TOTAL risk score for predicting safe very early discharge in patients with ST-elevation myocardial infarction (STEMI)

Abstract

Abstract Background/Introduction Previously validated risk scores for identifying low-risk patients after ST-segment elevation myocardial infarction (STEMI) have led to acceptance of the safety and feasibility of discharge after 48–72 hours of hospitalization, reducing hospital length of stay and costs. With ongoing improvements in outcomes, it may be possible to select patients who are safe to discharge very early (24–48 hours) but this has never been evaluated. Purpose We sought to develop and validate a novel risk score for identifying low-risk patients suitable for very early discharge (≤48 hours of hospitalization) post-STEMI. Methods We derived a novel risk score using data from patients enrolled in the Trial of Routine Aspiration Thrombectomy with PCI versus PCI alone in Patients with STEMI (TOTAL). The TOTAL database was randomly divided into a derivation cohort with 2/3 of the composite events and non-events and remaining 1/3 as the internal validation cohort. Using the derivation cohort, we identified risk factors for cardiovascular death (CV) or non-fatal cardiac arrest by performing a univariate and multivariable stepwise regression analysis of baseline clinical and angiographic characteristics. Each co-variate was assigned an integer score based on regression coefficients and the novel TOTAL risk score was developed by adding points from each risk factor profile. We externally validated the TOTAL score using data from the Radial versus Femoral Access for Coronary Intervention (RIVAL) trial. Results The TOTAL derivation cohort included 6331 participants with 287 events (CV death/cardiac arrest). Twelve independent risk-factors associated with risk of CV death and non-fatal cardiac arrest at 1 year were selected and weighted for the TOTAL risk score (Table 1). In the TOTAL validation cohort (n=3166), patients with a TOTAL score of 0–4 points (n=779 (24.6%)) were categorized as very low risk with only a 0.1% risk of CV death/cardiac arrest observed within 24 hours of hospitalization, and no further events observed between 24 hours and 30 days post-STEMI. In the RIVAL validation dataset (n=1451), patients with a TOTAL score of 0–4 points (n=737 (50.7%)) had a 0.3% risk of CV death/cardiac arrest within 24 hours, with no further events observed between 24 hours and 72 hours of hospitalization. Conclusion The TOTAL risk score identified a very low risk subset of patients for whom early discharge, 24–48 hours post-STEMI, is likely safe. These findings have the potential to change practice and support early discharge after STEMI. Funding Acknowledgement Type of funding sources: None.