Assessment of Myocardial Viability and Risk Stratification in Coronary Chronic Total Occlusion: A Qualitative and Quantitative Stress Cardiac MRI Study

BACKGROUND

Indicators for assessing myocardial viability and risk stratification in patients with coronary chronic total occlusion (CTO) are still in the research stage.

PURPOSE

To use stress-MRI to assess myocardial function, blood perfusion, and viability and to explore their relationship with collateral circulation.

STUDY TYPE

Prospective.

SUBJECTS

Fifty-one patients with CTO in at least one major artery confirmed by X-ray coronary angiography (male: 46; age 55.2 ± 10.8 years).

FIELD STRENGTH/SEQUENCE

3.0T; TurboFlash, balanced steady-state free precession cine, and phase-sensitive inversion recovery sequences.

ASSESSMENT

Stress-MRI was used to obtain qualitative and quantitative parameters of segmental myocardium. Myocardial segments supplied by CTO target vessels were grouped according to the degree of collateral circulation assessed by radiographic coronary angiography (no/mild, moderate, or good). Depending on qualitative stress perfusion assessment and late gadolinium enhancement (LGE) extent, segments were also categorized as negative, viable, or trans-infarcted.

STATISTICAL TESTS

Independent sample Student's t-test, one-way analysis of variance (ANOVA) test, Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient (r). P < 0.05 was considered statistically significant.

RESULTS

A total of 334 segments were supplied by CTO target vessels. The radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of the negative, viable, and trans-infarcted regions showed a significant and stepwise impairment. Myocardial blood flow at rest was positively correlated with RS, CS, and LS (r = 0.42, 0.43, 0.38, respectively). Among the different collateral circulation, there were no significant differences in RS, CS, LS, and LGE volume (P = 0.788, 0.562, 0.122, 0.170, respectively), and there were also no statistically significant differences in the proportions of negative, viable, and trans-infarcted regions (P = 0.372).

DATA CONCLUSION

Myocardial perfusion obtained by stress-MRI combined with strain and LGE may comprehensively evaluate myocardial function and viability, and has potential to facilitate risk stratification of CTO.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 1.

Computed Tomography Angiography-Derived Scores for Prediction of Chronic Total Occlusion Percutaneous Coronary Intervention Using the Hybrid Algorithm

Whereas coronary computed tomography angiography (CCTA) exceeds invasive angiography for predicting the procedural outcome of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), CCTA-derived scores have never been validated in the hybrid CTO PCI population. In this single-center, retrospective, observational study, we included 108 consecutive patients with 110 CTO lesions and preprocedural CCTA who underwent hybrid CTO PCI to assess the diagnostic accuracy of CCTA-derived scoring systems. Successful guidewire crossing within 30 min was set as the primary endpoint. The secondary endpoints were final procedural success and the need for using any non-antegrade wiring (AW) strategy within the hybrid algorithm. Time-efficient guidewire crossing and final procedural success were achieved in 53.6% and 89.1% of lesions, respectively, while in 36.4% of the procedures, any non-AW strategy was applied. The median J-CTO score was 1 (interquartile range (IQR): 0, 2), while the CT-RECTOR, KCCT, J-CTOCCTA, and RECHARGECCTA scores were 2 (IQR: 1, 3), 3 (IQR: 2, 5), 1 (IQR: 0, 3), and 2 (IQR: 1, 3), respectively. All scores were significantly higher in the lesions with failed versus successful time-efficient guidewire crossing. Although all of the CCTA-derived scores had numerically higher predictive values than the angiographic J-CTO score, no significant differences were noted between the scores in any of the analyzed study endpoints. High sensitivity of the CT-RECTOR and RECHARGECCTA scores (both 89.8%) for predicting successful guidewire crossing within 30 min, and high sensitivity (90.8%) of the KCCT score for predicting final procedural success, were noted. CCTA-derived scoring systems are accurate, noninvasive tools for the prediction of the procedural outcome of hybrid CTO PCI, and may aid in identifying the need for use of the hybrid algorithm.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes

BACKGROUND

Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.

