John Bahadorani

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.

Outcomes With the Use of the Retrograde Approach for Coronary Chronic Total Occlusion Interventions in a Contemporary Multicenter US Registry

Background—We sought to examine the efficacy and safety of chronic total occlusion percutaneous coronary intervention using the retrograde approach. Methods and Results—We compared the outcomes of the retrograde versus antegrade-only approach to chronic total occlusion percutaneous coronary intervention among 1301 procedures performed at 11 experienced US centers between 2012 and 2015. The mean age was 65.5±10 years, and 84% of the patients were men with a high prevalence of diabetes mellitus (45%) and previous coronary artery bypass graft surgery (34%). Overall technical and procedural success rates were 90% and 89%, respectively, and in-hospital major adverse cardiovascular events occurred in 31 patients (2.4%). The retrograde approach was used in 539 cases (41%), either as the initial strategy (46%) or after a failed antegrade attempt (54%). When compared with antegrade-only cases, retrograde cases were significantly more complex, both clinically (previous coronary artery bypass graft surgery prevalence, 48% versus 24%; P<0.001) and angiographically (mean Japan-chronic total occlusion score, 3.1±1.0 versus 2.1±1.2; P<0.001) and had lower technical success (85% versus 94%; P<0.001) and higher major adverse cardiovascular events (4.3% versus 1.1%; P<0.001) rates. On multivariable analysis, the presence of suitable collaterals, no smoking, no previous coronary artery bypass graft surgery, and left anterior descending artery target vessel were independently associated with technical success using the retrograde approach. Conclusions—The retrograde approach is commonly used in contemporary chronic total occlusion percutaneous coronary intervention, especially among more challenging lesions and patients. Although associated with lower success and higher major adverse cardiovascular event rates in comparison to antegrade-only crossing, retrograde percutaneous coronary intervention remains critical for achieving overall high success rates.

Invasive Cardiologists Are Exposed to Greater Left Sided Cranial Radiation: The BRAIN Study (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures).

OBJECTIVES This study sought to determine radiation exposure across the cranium of cardiologists and the protective ability of a nonlead, XPF (barium sulfate/bismuth oxide) layered cap (BLOXR, Salt Lake City, Utah) during fluoroscopically guided, invasive cardiovascular (CV) procedures. BACKGROUND Cranial radiation exposure and potential for protection during contemporary invasive CV procedures is unclear. METHODS Invasive cardiologists wore an XPF cap with radiation attenuation ability. Six dosimeters were fixed across the outside and inside of the cap (left, center, and right), and 3 dosimeters were placed outside the catheterization lab to measure ambient exposure. RESULTS Seven cardiology fellows and 4 attending physicians (38.4 ± 7.2 years of age; all male) performed diagnostic and interventional CV procedures (n = 66.2 ± 27 cases/operator; fluoroscopy time: 14.9 ± 5.0 min). There was significantly greater total radiation exposure at the outside left and outside center (106.1 ± 33.6 mrad and 83.1 ± 18.9 mrad) versus outside right (50.2 ± 16.2 mrad; p < 0.001 for both) locations of the cranium. The XPF cap attenuated radiation exposure (42.3 ± 3.5 mrad, 42.0 ± 3.0 mrad, and 41.8 ± 2.9 mrad at the inside left, inside center, and inside right locations, respectively) to a level slightly higher than that of the ambient control (38.3 ± 1.2 mrad, p = 0.046). After subtracting ambient radiation, exposure at the outside left was 16 times higher than the inside left (p < 0.001) and 4.7 times higher than the outside right (p < 0.001). Exposure at the outside center location was 11 times higher than the inside center (p < 0.001), whereas no difference was observed on the right side. CONCLUSIONS Radiation exposure to invasive cardiologists is significantly higher on the left and center compared with the right side of the cranium. Exposure may be reduced similar to an ambient control level by wearing a nonlead XPF cap. (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures [BRAIN]; NCT01910272).

