Acute pulmonary embolism (PE) may cause elevated levels of cardiac troponin I (cTnI) and troponin T due to right ventricular strain and subsequent myocardial injury. We investigated whether cTnI concentrations following acute PE correlate with the severity of radionuclide mismatch on ventilation/perfusion (V/Q) lung scan and prognosis.
Between 1998 and 2000, 137 consecutive patients with acute PE underwent a V/Q scan and cTnI measurement (upper limit of normal = 0.9 ng/mL) within 24 hours of diagnosis. Medical records were abstracted for baseline clinical data and V/Q scans were reviewed for mismatched segmental lesions. Number of V/Q mismatched defects, cTnI concentrations and outcomes were compared.
At the time of PE diagnosis, 46 (33%) patients with a mean age of 72 ± 14 years had elevated cTnI (=> 1 ng/mL) (mean cTnI of 4.2 ± 0.3 ng/mL), and 92 (67%) patients with a mean age of 65 ± 17 years had normal cTnI (< 1 ng/mL) (mean cTnI 0.2 ± 0.3 ng/mL). The mean number of V/Q mismatched segments was significantly increased in the cTnI positive compared to cTnI negative group (5.1 ± 3.8 vs. 3.6 ± 2.6, p=0.005). At 30 days followup, 23 (17%) patients died and elevated cTnI (61% vs. 27%, p=0.002) was associated with higher mortality.CONCLUSIONS: In acute PE, elevated levels of cTnI are associated with more extensive perfusion abnormalities and reduced survival.
Raised cTnI levels during acute PE are associated with worse survival and are a more useful prognostic factor than the number of V/Q mismatched segments.
J.A. Sallach, None.