Ventricular Arrhythmias Among Implantable Cardioverter-Defibrillator Recipients for Primary Prevention

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion

AIMS

Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation.

METHODS AND RESULTS

The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151).

CONCLUSION

Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

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.

Long-Term Outcomes in Patients With Chronic Total Occlusion

Although a chronic total occlusion (CTO) in the setting of an acute coronary syndrome is associated with greater risk, the prognosis of patients with a CTO and stable coronary artery disease (CAD) remains unknown. This study aimed to investigate adverse event rates in patients with stable CAD with and without a CTO. In 3,597 patients with stable CAD (>50% coronary luminal stenosis) who underwent cardiac catheterization, all-cause mortality, cardiovascular mortality, and the composite major adverse cardiac event (MACE) rates for cardiovascular death, myocardial infarction, and heart failure hospitalization were evaluated. Cox proportional hazards and Fine and Gray subdistribution hazard models were used to compare event-free survival in patient subsets after adjustment for covariates. Event rates were higher in patients with CTOs than in those without CTOs after adjusting for demographic and clinical characteristics (cardiovascular death hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.05 to 1.57, p = 0.012). Patients with CTO revascularization had lower event rates than those of patients without CTO revascularization (cardiovascular death HR 0.43, CI 0.26 to 0.70, p = 0.001). Those with nonrevascularized CTOs were at particularly great risk when compared with those without CTO (cardiovascular death HR 1.52, CI 1.25 to 1.84, p <0.001). Moreover, those with revascularized CTOs had similar event rates to those of patients with CAD without CTOs. Patients with CTO have higher rates of adverse cardiovascular events than those of patients with significant CAD without CTO. This risk is greatest in patients with nonrevascularized CTO.

The impact of concomitant chronic total occlusion on clinical outcomes in patients undergoing transcatheter aortic valve replacement: a large single-center analysis

Background

Coronary artery disease (CAD) is a common finding in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement (TAVR). However, the impact on prognosis of chronic total occlusions (CTOs), a drastic expression of CAD, remains unclear.

Methods and results

We retrospectively reviewed 1,487 consecutive TAVR cases performed at a single tertiary care medical center. Pre-TAVR angiograms were analyzed for the presence of a CTO. At the time of TAVR, 11.2% (n = 167) patients had a CTO. There was no significant association between the presence of a CTO and in-hospital or 30-day mortality. There was also no difference in long-term survival. LV ejection fraction and mean aortic gradients were lower in the CTO group.

Conclusions

Our analysis suggests that concomitant CTO lesions in patients undergoing TAVR differ in their risk profile and clinical findings to patients without CTO. CTO lesion per se were not associated with increased mortality, nevertheless CTOs which supply non-viable myocardium in TAVR population were associated with increased risk of death. Additional research is needed to evaluate the prognostic significance of CTO lesions in TAVR patients.

A non-interventional cardiologist's guide to coronary chronic total occlusions

Coronary chronic total occlusions (CTO) are present in up to one-third of patients with coronary artery disease (CAD). It is thus essential for all clinical cardiologists to possess a basic awareness and understanding of CTOs, including optimal evaluation and management. While percutaneous coronary intervention (PCI) for CTO lesions has many similarities to non-CTO PCI, there are important considerations pertaining to pre-procedural evaluation, interventional techniques, procedural complications, and post-procedure management and follow-up unique to patients undergoing this highly specialized intervention. Distinct from other existing topical reviews, the current manuscript focuses on key knowledge relevant to non-interventional cardiologists.

Incidence of ventricular arrhythmias in patients with chronic total coronary occlusion: Results of the VACTOR study

Background

A chronic total coronary occlusion (CTO) is associated with ventricular arrhythmias (VA) in patients with an implantable cardioverter-defibrillator (ICD). Limited data is available on the incidence of VA in CTO patients without an ICD.

Objectives

To investigate the incidence of sustained VA in CTO patients after successful CTO revascularization and in patients with untreated CTO or failed CTO revascularization.