OBJECTIVES

This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.

METHODS

We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.

RESULTS

The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).

CONCLUSIONS

Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Incidence, Predictors, and Strategies for Retrograde Wire Tracking Failure via Poor Septal Collateral Channels in Chronic Total Occlusion

Background

Retrograde guidewire (GW) tracking success via a poor septal collateral channel (CC) when an antegrade approach fails is crucial for successful revascularization of coronary chronic total occlusion (CTO) with poor septal CC. However, the incidence, predictors, and management strategies for retrograde GW tracking failure via poor septal CC remain unclear.

Methods

In total, 122 CTO patients who underwent retrograde septal percutaneous coronary intervention (PCI) with poor CC between January 2017 and May 2022 were retrospectively analyzed. Patients were divided into the retrograde GW tracking success group (success group) and the retrograde GW tracking failure group (failure group). Clinical and angiographic data were compared to investigate the predictors of retrograde GW tracking failure.

Results

The incidence of GW tracking failure was 22.1% (27/122). Patients in the failure group had a higher prevalence of left anterior descending artery (LAD) CTO (66.7% vs 37.9%; p = 0.009) and a higher incidence of well-developed non-septal collateral (66.7% vs 30.5%; p = 0.001). Patients with a septal CC diameter ≥ 1 mm (48.1% vs 70.5%; p = 0.040), ≥ 3 septal CCs (44.4% vs 66.3%; p = 0.046), and initial retrograde application of Guidezilla (37.0% vs 60.0%; p = 0.048) were significantly lower in the failure group than in the success group. The binary logistics regression model showed that a CC diameter < 1 mm, well-developed non-septal collateral, and LAD CTO were independent predictors for GW tracking failure in patients undergoing retrograde CTO PCI via poor septal CC.

Conclusion

The success rate of retrograde GW tracking via poor septal CC was high, with a relatively high procedural success rate. A CC diameter < 1 mm, well-developed non-septal collateral, and LAD CTO were independent predictors of GW tracking failure in patients undergoing retrograde CTO PCI via poor septal CC.

Safety and Efficiency of Rotational Atherectomy in Chronic Total Coronary Occlusion-One-Year Clinical Outcomes of an Observational Registry

The study sought to assess the procedural success of rotational atherectomy (RA) in coronary chronic total occlusion (CTO) and to investigate the in-hospital and one-year outcomes following RA. From 2015 to 2019, patients undergoing percutaneous coronary intervention for CTO (CTO PCI) were retrospectively included into the hospital database. The primary endpoint was procedural success. Secondary endpoints were in-hospital and one-year major adverse cardiovascular and cerebral event (MACCE) rates. During the study period of 5 years, 2.789 patients underwent CTO PCI. Patients treated with RA (n = 193, 6.92%) had a significantly higher procedural success (93.26% vs. 85.10%, p = 0.0002) compared to those treated without RA (n = 2.596, 93.08%). Despite a significantly higher rate of pericardiocentesis (3.11% vs. 0.50%, p = 0.0013) in the RA group, the in-hospital and one-year MACCE rate was similar in both groups (4.15% vs. 2.77%, p = 0.2612; 18.65% vs. 16.72%, p = 0.485). In conclusion, RA is associated with higher procedural success for CTO PCI, but has higher risks for pericardial tamponade than CTO PCI without the need for RA. Nevertheless, in-hospital and one-year MACCE rates did not differ in-between both groups.

