Loss of miR-144/451 alleviates β-thalassemia by stimulating ULK1-mediated autophagy of free α-globin

Most cells can eliminate unstable or misfolded proteins through quality control mechanisms. In the inherited red blood cell disorder β-thalassemia, mutations in the β-globin gene (HBB) lead to a reduction in the corresponding protein and the accumulation of cytotoxic free α-globin, which causes maturation arrest and apoptosis of erythroid precursors and reductions in the lifespan of circulating red blood cells. We showed previously that excess α-globin is eliminated by Unc-51-like autophagy activating kinase 1 (ULK1)-dependent autophagy and that stimulating this pathway by systemic mammalian target of rapamycin complex 1 (mTORC1) inhibition alleviates β-thalassemia pathologies. We show here that disrupting the bicistronic microRNA gene miR-144/451 alleviates β-thalassemia by reducing mTORC1 activity and stimulating ULK1-mediated autophagy of free α-globin through 2 mechanisms. Loss of miR-451 upregulated its target messenger RNA, Cab39, which encodes a cofactor for LKB1, a serine-threonine kinase that phosphorylates and activates the central metabolic sensor adenosine monophosphate-activated protein kinase (AMPK). The resultant enhancement of LKB1 activity stimulated AMPK and its downstream effects, including repression of mTORC1 and direct activation of ULK1. In addition, loss of miR-144/451 inhibited the expression of erythroblast transferrin receptor 1, causing intracellular iron restriction, which has been shown to inhibit mTORC1, reduce free α-globin precipitates, and improve hematological indices in β-thalassemia. The beneficial effects of miR-144/451 loss in β-thalassemia were inhibited by the disruption of Cab39 or Ulk1 genes. Together, our findings link the severity of β-thalassemia to a highly expressed erythroid microRNA locus and a fundamental, metabolically regulated protein quality control pathway that is amenable to therapeutic manipulation.

Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods

BACKGROUND

Hyperleukocytosis in patients with acute myeloid leukemia (AML) has been associated with worse outcomes. For cytoreduction, leukapheresis has been used but its clinical utility is unknown, and low-dose cytarabine (LD-cytarabine) is used as an alternative method.

METHODS

Children with newly diagnosed AML treated between 1997 and 2017 in institutional protocols were studied. Hyperleukocytosis was defined as a leukocyte count of ≥100 × 109 /L at diagnosis. Clinical characteristics, early complications, survival data, and effects of cytoreductive methods were reviewed. Among 324 children with newly diagnosed AML, 49 (15.1%) presented with hyperleukocytosis. Initial management of hyperleukocytosis included leukapheresis or exchange transfusion (n = 16, considered as one group), LD-cytarabine (n = 18), hydroxyurea (n = 1), and no leukoreduction (n = 14).

RESULTS

Compared with patients who received leukapheresis, the percentage decrease in leukocyte counts following intervention was greater among those who received LD-cytarabine (48% vs. 75%; p = .02), with longer median time from diagnosis to initiation of protocol therapy (28.1 vs. 95.2 hours; p < .001). The incidence of infection was higher in patients (38%) who had leukapheresis than those who receive LD-cytarabine (0%) or leukoreduction with protocol therapy (14%) (p = .008). No differences were noted in the outcomes among the intervention groups. Although patients with hyperleukocytosis had higher incidences of pulmonary and metabolic complications than did those without, no early deaths occurred, and the complete remission, event-free survival, overall survival rates, and outcomes of both groups were similar.

CONCLUSION

LD-cytarabine treatment appears to be a safe and effective means of cytoreduction for children with AML and hyperleukocytosis.

Gene Therapy and Gene Editing for β-Thalassemia

After many years of intensive research, emerging data from clinical trials indicate that gene therapy for transfusion-dependent β-thalassemia is now possible. Strategies for therapeutic manipulation of patient hematopoietic stem cells include lentiviral transduction of a functional erythroid-expressed β-globin gene and genome editing to activate fetal hemoglobin production in patient red blood cells. Gene therapy for β-thalassemia and other blood disorders will invariably improve as experience accumulates over time. The best overall approaches are not known and perhaps not yet established. Gene therapy comes at a high cost, and collaboration between multiple stakeholders is required to ensure that these new medicines are administered equitably.

