Heart Vision

Summary

OVER VIEW OF PATIENT AND VESSEL ANALYSIS

  • 1% (n=1) of the patients had a significant stenosis missed on CT and were upgraded after catheter.
  • 12% (n=10) of the patients were downgraded from significant stenosis to no significant stenosis after catheter.
  • If CT triages a patient as not significant stenosis, 7% (n=1) of the patients will be upgraded to significant after catheter.
  • If CT triages a patient as significant stenosis, 15% (n=10) of the patients will be downgraded to not significant after catheter.
  • Of the 41 patients that were true positives for severe stenosis in any vessel, 22% (n=9) of those patients were also false negative in another vessel for a severe stenosis, so the patient was concordant, but not all the vessels were concordant. 
  • In addition 2% (n=1) of the 41 severely stenosed patients were correctly triaged by patient as severe by ‘chance'; these patients were false positive in one vessel and false negative in another, so no vessels were concordant, but the patient classification was concordant. (Patient no;1, visit no; 2695811, NHI; LTB7580)
  • 6% (n=5) of the patients had a severe stenosis missed on CT and were upgraded after catheter.
  • 7% (n=6) of patients were downgraded from severe stenosis on CT after catheter.
  • If CT triages a patient as not severe, 14% (n=5) of the patients will be upgraded to severe after catheter.
  • If CT triages a patient as severe, 13% (n=6) of the patients will be downgraded to not severe after catheter.

Accuracy and Precision

  • CTCA is 86.5% accurate at a patient concordance of ≥50%, and 85.3% precise.
  • CTCA is also 86.5% accurate at a patient concordance of ≥70%, and 87.2% precise.
  • Accuracy is the proportion of true results (both true positives and true negatives) in the study.
  • Precision is the proportion of the true positives against all the positive results (both true positives and false positives) in the study.