Target Lesion Lipid Content Detected by Near-Infrared Spectroscopy After Stenting and the Risk of Subsequent Target Lesion Failure.

[Figure: see text].

Spatial relationships among hemodynamic, anatomic, and biochemical plaque characteristics in patients with coronary artery disease.

BACKGROUND AND AIMS: We aimed to characterize the spatial proximity of plaque destabilizing features local endothelial shear stress (ESS), minimal luminal area (MLA), plaque burden (PB), and near-infrared spectroscopy (NIRS) lipid signal in high- vs. low-risk plaques. METHODS: Coronary arteries imaged with angiography and NIRS-intravascular ultrasound (IVUS) underwent 3D reconstruction and computational fluid dynamics calculations of local ESS. ESS, PB, MLA, and lipid core burden index (LCBI), for each 3-mm arterial segment were obtained in arteries with large lipid-rich plaque (LRP) vs. arteries with smaller LRP. The locations of the MLA, minimum ESS (minESS), maximum ESS (maxESS), maximum PB (maxPB), and maximum LCBI in a 4-mm segment (maxLCBI4mm) were determined along the length of each plaque. RESULTS: The spatial distributions of minESS, maxESS, maxPB, and maxLCBI4mm, in reference to the MLA, were significantly heterogeneous within and between each variable. The location of maxLCBI4mm was spatially discordant from sites of the MLA (p<0.0001), minESS (p = 0.003), and maxESS (p = 0.003) in arteries with large LRP (maxLCBI4mm ≥ 400) and non-large LRP. Large LRP arteries had higher maxESS (9.31 ± 4.78 vs. 6.32 ± 5.54 Pa; p = 0.023), lower minESS (0.41 ± 0.16 vs. 0.61 ± 0.26 Pa; p = 0.007), smaller MLA (3.54 ± 1.22 vs. 5.14 ± 2.65 mm2; p = 0.002), and larger maxPB (70.64 ± 9.95% vs. 56.70 ± 13.34%, p<0.001) compared with non-large LRP arteries. CONCLUSIONS: There is significant spatial heterogeneity of destabilizing plaque features along the course of both large and non-large LRPs. Large LRPs exhibit significantly more abnormal destabilizing plaque features than non-large LRPs. Prospective, longitudinal studies are required to determine which patterns of heterogeneous destabilizing features act synergistically to cause plaque destabilization.

Network latency and long-distance robotic telestenting: Exploring the potential impact of network delays on telestenting performance.

OBJECTIVE: This study evaluated the impact of network latency on telestenting performance. BACKGROUND: The feasibility of long-distance robotic telestenting was recently demonstrated, yet the impact of network performance on telestenting remains unknown. METHODS: Ex vivo and in vivo telestenting models were constructed by connecting a robotic drive over a wired network to a robotic control system up to 103 miles away. During consecutive attempts to robotically wire a coronary artery, investigators randomly added signal latencies from 0 to 1,000 ms. Outcomes included wiring success, wiring time (time to advance wire to preselected target landmark), and perceived latency score (5 = imperceptible; 4 = noticeable but minor; 3 = noticeable; 2 = noticeable and major; 1 = unacceptable). RESULTS: Wiring success was achieved in 95 of 95 attempts in the ex vivo model and in 57 of 57 attempts in vivo. No significant difference in wiring time was observed across added latencies from 0 to 1,000 ms in the ex vivo (p = .64) or in vivo (p = .40) models. Compared to an added latency of 0 ms, perceived latency scores were not significantly different for added latencies of 150 and 250 ms (p = NS for both), but were significantly lower for latencies ≥400 ms (p < .001). CONCLUSIONS: Added latencies up to 250 ms were not associated with perceived latency, but latencies ≥400 ms were perceptible. Based on these findings, future telestenting studies should utilize networks with latencies ≤250 ms if perceived latency is to be avoided.

Patient Body Mass Index and Physician Radiation Dose During Coronary Angiography.

