Proportional troponin changes and risk for outcomes with intervention strategies in non-ST-elevation acute coronary syndrome across kidney function.

Aims: This analysis evaluates whether proportional serial cardiac troponin (cTn) change predicts benefit from an early versus delayed invasive, or conservative treatment strategies across kidney function in non-ST-elevation acute coronary syndrome (NSTE-ACS).

Methods: Patients diagnosed with NSTE-ACS in the Veterans Health Administration between 1999 and 2022 were categorized into terciles (<20%, 20 to ≤80%, >80%) of proportional change in serial cTn. Primary outcome included mortality or rehospitalization for myocardial infarction at 6 and 12 months, in survivors of index admission. Adjusted hazard ratio (HR) with 95% confidence Intervals (95% confidence interval [CI]) were calculated for the primary outcome for an early invasive (≤24 h of the index admission), delayed invasive (>24 h of index admission to 90-days postdischarge), or a conservative management.

Results: Chronic kidney disease (CKD) was more prevalent (45.3%) in the lowest versus 42.2% and 43% in middle and highest terciles, respectively (p < 0.001). Primary outcome is more likely for conservative versus early invasive strategy at 6 (HR: 1.44, 95% CI: 1.37-1.50) and 12 months (HR: 1.44, 95% CI: 1.39-1.50). A >80% proportional change demonstrated HR (95% CI): 0.90 (0.83-0.97) and 0.93 (0.88-1.00; p = 0.041) for primary outcome at 6 and 12 months, respectively, when an early versus delayed invasive strategy was used, across CKD stages.

Conclusions: Overall, the invasive strategy was safe and associated with improved outcomes across kidney function in NSTE-ACS. Additionally, >80% proportional change in serial troponin in NSTE-ACS is associated with benefit from an early versus a delayed invasive strategy regardless of kidney function. These findings deserve confirmation in randomized controlled trials.