Contemporary overview and clinical perspectives of chronic total occlusions

Impact of a Chronic Total Coronary Occlusion on the Incidence of Appropriate Implantable Cardioverter-Defibrillator Shocks and Mortality: A Substudy of the Dutch Outcome in ICD Therapy (DO-IT)) Registry

BACKGROUND

Chronic total coronary occlusions (CTO) substantially increase the risk for sudden cardiac death. Among patients with chronic ischemic heart disease at risk for sudden cardiac death, an implantable cardioverter defibrillator (ICD) is the favored therapy for primary prevention of sudden cardiac death. This study sought to investigate the impact of CTOs on the risk for appropriate ICD shocks and mortality within a nationwide prospective cohort.

METHODS AND RESULTS

This is a subanalysis of the nationwide Dutch-Outcome in ICD Therapy (DO-IT) registry of primary prevention ICD recipients in The Netherlands between September 2014 and June 2016 (n=1442). We identified patients with chronic ischemic heart disease (n=663) and assessed available coronary angiograms for CTO presence (n=415). Patients with revascularized CTOs were excluded (n=79). The primary end point was the composite of all-cause mortality and appropriate ICD shocks. Clinical follow-up was conducted for at least 2 years. A total of 336 patients were included, with an average age of 67±9 years, and 20.5% was female (n=69). An unrevascularized CTO was identified in 110 patients (32.7%). During a median follow-up period of 27 months (interquartile range, 24-32), the primary end point occurred in 21.1% of patients with CTO (n=23) compared with 11.9% in patients without CTO (n=27; P=0.034). Corrected for baseline characteristics including left ventricular ejection fraction, and the presence of a CTO was an independent predictor for the primary end point (hazard ratio, 1.82 [95% CI, 1.03-3.22]; P=0.038).

CONCLUSIONS

Within this nationwide prospective registry of primary prevention ICD recipients, the presence of an unrevascularized CTO was an independent predictor for the composite outcome of all-cause mortality and appropriate ICD shocks.

Early and long-term prognosis in patients with remaining chronic total occlusions after revascularization attempt. A cohort study from the SKEJ-CTO registry

OBJECTIVES

The present study aimed to compare safety and long-term prognosis of patients with chronic total coronary occlusions (CTO) stratified for remaining CTOs after percutaneous coronary intervention (PCI).

DESIGN

The study cohort consisted of patients with coronary artery disease who underwent CTO PCI in a high volume tertiary center from 2009 to 2019 and were registered in Danish high-quality registers. Patients with successful PCI of all CTOs were compared to patients with ≥1 remaining CTO post-procedural. Primary endpoints were analysed using Cox-regression and Kaplan-Meier estimates, and included all-cause mortality, major adverse cardio- and cerebrovascular events (MACCE) and a 30-day safety endpoint.

RESULTS

Procedural success rate was 87.7%, and 76.5% of patients had all CTO(s) opened post-PCI. Safety endpoint occurred in 4.6% of patients, and more frequently in patients with remaining CTO(s) (RD 4.9, 95%CI 0.1, 9.8). All-cause mortality was higher in patients with remaining CTO(s) (Unadjusted HR 1.65, 95% CI 1.03, 2.47, p = .015. Adjusted HR 1.32, 95%CI 0.88-1.99, p = .18) after eight years of follow-up. Risk of MACCE was significantly higher in patients with remaining CTO(s) (Unadjusted HR 1.79, 95% CI 1.34-2.41, p < .001. Adjusted HR 1.51, 95% CI 1.11-2.05, p = .009).

CONCLUSIONS

In our centre, CTO PCI was associated with high success rate and low risk of 30-days complications. Presence of remaining CTO(s) after final revascularization attempt was associated with higher but statistically insignificant long-term mortality but was an independent predictor of MACCE.

B, Kappelmayer J, Kőszegi Z, Csanádi Z, Szük T. Technically Challenging Percutaneous Interventions of Chronic Total Occlusions Are Associated with Enhanced Platelet Activation

Percutaneous coronary intervention (PCI) is a frequently performed treatment option for recanalization in patients with chronic total occlusion (CTO). As CTO-PCIs are often complicated and challenging for interventionalists, the stressful and damaging nature of the procedure can be remarkable, thus platelets can be easily activated. Our aim was to investigate the effect of CTO-PCI on platelet activation and the expression of selected circulating microRNAs (miR) of platelet and endothelium origin after CTO-PCI. In this study, 50 subjects after CTO-PCI were enrolled. Blood samples were obtained before PCI, at 2 days and 3-6 months after the procedure to measure the degree of platelet activation and the level of plasma miR-223, miR-181b, and miR-126. Patients were divided based on the characteristics of the intervention. Patients with higher Japanese CTO scores and longer duration of PCI showed significantly elevated platelet P-selectin positivity (p = 0.004 and p = 0.013, respectively) 2 days after the procedure compared to pre-PCI and increased concentration of soluble P-selectin 3-6 months after the intervention (higher Japanese CTO score: p = 0.028 and longer duration of PCI: p = 0.023) compared to baseline values. Shorter total stent length caused a significantly lower miR-181b expression at 3-6 months after the intervention (p = 0.031), while no difference was observed in miR-223 and miR-126. One stent thrombosis occurred during the follow-up period. Although these technically challenging CTO-PCIs may cause enhanced platelet activation right after the intervention and long-term endothelial cell dysfunction, these interventions are not associated with more adverse clinical events.

