Visual Estimates of Coronary Slow Flow Are Not Associated with Invasive Wire-Based Diagnoses of Coronary Microvascular Dysfunction

Background: Coronary slow flow (CSF) by invasive coronary angiography is frequently understood to be an indicator of coronary microvascular dysfunction (CMD) in patients with ischemia with non-obstructive coronary arteries (INOCA). However, the relationship between visual estimates of CSF and quantitative wire-based invasive diagnosis of CMD is uncertain. Methods: We prospectively enrolled adults age ≥18 years with stable ischemic heart disease who were referred for invasive coronary angiography. Individuals with ≥50% epicardial coronary artery stenosis were excluded. Invasive coronary angiography was reviewed for CSF, defined as ≥3 cardiac cycles to opacify distal vessels with contrast. Coronary function testing was performed in the left anterior descending (LAD) coronary artery using bolus coronary thermodilution techniques to measure coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). Invasively determined CMD was defined as abnormal CFR (<2.5), abnormal IMR (≥25), or both. Results: Among 104 participants, the median age was 61.5 and 79% were female. The median CFR was 3.6 (IQR 2.5-4.7) and the median IMR was 21 (IQR 13.3-28.0). Overall, 24.0% of participants had abnormal CFR, 34.6% had abnormal IMR, and 48.1% had a final diagnosis of invasively determined CMD. CSF was present in 23 participants (22.1%). The proportions of patients with CMD (56.5% vs 45.7%, p=0.36), abnormal CFR (17.4% vs 25.9%, p=0.40) and abnormal IMR (43.5% vs. 32.1%, p=0.31) were not different in patients with versus without CSF. Conclusions: Among patients with INOCA, CSF was not associated with abnormal CFR, IMR, or either abnormal CFR or IMR. CSF is not a reliable angiographic surrogate of abnormal CFR or IMR as determined by invasive, wire-based physiology testing.

Embolization of a Large Intracoronary Thrombus During ST-Segment Elevation Myocardial Infarction

Aspiration thrombectomy was performed to retrieve intact thrombus in a 69-year-old woman. Bradycardia and hypotension rapidly resolved. Balloon angioplasty was performed at the site of proximal RCA in-stent restenosis with improved angiographic appearance and TIMI 3 flow in the major branches.

Effect of Left Versus Right Radial Artery Approach for Coronary Angiography on Radiation Parameters in Patients With Predictors of Transradial Access Failure

Left transradial approach (TRA) for coronary angiography is associated with lower radiation parameters than right TRA in an all-comers population. The aim of this study was to determine the effects of left versus right TRA on radiation parameters in patients with predictors of TRA failure. Patients with predictors of TRA failure (≥3 of 4 following criteria: age ≥70 years, female gender, height ≤64 inches, and hypertension) referred to TRA operators were randomized to either right (n = 50) or left (n = 50) TRA, whereas those referred to transfemoral approach (TFA) operators were enrolled in a prospective registry (n = 50). The primary end point was the radiation measure of dose-area product (DAP). In an intention-to-treat analysis, DAP (34.1 Gy·cm(2) [24.9 to 45.6] vs 41.9 Gy·cm(2) [27.3 to 58.0], p = 0.08), fluoroscopy time (3.7 minutes [2.4 to 6.3] vs 5.6 minutes [3.1 to 8.7], p = 0.07), and operator radiation exposure (516 μR [275 to 967] vs 730 μR [503 to 1,165], p = 0.06) were not significantly different between left and right TRA, but total dose (411 mGy [310 to 592] vs 537 mGy [368 to 780], p = 0.03) was significantly lower with left versus right TRA. Radiation parameters were lowest in the TFA cohort (DAP 24.5 Gy·cm(2) [15.7 to 33.2], p <0.001; fluoroscopy time 2.3 minutes [1.5 to 3.7], p <0.001; operator radiation exposure 387 μR [264 to 557]; total dose 345 mGy [250 to 468], p = 0.001). Results were similar after adjustment for differences in baseline characteristics. In conclusion, median measurements of radiation were overall not significantly different between left versus right TRA in this select population of patients with predictors of TRA failure. All measurements of radiation were lowest in the TFA group.