Effective therapies for sickle cell disease: are we there yet?

Sickle cell disease (SCD) is a common genetic blood disorder associated with acute and chronic pain, progressive multiorgan damage, and early mortality. Recent advances in technologies to manipulate the human genome, a century of research and the development of techniques enabling the isolation, efficient genetic modification, and reimplantation of autologous patient hematopoietic stem cells (HSCs), mean that curing most patients with SCD could soon be a reality in wealthy countries. In parallel, ongoing research is pursuing more facile treatments, such as in-vivo-delivered genetic therapies and new drugs that can eventually be administered in low- and middle-income countries where most SCD patients reside.

Phase I Dose-Finding, Safety, and Tolerability Trial of Romiplostim to Improve Platelet Recovery After UCB Transplantation

Platelet recovery is delayed after umbilical cord blood transplant (UCBT). Romiplostim is a thrombopoietin receptor agonist that has the potential to improve platelet engraftment after UCBT. The purpose of this study was to determine the safety profile and maximum tolerated dose (MTD) of romiplostim and to investigate whether romiplostim accelerates platelet recovery post-UCBT. It was a single-center, dose-finding, safety and tolerability phase I trial of weekly romiplostim in 20 adult patients who failed to achieve an un-transfused platelet count of 20 × 10⁹/L by day +28 post-UCBT. Romiplostim was administered at the assigned dose as 6 weekly injections beginning by day +42 post-UCBT. Four dose levels (4, 6, 8, and 10 µg/kg per dose) were evaluated. The MTD of romiplostim was determined by the continual reassessment method, with a goal to identify a dose level with desired toxicity rate of ≤20%. Median age of the patients was 59.5 years, and 60% were female. Eleven patients received nonmyeloablative (NMA) double UCBT, seven patients received myeloablative single UCBT, and two patients received NMA single UCBT. Two patients received 4 µg/kg per dose, two received 6 µg/kg per dose, four received 8 µg/kg per dose, and the remaining 12 received 10 µg/kg per dose. Only five patients completed the full six doses of treatment. Of the 15 patients who received fewer than six doses, 12 were due to a platelet count of >100 × 10⁹/L, two were due to platelet count of >400 × 10⁹/L, and one was due to right upper extremity edema without thrombosis. All romiplostim-treated patients achieved platelet engraftment to 20 × 10⁹/L at a median of 45 days post-UCBT compared to 90% of controls at a median of 45 days (P = .08). Similarly, 90% of romiplostim-treated patients achieved platelet engraftment to 50 × 10⁹/L at a median of 48 days compared to 75% of controls at a median of 52 days (P = .09). All dose levels were effective with low toxicity; therefore, the MTD of romiplostim was 10 µg/kg per dose, and romiplostim is a safe and potentially effective therapy to counter delayed platelet recovery post-UCBT.

Hereditary elliptocytosis-associated alpha-spectrin mutation p.L155dup as a modifier of sickle cell disease severity

The broad phenotypic variability among individuals with sickle cell disease (SCD) suggests the presence of modifying factors. We identified two unrelated SCD patients with unusually severe clinical and laboratory phenotype that were found to carry the hereditary elliptocytosis-associated alpha-spectrin mutation c.460_462dupTTG (p.L155dup), a mutation enriched due to positive selective pressure of malaria, similar to the SCD globin mutations. A high index of suspicion for additional hematologic abnormalities may be indicated for challenging patients with SCD. These cases highlight the validity of specialized testing such as ektacytometry and next-generation sequencing for patients and family members to assess genotype/phenotype correlations.

Impact of Chronic Total Occlusion Revascularization Attempts on Subsequent Clinical Outcomes

OBJECTIVES

We examined a contemporary, unselected cohort of patients with coronary chronic total occlusions (CTOs) to determine the impact of CTO revascularization on long-term outcomes.

METHODS

We retrospectively assessed the impact of CTO revascularization on clinical outcomes of consecutive patients found to have a CTO during coronary angiography performed at our institution during 2011 and 2012. The primary endpoint was the incidence of a major adverse cardiac event (MACE, defined as a composite of death, myocardial infarction, stroke, and target-vessel revascularization [TVR]). Survival analysis was performed in the overall and propensity-matched retrospective cohorts of patients stratified by prior coronary artery bypass graft (CABG) surgery. Propensity-adjusted hazard ratio (HR) and 95% confidence interval (95% CI) were calculated with Cox proportional hazards analysis. All analyses were by intention to treat.

