Temporal trends of fluoroscopy time and contrast utilization in coronary chronic total occlusion revascularization: insights from a multicenter United States registry.

BACKGROUND: The impact of operator experience on fluoroscopy time and contrast utilization during percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs) has received limited study. METHODS: We evaluated temporal trends in fluoroscopy time and contrast utilization among 1,363 consecutive CTO PCIs performed at three US institutions between January 2006 and November 2011. RESULTS: Mean age was 65 ± 11 years, 85% of patients were men, 40% had diabetes, 37% had prior coronary artery bypass graft surgery, and 42% had prior PCI. The CTO target vessel was the right coronary artery (55%), circumflex (23%), left anterior descending artery (21%), and left main or bypass graft (1%). The retrograde approach was used in 34% of all procedures. The technical and procedural success rates were 85.5 and 84.2%, respectively. The mean procedural time, fluoroscopy time, and contrast utilization were 113 ± 61 min, 42 ± 29 min, and 294 ± 158 mL, respectively. Years since initiation of CTO PCI were independently associated with higher technical success rate (odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.52-1.70, P < 0.001), lower fluoroscopy time (OR = 0.84, 95% CI = 0.75-0.95, P = 0.005), and contrast utilization (OR = 0.84, 95% CI = 0.62-0.79, P < 0.001) during the study period. CONCLUSIONS: Among selected US-based institutions performing CTO PCI, we observed a significant reduction in total fluoroscopy time and contrast utilization paralleled with an improved technical success rate over time.

Procedural outcomes of revascularization of chronic total occlusion of native coronary arteries (from a multicenter United States registry).

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) is a rapidly evolving area of interventional cardiology. We sought to examine the immediate procedural and in-hospital clinical outcomes of native coronary artery CTO PCI from a multicenter United States (US) registry. We retrospectively examined the procedural outcomes of 1,361 consecutive native coronary artery CTO PCIs performed at 3 US institutions from January 2006 to November 2011. Mean age was 65 ± 11 years, 85% of patients were men, 40% had diabetes, 37% had previous coronary artery bypass graft surgery, and 42% had previous PCI. The CTO target vessel was the right coronary artery (55%), circumflex (23%), left anterior descending artery (21%), and left main or bypass graft (1%). The retrograde approach was used in 34% of all procedures. The technical and procedural success rates were 85.5% and 84.2%, respectively. The mean procedural time, fluoroscopy time, and contrast utilization were 113 ± 61 minutes, 42 ± 29 minutes, and 294 ± 158 ml, respectively. In multivariate analysis, female gender, no previous coronary artery bypass surgery, and years since initiation of CTO PCI at each center were independent predictors of procedural success. Major complications occurred in 24 patients (1.8%). In conclusion, among selected US-based institutions with experienced operators, native coronary artery CTO PCI can be performed with high success and low major complication rates.

Development of a high-volume, multiple-operator program for percutaneous chronic total coronary occlusion revascularization: procedural, clinical, and cost-utilization outcomes.

BACKGROUND: Development of a specialized chronic total coronary occlusion (CTO) revascularization program attentive to procedural guidelines, quality oversight, and cost/resource utilization has not been described. METHODS: A single-center CTO interventional program was initiated with requirements including: extensive didactic training, on-site proctorship, routine determination of case appropriateness, adherence to procedural safety guidelines, and a 2-operator/case approach. Clinical and angiographic characteristics, procedural outcomes, in-hospital clinical events, and cost/resource utilization were examined. RESULTS: Among 145 patients, 160 consecutive CTO revascularization procedures were attempted between October 2009 and December 2010. Selected procedural and technical characteristics included: bilateral femoral access, 90.0%; planned retrograde guidewire placement, 37.5%; re-entry catheter, 10.0%; reattempt, 10.6%; fluoroscopic time, 67.4 ± 45.5 min; contrast volume, 403 ± 215 mL. Average stent number and total stent length per CTO vessel were 2.6 ± 1.1 and 64.7 ± 30.7 mm, respectively. Overall CTO success rate was 85.6% (137/160). In-hospital adverse outcomes included: death 0.6%; emergency bypass surgery, 0.6%; tamponade, 0.6%; myocardial infarction, 1.9%; transient nephropathy, 1.2%. Compared with patients undergoing non-CTO PCI, procedural and total cost per patient were significantly higher among the CTO cohort despite overall similar contribution margins ($5,173 ± 12,052 versus $5,730 ± 8,958, P = 0.58). CONCLUSIONS: Following initiation of a dedicated program with implementation of quality and performance guidelines, complex CTO revascularization may be safely performed with outcomes comparable with reports from established centers. Despite higher resource utilization, CTO revascularization is associated with a positive contribution margin. Requirement of educational and performance standards, mentorship from experts, consensus review for appropriateness and provision of catheterization laboratory policies may represent a model for program development.