Methods

Prospective, multicenter observational pilot study including CTO patients who were not eligible for an ICD and had a left ventricular ejection fraction >35 %. We enrolled patients with a successful CTO revascularization (group A) and patients with untreated CTO or failed CTO revascularization (group B). All patients received an implantable loop recorder with remote monitoring. The primary endpoint was sustained VA.

Results

Ninety patients were enrolled (mean age 63 ± 10 years, 83.3 % man, mean LVEF 55 ± 8 %). Group A (n = 45) had a higher prevalence of CTO in the left anterior descending artery in comparison to group B (n = 45) (28.9 % versus 4.4 %, P = 0.002). Other baseline characteristics were similar. During a median follow-up time of 26 months (IQR, 19-35), five patients (5.6 %) had a sustained VA. There was no difference in the incidence of sustained VA between groups (3-year cumulative event rate: 8.8 % (group A) versus 4.5 % (Group B), log-rank P = 0.71).

Conclusion

Patients with an CTO, who do not qualify for an ICD, have a substantial risk of sustained VA. In our study the incidence was not different between patients with revascularized and those with untreated CTO.

Effect of myocardial scar size on the risk of ventricular arrhythmias in patients with chronic total coronary occlusion

BACKGROUND

The presence of an untreated chronic total coronary occlusion (CTO) is associated with a higher risk of ventricular arrhythmias (VAs). This increased risk may be modulated by the presence of an existing scar.

OBJECTIVES

To evaluate whether scar size is associated with VA in patients with an implantable cardioverter-defibrillator (ICD) and a CTO.

METHODS

In this retrospective study we included patients with a CTO that received an ICD between 2005 and 2015. Scar size was estimated using the Selvester QRS score on a baseline 12‑lead ECG. The primary endpoint was any appropriate ICD therapy.

RESULTS

Our study population comprised 148 CTO patients with a median scar size at baseline of 18% (IQR, 9-27%). Patients with a scar size ≥18% more often had a CTO located in the left anterior descending artery and a higher proportion of poor left ventricular function (<35%) and infarct-related CTO compared to patients with a smaller scar size (<18%). During a median follow-up of 35 months (interquartile range [IQR], 8-60 months), 42 patients (28%) received appropriate ICD therapy. The cumulative 5-year event rate was higher in the patients with a large scar in comparison to those with a smaller or no scar (36% versus 19%, P = 0.04). Multivariable Cox regression analysis demonstrated that large scar and diabetes mellitus were independent factors associated with appropriate ICD therapy.

CONCLUSION

In ICD recipients with an untreated CTO, a larger scar is an independent factor associated with an increased risk of VA.

Outcomes of Transcatheter Aortic Valve Replacement With and Without Index Chronic Total Occlusion of Coronary Artery: A Propensity Matched Analysis

Transcatheter aortic valve replacement (TAVR) utilization is increasing, along with procedural success. Coronary angiography is frequently performed before the TAVR procedure for coronary artery disease workup. Chronic total occlusion (CTO) of the coronary artery shares common risk factors with aortic stenosis and could be challenging, especially in terms of procedural safety. The outcomes of TAVR among patients with concomitant CTO are not extensively studied. We analyzed the National Inpatient Sample database between October 2015 and December 2020 to evaluate the clinical characteristics, procedural safety, and outcomes among patients who underwent TAVR who had concomitant CTO lesions. A total of 304,330 TAVRs were performed between 2015 and 2020, 5,235 of which (1.72%) were in patients with TAVR-CTO and 299,095 (98.28%) in those with TAVR-no CTO. After propensity matching, there was no difference in the odds of in-hospital mortality (adjusted odds ratio [aOR] 1.28, 95% confidence interval [CI] 0.94 to 1.75, p = 0.11). However, TAVR-CTO was associated with an increased incidence of acute myocardial infarction (aOR 1.27, 95% CI 1.05 to 1.53, p = 0.01), cardiac arrest (aOR, 2.60, 95% CI 1.64 to 4.11, p <0.0001), and need for mechanical circulatory support (aOR 2.6, 95% CI 1.88 to 3.59, p <0.0001). There was no difference in the incidence of stroke, major bleeding, complete heart block, or requirement for permanent pacemaker between the 2 groups. However, the TAVR-CTO cohort had a slightly greater length of stay and total hospitalization cost. TAVR is a relatively safe procedure among those with concomitant CTO lesions; however, it is associated with a greater incidence of acute myocardial infarction, cardiac arrest, and requirement for mechanical circulatory support.

