Risk stratification and long-term outcomes in patients with chest pain and cardiac troponin flat curve
P Awamleh Garcia, J L Santiago Ruiz, P Rodriguez Montes, N Gil Mancebo, S Humanes Ybanez, M de la Serna Real de Asua, M Gutierrez Munoz, E F Parrales Sanchez, A Vilchez Alcocer, M Romero Osuna, M I Donoso Garcia, A Colomo Gutierrez, E Martinez Munoz, B Izquierdo Coronel, J J Alonso MartinAbstract
Introduction
Acute myocardial injury is defined by cardiac troponin (cTn) levels above the 99th percentile with a dynamic rise/fall pattern (Δ), usually suggesting acute coronary syndrome (ACS) when associated with compatible symptoms. Patients presenting with chest pain, elevated cTn and a flat curve (Δ<20%) represent a diagnostic challenge, as current guidelines do not associate this pattern with ACS. Early prognosis has been described, but the temporal evolution of risk and the adequacy of initial clinical management remain uncertain. We aimed to assess 12-month outcomes according to initial management strategy: admission in cardiology, admission in other departments or discharge from emergency department.
Methods
We prospectively analyzed 753 consecutive patients with suspected ACS and a cTn-flat-curve (Δ<20% in two high-sensitivity cTn-T determinations at 0 and 3 hours) between May 2023 and January 2026. Management decisions were based on comprehensive clinical evaluation. Six- and twelve-month follow-up assessed mortality, other major adverse cardiovascular events (MACE), and re-admissions.
Results
Mean age was 75.7±11.9 years and 63.3% were male. ACS was diagnosed predominantly in patients admitted to cardiology. Six-month follow-up was available in 614 patients and 12-month follow-up in 484 patients. At 12 months, patients admitted to non-cardiology departments showed the highest mortality (29.5%) and MACE rate (39%), largely driven by non-cardiovascular causes. Patients admitted to cardiology had intermediate event rates, whereas discharged patients maintained low mortality (7.5%) throughout follow-up, although they were not event-free. Kaplan–Meier curves demonstrated early and persistent separation between management groups, confirming distinct risk trajectories over time (Figure 1).
Conclusions
In patients with a cTn-flat-curve, risk extends beyond the early phase and differs markedly according to initial management. The sustained separation of survival curves supports the prognostic relevance of clinical decision-making. Importantly, the low long-term mortality among discharged patients validates the safety of careful, clinically guided risk stratification in this heterogeneous population.Table 1Figure 1:Kaplan-Meier curves