Racial disparities in chronic total occlusion percutaneous coronary interventions: insights from the PROGRESS-CTO registry.

OBJECTIVES: There is limited data on race and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The authors sought to evaluate CTO PCI techniques and outcomes in different racial groups. METHODS: We examined the baseline characteristics and procedural outcomes of 11 806 CTO PCIs performed at 44 US and non-US centers between 2012 and March 2023. In-hospital major adverse cardiac events (MACE) included death, myocardial infarction, repeat target-vessel revascularization, pericardiocentesis, cardiac surgery, and stroke prior to discharge. RESULTS: The most common racial group was White (84.5%), followed by Black (5.7%), "Other" (3.9%), Hispanic (2.9%), Asian (2.4%), and Native American (0.7%). There were significant differences in the baseline characteristics between different racial groups. When compared with non-White patients, the retrograde approach and antegrade dissection re-entry were more likely to be the successful crossing strategies in White patients without any significant differences in technical success (86.4% vs 86.4%; P = .93), procedural success (84.8% vs 85.0%; P = .79), and in-hospital MACE (2.0% vs 1.5%; P = .15) between the 2 groups. The technical success rate was significantly higher in the "Other" racial group (91.0% vs 86.4% in White, 86.9% in Asian, 84.5% in Black, 84.5% in Hispanic, and 83.3% in Native American; P = .03) without any significant differences in procedural success or in-hospital MACE rates between the groups. CONCLUSIONS: Despite differences in baseline characteristics and procedural techniques, the procedural success and in-hospital MACE of CTO PCI were not significantly different between most racial groups.

Randomized Comparison of a CrossBoss First Versus Standard Wire Escalation Strategy for Crossing Coronary Chronic Total Occlusions: The CrossBoss First Trial.

OBJECTIVES: The authors performed a multicenter, randomized-controlled, clinical trial comparing upfront use of the CrossBoss catheter versus antegrade wire escalation for antegrade crossing of coronary chronic total occlusions. BACKGROUND: There is equipoise about the optimal initial strategy for crossing coronary chronic total occlusions. METHODS: The primary endpoints were the time required to cross the chronic total occlusion or abort the procedure and the frequency of procedural major adverse cardiovascular events. The secondary endpoints were technical and procedural success, total procedure time, fluoroscopy time required to cross and total fluoroscopy time, total air kerma radiation dose, total contrast volume, and equipment use. RESULTS: Between 2015 and 2017, 246 patients were randomized to the CrossBoss catheter (n = 122) or wire escalation (n = 124) at 11 U.S. centers. The baseline clinical and angiographic characteristics of the study groups were similar. Technical and procedural success were 87.8% and 84.1%, respectively, and were similar in the 2 groups. Crossing time was similar: 56 min (interquartile range: 33 to 93 min) in the CrossBoss group and 66 min (interquartile range: 36 to 105 min) in the wire escalation group (p = 0.323), as was as the incidence of procedural major adverse cardiovascular events (3.28% vs. 4.03%; p = 1.000). There were no significant differences in the secondary study endpoints. CONCLUSIONS: As compared with wire escalation, upfront use of the CrossBoss catheter for antegrade crossing of coronary chronic total occlusions was associated with similar crossing time, similar success and complication rates, and similar equipment use and cost.

Improvement in Aortic Valve Area in Patients With Aortic Stenosis Through Use of a New "Hourglass-Shaped" Valvuloplasty Balloon.

OBJECTIVES: The study aim was to assess the effect of hourglass-shaped V8 and TAV8 balloons (InterValve, Inc) on aortic valve area (AVA) and other outcomes in patients with severe aortic stenosis undergoing balloon aortic valvuloplasty (BAV). BAV has re-emerged with transcatheter therapy. Cylindrical balloons have been the device of choice despite limitations. The hourglass-shaped balloons, with shorter, broader segments separated by a narrowed waist, permit enhanced fixation and better leaflet opening without annular or sinotubular compromise. METHODS: We compared outcomes of InterValve balloon use in patients undergoing BAV with outcomes of cylindrical balloon use in patients from a BAV database. Patients were propensity matched by age, gender, baseline AVA, left ventricular ejection fraction, and Society of Thoracic Surgeons mortality risk score. Endpoints included change in AVA and aortic insufficiency (AI) by echocardiography, new permanent pacemaker (PPM) implantation, and major adverse events (ie, procedural death, emergency surgery, or stroke). RESULTS: Forty InterValve balloon patients were matched with 40 cylindrical balloon patients. Postprocedure change in AVA trended strongly in favor of InterValve balloon patients (0.29 ± 0.17 cm² vs 0.22 ± 0.15 cm²; P=.06). Maximum balloon sizes were significantly smaller for InterValve balloon patients. Worsened AI occurred less frequently with InterValve balloons. There was no difference in postprocedure PPM implantations or major adverse events. CONCLUSIONS: Use of the hourglass-shaped balloons provided larger AVA, as compared with use of cylindrical balloons. Use of the novel balloons was not associated with an increase in AI, PPM, or major adverse events.

Intracoronary aminophylline for management of bradyarrhythmias during thrombectomy with the AngioJet catheter.

Thrombectomy with the AngioJet rheolytic thrombectomy catheter frequently causes bradyarrhythmias. This necessitates temporary pacemaker insertion and limits the device's use. Novel approaches for treatment of bradyarrhythmias are being tested. This article focuses on the evidence supporting the role of adenosine in bradyarrhythmias during thrombectomy and presents; data from a porcine model and the first human experience supporting the use of aminophylline, a competitive inhibitor of the adenosine receptor, via an intracoronary route, for prevention of bradyarrhythmias during thrombectomy.

Myocardial glucose uptake after dobutamine stress in chronic hibernating swine myocardium.