Non-revascularized chronic total occlusions impact on substrate and post-ablation results in drug-refractory electrical storm

Background and aims

There is limited data concerning the effect of non-revascularized chronic total occlusions (NR-CTOs) after VT ablation. This study sought to evaluate the impact of NR-CTOs after ablation for electrical storm (ES).

Methods

Post-hoc retrospective analysis of data regarding 64 consecutive post-myocardial infarction patients (out of which 12 patients with NR-CTOs and 52 without NR-CTOs) undergoing substrate ablation for ES with an available median follow-up of 37.53 (7.25-64.65) months. Ablation result was assessed by inducibility of sustained monomorphic VT (SMVT) during final programmed ventricular stimulation (PVS). The primary endpoints were all-cause mortality and VT/VF recurrences after ablation, respectively, stratified by the presence of NR-CTOs. The secondary endpoint was to assess the predictive effect of NR-CTOs on all-cause mortality and VT/VF recurrences in relation to other relevant prognostic factors.

Results

At baseline, the presence of NR-CTOs was associated with higher bipolar BZ-to-total scar ratio (72.4% ± 17.9% vs. 52% ± 37.7%, p = 0.022) and more failure to eliminate the clinical VT (25% (3) vs. 0% (0), p < 0.001). During follow-up, overall all-cause mortality and recurrences were more frequent in the NR-CTO subgroup (75% (9) vs. 19.2% (10), log rank p = 0.003 and 58.3% vs. 23.1% (12), log rank p = 0.042 respectively). After adjusting for end-procedural residual SMVT inducibility, NR-CTOs predicted death during follow-up (HR 3.380, p = 0.009) however not recurrence (HR 1.986, p = 0.154).

Conclusions

NR-CTO patients treated by RFCA for drug-refractory ES demonstrated a higher ratio of BZ-to-total-scar area. In this analysis, NR-CTO was associated with worse acute procedural results and may as well impact long-term outcomes which should be further assessed in larger patient populations.

Impact of Percutaneous Intervention Compared to Pharmaceutical Therapy on Complex Arrhythmias in Patients With Chronic Total Coronary Occlusion. Rationale and Design of the CTO-ARRHYTHMIA Study

Chronic total coronary occlusions (CTO) occur in up to 50 % of patients with coronary artery disease by angiography. In CTO-patients, clinically significant arrhythmia is potentially important and insufficiently investigated. Therefore, the purpose of the CTO-ARRHYTHMIA study was to investigate the incidence of loop recorder detected clinically significant arrhythmias and the effect on arrhythmias of revascularization by CTO-PCI. The study is an independent sub-study of the NOrdic-Baltic Randomized Registry Study for Evaluation of PCI in Chronic Total Coronary Occlusion (NOBLE-CTO); ClinicalTrials.gov Identifier NCT03392415. NOBLE-CTO prospectively collects procedural data, quality of life measures, echocardiographic and cardiac MRI findings before and after treatment as well as clinical outcomes in all CTO patients that may be treated by PCI.

The impact of chronic total occlusions in patients undergoing transcatheter aortic valve replacement: A systematic review and meta-analysis