RESULTS

Of 624 patients (319 without prior CABG and 305 with prior CABG) included in the present analysis, CTO revascularization (surgical or percutaneous) was attempted in 60% and 16% of patients without and with prior CABG, respectively. During a median follow-up of 26 months (range, 18-40 months), the incidence of MACE was 20.6%. CTO revascularization (achieved or attempted) was associated with lower incidence of MACE among patients without prior CABG (propensity-adjusted HR, 0.51; 95% CI, 0.27-0.94; P=.03), but not among prior CABG patients (propensity-adjusted HR, 1.38; 95% CI, 0.64-2.96; P=.41).

CONCLUSION

In a large, unselected patient population with coronary CTOs, a CTO revascularization attempt was associated with lower incidence of subsequent MACE among patients without prior CABG, but not among prior CABG patients.

Near-Infrared Spectroscopy Analysis of Coronary Chronic Total Occlusions

OBJECTIVE

To examine the presence and localization of lipid-core plaque (LCP) in coronary vessels with chronic total occlusions (CTOs) using near-infrared spectroscopy (NIRS).

METHODS

NIRS imaging was performed after guidewire crossing of the occlusion in 15 patients with CTOs. LCP was defined as ≥2 adjacent 2 mm yellow blocks on the block chemogram. We also measured the maximum lipid-core burden index (LCBI) in a 4 mm length of artery (maxLCBI4mm). Large LCP was defined as maxLCBI4mm ≥500.

RESULTS

Median patient age was 64 years (interquartile range [IQR], 61-67 years) and all patients were men with high prevalence of diabetes mellitus (64%) and prior coronary artery bypass graft surgery (27%). The CTO target vessel was the right coronary artery (46%), left anterior descending artery (27%), or circumflex artery (27%). Median occlusion length was 35 mm (IQR, 30-50 mm). LCP was present in 11 of 15 CTO vessels (73%) and a large LCP in 4 of 15 CTO vessels (27%). LCP was located at the proximal cap in 6 CTOs (55%), the CTO body in 6 CTOs (55%), and the distal cap in 2 CTOs (18%). The median overall LCBI and maxLCBI4mm were 145 (IQR, 79-243) and 415 (IQR, 267-505), respectively. All patients underwent successful stenting without any complications. The 12-month incidence of in-stent restenosis and target-lesion revascularization was 25%, and all patients who developed restenosis had an LCP at baseline.

CONCLUSIONS

LCPs are commonly encountered in coronary CTO vessels, suggesting an active intraplaque atherosclerotic process. The impact of LCP on postintervention outcomes requires further study.

Predictors of Excess Patient Radiation Exposure During Chronic Total Occlusion Coronary Intervention: Insights From a Contemporary Multicentre Registry

BACKGROUND

High patient radiation dose during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) might lead to procedural failure and radiation skin injury.

METHODS

We examined the association between several clinical and angiographic variables on patient air kerma (AK) radiation dose among 748 consecutive CTO PCIs performed at 9 experienced US centres between May 2012 and May 2015.

RESULTS

The mean age was 65 ± 10 years, 87% of patients were men, and 35% had previous coronary artery bypass graft surgery (CABG). Technical and procedural success was 92% and 90%, respectively. The median patient AK dose was 3.40 (interquartile range, 2.00-5.40) Gy and 34% of the patients received > 4.8 Gy (high radiation exposure). In univariable analysis male sex (P = 0.016), high body mass index (P < 0.001), history of hyperlipidemia (P = 0.023), previous CABG (P < 0.001), moderate or severe calcification (P < 0.001), tortuosity (P < 0.001), proximal cap ambiguity (P = 0.001), distal cap at a bifurcation (P = 0.006), longer CTO occlusion length (P < 0.001), blunt/no blunt stump (P < 0.001), and centre (P < 0.001) were associated with higher patient AK dose. In multivariable analysis high body mass index (P < 0.001), previous CABG (P = 0.005), moderate or severe calcification (P = 0.005), longer CTO occlusion length (P < 0.001), and centre (P < 0.001) were independently associated with higher patient AK dose.