BACKGROUND: In patients with hibernating myocardium, regional uptake of the glucose analog 2-fluorine 18-fluoro-2-deoxy-d-glucose (FDG) is increased under resting conditions. It is unclear whether the degree of increased FDG uptake correlates with the degree of impaired blood flow response and whether chronic changes in the glucose transporters may play a role in the enhanced FDG uptake under fasted conditions. METHODS AND RESULTS: Twelve swine were instrumented with a constrictor on the left anterior descending (LAD) artery. Serial echocardiography and positron emission tomography studies were done to assess temporal changes in myocardial function, blood flow, and FDG uptake. One week after surgery (early study), wall thickening, blood flow, and postdobutamine FDG uptake in LAD and remote territories were similar. By approximately 6 weeks (late study), baseline wall thickening in the LAD region was lower than in remote regions (20% +/- 7% and 36% +/- 6%, P <.05), as was dobutamine-stimulated blood flow (0.92 +/- 0.16 mL. min(-1). g(-1) and 1.17 +/- 0.20 mL. min(-1). g(-1) in LAD and remote regions, respectively; P <.05). After the dobutamine infusion, FDG uptake in the LAD region during fasted conditions was higher than in remote regions (0.128 +/- 0.053 micromol. min(-1). g(-1) and 0.098 +/- 0.044 micromol. min(-1). g(-1), respectively; P <.05), and the increase was proportional to the impairment in dobutamine blood flow (r(2) = 0.62, P <.001). After the animals were killed, the LAD region showed a higher content of GLUT4 by immunoblots and a greater degree of translocation as estimated by immunohistochemistry. In 5 additional hibernating pigs studied under resting fasted conditions, FDG uptake and GLUT4 translocation were also higher in the LAD region, in the absence of dobutamine stimulation. CONCLUSIONS: In hibernating myocardium, regional FDG uptake under fasting conditions is higher than in remote regions, both at rest and after an infusion of dobutamine. The degree of poststress FDG uptake is proportional to the impaired stress-induced blood flow. Total GLUT4 content as well as membrane-bound protein is higher in the hibernating tissue, and these changes may facilitate the observed increase in FDG uptake.

Repetitive supply-demand ischemia with dobutamine increases glucose uptake in postischemic and remote myocardium.

UNLABELLED: The goal of this study was to determine whether myocardial glucose uptake after repetitive ischemia differs in response to coronary occlusion-reperfusion versus supply-demand ischemia induced by dobutamine. Although glucose metabolism is increased after myocardial ischemia, the metabolic effect of supply-demand ischemia induced by dobutamine may increase glucose metabolism within remote myocardium. This would make it difficult to discriminate postischemic from remote myocardium with glucose tracers. METHODS: Eighteen swine with a hydraulic occluder and flow probe on the circumflex artery underwent repetitive ischemia. In group 1 (n = 9), the circumflex artery was occluded, whereas in group 2 (n = 9), circumflex flow was decreased by 30% before dobutamine (40 micro g/kg/min intravenously). Each pig underwent 15 min of ischemia, twice per day for 5 d. Echocardiography and PET to determine myocardial glucose ((18)F-FDG) uptake were performed after final ischemia, and tissue was later analyzed for activation of Akt, p38 mitogen-activated protein, and adenosine monophosphate (AMP) kinase. RESULTS: Wall thickening in the circumflex region was lower than in remote regions in both groups. (18)F-FDG uptake in the circumflex region was similar in groups 1 and 2 (0.22 +/- 0.03 and 0.23 +/- 0.04 micro mol/min/g, respectively; not statistically significant). In the remote region, (18)F-FDG uptake was lower than in the circumflex region in group 1 (0.14 +/- 0.03 micro mol/min/g; P < 0.05) but was similar to that in the circumflex region in group 2 (0.20 +/- 0.03 micro mol/min/g; not statistically significant). AMP kinase activity in the remote region was significantly lower than in the circumflex region in group 1 but was similar to that in the circumflex region in group 2. CONCLUSION: Unlike repetitive coronary artery occlusion-reperfusion, repetitive supply-demand ischemia with dobutamine alters glucose uptake within the remote myocardium, possibly as a result of AMP kinase activation. Clinically, these data suggest that (18)F-FDG studies have a limited role in discriminating postischemic from remote myocardium after dobutamine stress.

Glucose uptake and glycogen levels are increased in pig heart after repetitive ischemia.

Repetitive myocardial ischemia increases glucose uptake, but the effect on glycogen is unclear. Thirteen swine instrumented with a hydraulic occluder on the circumflex (Cx) artery underwent 10-min occlusions twice per day for 4 days. After 24 h postfinal ischemia and in the fasted state, echocardiogram and positron emission tomography imaging for blood flow ([(13)N]-ammonia) and 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) uptake were obtained. Tissue was then collected for ATP, creatine phosphate (CP), glycogen, and glucose transporter-4 content, and hexokinase activity. After reperfusion, regional function and CP-to-ATP ratios in the Cx and remote regions were similar. Despite the absence of stunning, the Cx region demonstrated higher glycogen levels (33 +/- 11 vs. 24 +/- 11 micromol/g; P < 0.05), and this increase correlated well with the increase in FDG uptake (r(2) = 0.78; P < 0.01). Hexokinase activity was also increased relative to remote regions (0.62 +/- 0.29 vs. 0.37 +/- 0.19 IU/g; P < 0.05), with no difference in GLUT-4 content. In summary, 24 h after repetitive ischemia, glucose uptake and glycogen levels are increased at a time that functional and bioenergetic markers of stunning have recovered. The significant correlation between glycogen content and FDG accumulation in the postischemic region suggests that increased rates of glucose transport and/or phosphorylation are linked to increased glycogen levels in hearts subjected to repetitive bouts of ischemia.