Association of serum cytokines with coronary chronic total occlusion and their role in predicting procedural outcomes

BACKGROUND

Cytokines are strongly associated with coronary artery disease (CAD); however, few studies have explored the relevance of cytokines in coronary chronic total occlusion (CTO). This study aimed to clarify the association of cytokines with CTO and its procedural outcomes.

METHODS

A total of 526 patients with suspected CAD but not acute myocardial infarction were enrolled and divided into CTO (n = 122) and non-CTO (n = 404) groups based on coronary angiography. Furthermore, serum levels of 12 cytokines [Interleukin-1β (IL-1β), IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, tumor necrosis factor-α (TNF-α), interferon-α (IFN-α), and IFN-γ] were measured for each patient.

RESULTS

Patients with CTO had higher rates of male (P = 0.001), smoking (P = 0.014), and diabetes (P = 0.008); higher levels of IL-6 (P < 0.001), total triglycerides (P = 0.020), serum creatine (P = 0.001), and high-sensitivity troponin I (P = 0.001); and lower IL-4 (P < 0.001), total cholesterol (P = 0.027), and high-density lipoprotein cholesterol (HDL-C) (P < 0.001) levels compared to those without CTO. IL-4 (OR = 0.216, 95%CI:0.135-0.345, P < 0.001), IL-6 (OR = 1.248, 95%CI:1.165-1.337, P < 0.001), and HDL-C (OR = 0.047, 95%CI:0.010-0.221, P < 0.001) were identified as independent predictors of CTO. And good predictive performance (AUC = 0.876) for CTO, with a sensitivity of 81.96% and specificity of 81.19%, could be achieved by combining these three predictors. Furthermore, patients with procedural success had younger age (P = 0.004) and lower serum IL-6 levels (P = 0.039) compared to those with procedural failure, and IL-6 levels (OR = 0.962, 95%CI: 0.931-0.995, P = 0.023) were associated with procedural success.

CONCLUSION

IL-4, IL-6, and HDL-C levels were strongly associated with CTO, and IL-6 also linked to procedural outcomes of CTO.

Computed Tomography Radiomics Model Predicts Procedure Success of Coronary Chronic Total Occlusions

BACKGROUND

Coronary computed tomography (CT) angiography imaging is useful for the preprocedural evaluation of chronic total occlusion (CTO). However, the predictive value of CT radiomics model for successful percutaneous coronary intervention (PCI) has not been studied. We aimed to develop and validate a CT radiomics model for predicting PCI success of CTOs.

METHODS

In this retrospective study, a radiomics-based model for predicting PCI success was developed on the training and internal validation sets of 202 and 98 patients with CTO, collected from 1 tertiary hospital. The proposed model was validated on an external test set of 75 CTO patients enrolled from another tertiary hospital. CT radiomics features of each CTO lesion were manually labeled and extracted. Other anatomical parameters, including occlusion length, entry morphology, tortuosity, and calcification burden, were also measured. Fifteen radiomics features, 2 quantitative plaque features, and CT-derived Multicenter CTO Registry of Japan score were used to train different models. The predictive values of each model were evaluated for predicting revascularization success.

RESULTS

In the external test set, 75 patients (60 men; 65 years [58.5, 71.5]) with 83 CTO lesions were assessed. Occlusion length was shorter (13.00 mm versus 29.30 mm, P=0.007) in PCI success group whereas the presence of tortuous course was more commonly presented in PCI failure group (1.49% versus 25.00%, P=0.004). The radiomics score was significantly smaller in PCI success group (0.10 versus 0.55, P<0.001). The area under the curve of CT radiomics-based model was significantly higher than that of CT-derived Multicenter CTO Registry of Japan score for predicting PCI success (area under the curve=0.920 versus 0.752, P=0.008). The proposed radiomics model accurately identified 89.16% (74/83) CTO lesions with procedure success.

CONCLUSIONS

CT radiomics-based model outperformed CT-derived Multicenter CTO Registry of Japan score for predicting PCI success. The proposed model is more accurate than the conventional anatomical parameters to identify CTO lesions with PCI success.

