥0.04 ng/ml) group had a significantly higher number of patients with a family history of coronary artery disease (CAD) (13.8% vs. 7.7%: p=0.017) and those on dialysis (3.2% vs. 0.5%: p=0.028) compared to the low Tnl group. Additionally, we did not find any significant difference in 30-day mortality or readmission between the two groups in our cohort. On average, each patient in the high TnI group spent $936 more for hospital admissions compared to patients in the low Tnl group. However, this difference was not statistically significant. Conclusions Tnl at admission did not reveal a significant impact on 30-day mortality or readmission, which is consistent with the findings of previous studies. A high Tnl at admission increased the cost of admission; however, the difference was not statistically significant in our cohort.