Mid-Term Outcome of Ventricular Arrhythmias Catheter Ablation in Patients with Chronic Coronary Total Occlusion Compared to Ischemic and Non-Ischemic Patients

Chronic coronary total occlusions (CTO) are considered an emerging predictor of ventricular arrhythmias (VAs), but currently there are few data on arrhythmic outcomes in patients affected by CTO undergoing radiofrequency catheter ablation of VAs. This study sought to evaluate the impact of unrevascularized CTO on the recurrence of VAs after catheter ablation. This was a single-center retrospective study enrolling 120 patients between 2015 and 2020. All patients were admitted for ventricular tachycardia (VT) or high premature ventricular contractions burden (>25% detected by Holter ECG), without evidence of acute coronary syndrome; they underwent coronary angiography, electrophysiology (EP) study, and three-dimensional electroanatomic mapping (3D-EAM) followed by VAs ablation. Twenty-eight patients (23%) of 120 patients showed CTO at coronary angiography. At baseline, the CTO group presented with higher prevalence of hypertension, chronic renal disease, systolic ventricular dysfunction, secondary prevention ICD implantation, and higher rate of LAVA by 3D-EAM compared with the non-CTO group. At a median follow-up of 15 months (range 1−96 months) after catheter ablation, the only independent predictor of VAs recurrence was the presence of moderate to severe left ventricular (LV) dysfunction. Therefore, the presence of CTO does not predict VAs recurrence after catheter ablation, which is instead predicted by LV dysfunction.

Femoral or Radial Approach in Treatment of Coronary Chronic Total Occlusion: A Randomized Clinical Trial

OBJECTIVES

The aim of this study was to compare transradial access (TRA) with transfemoral access (TFA) for chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

TRA reduces the risk for vascular access complications but may make complex PCI, such as CTO PCI, more challenging.

METHODS

FORT CTO (Femoral or Radial Approach in the Treatment of Coronary Chronic Total Occlusion) (NCT03265769) was a prospective, noninferiority, randomized controlled study of TRA vs TFA for CTO PCI. The primary study endpoint was procedural success, defined as technical success without any in-hospital major adverse cardiovascular events. The secondary study endpoint was major access-site complications.

RESULTS

Between 2017 and 2021, 610 of 800 patients referred for CTO PCI at 4 centers were randomized to TRA (n = 305) or TFA (n = 305). Mean J-CTO (Multicenter CTO Registry in Japan) (2.1 ± 0.1 vs 2.2 ± 0.1; P = 0.279), PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) (1.3 ± 0.9 vs 1.1 ± 1.0; P = 0.058) and PROGRESS CTO complication (2.4 ± 1.8 vs 2.3 ± 1.8; P = 0.561) scores and use of the retrograde approach (11% vs 14%; P = 0.342) were similar in the TRA and TFA groups. TRA was noninferior to TFA for procedural success (84% vs 86%; P = 0.563) but had fewer access-site complications (2.0% vs 5.6%; P = 0.019). There was no difference between TFA and TRA in procedural duration, contrast volume, or radiation dose.

CONCLUSIONS

TRA was noninferior to TFA for CTO PCI but had fewer access-site complications.

Contemporary Issues in Chronic Total Occlusion Percutaneous Coronary Intervention

Remarkable progress has been achieved in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent years, with refinement of the indications and technical aspects of the procedure, imaging, and complication management. Randomized controlled trials and rigorous prospective registries have provided high-quality data on the benefits and risks of CTO PCI. Global collaboration has led to an agreement on nomenclature, indications, endpoint definition, and principles of clinical trial design that have been distilled in global consensus documents such as the CTO Academic Research Consortium. Increased use of preprocedural coronary computed tomography angiography and intraprocedural intravascular imaging, as well as development of novel techniques and structured CTO crossing and complication management algorithms, allow a systematic, stepwise approach to this difficult lesion subset. This state-of-the-art review provides a comprehensive discussion about the most recent developments in the indications, preprocedural planning, technical aspects, complication management, and future directions of CTO PCI.

The association of interferon-alpha with development of collateral circulation after artery occlusion

Background

Previous studies have demonstrated that interferon (IFN) signaling is enhanced in patients with poor collateral circulation (CC). However, the role and mechanisms of IFN‐alpha in the development of CC remain unknown.

