Predictors of restenosis following contemporary subintimal tracking and reentry technique: The importance of final TIMI flow grade

OBJECTIVES

To identify predictors of restenosis after recanalization of chronic total occlusions (CTOs) with the Subintimal Tracking And Reentry (STAR) technique.

BACKGROUND

STAR is associated with high rates of restenosis but the associated factors are not clear. Understanding the underlying mechanisms may be important to improve STAR outcomes and possibly other contemporary CTO recanalization techniques utilizing extensive subintimal dissection and stenting.

METHODS

We retrospectively analyzed 211 lesions that underwent a STAR procedure (between 2002 and 2013) with a final Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3. One-hundred and nineteen lesions that received drug eluting stents (DES) and underwent follow-up angiography were included in the final analysis.

RESULTS

Of the 119 lesions treated with DES following STAR, 75 restenoses were observed (63.0%). Utilizing multivariate analysis, TIMI flow grade in the recanalized artery following stent implantation at the end of the index procedure was the only independent predictor of restenosis.

CONCLUSIONS

Following recanalization of a CTO with STAR, final TIMI flow predicted future restenosis or reocclusion. As a bailout technique, STAR resulted in a high acute success rate with good safety and acceptable long-term results. When poor flow is observed following recanalization, and prior to stent implantation, a two-step strategy whereby a second procedure is performed at an interval to maximize coronary flow at the end of the procedure may be considered with the goal to reduce the risk of future restenosis or total vessel occlusion following STAR.

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.

The efficacy and safety of the "hybrid" approach to coronary chronic total occlusions: insights from a contemporary multicenter US registry and comparison with prior studies

BACKGROUND

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is challenging and has been associated with low success rates. However, recent advancements in equipment and the flexibility to switch between multiple technical approaches during the same procedure ("hybrid" percutaneous algorithm) have dramatically increased the success of CTO-PCI. We sought to compare the contemporary procedural outcomes of hybrid CTO-PCI with previously published CTO-PCI studies.

METHODS

The procedural outcomes of 497 consecutive CTO-PCIs performed between January 2012 and August 2013 at five high-volume centers in the United States were compared with the pooled success and complication rates reported in 39 prior CTO-PCI series that included ≥100 patients and were published after 2000.

RESULTS

The baseline clinical and angiographic characteristics of the study patients were comparable to those of previous studies. Technical and procedural success was achieved in 455 cases (91.5%) and 451 cases (90.7%), respectively, and were significantly higher than the pooled technical and procedural success rates from prior studies (76.5%, P<.001 and 75.2%, P<.001, respectively). Major procedural complications occurred in 9/497 patients (1.8%) overall and included death (2 patients), acute myocardial infarction (5 patients), repeat target vessel PCI (1 patient), and tamponade requiring pericardiocentesis (2 patients). The incidence of major complications was similar to that of prior studies (pooled rate 2.0%; P=.72).

CONCLUSION

Use of the hybrid approach to CTO-PCI is associated with higher success and similar complication rates compared to prior studies, supporting its expanded use for treating these challenging lesions.

Thrombin injection for sealing epicardial collateral perforation during chronic total occlusion percutaneous coronary interventions

Epicardial collateral perforation is a serious complication of retrograde chronic total occlusion percutaneous coronary intervention. We describe two cases of epicardial collateral perforation that were successfully sealed with local thrombin injection.

The efficacy of "hybrid" percutaneous coronary intervention in chronic total occlusions caused by in-stent restenosis: insights from a US multicenter registry

OBJECTIVES

To examine the success and complication rates in percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) caused by in-stent restenosis (ISR).

BACKGROUND

PCI for in-stent total occlusive disease has traditionally been associated with low success rates. We sought to examine angiographic and procedural outcomes of patients who underwent CTO PCI due to ISR using the novel "hybrid" algorithm, and compare them with patients with de novo CTOs.

METHODS

We examined 521 consecutive patients who underwent CTO PCI at five high-volume PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, and procedural outcomes were compared between CTOs due to ISR and de novo CTOs.

RESULTS

The target CTO was due to ISR in 57 of 521 patients (10.9%). Compared to patients with de novo CTOs, those with CTO due to ISR had higher frequency of diabetes (56.1% vs. 39.6%, P = 0.02) and less calcification (5.3% vs. 16.2%, P <0.001), but longer occlusion length [38 (29-55) vs. 30 (20-51), P = 0.04]. Technical success in the ISR and de novo group was 89.4% and 92.5% (P = 0.43), respectively; procedural success was 86.0% and 90.3% (P = 0.31), respectively; and the incidence of major adverse cardiac events was 3.5% and 2.2% (P = 0.63), respectively.

CONCLUSIONS

Use of the "hybrid" approach to CTO PCI was associated with similarly high procedural success and similarly low major complication rates in patients with de novo and ISR CTOs.

Developments in coronary chronic total occlusion percutaneous coronary interventions: 2014 state-of-the-art update

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) is a rapidly developing field. In the present review, we summarize the most important CTO PCI related literature published in 2013.

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.

