Outcomes after planned invasive or conservative treatment strategy in patients with non-ST-elevation acute coronary syndrome and a normal value of high sensitivity troponin at randomisation: A Platelet Inhibition and Patient Outcomes (PLATO) trial biomarker substudy

Current guidelines for patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) recommend early invasive treatment in intermediate-to-high risk patients based on medical history, electrocardiogram (ECG) and elevated troponin. Patients with normal levels of cardiac troponin measured with a high-sensitivity method (cTnT-hs) might not benefit from early invasive procedures.

In this Prospective Randomized Platelet Inhibition and Patient Outcomes (PLATO) blood-core substudy, 1232 patients presented with NSTE-ACS had a high sensitivity cardiac troponin T (cTnT-hs) level <99^th percentile (<14 ng/l) at randomisation. The outcomes in relation to a planned invasive (n=473) vs planned conservative treatment (n=759), were evaluated by adjusted Cox proportional hazard analyses. In patients with a normal cTnT-hs at randomisation, regardless of randomised treatment, a planned invasive vs conservative treatment was associated with a 2.3-fold higher risk (7.3% vs 3.4%, p=0.0028) for cardiovascular (CV) death or myocardial infarction (MI), driven by higher rates of procedure-related MI (3.4% vs 0.1%), while there were no differences in rates of CV death (1.3% vs 1.3%, p=0.72) or spontaneous MI (3.0% vs 2.1%, p=0.28). There were significantly more major bleeds (hazard ratio (HR) 2.98, p<0.0001), mainly due to coronary artery bypass graft (CABG)-related (HR 4.05, p<0.0001) and non-CABG procedural-related major bleeding events (HR 5.31, p=0.0175), however there were no differences in non-procedure-related major bleeding (1.5% vs 1.9%, p=0.45). Findings were consistent for patients with a normal cTnI-hs at randomisation.

In patients with NSTE-ACS and normal cTnT-hs, a planned early invasive treatment strategy was associated with increased rates of procedure-related MI and bleeding but no differences in long-term spontaneous MI, non-procedure-related bleeding or mortality.