Methods

We studied the serum levels of IFN‐alpha and coronary CC in a case–control study using logistics regression, including 114 coronary chronic total occlusion (CTO) patients with good coronary CC and 94 CTO patients with poor coronary CC. Restricted cubic splines was used to flexibly model the association of the levels of IFN‐alpha with the incidence of good CC perfusion restoration after systemic treatment with IFN‐alpha was assessed in a mice hind‐limb ischemia model.

Results

Compared with the first IFN‐alpha tertile, the risk of poor CC was higher in the third IFN‐alpha tertile (OR: 4.79, 95% CI: 2.22–10.4, p < .001). A cubic spline‐smoothing curve showed that the risk of poor CC increased with increasing levels of serum IFN‐alpha. IFN‐alpha inhibited the development of CC in a hindlimb ischemia model. Arterioles of CC in the IFN‐alpha group were smaller in diameter than in the control group.

Conclusion

Patients with CTO and with poor CC have higher serum levels of IFN‐alpha than CTO patients with good CC. IFN‐alpha might impair the development of CC after artery occlusion.

A Clinical Analysis of the Treatment of Chronic Coronary Artery Occlusion With Antegrade Dissection Reentry

Objective: This study aimed to investigate the efficacy and safety of antegrade dissection re-entry (ADR) technique in the percutaneous coronary intervention (PCI) to open chronic total occlusion (CTO) lesions. Methods: The baseline, angiographic results, PCI success rate, and major adverse cardiac events (MACE) during the 12 months of follow-up were compared between 48 patients who did not use ADR in the treatment of CTO lesions (control group) and 50 patients who used ADR (treatment group). Results: The control group comprised 48 patients who had 52 CTO lesions, and the treatment group comprised 50 patients who had 58 CTO lesions. The success rate of PCI in the treatment group (89.7 vs. 71.2%, P = 0.047) was significantly higher than in the control group, where six patients had in-stent restenosis (ISR, ISR-CTO) that were all recanalized. The mean PCI time (71 ± 25 min vs. 95 ± 33 min, P = 0.041), X-ray exposure time (42 ± 17 min vs. 71 ± 22 min, P = 0.032), contrast agent dosage (98 ± 26 ml vs. 178 ± 63 ml, P = 0.029), MACE incidence during the 12 months of follow-up (22.0 vs. 41.7%, P = 0.046) and recurrent myocardial infarction incidence (10.0 vs. 27.1%, P = 0.047) were significantly lower in the treatment group than in the control group. The differences were all statistically significant. Conclusion: It is safe and effective to use the ADR technique in PCI for coronary artery CTO lesions. The technique shortens the operation time, reduces the radiation dose of doctors and patients and the use dose of contrast agents, and improves patients' prognoses.

Chronic total occlusion percutaneous coronary intervention in everyday clinical practice - an expert opinion of the Association of Cardiovascular Interventions of the Polish Cardiac Society

Coronary chronic total occlusions (CTO) are increasingly encountered during invasive and non-invasive coronary angiography and remain the most challenging lesions for percutaneous revascularization. During recent years success rates and safety outcomes of CTO percutaneous coronary intervention (PCI) have substantially improved, particularly due to the introduction of new techniques and dedicated equipment as well as specialized training programs of CTO operators. Significantly, the steady advances in CTO PCI techniques have coincided with the new data from randomized clinical trials supporting the role of percutaneous recanalization of CTO in relieving angina and improving the quality of life. The current expert consensus document outlines the rationale, clinical outcomes as well as technical, safety and reimbursement issues of CTO PCI. In addition, the requirements for achieving and maintaining competency in CTO PCI among interventional cardiologists are discussed. Finally, we present the modified hybrid algorithm (the so-called Polish hybrid algorithm) providing some unique refinements to the contemporary CTO PCI strategies. Continuous efforts (including active engagement with the payer) are urgently needed to increase guideline-recommended referrals to CTO PCI, and thus improve the quality of life of CTO patients in Poland.

