Diagnostic Performance and Pressure Stability of a Novel Myocardial Ischemic Diagnostic Index　― The Intracoronary-Electrocardiogram-Triggered Distal Pressure/Aortic Pressure Ratio ―

Abstract

Background: We hypothesized that the intracoronary-electrocardiogram (IC-ECG)-based pressure index would be more stable and precise than the instantaneous flow reserve (iFR). We investigated the usefulness of the IC-ECG-based pressure index for diagnosing myocardial ischemia. Methods and Results: Thirty-seven consecutive patients with coronary stenosis requiring physiological assessment were enrolled in the study. iFR was measured at rest and under hyperemia in 51 and 40 lesions, respectively. The IC-ECG-triggered distal pressure (Pd)/aortic pressure (Pa) ratio (ICE-T) was defined as the mean Pd/Pa ratio in the period corresponding to the isoelectric line. The ICE-T was significantly lower than the iFR both at rest and during hyperemia (P<0.00001 for both). Fluctuations in the ICE-T pressure parameters (Pd/Pa, Pa, and Pd) were significantly smaller than those of iFR both at rest and during hyperemia. The diagnostic accuracy of predicting a fractional flow reserve (FFR) ≤0.80 of the ICE-T at rest was significantly higher than that of iFR (P=0.008). Receiver operating characteristic curve analyses showed that the ICE-T predicts FFR ≤0.80 more accurately than the iFR (area under curve 0.897 vs. 0.810 for ICE-T and iFR, respectively). Conclusions: We identified the period in the IC-ECG in which resting Pd/Pa was low and constant. The IC-ECG-based algorithm may improve the accuracy of diagnosing myocardial ischemia, without increasing invasiveness, compared with pressure-dependent indices.

Stability of Flow Velocity and Intracoronary Resistance in the Intracoronary Electrocardiogram-triggered Pressure Ratio

“…Intracoronary electrocardiogram (IC-ECG) ndings are sensitive and selective in detecting regional myocardial potentials [13][14][15][16][17][18]. Although the sample size in our study was small, we have found that, in the period in which the resting Pd/Pa was low, the accuracy of the IC-ECG-triggered resting index (ICE-T) was superior to the iFR in diagnosing myocardial ischemia [19].…”

The stability of flow velocity and intracoronary resistance in the intracoronary electrocardiogram-triggered pressure ratio

“…Intracoronary electrocardiogram (IC-ECG) findings are sensitive and selective in detecting regional myocardial potentials 13 – 18 . Although the sample size in our previous study was small, we found that, in the period in which the resting Pd/Pa was low, the accuracy of the IC-ECG-triggered resting index (ICE-T) was superior to the iFR in diagnosing myocardial ischemia 19 .…”

Diagnosis of Arrhythmia for Patients with Occult Coronary Heart Disease Guided by Intracavitary Electrocardiogram under Data Mining Algorithm

“…Moreover, some people have studied and proposed that IEGM can detect the viable myocardium at the infarcted area of patients with acute myocardial infarction and predict the postoperative efficacy of coronary intervention. Therefore, the clinical application value of IEGM is very high [ 26 ].…”