Coronary artery disease (CAD) is frequently encountered in patients evaluated for transcatheter aortic valve replacement (TAVR) due to severe aortic stenosis. The prognostic relevance of chronic total occlusions (CTOs) in this setting is poorly understood. We conducted a search of MEDLINE and EMBASE to identify studies evaluating patients who underwent TAVR and evaluated outcomes depending on the presence of coronary CTOs. Pooled analysis was performed to estimate the rate and risk ratio for mortality. Four studies involving 25,432 patients fulfilled the inclusion criteria. The follow up ranged from in-hospital outcomes to 8-years follow-up. Coronary artery disease was present in 67.8% to 75.5% of patients in 3 studies which reported this variable. The prevalence of CTOs varied between 2% and 12.6% in this cohort. The presence of CTOs was associated with increase in length of stay (8.1 ± 8.2 vs. 5.9 ± 6.5, p < 0.01), cardiogenic shock (5.1% vs. 1.7%, p < 0.01), acute myocardial infarction (5.8% vs. 2.8%, p = 0.02) and acute kidney injury (18.6% vs. 13.9%, p = 0.048). The pooled 1-year death rate revealed 41 deaths in 165 patients in the CTO group and 396 deaths in 1663 patients with no CTO ((24.8%) vs. (23.8%)). The meta-analysis of death with CTO versus no CTO showed a nonsignificant trend toward increased mortality with CTOs (risk ratio 1.11 95% CI 0.90-1.40, I²  = 0%). Our analysis suggests that concomitant CTO lesions in patients undergoing TAVR are common, and its presence was associated with increased in-hospital complications. However, CTO presence by itself was not associated with increased long-term mortality, only a nonsignificant trend toward an increased risk of death in patients with CTO was found. Further studies are warranted to assess the prognostic relevance of CTO lesion in TAVR patients.

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.

Relevance of Chronic Total Occlusion for Outcome of Ventricular Tachycardia Ablation in Ischemic Cardiomyopathy

Background

Catheter ablation of ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) is an effective tool to prevent VT recurrences. Chronic total occlusion (CTO) represents a clinically relevant entity in ICM patients and is an independent predictor of ventricular arrhythmia and mortality. The effects of CTO on the outcome of VT ablation are not well-studied.

Objective

This analysis aimed to identify the impact of CTO, revascularized, or not revascularized, on the outcome of VT ablation.

Methods and Results

Of 385 consecutive subjects with ICM-VT who underwent catheter VT ablation for monomorphic VT at Heart Center Leipzig between 2008 and 2017, 108 patients without CTO and 191 patients with CTO were included in the analysis. Within a median follow-up time of 557 days (IQR 149, 1095), VT recurred in 77 (40%) patients in the CTO and 40 (37.0%) in the non-CTO cohort (p = 0.62). In a multivariable model, a 10% stepwise change in LVEF as well as ICD on admission was associated with VT recurrence (HR_adj 1.82, 95% CI 1.04–3.18 and HR_adj 1.35, 95% CI 1.23–1.61, respectively). Of the CTO cohort before ablation, 45% had received revascularization, which was independently associated with a higher risk for VT recurrence (HR 2.12, 95% CI 1.35–3.34) as compared to nonrevascularized CTO.

Conclusion

In ICM patients with and without CTO, VT ablation was associated with equal effectiveness with regard to VT recurrence. However, in revascularized CTO patients, the risk of recurrence of VT after ablation was significantly increased.

The Role of Multimodality Imaging for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusions

Background

Percutaneous coronary intervention (PCI) of Chronic total occlusions (CTOs) has been traditionally considered a challenging procedure, with a lower success rate and a higher incidence of complications compared to non-CTO-PCI. An accurate and comprehensive evaluation of potential candidates for CTO-PCI is of great importance. Indeed, assessment of myocardial viability, left ventricular function, individual risk profile and coronary lesion complexity as well as detection of inducible ischemia are key information that should be integrated for a shared treatment decision and interventional strategy planning. In this regard, multimodality imaging can provide combined data that can be very useful for the decision-making algorithm and for planning percutaneous CTO recanalization.

Aims

The purpose of this article is to appraise the value and limitations of several non-invasive imaging tools to provide relevant information about the anatomical characteristics and functional impact of CTOs that may be useful for the pre-procedural assessment and follow-up of candidates for CTO-PCI. They include echocardiography, coronary computed tomography angiography (CCTA), nuclear imaging, and cardiac magnetic resonance (CMR). As an example, CCTA can accurately delineate CTO location and length, distal coronary bed, vessel tortuosity and calcifications that can predict PCI success, whereas stress CMR, nuclear imaging and stress-CT can provide functional evaluation in terms of myocardial ischemia and viability and perfusion defect extension.