Incidence, Predictors, and Strategies for Failure of Retrograde Microcatheter Tracking After Successful Wiring of Septal Collateral Channels in Chronic Total Occlusions

Background

Retrograde microcatheter collateral channel (CC) tracking after successful wiring of septal CC is crucial for retrograde revascularization of coronary chronic total occlusion (CTO). However, the incidence, predictors, and strategies for failure of retrograde microcatheter CC tracking after successful wiring of septal CC remain unclear.

Methods

In total, 298 patients with CTO who underwent retrograde septal CC PCI between January 2015 and May 2019 were retrospectively analyzed. Clinical data were compared to investigate the predictors of initial microcatheter tracking failure.

Results

The initial and final microcatheter tracking success rates were 79.2% (236/298) and 96.6% (288/298), respectively. The procedural success rate was 94.0% (280/298). The right coronary artery-to-left anterior descending artery septal ratio (48.4% vs 33.1%, p=0.037) and CC tortuosity (34.6% vs 20.8%, p=0.045) were significantly higher in the initial microcatheter CC tracking failure group than in the successful tracking group. Multivariate logistic regression analysis revealed that severe collateral tortuosity (odds ratio [OR]: 13.241, 95% confidence interval [CI]: 3.429–27.057, p=0.038), CC entry angle of <90° (OR:4.921, 95% CI: 1.128–9.997, p=0.002), CC exit angle of <90° (OR:5.037, 95% CI: 2.237–11.182, p=0.004), use of Finecross MG as initial microcatheter (OR:1.826, 95% CI: 1.127–3.067, p=0.035), and shunning initial retrograde application of Guidezilla (OR:0.321, 95% CI: 0.267–0.915, p=0.024) were variables independently associated with initial microcatheter CC tracking failure in patients with CTO undergoing retrograde septal CC PCI.

Conclusion

The overall initial microcatheter CC tracking failure was 20.8%. Severecollateral tortuosity, CC entry, and exit angle of <90°, use of Finecross MG as initial microcatheter, and shunning initial retrograde application of Guidezilla were variables independently associated with initial microcatheter CC tracking failure in patients with CTO undergoing retrograde septal PCI.

The hybrid algorithm in treatment of coronary chronic total occlusions - MSWiA Lublin CTO 5-year registry

INTRODUCTION

Treatment of chronic total occlusions (CTO) despite improvement in techniques and results over the last years still seems to be limited to a small number of centres and operators. Application of the hybrid strategy may support further spread of CTO percutaneous coronary intervention (PCI) and increase procedural success rates.

AIM

Our single-centre prospective ongoing registry aims to provide details and results of recanalizations of coronary CTO performed according to the hybrid algorithm in a series of consecutive patients.

MATERIAL AND METHODS

Between January 2015 and September 2019 the clinical and procedural data of CTO PCI procedures on consecutive patients were collected. Lesion complexity was assessed according to the Multicenter CTO Registry of Japan (J-CTO) score: 0 - easy, 1 - intermediate, 2 - difficult, ≥ 3 - very difficult and PROGRESS score. Strategies applied were classified as: antegrade wire escalation (AWE), antegrade dissection and re-entry (ADR), retrograde wire escalation (RWE) and retrograde dissection and re-entry (RDR). Angiographic success was defined as < 30% residual stenosis with TIMI 3 flow. Angiographic and clinical complications were reported.

RESULTS

Two hundred sixty-six patients were included and 285 procedures were performed in total. Success rate was 87.7% (calculated per procedure) and 92.5% (calculated per patient). Four patients underwent successful staged double CTO recanalization. Fifteen patients out of 31 primary failures underwent a second attempt with a 73% success rate (11/15). Fifty-two patients (18.2%) were referred for a second attempt from other institutions. Mean J-CTO score was 2.6 (13 cases with J-CTO of 0, 41 cases with J-CTO of 1, 80 cases with J-CTO of 2, and 151 cases with J-CTO ≥ 3) and the success rate was respectively 92.3%, 95.1%, 91.3% and 83.4%. Higher complexity of occlusion required a higher number of applied strategies including retrograde access in over a quarter of cases. Complete revascularization was achieved in 215 (75.4%) cases. In-hospital MACCE rate was 3.5% - 1 patient died due to acute kidney injury complications, 9 (3.2%) patients sustained myocardial infarction (1 STEMI due to side branch occlusion). All 7 (2.5%) coronary perforations (Ellis 1 and Ellis 2) were treated conservatively and we recognised 10 (3.5%) cases of acute kidney injury (one dialysis).