Risk Factor Analysis and Construction of a Prognostic Model after Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion

Methods

The clinical data of 82 patients with CTO who underwent PCI in Lianshui County People's Hospital were collected in this study. The patients were divided into training set (n = 54) and validation set (n = 28) by random sampling method. Statistical difference test was performed for clinical features of patients. Univariate and multivariate Cox regression analyses were performed to determine the risk factors affecting progression of CTO. Nomogram was used to construct a prediction model for disease progression. C-index was calculated, and the accuracy of the model was tested by calibration curve.

Results

No statistically significant differences were incorporated in baseline characteristics of included patients (p > 0.05). There were 25 patients with adverse cardiac events during follow-up in the training set and 13 in the validation set. The results of multivariate Cox regression analysis demonstrated that the important factors affecting postoperative disease progression mainly came down to age, BMI, diabetes, creatinine clearance rate, and left ventricular fraction < 40%. A nomogram was constructed and C-index was calculated. The calibration curve was then used to evaluate and predict risk model of disease progression. The result showed an internal validation C-index of 0.6219 and an external validation C-index of 0.6453, which indicated the good prediction performance of the model.

Conclusion

The risk of disease progression in CTO patients treated with PCI can be effectively predicted by the risk model constructed in this study, which opens up a great possibility for enriching the means of predicting the prognosis of these patients in clinical practice.

The Comparison of Long-Term Outcome Between Patients with Single and Multiple Coronary Chronic Total Occlusions After Percutaneous Coronary Intervention

Background

Rapid advancements in percutaneous coronary intervention (PCI) have improved the outcome of chronic coronary total occlusions (CTOs); however, data regarding the difference in long-term outcomes in stable coronary artery disease (CAD) patients with single and multiple CTOs who underwent PCI are scarce. This study aimed to compare the long-term outcomes of patients with multiple CTOs and single CTO after PCI.

Methods

This study cohort included stable CAD patients who were diagnosed with CTO and treated with PCI from a single center. The primary endpoint was all-cause death.

Results

We retrospectively reviewed 670 consecutive patients with CTO-PCI. Among them, 539 patients had a single CTO, and 131 (19.7%) patients had multiple (at least two) CTOs. CTO revascularization was achieved in 470 (70.1%) patients. After a median follow-up duration of 33.7 months, the cumulative all-cause mortality (p = 0.037) and cardiac mortality (p = 0.003) were higher in patients with multiple CTOs than in those with a single CTO. In the multivariable model, multiple CTOs and left ventricular ejection fraction (LVEF) less than 40% were independent predictors for cardiac death (adjusted hazard ratio (HR) 2.53; P = 0.013 and adjusted HR 3.95; P < 0.001), while age older than 65 and LVEF less than 40% were independent predictors for all-cause death in CTO-PCI patients (adjusted hazard ratio (HR) 1.84; P = 0.035 and adjusted HR 2.54; P = 0.001).

Conclusion

In CTO-PCI patients, long-term survival was associated with multiple CTOs, age and LVEF, but not with CTO revascularization.

The Usefulness of C-Reactive Protein to Albumin Ratio in the Prediction of Adverse Cardiovascular Events in Coronary Chronic Total Occlusion Undergoing Percutaneous Coronary Intervention

Inflammation and nutrition as main factors can affect the prognosis of patients with chronic total coronary occlusion (CTO) undergoing percutaneous coronary intervention (PCI). The C-reactive protein to albumin ratio (CAR) can clarify the inflammation and nutrition status, which are highly related to clinical outcomes. This study aims to investigate the association between CAR and adverse cardiovascular events in patients with CTO undergoing PCI. For this study, 664 patients were divided into three groups based on the tertiles of CAR. The primary endpoint was all-cause mortality and the secondary endpoint was major adverse cardiovascular events (MACE). Over a median follow-up of 33.7 months, the primary endpoint occurred in 64 patients (9.6%) and the secondary endpoint occurred in 170 patients (25.6%). The patients with higher CAR represented a worse prognosis with all-cause death and cardiovascular death after the adjustment for the baseline risk factors. Adding the CAR values raised the predictive value for the incidence of the all-cause death and cardiovascular death but not MACE. The capacity of prognosis prediction was improved after the addition of the CAR value to the traditional prediction model.

Impact of sex on outcomes of percutaneous coronary intervention for chronic total occlusion: A meta-analysis

BACKGROUND

Women are underrepresented in chronic total occlusion (CTO) trials and little is known about sex differences in the outcomes of CTO percutaneous coronary intervention (PCI). This meta-analysis aims to compare the outcomes of CTO PCI in males and females.

METHODS

A comprehensive search of PubMed, EMBASE, Cochrane, Web of Science, and Google Scholar was performed for studies comparing outcomes of CTO PCI in females versus males from inception to January 26, 2021. The current statistical analysis was performed using STATA version 15.1 software (Stata Corporation, TX); P < 0.05 indicated statistical significance.