Factors associated with all-cause mortality in patients with coronary artery chronic total occlusions undergoing revascularization (percutaneous coronary intervention or surgery) or medical treatment

Aim    Chronic total occlusion of a coronary artery (CTO) is a predictor of early and late cardiovascular mortality and poor cardiovascular outcomes in patients with coronary artery disease. The purpose of this study was to identify predictors of all-cause mortality in CTO patients that underwent invasive treatment.Material and methods    Patients between 2012 and 2018 with CTO in at least one vessel, as demonstrated by coronary angiography, were included retrospectively in the study. The patients were divided into two groups, an intervention group (percutaneous and surgical revascularization) and a medical group.Results    A total of 543 patients were studied, 152 females (28%) and 391 males (72%). The median follow-up period was 49 (26-72) mos. A total of 186 (34.2%) patients in the medical group and 357 (65.8%) patients in the invasive therapy group were followed. The 5-yr death rate was observed in 50 (26.9%) patients in the medical group and 53 (14.8%) patients in the intervention group, and it was found to be statistically higher in the medical group (p=0.001). In multivariable analysis, heart failure (odds ratio (OR): 1.92, 95% CI: 1.18-3.14; p=0.01), higher glucose levels (OR: 1.05, 95% CI: 1,02-1.08; p=0.04), lower albumin levels (OR: 0.49, 95% Cl: 0.32-0.72; p=0.001), SYNTAX score (OR: 1.03, 95% CI: 1.01-1.05; p=0.001), and CTO (≥2 occluded artery) (OR: 0.42, 95% CI: 0.22-0.72; p=0.01) were independent factors for all-cause mortality.Conclusion    In comparison to the revascularized group, there was an increase in mortality among CTO patients treated medically. Heart failure, SYNTAX score, albumin, glucose, and CTO (≥2 occluded arteries) were independent risk factors for all-cause mortality.

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.

Revascularisation of chronic total occlusions and recurrence rate of ventricular arrhythmias

BACKGROUND

The impact of revascularisation of chronic total occlusions (CTO) on the incidence of ventricular arrhythmias (VA) remains to be elucidated.

METHODS

Based on prospectively gathered data, the recurrence rate of VAs following CTO treatment was retrospectively investigated. Patients presenting with VAs as clinical indication for CTO revascularisation were retrospectively selected out of three Belgian CTO registries (i.e. Ziekenhuis Oost-Limburg, UZ Leuven and CHR de la Citadelle). Freedom of VAs was defined as absence of non-sustained or sustained tachycardias (VT), ventricular fibrillations (Vfib) and ventricular extrasystoles (VES; <2500 VES/24 h). Long-term outcome in terms of reoccurrence of VAs was evaluated by reviewing patient records.

RESULTS

Between 2011 and 2019, 912 patients underwent a CTO-PCI across three Belgian centres. In total 43 patients (5%) presented with VAs as clinical indication for CTO revascularisation. Overall follow-up was 723 (391 - 1144) days. Fourteen (33%), 18 (42%), 5 (11%) and 6 (14%) presented with >2500 VES/24 hrs, non-sustained VT, sustained VT and Vfib, respectively. In those patients with a one-year follow-up available (n = 34), overall recurrence rate of VAs was 38% (within VA group: VES: 25%, non-sustained VT: 46%; sustained VT: 25% and Vfib: 60%).

CONCLUSION

Based on this retrospective data analysis, CTO revascularisation, in patients presenting with VAs as the main clinical indication, seems to beneficially impact the incidence of VAs, which ultimately might result in improved patients' outcome.

Infarct-related chronic total coronary occlusion and the risk of ventricular tachyarrhythmic events in out-of-hospital cardiac arrest survivors

Introduction

Chronic total coronary occlusion (CTO) has been identified as a risk factor for ventricular arrhythmias, especially a CTO in an infarct-related artery (IRA). This study aimed to evaluate the effect of an IRA-CTO on the occurrence of ventricular tachyarrhythmic events (VTEs) in out-of-hospital cardiac arrest survivors without ST-segment elevation.