Prospective, head-to-head comparison of quantitative coronary angiography, quantitative computed tomography angiography, and intravascular ultrasound for the prediction of hemodynamic significance in intermediate and severe lesions, using fractional flow reserve as reference standard (from the ATLANTA I and II Study)

The objective of this study was to compare the diagnostic accuracy of quantitative coronary angiography (QCA), coronary computed tomography angiography (CTA), and intravascular ultrasound (IVUS) with fractional flow reserve (FFR) measurements. Eighty-five lesions (40% to 99% diameter stenosis) in 85 patients were prospectively interrogated by QCA, CTA, IVUS, and FFR. Minimal lumen diameter (MLD), percent diameter stenosis (%DS), minimal lumen area (MLA), and percent area stenosis (%AS) were measured. Correlation, receiver operating characteristic analysis, kappa statistics, and multivariable logistic regression was used to assess relation between anatomic measurements and FFR. Average age was 61.3 ± 7.8; 62% were men. QCA-derived mean %DS was 55.3% ± 19.5%; mean FFR 0.81 ± 0.17; 27% had FFR ≤0.75. QCA had the strongest correlation, followed by CTA and then IVUS for MLD (r = 0.67, 0.47, and 0.29, respectively) and for %DS (r = -0.63, -0.52, and -0.22, respectively); QCA-derived MLD had area under the curve of 0.96, with 95% sensitivity and 82% specificity. Cut-point, area under the curve, sensitivity, and specificity for CTA-MLA and IVUS-MLA were 3.11 mm(2), 0.86, 81%, and 81% and 2.68 mm(2), 0.75, 70%, and 80%. In multivariable analysis for each modality, MLD on QCA (odds ratio [OR]: 0.002), %AS on CTA (OR: 1.09) and MLA on IVUS (OR: 0.28) remained independent predictors. In conclusion, in intermediate-to-severe lesions, QCA-, CTA-, and IVUS-derived quantitative anatomic measurements correlated with FFR. CTA-derived cut-points were similar to respective measurements on QCA and IVUS and had similar or better diagnostic performance compared with IVUS.

A peripheral blood gene expression score is associated with plaque volume and phenotype by intravascular ultrasound with radiofrequency backscatter analysis: results from the ATLANTA study

BACKGROUND

A composite, peripheral gene expression score based on quantitative RNA-measurements has been validated for detecting stenosis against invasive coronary X-ray angiography. IVUS/VH has been validated for quantitative measurements of coronary plaque volume and composition and has been shown to be predictive of outcomes and treatment effects. The correlation between peripheral gene expression and coronary plaque composition by intravascular ultrasound with radiofrequency backscatter (IVUS/VH) is unknown.

METHODS

Peripheral blood gene expression score (GES) was prospectively measured in 18 patients undergoing IVUS/VH. Plaque volume and composition [fibrous tissue (FI), fibro-fatty tissue (FF), necrotic core (NC) and dense calcium (DC)] were quantified in 3 dimensions in all plaques within the entire pullback. The relationship to GES was assessed by Spearman rank correlation.

RESULTS

Mean age was 61.1±8.6 years; 67% were male. 1,158 mm of coronary anatomy was imaged by IVUS/VH. Using a validated scale of 1-40, mean GES was 21.6±9.4. GES was associated with plaque volume (R(2)=0.55; P=0.018), NC volume (R(2)=0.56; P=0.015), DC volume (R(2)=0.60; P=0.007), and non-calcified plaque volume (R(2)=0.50; P=0.036) by Spearman rank correlation.

CONCLUSIONS

In this preliminary report, increased GES was associated with higher plaque volume and a more vulnerable plaque phenotype as evidenced by NC and DC. This composite GES is not only associated with obstructive coronary disease, but also with higher plaque volume and vulnerable phenotype.

Apoprotein B, small-dense LDL and impaired HDL remodeling is associated with larger plaque burden and more noncalcified plaque as assessed by coronary CT angiography and intravascular ultrasound with radiofrequency backscatter: results from the ATLANTA I study

Background

Apoprotein B–containing lipoproteins are atherogenic, but atheroprotective functions of apoprotein A–containing high‐density lipoprotein (HDL) particles are poorly understood. The association between lipoproteins and plaque components by coronary computed tomography angiography (CTA) and intravascular ultrasound with radiofrequency backscatter (IVUS/VH) has not been evaluated.

Methods and Results

Quantitative, 3‐dimensional plaque measurements were performed in 60 patients with CTA and IVUS/VH. Apoproteins, lipids, and HDL subpopulations were measured with 2‐dimensional (2D) gel electrophoresis, and correlation was assessed with univariate and multivariable models. ApoB particles were associated with a higher proportion of noncalcified plaque (NCP) and a lower proportion of calcified plaque (small, dense low‐density lipoprotein cholesterol and high‐density NCP: r=0.3, P=0.03; triglycerides and low‐density NCP: r=0.34, P=0.01). Smaller, dense, lipid‐poor HDL particles were associated with a shift from calcified plaque to NCP on CTA (α3‐HDL% and low‐density NCP: r=0.32, P=0.02) and with larger plaque volume on IVUS/VH (α4‐HDL%: r=0.41, P=0.01; α3‐HDL%: r=0.37, P=0.03), because of larger dense calcium (α4‐HDL%: r=0.37, P=0.03), larger fibrous tissue (α4‐HDL%: r=0.34, P=0.04), and larger necrotic core (α4‐HDL%: r=0.46, P<0.01; α3‐HDL%: r=0.37, P=0.03). Larger lipid‐rich HDL particles were associated with less low‐density NCP on CTA (α2‐HDL%: r=−0.34, P=0.02; α1‐HDL%: r=−0.28, P=0.05), with smaller plaque volume on IVUS/VH (pre‐α2‐HDL: r=−0.33, P=0.05; α1‐HDL%: r=−0.41, P=0.01; pre‐α2‐HDL: r=−0.33, P=0.05) and with less necrotic core (α1‐HDL: r=−0.42, P<0.01; pre‐α2‐HDL: r=−0.38, P=0.02; α2‐HDL: r=−0.35, P=0.03; pre‐α1‐HDL: r=−0.34, P=0.04). Pre‐β2‐HDL was associated with less calcification and less stenosis by both modalities.

Conclusions

ApoB and small HDL particles are associated with larger plaque burden and more noncalcified plaque, whereas larger HDL and pre‐β2‐HDL particles are associated with plaque burden and less noncalcified plaque by both CTA and IVUS/VH.