BACKGROUND: Consistent with the increasing prevalence of obesity in the general population, obesity has become more prevalent among patients undergoing cardiac catheterization. This study evaluated the association between patient body mass index (BMI) and physician radiation dose during coronary angiography. METHODS AND RESULTS: Real-time radiation exposure data were collected during consecutive coronary angiography procedures. Patient radiation dose was estimated using dose area product. Physician radiation dose in each case was recorded by a dosimeter worn by the physician and is reported as the personal dose equivalent (Hp10). Patient BMI was categorized as <25.0, 25.0 to 29.9, 30.0 to 34.9, 35.0 to 39.9, and ≥40. Among 1119 coronary angiography procedures, significant increases in dose area product and physician radiation dose were observed across increasing patient BMI categories ( P<0.001). Compared with a BMI <25, a patient BMI ≥40 was associated with a 2.1-fold increase in patient radiation dose (dose area product, 91.8 [59.6-149.2] versus 44.5 [25.7-70.3] Gy×cm2; P<0.001) and a 7.0-fold increase in physician radiation dose (1.4 [0.2-7.1] versus 0.2 [0.0-2.9] µSv; P<0.001). By multiple regression analysis, patient BMI remained independently associated with physician radiation dose (dose increase, 5.2% per unit increase in BMI; 95% CI, 3.0%-7.5%; P<0.0001). CONCLUSIONS: Among coronary angiography procedures, increasing patient BMI was associated with a significant increase in physician radiation dose. Additional studies are needed to determine whether patient obesity might have adverse effects on physicians, in the form of increased radiation doses during coronary angiography.

Impact of patient obesity on radiation doses received by scrub technologists during coronary angiography.

BACKGROUND: The impact of patient obesity on scrub technologist radiation dose during coronary angiography has not been adequately studied. METHODS: Real-time radiation exposure data were prospectively collected during consecutive coronary angiography cases. Patient radiation dose was estimated by dose area product (DAP). Technologist radiation dose was recorded by a dosimeter as the personal dose equivalent (Hp (10)). Patients were categorized according to their body mass index (BMI): <25.0, lean; 25.0-29.9, overweight; ≥30.0, obese. The study had two phases: in Phase I (N = 351) standard radiation protection measures were used; and in Phase II (N = 268) standard radiation protection measures were combined with an accessory lead shield placed between the technologist and patient. RESULTS: In 619 consecutive coronary angiography procedures, significant increases in patient and technologist radiation doses were observed across increasing patient BMI categories (p < 0.001 for both). Compared to lean patients, patient obesity was associated with a 1.7-fold increase in DAP (73.0 [52.7, 127.5] mGy × cm2 vs 43.6 [25.1, 65.7] mGy × cm2, p < 0.001) and a 1.8-fold increase in technologist radiation dose (1.1 [0.3, 2.7] µSv vs 0.6 [0.1, 1.6] µSv, p < 0.001). Compared to Phase I, use of an accessory lead shield in Phase II was associated with a 62.5% reduction in technologist radiation dose when used in obese patients (p < 0.001). CONCLUSIONS: During coronary angiography procedures, patient obesity was associated with a significant increase in scrub technologist radiation dose. This increase in technologist radiation dose in obese patients may be mitigated by use of an accessory lead shield.

Radiation Exposure Among Scrub Technologists and Nurse Circulators During Cardiac Catheterization: The Impact of Accessory Lead Shields.

OBJECTIVES: This study was performed to determine if the use of an accessory lead shield is associated with a reduction in radiation exposure among staff members during cardiac catheterization. BACKGROUND: Accessory lead shields that protect physicians from scatter radiation are standard in many catheterization laboratories, yet similar shielding for staff members is not commonplace. METHODS: Real-time radiation exposure data were prospectively collected among nurses and technologists during 764 consecutive catheterizations. The study had 2 phases: in phase I (n = 401), standard radiation protection measures were used, and in phase II (n = 363), standard radiation protection measures were combined with an accessory lead shield placed between the staff member and patient. Radiation exposure was reported as the effective dose normalized to dose-area product (EDAP). RESULTS: Use of an accessory lead shield in phase II was associated with a 62.5% lower EDAP per case among technologists (phase I: 2.4 [4.3] µSv/[mGy × cm2] × 10-5; phase II: 0.9 [2.8] µSv/[mGy × cm2] × 10-5; p < 0.001) and a 63.6% lower EDAP per case among nurses (phase I: 1.1 [3.1] µSv/[mGy × cm2] × 10-5; phase II: 0.4 [1.8] µSv/[mGy × cm2] × 10-5; p < 0.001). By multivariate analysis, accessory shielding remained independently associated with a lower EDAP among both technologists (34.2% reduction; 95% confidence interval: 20.1% to 45.8%; p < 0.001) and nurses (36.4% reduction; 95% confidence interval: 19.7% to 49.6%; p < 0.001). CONCLUSIONS: The relatively simple approach of using accessory lead shields to protect staff members during cardiac catheterization was associated with a nearly two-thirds reduction in radiation exposure among nurses and technologists.

Multimodality Intracoronary Imaging With Near-Infrared Spectroscopy and Intravascular Ultrasound in Asymptomatic Individuals With High Calcium Scores.