Impact of prior coronary artery bypass graft surgery on chronic total occlusion revascularisation: insights from a multicentre US registry.

OBJECTIVE: To investigate the impact of prior coronary artery bypass graft (CABG) surgery on the outcomes of percutaneous coronary intervention (PCI) for chronic total occlusions (CTO). DESIGN: Observational retrospective study. SETTING: Three tertiary hospitals in the USA. PARTICIPANTS: 1363 consecutive patients who underwent CTO PCI between 2006 and 2011. MAIN OUTCOME MEASURES: Procedural success and inhospital complications, which were compared between patients with and without prior CABG. RESULTS: Compared to patients without prior CABG, those with prior CABG were older, had more comorbidities, were treated more frequently with the retrograde approach (46.7% vs 27.1%, p<0.001) and had lower technical success rates (79.7% vs 88.3%, p=0.015). Of the 24 (1.8%) major inhospital complications, 11 occurred in patients with prior CABG and 13 in patients without prior CABG (2.1% vs 1.5%, p=0.392). In multivariable analysis prior CABG was independently associated with lower technical success rate (OR 0.49, 95% CIs 0.35 to 0.70, p<0.001). CONCLUSIONS: In a large multicentre registry, CTO PCI was frequently performed among patients with prior CABG, with higher use of the retrograde approach and similar complications but lower technical success rates compared to patients without prior CABG.

The M235T single nucleotide polymorphism in the angiotensinogen gene is associated with coronary artery calcium in patients with a family history of coronary artery disease.

Little is known about the contribution of genetics and lipoprotein subclasses to the development of coronary artery calcification (CAC) in asymptomatic, first-degree relatives of patients with CAD. We evaluated 100 asymptomatic, non-smoking, lipid-lowering therapy-naïve, first-degree relatives of patients with obstructive CAD through testing for 27 biomarkers, 15 single nucleotide polymorphisms in 12 candidate genes, and CAC and compared them to matched controls without family history. We compared prevalence of CAC in those with and without family history and biomarkers between those with and without CAC. Mean age was 41.6 ± 9 years; 58% were female. Significantly more subjects with family history had non-zero CAC (median Agatston: 13, range 1-1107) compared to those without family history (median Agatston: 43; range 1-345) (21% vs. 9%; p = 0.028). Among subjects with family history, in subjects with positive vs. negative CAC, multivariable analysis showed significantly lower HDL-2A (999 ± 333 vs. 1262 ± 397 nmol/L) and higher frequency of a substitution of threonine for methionine at codon 235 in the angiotensinogen gene (AGT M235T) (75% vs. 54%; p < 0.05; odds ratio of 2.6 for CAC). Population attributable risk of one copy of the risk allele at the AGT locus was 16%, highest of any variable tested. In conclusion, in this population of healthy, low-risk subjects with a family history of CAD, the AGT M235T variant was the most significant predictor of CAC independent of blood pressure, raising the possibility of an alternative biological pathway.

Retrograde coronary chronic total occlusion revascularization: procedural and in-hospital outcomes from a multicenter registry in the United States.