CONCLUSIONS

The hybrid algorithm in CTO PCI can be successfully applied with good early results and low complication rates. Higher complexity CTOs require more procedural strategies with a significantly lower success rate in very difficult cases.

Procedural and In-hospital Outcomes of Rotational Atherectomy in Retrograde Coronary Chronic Total Occlusion Intervention

Coronary chronic total occlusions (CTOs) are characterized by a high incidence of severe plaque calcifications, which are associated with a high use of the retrograde approach and a low success rate of percutaneous coronary intervention (PCI). However, the feasibility of rotational atherectomy (RA) in retrograde CTO-PCI remains unknown. The aim of the present study is to examine the safety and efficacy of RA in retrograde CTO-PCI. Consecutive patients (n = 129) who underwent RA during CTO-PCI were categorized into anterograde and retrograde groups according to the CTO crossing approach. The distributions of the baseline characteristics were similar in the 2 groups, but the lesion type was more complex (P = .001), and the starting burr size was smaller (P = .003) in the retrograde group than in the anterograde group. There was a trend of a higher incidence of procedural complications in the retrograde group than in the anterograde group (P = .054). Technical and procedural success and in-hospital outcomes were not significantly different between the 2 groups. In conclusion, RA was feasible in retrograde CTO PCI, but some specific precautions are required before and during the procedure. In addition, further investigation of the long-term outcomes of RA in retrograde CTO PCI is necessary.

Incidence, Predictors, and Prognosis of Coronary Slow-Flow and No-Reflow Phenomenon in Patients with Chronic Total Occlusion Who Underwent Percutaneous Coronary Intervention

Background

The incidence and prognosis of coronary slow-flow (CSF) and no-reflow phenomenon (NRP) in patients with coronary chronic total occlusion (CTO) who underwent percutaneous coronary intervention (PCI) remain unclear.

Methods

This single-center prospective study aimed to investigate the incidence of CSF/NRP during CTO interventional therapy, determine predictors of CSF/NRP, and evaluate its effect on patient outcomes.

Results

In this study, 552 patients with CTO who underwent PCI were included. CSF/NRP occurred in 16.1% of them. They had higher incidences of diabetes mellitus (53.9% vs 36.3%, p=0.002) and hypertension (50.6% vs 37.1%, p=0.018) and a lower incidence of retrograde filling grade >2 (34.8% vs 47.1%, p=0.036). Patients with CSF/NRP had a higher neutrophil ratio (55.6±19.4 vs 52.4±18.3, p=0.038) and levels of low-density lipoprotein (LDL; 3.0±0.8 vs 2.8±0.6, p=0.029), fasting glucose (FG; 8.3±1.3 vs 6.8±1.1, p=0.005), uric acid (332.6±82.9 vs 308.2±62.8, p=0.045), and high-sensitivity C-reactive protein (Hs-CRP; 9.8±4.8 vs 7.3±3.9, p=0.036). A multivariate logistic regression analysis revealed that diabetes mellitus (odds ratio [OR], 1.962; 95% confidence interval [CI]: 1.198–2.721; p=0.042), mean platelet volume (MPV; OR,1.284; 95% CI, 1.108–1.895; p=0.046), LDL cholesterol (LDL-C; OR, 1.383; 95% CI, 1.105–2.491; p=0.036), FG (OR, 2.095; 95% CI, 1.495–2.899; p=0.018), Hs-CRP(OR, 2.218; 95% CI, 1.556–3.519; p=0.029), and retrograde filling of grade >2 (OR, 0.822; 95% CI, 0.622–0.907; p=0.037) were independent predictors of CSF/NRP in CTO patients who underwent PCI. Kaplan-Meier analysis revealed that the patients in the CSF/NRP group had a significantly lower cumulative major cardiac and cerebrovascular events (MACCE)-free survival than those in the non-CSF/NRP group (p<0.0001).

