title: Are clinical parameters and biomarkers predictive of severity of acute pulmonary emboli on CTPA?
abstract: BACKGROUND
  Previous studies have shown that findings of computed tomography pulmonary angiography (CTPA) relate to outcome in pulmonary embolus (PE). These include clot burden as quantified using an obstruction index and markers of pressure overload such as right ventricle to left ventricle size ratio (RV/LV ratio). Little data exists correlating these findings with clinical presentation and biomarkers.
  
  
  OBJECTIVE
  To explore the link between clinical presentation and biomarkers with CTPA findings.
  
  
  METHODS
  Retrospective case note analysis of consecutive cases presenting to a large teaching hospital. An independent radiologist reviewed CTPAs and clot burden quantified using an obstruction index.
  
  
  RESULTS
  One hundred and seventy cases were identified and notes retrieved in 137 cases. (i)
  
  
  METHODS
  correlation was seen between clot burden and systolic blood pressure (BP) (r = -0.299, P = 0.0006) and heart rate (r = 0.240, P = 0.0056). Median obstruction index was significantly higher in those with a presenting BP <90 mmHg [41.25% (95% CI 30-50) vs. 15% (95% CI 12.5-25), (P = 0.0004)]. Clot burden was significantly higher in patients with temperature of >37.5 degrees C [30% (95% CI 25.0-42.5) vs. 15% (95% CI 12.5-28.3), P = 0.02)] and (ii)Biomarkers: significant correlation between clot burden and D-dimer was seen (r = 0.36, P = 0.0001). Location of thrombus was associated with significant differences in D-dimer level. A subgroup of patients had cardiac biomarkers measured (n = 24). There was a statistically significant correlation between troponin I and clot burden (r = 0.412, P = 0.048) and RV/LV ratio (r = 0.699, P = 0.0013).
  
  
  CONCLUSIONS
  These findings suggest that clinical parameters and biomarkers have a role in predicting the radiological severity of PE. These data support the need for further studies of risk stratification in patients presenting with acute PE.
authors.affiliation: Department of Respiratory Medicine, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, UK. chinoo@hotmail.co.uk
authors.forename: V
authors.initials: V
authors.lastname: Jeebun
authors.forename: S J
authors.initials: SJ
authors.lastname: Doe
authors.forename: L
authors.initials: L
authors.lastname: Singh
authors.forename: S A
authors.initials: SA
authors.lastname: Worthy
authors.forename: I A
authors.initials: IA
authors.lastname: Forrest
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D015415:Biomarkers / Q000032:analysis; D001794:Blood Pressure; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006339:Heart Rate; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D