RESULTS

Fourteen observational studies were included in the analysis with 75% males and 25% females. The mean age was 64.47 ± 10.5 years and 68.98 ± 9.5 years for males and females, respectively. The median follow-up duration was 2.4 years. Males had a higher Japanese-CTO (J-CTO) score compared with females (MD = -0.17; 95% CI: -0.25 to -0.10). Females had statistically higher success rates of CTO PCI (RR = 1.03; 95% CI: 1.01 to1.05), required less contrast volume (MD = -18.64: 95% CI: -30.89 to -6.39) and fluoroscopy time (MD = -9.12; 95% CI: -16.90 to -1.34) compared with males. There was no statistical difference in in-hospital (RR = 1.50; 95% CI: 0.73 to 3.09) or longer term (≥6 months) all-cause mortality (RR = 1.10; 95% CI: 0.86 to 1.42) between the two groups.

CONCLUSIONS

CTO PCI is feasible and safe in female patients with comparable outcomes in female versus male patients.

Completeness of revascularisation in acute coronary syndrome patients with multivessel disease

A significant proportion of patients presenting with acute coronary syndromes (ACS) have multivessel disease (MVD). Despite the abundance of clinical trials in this area, several questions regarding the procedure of complete coronary revascularisation remain unanswered. This state-of-the-art review summarises the latest evidence on complete revascularisation (CR) in this subset of patients and critically appraises clinical decision making based on non-culprit lesion (NCL) assessment. Future areas of research are put into perspective.

Percutaneous Coronary Intervention for Chronic Total Occlusion in Single Coronary Arteries

We retrospectively compared the results of percutaneous coronary intervention (PCI) and optimal medical therapy (OMT) for chronic total occlusion (CTO) in single coronary arteries to determine whether outcomes depend on the artery involved. From January 2004 through November 2015, a total of 731 patients were treated at our center for CTO in the left anterior descending coronary artery (LAD) (234 patients, 32%), left circumflex coronary artery (LCx) (184, 25.2%), or right coronary artery (RCA) (313, 42.8%). We further classified patients by treatment (PCI or OMT) and compared the cumulative incidence of major adverse cardiac events (MACE) and the composite of total death or myocardial infarction, as well as change in left ventricular ejection fraction from baseline. The 5-year cumulative incidence of MACE was similar between the treatment groups regardless of target vessel. The 5-year cumulative incidence of the composite of total death or myocardial infarction was significantly lower after PCI than after OMT or failed PCI in the LCx (2.6% vs 11.5%; P=0.020; log-rank) and RCA (5.8% vs 17.2%; P=0.002) groups, but not in the LAD group. Cox proportional hazards regression analysis indicated that PCI independently predicted a lower incidence of the composite of total death or myocardial infarction in the LCx group (hazard ratio [HR]=0.184; 95% CI, 0.0035-0.972; P=0.046) and the RCA group (HR=0.316; 95% CI, 0.119-0.839; P=0.021). The artery involved does not appear to affect clinical outcomes of successful PCI for single-vessel CTO. Further investigation in a randomized clinical trial is warranted.

Predictors and outcomes of procedural failure of percutaneous coronary intervention of a chronic total occlusion-A subanalysis of the EXPLORE trial

OBJECTIVE

To evaluate predictors of procedural success of percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) in a non-infarct-related artery following ST-segment elevation myocardial infarction (STEMI), and demonstrate the effect on left ventricular functionality (LVF), infarct size (IS), and pro-arrhythmic electrocardiogram (ECG) parameters.

BACKGROUND

Predictors of unsuccessful revascularization of a CTO are numerous, although following STEMI, these are lacking. Besides, effects of failed CTO PCI (FPCI) on the myocardium are unknown.

METHODS

This is a subanalysis of the EXPLORE trial, in which 302 STEMI patients with a concurrent CTO were randomized to CTO PCI (n = 147) or no-CTO PCI (NPCI, n = 154). For the purpose of this subanalysis, we divided patients into successful CTO PCI (SPCI, n = 106), FPCI (n = 41), and NPCI (n = 154) groups. Cardiac magnetic resonance imaging and angiographic data were derived from the EXPLORE database, combined with ECG parameters. To gain more insight, all outcomes were compared with patients that did not undergo CTO PCI.

RESULTS

In multivariate regression, only CTO lesion length >20 mm was an independent predictor of procedural failure (OR 3.31 [1.49-7.39]). No significant differences in median left ventricular ejection fraction, left ventricular end-diastolic volume, IS, and the pro-arrhythmic ECG parameters such as QT-dispersion, QTc-time, and TpTe-intervals were seen between the SPCI and FPCI groups at 4 months follow-up.