Conclusion

Of the patients with CTO who underwent PCI, 16.1% developed CSF/NRP and had a significantly lower cumulative MACCE-free survival rate. Diabetes mellitus; higher levels of MPV, LDL-C, FG, and Hs-CRP; and a lower incidence of retrograde filling grade >2 were independent predictors of CSF/NRP in CTO patients who underwent PCI. Thus, they can be used for risk stratification.

Serial Fractional Flow Reserve Measurements Post Coronary Chronic Total Occlusion Percutaneous Coronary Intervention

Background The aim of this study was to evaluate the functional result of chronic total occlusion percutaneous coronary intervention (PCI) measured by fractional flow reserve (FFR) immediately post the index procedure and at short-term follow-up. Methods and Results This was a prospective single-center observational study. Consecutive patients with right coronary artery chronic total occlusion scheduled for elective PCI were included. FFR measurements were performed immediately after successful PCI and at 4 months follow-up. Twenty-six patients completed baseline and follow-up measurements. Mean age was 61.2±9.7 years, 88.5% of the patients were male, and 19.2% were diabetic. The mean FFR immediately after successful chronic total occlusion PCI was 0.82±0.10 and significantly increased to 0.89±0.07 at 4 months ( P<0.001). The FFR increased in 77% of the patients with a mean absolute increase of 0.07±0.08. The incidence of FFR ≤0.80 immediately after PCI was significantly higher amongst patients with subintimal versus intraplaque recanalization (23% versus 12%; P=0.03). At 4 months, FFR ≤0.80 was found only in 2 patients with subintimal recanalization. At follow-up, 42.7% of the patients continued to have an FFR <0.90. Conclusions Post chronic total occlusion PCI, FFR increased significantly at short-term follow-up compared with measurements post index procedure. Because FFR remained <0.90 in many cases, further efforts should be made to optimize procedural results.

The trap and occlude technique for retrograde wire externalization during chronic total occlusion revascularization

Different strategies of retrograde approach were introduced in recent years to improve the success rate of percutaneous coronary intervention for coronary chronic total occlusions. The aim of this report is to describe a new technique, called "Trap and Occlude Technique," for retrograde wire externalization during CTO percutaneous revascularization. This technique may save time and reduce radiation exposure and procedure-related bleeding.

Impact of Neutrophil to Lymphocyte Ratio (NLR) Index and Its Periprocedural Change (NLRΔ) for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion

We assessed the association between neutrophil to lymphocyte ratio (NLR) and chronic coronary total occlusion (CTO), as well as clinical prognosis of percutaneous coronary intervention (PCI). Patients referred for elective coronary angiography for stable angina pectoris were enrolled, including a CTO (n = 160) and a non-CTO group (n = 160). Neutrophil to lymphocyte ratio on admission and post-PCI was measured, and NLR_Δ was defined as the change between the 2 values. Subgroup analysis was performed based on the value of NLR_Δ (≥0.5 vs <0.5). Clinical characteristics, angiographic data, and follow-up data were recorded. Compared with the non-CTO group, the total white blood cell count, neutrophil counts, and NLR were significantly higher in the CTO group. In the NLR_Δ ≥ 0.5 subgroup, the incidence of severe dissection, slow coronary flow, in-stent restenosis (ISR), and major adverse cardiac events (MACEs) was obviously higher. In multivariate analysis, NLR_Δ was independently and positively associated with higher risks of ISR and MACE. The NLR could be a potential predictor of CTO, and NLR_Δ is independently associated with the adverse clinical outcomes in patients who underwent PCI.