CONCLUSIONS

Approximately 1 in 3 patients who undergo CTO PCI receive high AK radiation dose (> 4.8 Gy). Several baseline clinical and angiographic characteristics can help predict the likelihood of high radiation dose and assist with intensifying efforts to reduce radiation exposure for the patient and the operator.

Prospective Evaluation of the Impact of Side-Holes and Guide-Catheter Disengagement From the Coronary Ostium on Fractional Flow Reserve Measurements

BACKGROUND

We prospectively examined the impact of side-holes and guide-catheter disengagement on fractional flow reserve (FFR) measurements.

METHODS

Twenty-five patients undergoing clinically indicated FFR measurement for intermediate coronary artery stenosis were enrolled. Four FFR measurements were made in random order during intravenous adenosine infusion with: (a) an engaged side-hole guide catheter; (b) a disengaged side-hole guide catheter; (c) an engaged non-side-hole guide catheter; and (d) disengaged non-side-hole guide catheter.

RESULTS

Mean patient age was 65 ± 9 years and 100% were men. The mean distal poststenotic pressure/proximal aortic pressure (Pd/Pa) at baseline was 0.93 ± 0.05 mm Hg. Using intravenous adenosine infusion, the mean FFR measured with engaged vs disengaged non-side-hole guide catheters was 0.87 ± 0.09 vs 0.83 ± 0.10, respectively (mean difference, 0.039 ± 0.04; P<.001). The mean FFR with engaged vs disengaged side-hole guide catheters was 0.85 ± 0.10 vs 0.83 ± 0.10 (mean difference, 0.020 ± 0.02; P<.001). The mean difference in FFR measurements was 0.024 ± 0.03 (P<.001) among engaged guide catheters and 0.005 ± 0.03 (P=.47) among disengaged guide catheters.

CONCLUSIONS

When FFR measurements are performed with engaged guide catheters, side-hole catheters provide lower measurements. When FFR measurements are obtained with disengaged guide catheters, they are even lower and similar between guide catheter types.

Contrast Utilization During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry

BACKGROUND

Administration of a large amount of contrast volume during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) may lead to contrast-induced nephropathy.

METHODS

We examined the association of clinical, angiographic and procedural variables with contrast volume administered during 1330 CTO-PCI procedures performed at 12 experienced United States centers.

RESULTS

Technical and procedural success was 90% and 88%, respectively, and mean contrast volume was 289 ± 138 mL. Approximately 33% of patients received >320 mL of contrast (high contrast utilization group). On univariable analysis, male gender (P=.01), smoking (P=.01), prior coronary artery bypass graft surgery (P=.04), moderate or severe calcification (P=.01), moderate or severe tortuosity (P=.04), proximal cap ambiguity (P=.01), distal cap at a bifurcation (P<.001), side branch at the proximal cap (P<.001), blunt/no stump (P=.01), occlusion length (P<.001), higher J-CTO score (P=.02), use of antegrade dissection and reentry or retrograde approach (P<.001), ad hoc CTO-PCI (P=.04), dual arterial access (P<.001), and 8 Fr guide catheters (P<.001) were associated with higher contrast volume; conversely, diabetes mellitus (P=.01) and in-stent restenosis (P=.01) were associated with lower contrast volume. On multivariable analysis, moderate/severe calcification (P=.04), distal cap at a bifurcation (P<.001), ad hoc CTO-PCI (P<.001), dual arterial access (P=.01), 8 Fr guide catheters (P=.02), and use of antegrade dissection/reentry or the retrograde approach (P<.001) were independently associated with higher contrast use, whereas diabetes (P=.02), larger target vessel diameter (P=.03), and presence of "interventional" collaterals (P<.001) were associated with lower contrast utilization.

CONCLUSIONS

Several baseline clinical, angiographic, and procedural characteristics are associated with higher contrast volume administration during CTO-PCI.

Accuracy of remote chest X-ray interpretation using Google Glass technology

OBJECTIVES

We sought to explore the accuracy of remote chest X-ray reading using hands-free, wearable technology (Google Glass, Google, Mountain View, California).