CONCLUSION

This subanalysis of the EXPLORE trial has demonstrated that a CTO lesion length >20 mm is an independent predictor of CTO PCI failure, whereas procedural failure did not lead to any adverse effects on LVF nor pro-arrhythmic ECG parameters.

Incidence and outcomes of chronic total occlusion percutaneous coronary intervention in the Netherlands: data from a nationwide registry

Background

Patients with chronic total coronary occlusions (CTO) are at increased risk for poor clinical outcomes. We aimed to determine the incidence of CTO percutaneous coronary intervention (PCI) and to identify CTO patients at risk for cardiac events in the nationwide Netherlands Heart Registration (NHR).

Methods

We included all PCI procedures with ≥1 CTO registered in the NHR from January 2015 to December 2018, excluding acute interventions. We used multivariable logistic regression of baseline characteristics to calculate the risk for events as odds ratios (OR) with 95% confidence intervals (CI).

Results

Of the PCIs performed during the study period, 6.3% (8,343/133,042) were for CTOs, with the percentage increasing significantly over time from 5.9% in 2015 to 6.6% in 2018 (p < 0.001). Coronary artery bypass grafting <24 h was carried out in 0.3%, and the only significant predictor was diabetes mellitus (OR 2.97, 95% CI 1.04–8.49, p = 0.042). Myocardial infarction (MI) <30 days occurred in 0.5%, and renal insufficiency (i.e. estimated glomerular filtration rate <30 ml/min per 1.73 m²) was identified as an independent predictor (OR 4.70, 95% CI 1.07–20.61, p = 0.040). Among patients undergoing CTO-PCI, 1‑year mortality was 3.7%, and independent predictors included renal insufficiency (OR 5.59, 95% CI 3.25–9.59, p < 0.001), left ventricular ejection fraction <30% (OR 3.43, 95% CI 2.00–5.90, p < 0.001), previous MI (OR 1.62, 95% CI 1.14–2.31, p = 0.007) and age (OR 1.06 per year increment, 95% CI 1.04–1.07, p < 0.001). Target-vessel revascularisation <1 year occurred in 11.3%.

Conclusion

CTO-PCI is still infrequently performed in the Netherlands. The most important predictor of mortality after CTO-PCI was renal insufficiency. Identification of patients at risk may help improve the prognosis of CTO patients in the future.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01521-y) contains supplementary material, which is available to authorized users.

Improvement of the frontal QRS-T angle after successful percutaneous coronary revascularization in patients with chronic total occlusion

BACKGROUND

The QRS-T angle (QRS-Ta) is a novel marker of myocardial repolarization heterogeneity which is related to adverse cardiovascular events. Our aim in this study was to investigate the effect of successful percutaneous coronary intervention (PCI) on frontal QRS-Ta in patients with chronic total occlusion (CTO).

MATERIALS AND METHODS

A total of 132 patients undergoing PCI for CTO were included in this study. Successful PCI of CTO segment was performed in 84 patients (group 2) while 48 who failed CTO were observed (group 1). Baseline demographic and clinical variables were evaluated and, 12-lead surface ECGs of all subjects were recorded before performing coronary angiography and 1-month and 6-month after the index procedure.

RESULTS

QRS-Ta values significantly decreased during follow-up visits compared to baseline values [92.5 (63.25-110.75); 85.0 (59.0-101.0); 80.0 (53.0-99.0), P < 0.001] in group 2 patients. Moreover, there was no significant difference in frontal QRS-Ta measurements in group 1 patients in their clinical 6-month follow-up [87.0 (48.25-103.0); 86.5 (46.0-101.75); 84.0 (49.0-103.75); P = 0.320]. First month frontal QRS-Ta values [92.5 (63.25-110.75); 85.0 (59.0-101.0), P = 0.002] and sixth month frontal QRS-Ta values [92.5 (63.25-110.75); 80.0 (53.0-99.0), P < 0.001] were lower than baseline values while sixth month values [85.0 (59.0-101.0); 80.0 (53.0-99.0), P = 0.002] was lower compared to first month values. Additionally, a decrease in frontal QRS-Ta was observed regardless of target vessel or Rentrop classification.

CONCLUSION

Successful percutaneous revascularization of CTO was effective in ventricular repolarization. Frontal QRS-Ta significantly decreased after successful PCI on CTO patients at a 6-month follow-up.

Clinical Implications of "Tailored" Antiplatelet Therapy in Patients With Chronic Total Occlusion

Background

Clopidogrel nonresponsiveness is a prognostic marker after percutaneous coronary intervention. Prasugrel and ticagrelor provide a better platelet inhibition and represent the first‐line antiplatelet treatment in acute coronary syndrome. We sought to assess the prognostic impact of high platelet reactivity (HPR) and the potential clinical benefit of a “tailored” escalated or changed antiplatelet therapy in patients with chronic total occlusion.