BACKGROUND: This study sought to determine the frequency of large lipid-rich plaques (LRP) in the coronary arteries of individuals with high coronary artery calcium scores (CACS) and to determine whether the CACS correlates with coronary lipid burden. METHODS AND RESULTS: Combined near-infrared spectroscopy and intravascular ultrasound was performed in 57 vessels in 20 asymptomatic individuals (90% on statins) with no prior history of coronary artery disease who had a screening CACS ≥300 Agatston units. Among 268 10-mm coronary segments, near-infrared spectroscopy images were analyzed for LRP, defined as a bright yellow block on the near-infrared spectroscopy block chemogram. Lipid burden was assessed as the lipid core burden index (LCBI), and large LRP were defined as a maximum LCBI in 4 mm ≥400. Vessel plaque volume was measured by quantitative intravascular ultrasound. Vessel-level CACS significantly correlated with plaque volume by intravascular ultrasound (r=0.69; P<0.0001) but not with LCBI by near-infrared spectroscopy (r=0.24; P=0.07). Despite a high CACS, no LRP was detected in 8 (40.0%) subjects. Large LRP having a maximum LCBI in 4 mm ≥400 were infrequent, found in only 5 (25.0%) of 20 subjects and in only 5 (1.9%) of 268 10-mm coronary segments analyzed. CONCLUSIONS: Among individuals with a CACS ≥300 Agatston units mostly on statins, CACS correlated with total plaque volume but not LCBI. This observation may have implications on coronary risk among individuals with a high CACS considering that it is coronary LRP, rather than calcification, that underlies the majority of acute coronary events.

Percutaneous coronary intervention using a combination of robotics and telecommunications by an operator in a separate physical location from the patient: an early exploration into the feasibility of telestenting (the REMOTE-PCI study).

AIMS: The present study explores the feasibility of telestenting, wherein a physician operator performs stenting on a patient in a separate physical location using a combination of robotics and telecommunications. METHODS AND RESULTS: Patients undergoing robotic stenting were eligible for inclusion. All manipulations of guidewires, balloons, and stents were performed robotically by a physician operator located in an isolated separate room outside the procedure room housing the patient. Communication between the operating physician and laboratory personnel was via telecommunication devices providing real-time audio and video connectivity. Among 20 patients who consented to participate, technical success, defined as successful advancement and retraction of guidewires, balloons, and stents by the robotic system without conversion to manual operation, was achieved in 19 of 22 lesions (86.4%). Procedural success, defined as <30% residual stenosis upon completion of the procedure in the absence of death or repeat revascularisation prior to hospital discharge, was achieved in 19 of 20 patients (95.0%). There were no deaths or repeat revascularisations prior to hospital discharge. CONCLUSIONS: To the best of our knowledge, the present study is the first to explore the feasibility of telestenting. Additional studies are required to determine if future advancements in robotics will facilitate telestenting over greater geographic distances.

Impact of robotics and a suspended lead suit on physician radiation exposure during percutaneous coronary intervention.

BACKGROUND: Reports of left-sided brain malignancies among interventional cardiologists have heightened concerns regarding physician radiation exposure. This study evaluated the impact of a suspended lead suit and robotic system on physician radiation exposure during percutaneous coronary intervention (PCI). METHODS: Real-time radiation exposure data were prospectively collected from dosimeters worn by operating physicians at the head- and chest-level during consecutive PCI cases. Exposures were compared in three study groups: 1) manual PCI performed with traditional lead apparel; 2) manual PCI performed using suspended lead; and 3) robotic PCI performed in combination with suspended lead. RESULTS: Among 336 cases (86.6% manual, 13.4% robotic) performed over 30weeks, use of suspended lead during manual PCI was associated with significantly less radiation exposure to the chest and head of operating physicians than traditional lead apparel (chest: 0.0 [0.1] µSv vs 0.4 [4.0] µSv, p<0.001; head: 0.5 [1.9] µSv vs 14.9 [51.5] µSv, p<0.001). Chest-level radiation exposure during robotic PCI performed in combination with suspended lead was 0.0 [0.0] µSv, which was significantly less chest exposure than manual PCI performed with traditional lead (p<0.001) or suspended lead (p=0.046). In robotic PCI the median head-level exposure was 0.1 [0.2] µSv, which was 99.3% less than manual PCI performed with traditional lead (p<0.001) and 80.0% less than manual PCI performed with suspended lead (p<0.001). CONCLUSIONS: Utilization of suspended lead and robotics were observed to result in significantly less radiation exposure to the chest and head of operating physicians during PCI.