Abstract 9563: High-frequency QRS Analysis is More Specific and Accurate Than Conventional ST-segment Analysis in Diagnosing Coronary Ischaemia

Purpose: High-frequency QRS analysis (HFQRS) is a new tool for detecting stress-induced coronary ischaemia. This study aims to compare HFQRS with conventional ST-segment analysis (STA) in the diagnostic performance in patients with chest pain and no history of coronary artery disease, which has not been investigated before. Methods: One hundred and seventy-five patients (120 men; mean age 58.2±7.5) with chest pain referred for diagnostic workup of coronary ischaemia were recruited. They underwent symptom-limited exercise treadmill test with both HFQRS and STA, followed by myocardial perfusion imaging (MPI) to confirm presence or absence of ischaemia. Results: Coronary ischaemia was present in 20 (11.4%) patients by MPI. HFQRS was more specific (85.8 vs 68.4%; p=0.002) and similarly sensitive (45 vs 60%; p=0.371) compared with STA. HFQRS had a higher positive predictive value (29 vs 19.7%; p=0.01) and similar negative predictive value (92.4 vs 93%; p=0.61) compared with STA. The diagnostic accuracy for coronary ischaemia by HFQRS was significantly higher than STA (81.1 vs 67.4%; p=0.001). Conclusions: HFQRS is more specific and accurate than STA in diagnosing coronary ischaemia in patients with chest pain and no prior history of coronary artery disease.