Methods and Results

From Florence CTO‐PCI (chronic total occlusion‐percutaneous coronary intervention) registry, platelet function assessed by light transmission aggregometry, was available for 1101 patients. HPR was defined by adenosine diphosphate test ≥70% and optimal platelet reactivity by adenosine diphosphate test <70%. The endpoint of the study was long‐term cardiac survival. Patients were stratified according to light transmission aggregometry results: optimal platelet reactivity (82%) and HPR (18%). Means for the adenosine diphosphate test were 44±16% versus 77±6%, respectively. Three‐year survival was significantly higher in the optimal platelet reactivity group compared with HPR patients (95.3±0.8% versus 86.2±2.8%; P<0.001). With the availability of new P2Y₁₂ inhibitors, a deeper platelet inhibition (46±17%) and similar survival to the optimal platelet reactivity group were achieved in patients with HPR on clopidogrel therapy after escalation. Conversely, HPR on clopidogrel therapy “not switched” was associated with cardiac mortality (hazard ratio 2.37; P=0.003) after multivariable adjustment.

Conclusions

HPR on treatment could be a modifiable prognostic marker by new antiaggregants providing a deeper platelet inhibition associated with clinical outcome improvement in complex chronic total occlusion patients. A “tailored” antiplatelet therapy, also driven by the entity of platelet inhibition, could be useful in these high risk setting patients.

The effect of revascularization of a chronic total coronary occlusion on electrocardiographic variables. A sub-study of the EXPLORE trial

INTRODUCTION

Chronic total coronary occlusions (CTOs) have been associated with a higher prevalence of ventricular arrhythmias compared to patients without a CTO. We evaluated the effect of CTO revascularization on electrocardiographic (ECG) variables.

METHODS

We studied a selection of ST-elevation myocardial infarction patients with a concomitant CTO enrolled in the EXPLORE trial. ECG variables and cardiac function were analysed at baseline and at 4 months follow-up.

RESULTS

Patients were randomized to percutaneous coronary intervention (PCI) of their CTO (n = 77) or to no-CTO PCI (n = 81). At follow-up, median QT dispersion was significantly lower in the CTO PCI group compared to the no-CTO PCI group (46 ms [33-58] vs. 54 ms [37-68], P = 0.043). No independent association was observed between ECG variables and cardiac function.

CONCLUSION

Revascularization of a CTO after STEMI significantly shortened QT dispersion at 4 months follow-up. These findings support the hypothesis that CTO revascularization reduces the pro-arrhythmic substrate in CTO patients.

Impact of collateralisation to a concomitant chronic total occlusion in patients with ST-elevation myocardial infarction: a subanalysis of the EXPLORE randomised controlled trial

Objective

The impact on cardiac function of collaterals towards a concomitant chronic total coronary occlusion (CTO) in patients with ST-elevation myocardial infarction (STEMI) has not been investigated yet. Therefore, we have evaluated the impact of well-developed collaterals compared with poorly developed collaterals to a concomitant CTO in STEMI.

Methods and results

In the EXPLORE trial, patients with STEMI and a concomitant CTO were randomised to either CTO percutaneous coronary intervention (PCI) or no-CTO PCI. Collateral grades were scored angiographically using the Rentrop grade classification. Left ventricular ejection fraction (LVEF) and left ventricular end-diastolic volume (LVEDV) at 4 months were measured using cardiac magnetic resonance imaging. Well-developed collaterals (Rentrop grades 2-3) to the CTO were present in 162 (54%) patients; these patients had a significantly higher LVEF at 4 months (46.2±11.4% vs 42.1±12.7%, p=0.004) as well as a trend for a lower LVEDV (208.2±55.7 mL vs 222.6±68.5 mL, p=0.054) when compared with patients with poorly developed collaterals to the CTO. There was no significant difference in the total amount of scar in the two groups. Event rates were statistically comparable between patients with well-developed collaterals and poorly developed collaterals to the CTO at long-term follow-up.

Conclusions

In patients with STEMI and a concomitant CTO, the presence of well-developed collaterals to a concomitant CTO is associated with a better LVEF at 4 months. However, this effect on LVEF did not translate into improvement in clinical outcome. Therefore, the presence of well-developed collaterals is important, but should not solely guide in the clinical decision-making process regarding any additional revascularisation of a concomitant CTO in patients with STEMI.

Clinical trial registration

NTR1108.

Evaluation of the Impact of a Chronic Total Coronary Occlusion on Ventricular Arrhythmias and Long-Term Mortality in Patients With Ischemic Cardiomyopathy and an Implantable Cardioverter-Defibrillator (the eCTOpy-in-ICD Study)

Background

Previous studies report conflicting results about a higher incidence of ventricular arrhythmias in patients with a chronic total coronary occlusion (CTO). We aimed to investigate this association in a large cohort of implantable cardioverter defibrillator patients with long‐term follow‐up.