METHODS

We compared interpretation of twelve chest X-rays with 23 major cardiopulmonary findings by faculty and fellows from cardiology, radiology, and pulmonary-critical care via: (1) viewing the chest X-ray image on the Google Glass screen; (2) viewing a photograph of the chest X-ray taken using Google Glass and interpreted on a mobile device; (3) viewing the original chest X-ray on a desktop computer screen. One point was given for identification of each correct finding and a subjective rating of user experience was recorded.

RESULTS

Fifteen physicians (5 faculty and 10 fellows) participated. The average chest X-ray reading score (maximum 23 points) as viewed through the Google Glass, Google Glass photograph on a mobile device, and the original X-ray viewed on a desktop computer was 14.1±2.2, 18.5±1.5 and 21.3±1.7, respectively (p<0.0001 between Google Glass and mobile device, p<0.0001 between Google Glass and desktop computer and p=0.0004 between mobile device and desktop computer). Of 15 physicians, 11 (73.3%) felt confident in detecting findings using the photograph taken by Google Glass as viewed on a mobile device.

CONCLUSION

Remote chest X-ray interpretation using hands-free, wearable technology (Google Glass) is less accurate than interpretation using a desktop computer or a mobile device, suggesting that further technical improvements are needed before widespread application of this novel technology.

Clinical Utility of the Japan-Chronic Total Occlusion Score in Coronary Chronic Total Occlusion Interventions: Results from a Multicenter Registry

BACKGROUND

The performance of the Japan-chronic total occlusion (J-CTO) score in predicting success and efficiency of CTO percutaneous coronary intervention has received limited study.

METHODS AND RESULTS

We examined the records of 650 consecutive patients who underwent CTO percutaneous coronary intervention between 2011 and 2014 at 6 experienced centers in the United States. Six hundred and fifty-seven lesions were classified as easy (J-CTO=0), intermediate (J-CTO=1), difficult (J-CTO=2), and very difficult (J-CTO≥3). The impact of the J-CTO score on technical success and procedure time was evaluated with univariable logistic and linear regression, respectively. The performance of the logistic regression model was assessed with the Hosmer-Lemeshow statistic and receiver operator characteristic curves. Antegrade wiring techniques were used more frequently in easy lesions (97%) than very difficult lesions (58%), whereas the retrograde approach became more frequent with increased lesion difficulty (41% for very difficult lesions versus 13% for easy lesions). The logistic regression model for technical success demonstrated satisfactory calibration and discrimination (P for Hosmer-Lemeshow =0.743 and area under curve =0.705). The J-CTO score was associated with a 2-fold increase in the odds of technical failure (odds ratio 2.04, 95% confidence interval 1.52-2.80, P<0.001). Procedure time increased by ≈20 minutes for every 1-point increase of the J-CTO score (regression coefficient 22.33, 95% confidence interval 17.45-27.22, P<0.001).

CONCLUSIONS

J-CTO score was strongly associated with final success and efficiency in this study, supporting its expanded use in CTO interventions.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Predictors and Outcomes of Side-Branch Occlusion in Coronary Chronic Total Occlusion Interventions

OBJECTIVES

We investigated whether side-branch loss during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) could adversely impact clinical outcomes.

BACKGROUND

Side-branch occlusion during PCI has been associated with periprocedural myocardial infarction and higher incidence of major adverse cardiac event (MACE), but has received limited study in CTO-PCI.

METHODS

We retrospectively reviewed the medical records and coronary angiograms for 109 consecutive CTOPCI cases performed at our institution during 2012 and 2013. Post-PCI patency of ≥1 mm diameter side branches and associated clinical outcomes were assessed.

RESULTS

Mean age was 65 ± 8 years and 99.1% of the patients were men. The CTO target vessel was the right coronary artery (54%), circumflex (26%), and left anterior descending artery (20%). Side-branch loss occurred in 28 cases (25.7%) due to antegrade dissection/reentry (n = 9), retrograde dissection/reentry (n = 5), stenting over the branch (n = 12), and dissection during antegrade crossing attempts (n = 2). Recanalization of the occluded side branch was pursued in 8 cases (28.6%) and was successful in 4 patients. Patients with side-branch loss had higher post-PCI increase in CK-MB levels (8.4 ng/mL [interquartile range, 2.7-33.5 ng/mL] vs 1.8 ng/mL [interquartile range, 0.025-6.775 ng/mL]; P<.001) and higher 12-month incidence of all-cause death (17.3% vs 2.8%; P=.02) and cardiovascular death (7.4% vs 0.0%; P=.02).

