214: Interpreting troponin elevation in relation to symptom onset in intermediate-risk pulmonary embolism

Abstract

Troponin elevation in the setting of acute pulmonary embolism (PE) is of small magnitude and short duration and can go unnoticed in pts referred late after symptom onset. Prospective, single-center registry of pts with confirmed intermediate-risk PE, defined as at least 1 echocardiographic finding of right ventricular (RV) dysfunction (endo-diastolic (EDRV)/left ventricular (EDLV) end-diastolic diameter ratio >=1 in the 4-chamber view, paradoxical septal systolic motion or pulmonary hypertension defined as RV/atrial gradient >30mmHg), or positive troponin test. Combined in-hospital endpoint was defined as death, non-fatal recurrent PE, or residual pulmonary vascular obstruction (RPVO) ≥35%. 282 pts were included, age 66±14 years, 59% women, 174 (62%) referred ≤5 days after symptom onset, 108 (38%) after >5 days. Troponin elevation was observed in 126 (72%) treated within ≤5 days, in 60 (56%) treated after >5 days (p=0.004). A significant interaction was observed between time since symptom onset and both troponin elevation and persistence of EDRV/EDLV diameter ratio>1 at 48h. The negative predictive value of troponin elevation was 85% in patients treated within 5 days of symptoms, but fell to 70% in those admitted >5 days after symptom onset (p=0.002). Positive troponin was an independent predictor of adverse outcome (OR=1.43 [1.08-5.56]). ROC curves show that prognostic value of positive troponin test was higher in pts referred ≤5 days than in pts referred >5 days after symptom onset (p=0.01). There is a significant relation between troponin elevation and time since symptom onset in patients with intermediate-risk PE. Negative predictive value of troponin elevation is adequate in pts treated early (≤5 days) but is suboptimal in pts treated >5 days after symptom onset. Table Results <=5 days since symptom onset >5 days since symptom onset p Sensitivity 72% (61.3-82.7) 51% (42.4-59.6) 0.005 Specificity 42% (44.5-49.5) 47% (39.1-54.9) 0.33 PPV 26% (18.4-33.6) 30% (22.2-37.8) 0.81 NPV 85% (78.4-91.6) 70% (63-77) 0.002