Methods and Results

All consecutive patients from 1992 onwards who underwent implantable cardioverter defibrillator implantation for ischemic cardiomyopathy at the Leiden University Medical Center were evaluated. Coronary angiograms were reviewed for the presence of a CTO. The occurrence of ventricular arrhythmias and survival status at follow‐up were compared between patients with and patients without a CTO. A total of 722 patients constitute the study cohort (age 66±11 years; 84% males; 74% primary prevention, median left ventricular ejection fraction 30% [first–third quartile: 25–37], 44% received a cardiac resynchronization therapy defibrillator). At baseline, 240 patients (33%) had a CTO, and the CTOs were present for at least 44 (2–127) months. The median follow‐up duration was 4 (2–6) years. On long‐term follow‐up, CTO patients had a higher crude appropriate device therapy rate (37% versus 27%, P=0.010) and a lower crude survival rate (51% versus 67%, P<0.001) compared with patients without a CTO. Corrected for baseline characteristics including left ventricular ejection fraction, the presence of a CTO was an independent predictor for appropriate device therapy.

Conclusions

The presence of a CTO in implantable cardioverter defibrillator patients was associated with more appropriate device therapy and worse prognosis at long‐term follow‐up. Further investigation is warranted regarding a potential beneficial effect of CTO revascularization on the incidence of ventricular arrhythmias.

Coronary chronic total occlusion intervention: utility or futility

INTRODUCTION

Despite an incidence of about 18-52% of the patients undergoing coronary angiography, chronic total occlusions (CTO) are rarely revascularised by percutaneous angioplasty (PCI). Nevertheless, current evidence suggests that successful CTO angioplasty improves symptoms, quality of life and long-term survival. During the last decade, the improvement of specific tools and techniques for these complex procedures, and the increasing experience of operators, have led to the achievement of success and complication rates almost equivalent to non-CTO angioplasty. Areas covered: This review focuses on the clinical benefits of CTO revascularization and on appropriate patient selection. Expert commentary: Current evidence suggests that successful CTO-PCI improves symptoms, quality of life and long-term survival. During the last years, the improvement of specific techniques for these complex procedures and the increasing experience of operators, have led to the achievement of success and complication rates almost equivalent to non-CTO lesion angioplasty.

Natural History of Untreated Coronary Total Occlusions Revealed with Follow-Up Semi-Automated Quantitative Coronary CT Angiography: The Morphological Characteristics of Initial CT Predict Occlusion Shortening

Objective

To investigate the morphological changes of coronary chronic total occlusion (CTO) as determined by coronary computed tomography angiography (CCTA) follow-up using semi-automated quantitative analysis.

Materials and Methods

Thirty patients with 31 CTO lesions confirmed by invasive coronary angiography and baseline/follow-up CCTA were retrospectively included. CTOs were quantitatively analyzed by a semi-automated coronary plaque analysis software (Coronary Plaque Analysis, version 2.0, Siemens) after manually determining the lesion border. Recanalized lumen was defined as the linear-like enhanced opacity traversing the non-opacified occluded segment. Other parameters, such as total occlusion length, total occlusion volume, volume with low attenuation component (< 30 Hounsfield unit [HU]), volume with middle to high attenuation component (30–190 HU) as well as the calcification volume, were also recorded.

Results

Recanalized lumen was found within 48.4% (15/31) occlusions on the follow-up CCTA, compared to 45.2% (14/31) occlusions on the baseline CCTA. Eleven of 14 lesions (78.6%) with CT-visible recanalized lumen within CTOs had a shorter occlusion length on follow-up compared to only 3 of 17 lesions (17.6%) without CT-visible recanalized lumen (odds ratio, 17.1, p < 0.001). The percentage of low attenuation component of occlusions was smaller on follow-up CCTA compared to baseline value (18.1 ± 20.1% vs. 22.6 ± 19.6%, p = 0.033).

Conclusion

Coronary computed tomography angiography enables non-invasive characterization of natural progression of untreated CTO lesions. Recanalized lumen within CTOs observed at baseline CCTA was associated with shortening of occlusion length on follow-up. Compared to their earlier stage, occlusions of later stage were presented with higher density of non-calcified components.