CONCLUSIONS

Side-branch loss occurs in approximately 1 in 4 CTO-PCIs and is associated with higher risk for periprocedural myocardial infarction and higher mortality.

Impact of Crossing Strategy on Intermediate-term Outcomes After Chronic Total Occlusion Percutaneous Coronary Intervention

BACKGROUND

There is ongoing controversy about the optimal crossing strategy selection for chronic total occlusion (CTO) percutaneous coronary intervention (PCI), especially regarding the relative merits of antegrade dissection/re-entry and the retrograde approach.

METHODS

We retrospectively examined the clinical outcomes of 173 consecutive patients who underwent successful CTO PCI at our institution between January 2012 and March 2015.

RESULTS

The mean age was 65 ± 8 years, and 98% of the patients were men with a high prevalence of diabetes (60%), previous coronary artery bypass grafting (CABG) (31%), and previous PCI (54%). The successful CTO crossing strategy was antegrade wire escalation in 79 patients (45.5%), antegrade dissection/re-entry in 58 patients (33.5%), retrograde wire escalation in 11 patients (6.4%), and retrograde dissection and re-entry in 25 patients (14.5%). The retrograde approach was more commonly used in lesions with interventional collaterals (P < 0.0001), moderate/severe calcification (P = 0.02), blunt stump (P = 0.01), and a higher Japan Chronic Total Occlusion score (P = 0.0002). Use of dissection and re-entry (both antegrade and retrograde) was associated with bifurcation and the distal cap (P = 0.004), longer CTO occlusion length (P < 0.0001), and longer stent length (P < 0.0001). Median follow-up was 11 months. The 12-month incidence of death, myocardial infarction, and the composite of acute coronary syndrome/target lesion revascularization/target vessel revascularization was 2.5%, 4.9%, and 24.4%, respectively, and was similar with intimal and subintimal crossing strategies.

CONCLUSIONS

Antegrade dissection/re-entry and retrograde approaches are frequently used during CTO PCI and were associated with similarly favorable intermediate-term outcomes as antegrade wire escalation.

Comparison of Iodixanol and Ioxaglate for Coronary Optical Coherence Tomography Imaging

BACKGROUND

The impact of contrast type on coronary imaging using optical coherence tomography (OCT) has received limited study. We compared OCT imaging obtained using the non-ionic, iso-osmolar iodixanol with the ionic, low-osmolar ioxaglate.

METHODS

Twenty-two vessels in 20 patients were imaged twice using manual injection of iodixanol and ioxaglate in random order. OCT images were analyzed at 1 mm intervals to determine lumen area, artifact diameter and area, as well as stent strut coverage and malapposition in OCT pullbacks that included stents.

RESULTS

There were no complications related to OCT imaging or to contrast administration. A total of 2184 cross-sections (1092 with iodixanol and 1092 with ioxaglate) were analyzed. Compared with iodixanol, imaging using ioxaglate provided similar mean lumen area (6.21 ± 2.83 mm2 vs 6.27 ± 2.83 mm2; Spearman's rho, 0.982), mean minimum lumen diameter (2.47 ± 0.59 mm vs 2.50 ± 0.58 mm; Spearman's rho, 0.939), and mean maximum lumen diameter (2.99 ± 0.71 mm vs 3.01 ± 0.70 mm; Spearman's rho, 0.964), but lower mean artifact area per cross-section (0.099 ± 0.325 mm2 vs 0.068 ± 0.329 mm2; P<.001). Analyses of 3303 stent struts in 388 cross-sections (194 with iodixanol and 194 with ioxaglate) demonstrated similar strut malapposition rates (11.82% vs 13.90%; P=.10) and strut coverage (41.92% vs 40.33%; P=.35).

CONCLUSIONS

Compared with iodixanol, OCT imaging using ioxaglate provided similar lumen and diameter measurements and stent strut characterization, but smaller area of artifact.

Interpretation of Coronary Angiograms Recorded Using Google Glass: A Comparative Analysis

INTRODUCTION

Google Glass (Google, Inc) is a voice-activated, hands-free, optical head-mounted display device capable of taking pictures, recording videos, and transmitting data via wi-fi. In the present study, we examined the accuracy of coronary angiogram interpretation, recorded using Google Glass.