Methods

We conducted a post hoc analysis of the COACT trial, a multicentre randomised controlled trial. Patients were included when they survived index hospitalisation after cardiac arrest and demonstrated coronary artery disease on coronary angiography. The primary endpoint was the occurrence of a VTE, defined as appropriate implantable cardioverter-defibrillator (ICD) therapy, sustained ventricular tachyarrhythmia or sudden cardiac death.

Results

A total of 163 patients from ten centres were included. Unrevascularised IRA-CTO in a main vessel was present in 43 patients (26%). Overall, 61% of the study population received an ICD for secondary prevention. During a follow-up of 1 year, 12 patients (7.4%) experienced at least one VTE. The cumulative incidence rate of VTEs was higher in patients with an IRA-CTO compared to patients without an IRA-CTO (17.4% vs 5.6%, log-rank p = 0.03). However, multivariable analysis only identified left ventricular ejection fraction < 35% as an independent factor associated with VTEs (adjusted hazard ratio 8.7, 95% confidence interval 2.2–35.4). A subanalysis focusing on CTO, with or without an infarct in the CTO territory, did not change the results.

Conclusion

In out-of-hospital cardiac arrest survivors with coronary artery disease without ST-segment elevation, an IRA-CTO was not an independent factor associated with VTEs in the 1st year after the index event.

Supplementary Information

The online version of this article (10.1007/s12471-021-01578-3) contains supplementary material, which is available to authorized users.

Ventricular fibrillation storm after revascularization of chronic total occlusion of the left anterior descending artery: is this reperfusion arrhythmia?

Electrical storm is a life-threatening emergency condition defined as three or more episodes of ventricular tachycardia or ventricular fibrillation (VF) within 24 hours requiring anti-tachycardia therapy, electrical cardioversion, or defibrillation. However, studies of the incidence of electrical storm after chronic total occlusion-percutaneous coronary intervention (CTO-PCI) are limited,⁷ and post-procedural VF after revascularization of CTO has not been described. The purpose of this article was to present a case of post-operative VF electrical storm after revascularization of CTO of the left anterior descending (LAD) artery to determine whether the electrical storm was caused by reperfusion arrhythmia or compromise of either branch vessels or the collateral circulation during intervention.

Antegrade versus retrograde techniques for Chronic Total Occlusions (CTO): a review and comparison of techniques and outcomes

Introduction: As the field of chronic total occlusion percutaneous coronary intervention has evolved, technical approaches have evolved and been refined.Areas covered: In this review, we discuss the major techniques utilized in modern CTO PCI including antegrade wiring, antegrade dissection reentry, retrograde wiring, and retrograde dissection reentry. Retrograde techniques have been extensively studied in comparison to antegrade techniques. Retrograde techniques have contributed to increases in CTO PCI success rates and are generally used in higher complexity lesions. Observational data ssuggestincreased sshort-termcomplications in procedures requiring the use of retrograde techniques; however, llong-termCTO PCI durability and patient outcomes have been shown to be similar among procedures using antegrade only versus retrograde techniques.Expert opinion: Retrograde techniques play a vital role in the technical success of CTO PCI, particularly among more complex lesions and in patients with high burdens of comorbidities. Increases in procedural safety with equipment iteration and in the use of adjunctive imaging will play an important role in the selection of appropriate retrograde conduits and the overall success rates of CTO PCI.

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.

Cardiac and sudden death after chronic total occlusion percutaneous coronary intervention: Prognostic role of the target vessel

BACKGROUND

The role of the target vessel in percutaneous revascularization of chronic total occlusion (CTO) is unclear.

OBJECTIVE

We sought to assess the long-term results of percutaneous coronary intervention (PCI) for CTO lesions in each coronary artery and to investigate the impact of successful revascularization and previous myocardial infarction (MI) in the territory of the target vessel.