Use of antegrade dissection re-entry in coronary chronic total occlusion percutaneous coronary intervention in a contemporary multicenter registry

BACKGROUND We assessed efficacy and safety of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) using antegrade dissection re-entry (ADR). METHODS We examined outcomes of ADR among 1313 CTO PCIs performed at 11 US centers between 2012-2015. RESULTS 84.1% of patients were men. Prevalence of prior coronary artery bypass graft surgery was 34.3%. Overall technical and procedural success were 90.1% and 88.7%, respectively. In-hospital major adverse cardiovascular events (MACE) occurred in 31 patients (2.4%). ADR was used in 458 cases (34.9%), and was the first strategy in 169 cases (12.9%). ADR cases were angiographically more complex than non-ADR cases (mean J-CTO score: 2.8±1.2 vs. 2.4±1.2, p<0.001). ADR was performed using the CrossBoss catheter in 246 of 458 (53.7%) and the Stingray system in 251 ADR cases (54.8%). Compared with non-ADR cases, ADR cases had lower technical (86.9% vs. 91.8%, p=0.005) and procedural success (85.0% vs. 90.7%, p=0.002), but similar risk for MACE (2.9% vs. 2.2%, p=0.42). ADR was associated with longer procedure and fluoroscopy time, and higher patient air kerma dose and contrast volume (all p<0.001). After excluding retrograde cases, ADR and antegrade wire escalation (AWE) had similar technical success (92.7% vs. 94.2%, p=0.43), procedural success (91.8% vs. 94.1%, p=0.23), and MACE (2.1% vs. 0.6%, p=0.12). CONCLUSIONS ADR is used relatively frequently in contemporary CTO PCI, especially for challenging lesions and after failure of other strategies. ADR is associated with similar success rates and risk for complications as compared with AWE, and is important for achieving high procedural success.

First-in-human robotic percutaneous coronary intervention for unprotected left main stenosis

The safety and feasibility of robotically‐assisted percutaneous coronary intervention (PCI) for simple coronary lesions has been demonstrated. The CorPath robotic system (Corpath 200, Corindus, Waltham, MA) consists of a robotic arm mounted on the cardiac catheterization table that consists of a drive housing a single‐use sterile cassette, which is connected to the guiding catheter. While sitting in the nonsterile, radiation‐shielded cockpit, the operator remotely controls delivery and removal of coronary guidewires, angioplasty balloons, and stents. The database for the ongoing PRECISION registry was queried at a single center and results of unprotected left main robotic PCI procedures are reported. Of 102 robotic PCI procedures performed at this center, 6 were unprotected left main lesions (age 69 ± 14 years; 67% male). All 6 subjects underwent successful PCI (fluoroscopy time 26.8 ± 11.4 min;1.8 stents and 2.2 vessels treated/patient) with three requiring hemodynamic support (two with percutaneous left ventricular assistance using the Impella 2.5 (Abiomed, Danvers, MA) and one with intraaortic balloon pump counterpulsation). This report demonstrates the feasibility of performing robotically assisted unprotected left main PCI with or without hemodynamic support.

Endovascular therapy for critical limb ischemia

Critical limb ischemia (CLI) represents an advanced disease state of peripheral arterial disease. It manifests as lower extremity ischemic rest pain or ischemic skin lesions leading to ulceration or gangrene. Patients with CLI often have multiple medical comorbidities and a 1-year mortality rate of 25% and a 1-year amputation rate of 25%. Historically, bypass surgery with autogenous veins for flow restoration has been the first-line therapy for CLI. However, advances in endovascular techniques and device technology have changed the treatment paradigm. Catheter-based technologies are rapidly evolving at a rate that is outpacing large-scale studies evaluating relevant clinical outcomes. Patients with CLI require a multidisciplinary management approach centered on aggressive medical therapies, wound care and prompt revascularization, with an emphasis on limb salvage. This review summarizes the contemporary endovascular therapies including balloon angioplasty, atherectomy and bare-metal stenting. In addition, we review emerging technologies, such as drug-eluting stents, drug-coated balloons and chronic total occlusion recanalization devices.

Comparison of various scores for predicting success of chronic total occlusion percutaneous coronary intervention.

BACKGROUND Various scoring systems have been developed to predict the technical outcome and procedural efficiency of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS We examined the predictive capacity of 3 CTO PCI scores (Clinical and Lesion-related [CL], Multicenter CTO registry in Japan [J-CTO] and Prospective Global Registry for the Study of Chronic Total Occlusion Intervention [PROGRESS CTO] scores) in 664 CTO PCIs performed between 2012 and 2016 at 13 US centers. RESULTS Technical success was 88% and the retrograde approach was utilized in 41%. Mean CL, J-CTO and PROGRESS CTO scores were 3.9±1.9, 2.6±1.2 and 1.4±1.0, respectively. All scores were inversely associated with technical success (p<0.001 for all) and had moderate discriminatory capacity (area under the curve 0.691 for the CL score, 0.682 for the J-CTO score and 0.647 for the PROGRESS CTO score [p=non-significant for pairwise comparisons]). The difference in technical success between the minimum and maximum CL score strata was the highest (32%, vs. 15% for J-CTO and 18% for PROGRESS CTO scores). All scores tended to perform better in antegrade-only procedures and correlated significantly with procedure time and fluoroscopy dose; the CL score also correlated significantly with contrast utilization. CONCLUSIONS CL, J-CTO and PROGRESS CTO scores perform moderately in predicting technical outcome of CTO PCI, with better performance for antegrade-only procedures. All scores correlate with procedure time and fluoroscopy dose, and the CL score also correlates with contrast utilization.

