PURPOSE: To assess the frequency of cardiac troponin I (cTnI) elevation at various cut off levels among all patients with pulmonary embolism, and to assess the correlation of cTnI levels with in-hospital mortality and intensive care unit stay.
METHODS: All in-patients with a diagnosis of pulmonary embolism (n=138) during a two-year period from May 2003 were screened. The frequency of cTnI levels at two cut off levels of >0.06 ng/ml (99th centile for cTnI level) and >0.6 ng/ml (threshold value used to diagnose myocardial infarction) was determined. The correlation between cTnI at these two cut off levels were made to outcome measures like in-hospital mortality, ICU admission and duration of ICU stay.
RESULTS: 86 patients met the inclusion criteria out of which 36 patients (42%) had cTnI level more than 0.06 ng/ml, while 7 patients (8%) had more than 0.6 ng/ml. In-hospital mortality was 11% (4 out of 36) in those with cTnI >0.06 ng/ml compared to 2% (1 out of 49) in those with lower concentrations. At the cut off level of >0.6 ng/ml in-hospital mortality was 30% (2 out of 7) vs. 4%.14 out of 36 patients (39%) with cTnI >0.06 ng/ml were admitted to the ICU compared to 6 out of 50 (12%) with lower levels and the odds ratio for being in the ICU at this level was 4.67 (95% CI 1.5 –13.8). The mean duration of ICU stay 1.86 vs. 0.66 days (p 0.047)in the 2 groups. At the higher cut off level of 0.6 ng/ml the likelihood of being in the ICU was even higher and was 57% (4 out of 7) vs. 20% (16 out of 79).
CONCLUSION: cTnI of > 0.06 was highly predictive of mortality, ICU admission and duration of ICU stay and a higher level of 0.6 ng/ml were associated with even higher event rates.
CLINICAL IMPLICATIONS: This helps in risk stratification of patients with pulmonary embolism and to select patients for more aggressive treatment.
DISCLOSURE: Lisa Francis, None.