Predictors of successful percutaneous coronary intervention in chronic total coronary occlusions

Introduction

Percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) is one of the most challenging procedures of interventional cardiology and is associated with increased risk of significant complications. However, debate continues in regard to which factors adversely influence the success rate of PCI and whether the benefits of revascularization of CTO outweigh the risks and challenges.

Aim

To analyze the relationship between lesion characteristics and overall success rates as well as in-hospital outcomes after PCI for CTO.

Material and methods

We retrospectively examined the procedural outcomes of 173 consecutive native coronary artery CTO PCIs performed from February 2012 to March 2013 (78% men; mean age: 60.3 ±12.1 years).

Results

The CTO target vessel was the right coronary artery (53.8%), circumflex (10.4%) and left anterior descending artery (35.8%), respectively. The retrograde approach was used in 13.9% of all procedures. Successful revascularization was achieved in 83.2% of patients. Major complications occurred in 13.3% of patients. In multivariate analysis, bridge collaterals, severe calcification and tortuosity as well as tandem occlusions were independent predictors of procedural failure, whereas existence of micro-channels was the only predictor of procedural success.

Conclusions

Revascularization of coronary CTOs may be performed with high success and low major complication rates. Bridge collaterals, severe calcification and tortuosity, tandem/multiple occlusions and micro-channels were independent predictors of successful CTO revascularization.

The relationship between the neutrophil-lymphocyte ratio and the coronary collateral circulation in patients with chronic total occlusion

OBJECTIVES

Previous studies showed the association between the major adverse cardiovascular outcomes and both higher neutrophil and lower lymphocyte counts. We aimed to investigate whether there is an association between the neutrophil-lymphocyte ratio (NLR) value and the development of coronary collateral circulation (CCC) in patients with coronary chronic total occlusion (CTO).

METHODS

A total of 274 patients with CTO were included in this study. Patients were then classified according to their Rentrop collateral grades as either poor (Rentrop grades 0-1) or good (Rentrop grades 2-3). Clinical information and analyses of blood samples were obtained from a review of the patients' charts.

RESULTS

Although there was no difference between the two groups with regard to cardiovascular risk profiles, the NLR values were significantly higher in the patients who had poorly developed CCC (2.6 ± 0.5 vs 2.2 ± 0.4, p<0.001). NLR, high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBC), age, diabetes, fasting glucose levels and body mass index were found to have univariate association with poorly developed CCC (p<0.1). In a multivariate logistic regression model, NLR (odds ratio 1.88, 95% confidence interval (CI) 1.37-2.74; p<0.001), high-sensitivity C-reactive protein and WBC were found to be the independent predictors of poor CCC. In receiver operator characteristic curve analysis, the optimal cut-off value of NLR to predict poor CCC was found as 2.17, with 77% sensitivity and 65% specificity.

CONCLUSION

NLR, as a novel cardiovascular risk marker, is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO.

Coronary Chronic Total Occlusion Recanalisation - Current Techniques and Approaches

Coronary chronic total occlusions (CTOs) are among the most challenging coronary artery lesions to treat percutaneously. In the last decade, great strides have been made to develop techniques to improve success rates. While success rates among high-volume operators are >90 %, non-CTO operators still continue to struggle with this lesion subset. Thus, efforts have been made to develop algorithms to help operators achieve successful recanalisation consistently and improve patient outcomes. The North American Total Occlusion (NATO) algorithm emphasises dual coronary injection using two guide catheters, which allows for switching from an antegrade to retrograde approach or vice versa should the initial strategy fail - the so-called 'hybrid' approach. Special attention is paid to four angiographic characteristics: 1) location of the proximal cap, 2) lesion length, 3) presence and suitability of collateral vessels for retrograde crossing and 4) location and quality of target vessel distal cap. The ultimate goal of this algorithm is to provide a strategy to achieve successful CTO revascularisation while using the least amount of fluoroscopy, contrast and equipment possible.