The safety and feasibility of guidezilla catheter in complex coronary interventions and an observational study

The monorail Guidezilla guide extension catheter was designed to provide additional backup and facilitate device delivery in percutaneous coronary intervention (PCI) for complex coronary anatomy such as chronic total occlusion (CTO), extreme vessel tortuosity, diseased bypass grafts, and anomalous coronary arteries, among others.The present retrospective, single-center study included 188 consecutive patients who underwent PCI using the Guidezilla catheter from March 2015 to August 2016. Study outcomes were rates of target lesion crossing success, procedural success, and complications.The Guidezilla catheter was used most commonly in PCI of CTOs (45%) and heavy proximal calcification (37%), followed by tortuosity (10%), previously deployed proximal stents (4%), and coronary artery anomaly (4%). The right coronary artery (48%) was most commonly intervened followed by the left ascending (35%) and left circumflex (17%) arteries. Rates of target lesion crossing success and procedural success were both 99%, with one device-related periprocedural complication, namely proximal vessel dissection secondary to deep insertion which was successfully treated with stent implantation. Ninety percent of PCI were performed and completed successfully by radial access.In a single center with experienced operators, the use of the Guidezilla guide extension catheter in PCI of complex coronary anatomy performed mostly via radial artery access appeared safe and efficacious, and greatly facilitated device delivery.

Assessment of Inducible Myocardial Ischemia, Quality of Life, and Functional Status After Successful Percutaneous Revascularization in Patients With Chronic Total Coronary Occlusion

The benefits of chronic total coronary occlusion (CTO) revascularization are not well established. In this prospective cohort study, 47 consecutive patients with successful percutaneous recanalization of CTO underwent adenosine stress cardiac magnetic resonance (CMR), 6-minute walk test (6MWT), and the Short Form-36 Health Survey before and 6 months after the procedure. Successful recanalization of a CTO was followed by significant improvement of (1) global physical and mental health status; (2) the distance walked in the 6MWT; (3) the incidence of chest pain at the end of the 6MWT; and (4) the score of a novel CMR ischemic burden index on the basis of the characteristics of adenosine stress perfusion defects (extension, persistence, transmurality, and induced contractile regional dysfunction). Patients with greater CMR ischemic index before percutaneous revascularization showed better improvement in the 6MWT. In conclusion, successful recanalization of a CTO leads to a concurrent improvement in ischemic burden, exercise tolerance, angina frequency, and quality of life scores. Patients with a high ischemic CMR score before CTO recanalization showed the better improvement in exercise tolerance.

Knowledge of chronic total occlusion among Polish interventional cardiologists

Introduction

Chronic total occlusion (CTO) recanalization is indicated in patients with symptoms and evidence of ischemia, but in most cases those types of lesions are still treated medically. In the last few years CTO angioplasty technique has changed dramatically due to considerable advances in techniques and dedicated equipment.

Aim

An attempt to assess the state of knowledge of technical aspects of CTO angioplasty of coronary arteries among Polish interventional cardiologists.

Material and methods

Questionnaire survey performed during two major Polish invasive cardiology workshops.

Results

In the study there participated 113 physicians with an average length of work experience of 13 years, most of them cardiologists certified as independent primary operators. The majority of respondents recognized the need of prevention of thrombotic complications through control of activated coagulation time during the CTO procedures. Prevention of renal complications and X-ray protection are also recognized as a significant part of the procedures. The benefits from the use of over-the-wire microcatheters and balloons, the proper choice of dedicated guidewires, contralateral injections and retrograde technique are underestimated.

Conclusions

Despite satisfactory knowledge about indications and qualification for the CTO procedure, the awareness of procedural aspects (particularly the retrograde technique) as well as the dedicated CTO equipment among Polish interventional cardiologists is still insufficient.

Performance of currently available risk models in a cohort of mechanically supported high-risk percutaneous coronary intervention--From the PROTECT II randomized trial

BACKGROUND

Procedural risk scores facilitate clinical decision making by using individual patient characteristics to estimate the risk of adverse events. The performance of PCI-based risk scores is not well-described among patients undergoing hemodynamically supported high risk PCI.

METHODS AND RESULTS

A total of 427 patients with unprotected left main disease, last remaining vessel or three-vessel disease with severely reduced left ventricular function underwent supported high-risk PCI with an intra-aortic balloon pump (IABP, N = 211) or a left ventricular assist device (Impella 2.5, N = 216) as part of the PROTECT II trial. We examined the performance of the additive Euroscore, logistic Euroscore, STS mortality score, STS morbidity and mortality score, Mayo Clinic risk score and New York state PCI risk score on the endpoint of 90-day mortality in this unique high-risk population. Mean age was 67.2 ± 10.9 years; 65.8% of patients were in NYHA class III/IV, and mean LVEF was 24%. All-cause 90-day mortality was 10.4%. The scores were generally correlated (p < 0.0001 for all comparisons), with R(2) values ranging from 0.28 (STS morbidity/mortality and Mayo Clinic) to 0.68 (logistic Euroscore and STS mortality). However, receiver-operator curves for 90-day all-cause mortality for all risk scores demonstrated poor discriminatory performance with c-statistics of 0.542-0.616. Calibration of the risk scores was not poor, but varied according to the specific score examined.

CONCLUSION

The discriminatory capacity of currently available risk models is suboptimal when applied to a cohort of mechanically supported complex high-risk PCI. A risk score designed specifically for this population could help to further refine risk assessment.