OBJECTIVES: This study sought to examine the contemporary outcomes of retrograde chronic total occlusion (CTO) interventions among 3 experienced U.S. centers. BACKGROUND: The retrograde approach, pioneered and developed in Japan, has revolutionized the treatment of coronary CTO, yet limited information exists on procedural efficacy, safety, and reproducibility of outcomes in other settings. METHODS: Between 2006 and 2011, 462 consecutive retrograde CTO interventions were performed at 3 U.S. institutions. Patient characteristics, procedural outcomes, and in-hospital clinical events were ascertained. RESULTS: Mean patient age was 65 ± 9.7 years, 84% were men, and 50% had prior coronary artery bypass surgery. The CTO target vessel was the right coronary artery (66%), circumflex (18%), left anterior descending artery (15.5%), and left main artery or bypass graft (0.5%). The retrograde approach was used as the primary method in 46% of cases and after failed antegrade recanalization in 54%. Retrograde collateral vessels were septal (68%), epicardial (24%), and bypass grafts (8%). Technical and procedural success was 81.4% (n = 376) and 79.4% (n = 367), respectively. The mean contrast volume and fluoroscopy time were 345 ± 177 ml and 61 ± 40 min, respectively. A major complication occurred in 12 patients (2.6%). In multivariable analysis, years since initiation of retrograde CTO percutaneous coronary intervention (PCI) at each center, female sex, and ejection fraction ≥40% were associated with higher technical success. CONCLUSIONS: Among selected U.S. programs, retrograde CTO PCI is often performed in patients with prior coronary bypass graft surgery and is associated with favorably high success and low complication rates.

Demonstration of the Glagov phenomenon in vivo by CT coronary angiography in subjects with elevated Framingham risk.

Computed tomography coronary angiography (CTA) is a novel, non-invasive method for coronary plaque detection and quantification. We hypothesized that CTA can detect early vessel wall thickening with preserved luminal size in patients without known coronary artery disease and intermediate/high Framingham Risk Score (FRS) compared to those with low FRS. Vessel-wall and plaque geometrical and compositional parameters were measured on CTA in 375 coronary segments with a highly standardized method. These parameters were then compared in patients with low versus intermediate/high FRS. The relationship between coronary artery calcium by non-contrast CT scanning (Agatston score) and percent atheroma volume (PAV) was determined by linear regression. P value <0.05 was considered significant. PAV and remodeling index were significantly higher in patients with intermediate/high FRS compared to those with low FRS (45.9 ± 6.8 vs. 42.3 ± 6.7; P = 0.004) and (0.97 ± 0.15 vs. 0.92 ± 0.13; P = 0.04), while minimal luminal diameter and minimal luminal area were similar. There was significant correlation between Agatston score and PAV (r(2) = 0.42, P = 0.0036). However, Agatston score and plaque compositional parameters were similar between the groups. In conclusion, we demonstrated that CTA can detect early vessel-wall thickening with preserved luminal size in patients with intermediate/high versus low FRS.

Relationship between chest lateral width, tube current, image noise, and radiation exposure associated with coronary artery calcium scanning on 320-detector row CT.

BACKGROUND: The relationship between chest lateral width, tube current, image noise, and radiation exposure on 320-detector row CT has not been reported. OBJECTIVE: We investigated the relationships between chest lateral width, estimated radiation exposure (DLPe), and image noise in 300 patients undergoing clinical coronary calcium scanning. METHODS: Patients undergoing coronary calcium scanning with 320-detector row CT (prospective, volumetric mode, 120 kV of tube voltage, 100-550 mA of tube current, 0.5-mm detector width) were grouped by chest lateral width (small, medium, and large) from anteroposterior topograms and 100 consecutive patients were selected from each group (n = 300). Tube current, DLPe, and noise were compared among groups with Kruskal-Wallis or one-way ANOVA. Phantom experiments were performed to evaluate the accuracy of calcium quantification as a function of size and tube current. RESULTS: Median tube current in small, medium, and large patients was 130, 200, and 250 mA, respectively (P < 0.0001). Despite the use of higher tube current settings, noise levels also increased with size (20.2 ± 4.5 HU, 22.0 ± 3.9 HU, and 25.1 ± 4.9 HU, respectively; global P < 0.001). DLPe was significantly higher with increasing size (54, 83, and 104 mGy · cm, respectively; P < 0.0001). Phantom experiments showed that 50-100 mA, 150-200 mA, and approximately 300 mA in small, medium, and large phantoms were associated with stable estimate of calcium. CONCLUSIONS: Increasing chest lateral width is associated with increasing radiation exposure and image noise. The use of 50-100 mA in small and 150-200 mA in medium patients is associated with acceptable noise and stable estimate of coronary artery calcium. In large patients, precise identification of individual calcified lesions remains difficult despite increasing tube current and radiation exposure.