METHODS

Google Glass was used to record 15 angiograms with 17 major findings and the participants were asked to interpret those recordings on: (1) an iPad (Apple, Inc); or (2) a desktop computer. Interpretation was compared with the original angiograms viewed on a desktop. Ten physicians (2 interventional cardiologists and 8 cardiology fellows) participated. One point was assigned for each correct finding, for a maximum of 17 points.

RESULTS

The mean angiogram interpretation score for Google Glass angiogram recordings viewed on an iPad or a desktop vs the original angiograms viewed on a desktop was 14.9 ± 1.1, 15.2 ± 1.8, and 15.9 ± 1.1, respectively (P=.06 between the iPad and the original angiograms, P=.51 between the iPad and recordings viewed on a desktop, and P=.43 between the recordings viewed on a desktop and the original angiograms). In a post-study survey, one of the 10 physicians (10%) was "neutral" with the quality of the recordings using Google Glass, 6 physicians (60%) were "somewhat satisfied," and 3 physicians (30%) were "very satisfied."

CONCLUSION

This small pilot study suggests that the quality of coronary angiogram video recordings obtained using Google Glass may be adequate for recognition of major findings, supporting its expanding use in telemedicine.

The impact of percutaneous coronary intervention of chronic total occlusions on left ventricular function and clinical outcomes

A meta-analysis by Hoebers et al. reported that successful chronic total occlusion (CTO) recanalization resulted in an increase in left ventricular (LV) ejection fraction by 4.44% (P<0.01) and a reduction in LV end-diastolic volume by 6.14 mL/m(2) during follow-up as compared with baseline, suggesting beneficial LV remodeling. These findings are important as the myocardium supplied by a CTO frequently has sustained irreversible injury and further support the clinical benefits of CTO interventions.

Evolution of the American College of Cardiology/American Heart Association Clinical Guidelines

BACKGROUND

The American College of Cardiology (ACC) and the American Heart Association (AHA) have been developing clinical guidelines to assist practicing clinicians.

OBJECTIVES

The goal of this study was to evaluate changes in ACC/AHA guideline recommendations between 2008 and 2014.

METHODS

The previous and current ACC/AHA guideline documents that were updated between 2008 and June 2014 were compared to determine changes in Class of Recommendation (COR) and Level of Evidence (LOE). Each recommendation was classified as new, dropped, revised, or unchanged, and the changes in evidence were examined.

RESULTS

During the study period, 11 guideline documents (9 disease based and 2 interventional procedure based) were updated. The total number of recommendations decreased from 2,067 to 1,869 (321 fewer recommendations in disease-based guidelines and 123 additional recommendations in interventional procedure-based guidelines). The recommendation class distribution of the updated guidelines was 50.1% Class I (previously 50.8%), 39.4% Class II (previously 35.4%), and 10.4% Class III (previously 13.8%) (p = 0.001). The LOE distribution among updated versions was 15.0% for LOE: A (previously 13.3%), 50.8% for LOE: B (previously 41.4%), and 34.2% for LOE C (previously 45.3%) (p < 0.001). Among all guidelines, 859 recommendations were new, 1,339 were dropped, 881 were unchanged in COR and LOE, and 129 were revised. Of the revised guidelines, 75 recommendations had an increase in LOE (the majority from LOE: C to LOE: B); 34 recommendations had a decrease in LOE; and 20 recommendations had class changes. LOE increases were justified by introduction of new randomized controlled trials, new studies, and new meta-analyses.

CONCLUSIONS

The ACC/AHA guideline recommendations are undergoing significant changes, becoming more evidence based and scientifically robust with a tendency to exclude recommendations with insufficient scientific evidence.

Application and outcomes of a hybrid approach to chronic total occlusion percutaneous coronary intervention in a contemporary multicenter US registry

BACKGROUND

A hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) prioritizing and combining all available crossing techniques was developed to optimize procedural efficacy, efficiency, and safety, but there is limited published data on its outcomes.

METHODS

We examined the procedural techniques and outcomes of 1036 consecutive CTO PCIs performed using a hybrid approach between 2012 and 2015 at 11 US centers.

