Objectives: To evaluate, using continuous 12-lead ECG ST-segment monitoring, the role of circulating levels of both cardiac troponin I (cTnI) and high-sensitivity C reactive protein (hs-CRP), on presentation, in the prediction of intravenous thrombolysis outcome in patients with ST-segment elevation myocardial infarction (STEMI).
Design and setting: Prospective observational study in a tertiary referral centre.
Patients: 786 consecutive patients with STEMI, who received intravenous thrombolysis in the first 6 h from index pain.
Main outcome measures: The incidence of failed thrombolysis and of cardiac death by 30 days. Failed thrombolysis was defined as the absence of abrupt and sustained > or =50% ST-segment recovery in the first 90 min after the initiation of intravenous thrombolysis.
Results: The incidence of failed thrombolysis and 30-day cardiac death was 57.4% and 11.8%, respectively. By multivariate logistic regression analysis according to tertiles of both cTnI (RR, 1.5; 95% CI 1.1 to 1.8, p = 0.004 for highest vs middle third; 2.2, 1.9 to 3.5, p<0.001 for highest vs lowest third; 1.5, 1.2 to 1.8, p = 0.001 for middle vs lowest third) and hs-CRP (RR, 2.0, 95% CI, 1.6 to 2.2; p<0.001 for highest vs middle third; 2.6, 2.1 to 3.5, p<0.001 for highest vs lowest third; 1.3, 1.2 to 1.7, p = 0.02 for middle vs lowest third), were independently associated with failed thrombolysis. Moreover, by multivariate Cox regression analysis according to tertiles of both cTnI (HR 1.2, 95% CI 1.1 to 1.8, p = 0.03 for highest vs middle third; 1.5, 1.2 to 2.2, p = 0.004 for highest vs lowest third; 1.1, 0.6 to 1.4, p = 0.6 for middle vs lowest third) and hs-CRP (HR1.2, 95% CI 1.1 to 1.6, p = 0.04 for highest vs middle third; 1.7, 1.3 to 2.6, p = 0.001 for highest vs lowest third; 1.1, 0.9 to 2.1, p = 0.1 for middle vs lowest third), were independently related with an increased risk of 30-day cardiac death.
Conclusions: High circulating levels of both cTnI and hs-CRP are related with an independent increased risk of intravenous thrombolysis failure and 30-day cardiac death in patients who received intravenous thrombolysis in the first 6 h of STEMI.