Association of Coronary Computed Tomography-Defined Myocardial Bridge With Pre- and Post-Procedural Fractional Flow Reserve in Patients Undergoing Elective Percutaneous Coronary Intervention.

BACKGROUND: Myocardial bridge (MB) is a common coronary anomaly characterized by a tunneled course through the myocardium. Coronary computed tomography angiography (CCTA) can identify MB. The impact of MB detected by CCTA on coronary physiological parameters before and after percutaneous coronary intervention (PCI) is unknown.Methods and Results: We investigated 141 consecutive patients who underwent pre-PCI CCTA and fractional flow reserve (FFR)-guided elective PCI for de novo single proximal lesions in the left anterior descending artery (LAD). We compared clinical demographics and physiological parameters between patients with and without CCTA-defined MB. MB was identified in 46 (32.6%) patients using pre-PCI CCTA. The prevalence of diabetes was higher among patients with MB. Median post-PCI FFR values were significantly lower among patients with than without MB (0.82 [interquartile range 0.79-0.85] vs. 0.85 [interquartile range 0.82-0.89]; P=0.003), whereas pre-PCI FFR values were similar between the 2 groups. Multivariable linear regression analysis revealed that the presence of MB and greater left ventricular mass volume in the LAD territory were independently associated with lower post-PCI FFR values. Multivariable logistic regression analysis also revealed that the presence of MB and lower pre-PCI FFR values were independent predictors of post-PCI FFR values ≤0.80. CONCLUSIONS: CCTA-defined MB independently predicted both lower post-PCI FFR as a continuous variable and ischemic FFR as a categorical variable in patients undergoing elective PCI for LAD.

Ventricular Fibrillation During Optical Coherence Tomography/Optical Frequency Domain Imaging　- A Large Single-Center Experience.

BACKGROUND: The risks of ventricular fibrillation (Vfib) associated with frequency-domain optical coherence tomography (OCT)/optical frequency domain imaging (OFDI) remain undetermined.Methods and Results:We retrospectively studied the occurrence of Vfib during OCT/OFDI for unselected indications. The frequency of Vfib and patient and procedural characteristics were investigated. A total of 4,467 OCT/OFDI pullback examinations were performed in 1,754 patients (median of 2.0 [2.0-3.0] pullbacks for 1.0 [1.0-1.3] vessels). OCT/OFDI was performed during PCI in 899 patients (51.3%). The contrast injection volume per pullback was 14.4 (11.7-17.2) mL with a flow rate of 3.4 (3.2-3.5) mL/s. Vfib occurred in 31 pullbacks (0.69%) in 30 patients (1.7%). No cases of Vfib occurred when using low-molecular-weight dextran. On multivariate analysis, contrast volume was the only independent factor for predicting Vfib (odds ratio, 1.080; 95% confidence interval, 1.008-1.158, P=0.029). The best cutoff value of contrast volume for predicting Vfib was 19.2 mL (area under the curve, 0.713, P<0.001; diagnostic accuracy, 87.1%). CONCLUSIONS: The present large, single-center registry study indicated that Vfib during OCT/OFDI was rare for unselected indications. Contrast injection volume used to displace blood should be limited to avoid Vfib.

Impact of Pressure Signal Drift on Fractional Flow Reserve-Based Decision-Making for Patients With Intermediate Coronary Artery Stenosis.

BACKGROUND: Fractional flow reserve (FFR) is an important physiological measure of intermediate coronary artery stenosis. Pressure signal drift (PD) is widely recognized but has largely been ignored in FFR measurements. We sought to determine the effect of PD on FFR-derived decision-making. METHODS AND RESULTS: We analyzed 1,218 FFR measurements for intermediate stenosis in 940 patients, in which the pullback maneuver confirmed PD ≤3 mmHg. The primary objectives were to determine the frequency and magnitude of PD and its effect on decision-making on the basis of an FFR cutoff of 0.80. In all, 479 (39.3%) measurements showed PD. PD was significantly associated with age, hypertension, reference diameter, left anterior descending artery lesion location, and read-out FFR values. Classification discordance between read-out and PD-corrected FFR values was detected in 44 (3.6%) measurements in total and in 9.2% of PD cases. The decision changed from FFR ≤0.80 to FFR >0.80 in 40 (3.3%) and vice versa in 4 (0.3%) measurements. PD showed no effect on decision-making when the FFR read-out value was ≤0.76 or ≥0.83. CONCLUSIONS: PD is not uncommon, and its effect on FFR-based decision-making was not negligible in the range between 0.77 and 0.82 where reclassification occurred in 18.7% of FFR measurements. (Circ J 2016; 80: 1812-1819).

Impact of Impella on Coronary Flow Assessed by Transthoracic Doppler Echocardiography.

A 66-year-old male patient presented with anterior ST-elevated myocardial infarction and cardiogenic shock. After placement of the Impella device (Abiomed, Danvers, Massachusetts), the patient successfully underwent percutaneous coronary intervention for lesions in the left anterior descending artery (LAD) and left circumflex artery. Coronary flow in the LAD according to the support setting was evaluated using transthoracic Doppler echocardiography during Impella weaning.

Early effect of percutaneous coronary intervention of non-left anterior descending artery on coronary flow velocity reserve of left anterior descending artery assessed by transthoracic Doppler echocardiography.

BACKGROUND: Limited data are available regarding the influence of percutaneous coronary intervention (PCI) of non-totally occluded lesions (non-CTO) on the coronary flow of non-target vessels. We sought to investigate the short-term impact of the non-left anterior descending artery (non-LAD) PCI on the coronary flow physiology of LAD using transthoracic Doppler echocardiography (TDE). METHODS AND RESULTS: We consecutively studied 50 patients who underwent successful PCI of non-LAD and non-CTO lesions and a coronary flow velocity assessment of LAD at rest and maximal hyperemia before and at 2 days after the procedure by TDE. Coronary flow velocity reserve (CFVR) was calculated as the ratio of hyperemic to resting diastolic peak velocity (hDPV/bDPV). We evaluated the changes in LAD coronary flow characteristics after PCI of non-LAD and explored the determinants of the change in LAD-CFVR. The median fractional flow reserve (FFR) of the culprit lesion and the LAD quantitative flow ratio (QFR) were 0.67 and 0.88, respectively. After non-LAD PCI, LAD-CFVR was decreased in 33 patients (66.0%). LAD-CFVR significantly decreased (pre-PCI: 2.41, post-PCI: 2.03, p = 0.001) due to a significant decrease in LAD-hDPV (P = 0.007). The prevalence of impaired LAD-CFVR (≤2.0) significantly increased (pre: 30%, post: 48%, P = 0.027). Multivariable linear regression analysis showed that pre-PCI LAD-CFVR was independent predictor of the change in LAD-CFVR after PCI. CONCLUSIONS: LAD-CFVR significantly decreased after successful non-LAD PCI due to the postprocedural reduction of coronary flow assessed by LAD-hDPV.