RESULTS

Mean age was 65 ± 10 years and 86% of the patients were men, with a high prevalence of diabetes mellitus (43%) and prior coronary artery bypass graft surgery (34%). Most target CTOs were located in the right coronary artery (59%), followed by the left anterior descending artery (23%) and the circumflex (19%). Dual injection was used in 71%. Technical success was achieved in 91% and a major procedural complication occurred in 1.7% of cases. The final successful crossing technique was antegrade wire escalation in 46%, antegrade dissection/re-entry in 26%, and retrograde in 28%. The initial crossing strategy was successful in 58% of the lesions, whereas 39% required an additional approach. Overall, antegrade wire escalation was used in 71%, antegrade dissection/re-entry in 36%, and the retrograde approach in 42% of procedures. Median contrast volume, fluoroscopy time, and air kerma radiation dose were 260 (200-360) ml, 44 (27-72) min, and 3.4 (2.0-5.4) Gray, respectively.

CONCLUSION

Application of a hybrid approach to CTO crossing resulted in high success and low complication rates across a varied group of operators and hospital practice structures, supporting its expanding use in CTO PCI.

Meta-analysis of clinical outcomes of patients who underwent percutaneous coronary interventions for chronic total occlusions

Successful percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) has been associated with clinical benefit. There are no randomized controlled trials on long-term clinical outcomes after CTO PCI, limiting the available evidence to observational cohort studies. We sought to perform a weighted meta-analysis of the long-term outcomes of successful versus failed CTO PCI. A total of 25 studies, published from 1990 to 2014, with 28,486 patients (29,315 CTO PCI procedures) were included. We analyzed data on mortality, subsequent coronary artery bypass grafting (CABG), myocardial infarction, major adverse cardiac events, angina pectoris, stroke, and target vessel revascularization using random-effects models. Procedural success was 71% (range 51% to 87%). During a weighted mean follow-up of 3.11 years, compared with unsuccessful, successful CTO PCI was associated with lower mortality (odds ratio [OR] 0.52, 95% confidence interval [CI] 0.43 to 0.63), less residual angina (OR 0.38, 95% CI 0.24 to 0.60), lower risk for stroke (OR 0.72, 95% CI 0.60 to 0.88), less need for subsequent coronary artery bypass grafting (OR 0.18, 95% CI 0.14 to 0.22), and lower risk for major adverse cardiac events (0.59, 95% CI 0.44 to 0.79). There was no difference in the incidence of target vessel revascularization (OR 0.66, 95% CI 0.36 to 1.23) or myocardial infarction (OR 0.73, 95% CI 0.52 to 1.03). Outcomes were similar in patients who underwent balloon angioplasty only or stenting with bare metal or drug-eluting stents. Compared with failed procedures, successful CTO PCIs are associated with a lower risk of death, stroke, and coronary artery bypass grafting and less recurrent angina pectoris.

Procedural failure of chronic total occlusion percutaneous coronary intervention: Insights from a multicenter US registry

BACKGROUND

The hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly increased procedural success rates, yet some cases still fail. We sought to evaluate the causes of failure in a contemporary CTO PCI registry.

METHODS

We examined 380 consecutive patients who underwent CTO-PCI at 4 high volume CTO PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, complication, and efficiency outcomes were compared between successful and failed cases. Failed cases were individually reviewed by an independent reviewer to determine the cause of failure.

RESULTS

Procedural success was 91.3%. Compared with patients in whom CTO PCI was successful, those in whom CTO PCI failed had similar baseline clinical characteristics, but were more likely to have longer occlusion length, more tortuosity, more proximal cap ambiguity and blunt stump, and higher mean J-CTO scores (2.8 ± 1.1 vs. 3.5 ± 1.0, P < 0.001), and less likely to have collaterals suitable for the retrograde approach (66% vs. 45%, P = 0.021). Failure was due to a complication in 10 cases (30%). In the remaining 23 cases (70%) failure was due to inability to wire the lesion (n = 21, 4 of which were CTOs due to in-stent restenosis), or poor antegrade flow after PCI (n = 5).

CONCLUSIONS

Compared with successful cases, failed CTO-PCI cases are more likely to have higher J-CTO scores, longer occlusion length, ambiguous proximal cap and no appropriate collaterals for retrograde crossing. Development of novel CTO crossing techniques is needed to further increase CTO PCI success rates.