Prevalence, indications and management of balloon uncrossable chronic total occlusions: Insights from a contemporary multicenter US registry

Balloon uncrossable lesions can be challenging to treat, requiring specialized techniques and equipment.

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry.

Background Intravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention. Methods and Results We examined the frequency of use and outcomes of intravascular imaging among 619 CTO percutaneous coronary interventions performed between 2012 and 2015 at 7 US centers. Mean age was 65.4±10 years and 85% of the patients were men. Intravascular imaging was used in 38%: intravascular ultrasound in 36%, optical coherence tomography in 3%, and both in 1.45%. Intravascular imaging was used for stent sizing (26.3%), stent optimization (38.0%), and CTO crossing (35.7%, antegrade in 27.9%, and retrograde in 7.8%). Intravascular imaging to facilitate crossing was used more frequently in lesions with proximal cap ambiguity (49% versus 26%, P<0.0001) and with retrograde as compared with antegrade‐only cases (67% versus 31%, P<0.0001). Despite higher complexity (Japanese CTO score: 2.86±1.19 versus 2.43±1.19, P=0.001), cases in which imaging was used for crossing had similar technical and procedural success (92.8% versus 89.6%, P=0.302 and 90.1% versus 88.3%, P=0.588, respectively) and similar incidence of major cardiac adverse events (2.7% versus 3.2%, P=0.772). Use of intravascular imaging was associated with longer procedure (192 minutes [interquartile range 130, 255] versus 131 minutes [90, 192], P<0.0001) and fluoroscopy (71 minutes [44, 93] versus 39 minutes [25, 69], P<0.0001) time. Conclusions Intravascular imaging is frequently performed during CTO percutaneous coronary intervention both for crossing and for stent selection/optimization. Despite its use in more complex lesion subsets, intravascular imaging was associated with similar rates of technical and procedural success for CTO percutaneous coronary intervention. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Cell-specific discrimination of desmosterol and desmosterol mimetics confers selective regulation of LXR and SREBP in macrophages

Significance The beneficial effects of LXR-pathway activation have long been appreciated, but clinical application of synthetic LXR ligands has been limited by coactivation of SREBP1c and consequent hypertriglyceridemia. Natural LXR ligands such as desmosterol do not promote hypertriglyceridemia because of coordinate down-regulation of the SREBP pathway. Here we demonstrate that synthetic desmosterol mimetics activate LXR in macrophages both in vitro and in vivo while suppressing SREBP target genes. Unexpectedly, desmosterol and synthetic desmosterol mimetics have almost no effect on LXR activity in hepatocytes in comparison with conventional synthetic LXR ligands. These findings reveal cell-specific differences in LXR responses to natural and synthetic ligands in macrophages and liver cells that provide a conceptually new basis for future drug development. Activation of liver X receptors (LXRs) with synthetic agonists promotes reverse cholesterol transport and protects against atherosclerosis in mouse models. Most synthetic LXR agonists also cause marked hypertriglyceridemia by inducing the expression of sterol regulatory element-binding protein (SREBP)1c and downstream genes that drive fatty acid biosynthesis. Recent studies demonstrated that desmosterol, an intermediate in the cholesterol biosynthetic pathway that suppresses SREBP processing by binding to SCAP, also binds and activates LXRs and is the most abundant LXR ligand in macrophage foam cells. Here we explore the potential of increasing endogenous desmosterol production or mimicking its activity as a means of inducing LXR activity while simultaneously suppressing SREBP1c-induced hypertriglyceridemia. Unexpectedly, while desmosterol strongly activated LXR target genes and suppressed SREBP pathways in mouse and human macrophages, it had almost no activity in mouse or human hepatocytes in vitro. We further demonstrate that sterol-based selective modulators of LXRs have biochemical and transcriptional properties predicted of desmosterol mimetics and selectively regulate LXR function in macrophages in vitro and in vivo. These studies thereby reveal cell-specific discrimination of endogenous and synthetic regulators of LXRs and SREBPs, providing a molecular basis for dissociation of LXR functions in macrophages from those in the liver that lead to hypertriglyceridemia.