METHODS AND RESULTS

Cohort observational study on 1,124 patients who have undergone CTO PCI attempt: 371 on left anterior descending artery (LAD), 485 right coronary artery, and 268 left circumflex. Patients were further stratified by successfully revascularized and not-revascularized CTO (CTO-NR). Vessels affected by a previous MI were defined as infarct-related artery (IRA). The primary endpoint was cardiac death; the secondary endpoint was the combined rate of sudden cardiac-death and sustained ventricular-arrhythmias (SCD/SVAs). Propensity score-matching was performed to evaluate LAD versus NON-LAD CTO. Up to 12-year follow-up, the clinical benefit associated with successful PCI was consistent across the three groups. CTO-NR had the greatest association with cardiac death and SCD/SVAs in each coronary artery and in IRA-CTO patients.

CONCLUSIONS

Unsuccessful percutaneous CTO revascularization was associated with lower cardiac survival and freedom from SCD/SVAs, irrespective of the vessel treated. This result was mainly driven by patients with an IRA CTO.

Scar channels in cardiac magnetic resonance to predict appropriate therapies in primary prevention

BACKGROUND

Scar characteristics analyzed by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related with ventricular arrhythmias. Current guidelines are based only on the left ventricular ejection fraction to recommend an implantable cardioverter-defibrillator (ICD) in primary prevention.

OBJECTIVES

Our study aims to analyze the role of imaging to stratify arrhythmogenic risk in patients with ICD for primary prevention.

METHODS

From 2006 to 2017, we included 200 patients with LGE-CMR before ICD implantation for primary prevention. The scar, border zone, core, and conducting channels (CCs) were automatically measured by a dedicated software.

RESULTS

The mean age was 60.9 ± 10.9 years; 81.5% (163) were men; 52% (104) had ischemic cardiomyopathy. The mean left ventricular ejection fraction was 29% ± 10.1%. After a follow-up of 4.6 ± 2 years, 46 patients (22%) reached the primary end point (appropriate ICD therapy). Scar mass (36.2 ± 19 g vs 21.7 ± 10 g; P < .001), border zone mass (26.4 ± 12.5 g vs 16.0 ± 9.5 g; P < .001), core mass (9.9 ± 8.6 g vs 5.5 ± 5.7 g; P < .001), and CC mass (3.0 ± 2.6 g vs 1.6 ± 2.3 g; P < .001) were associated with appropriate therapies. Scar mass > 10 g (25.31% vs 5.26%; hazard ratio 4.74; P = .034) and the presence of CCs (34.75% vs 8.93%; hazard ratio 4.07; P = .003) were also strongly associated with the primary end point. However, patients without channels and with scar mass < 10 g had a very low rate of appropriate therapies (2.8%).

CONCLUSION

Scar characteristics analyzed by LGE-CMR are strong predictors of appropriate therapies in patients with ICD in primary prevention. The absence of channels and scar mass < 10 g can identify patients at a very low risk of ventricular arrhythmias in this population.

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.

Prognostic impact of coronary chronic total occlusion on recurrences of ventricular tachyarrhythmias and ICD therapies

BACKGROUND

Despite a few studies evaluating the prognostic impact of coronary chronic total occlusion (CTO) in implantable cardioverter defibrillator (ICD) recipients, the impact of CTO on different types of recurrences of ventricular tachyarrhythmias, as well as their predictors has not yet been investigated in CTO patients.

METHODS

A large retrospective registry was used including all consecutive patients with ventricular tachyarrhythmias undergoing coronary angiography at index from 2002 to 2016. Only ICD recipients with CTO were compared to patients without (non-CTO). Kaplan-Meier and Cox regression analyses were applied for the primary end point of first recurrence of ventricular tachyarrhythmias at 5 years. Secondary end points comprised of the different types of recurrences, first appropriate ICD therapy and all-cause mortality at 5 years.

RESULTS

From a total of 422 consecutive ICD recipients with ventricular tachyarrhythmias at index, at least one CTO was present in 25%. CTO was associated with the primary end point of first recurrence of ventricular tachyarrhythmias at 5 years (55% vs. 39%; log rank p = 0.001; HR = 1.665; 95% CI 1.221-2.271; p = 0.001), as well as increased risk of first appropriate ICD therapy (40% vs. 31%; log rank p = 0.039; HR = 1.454; 95% CI 1.016-2.079; p = 0.041) and all-cause mortality at 5 years (26% vs. 16%; log rank p = 0.011; HR = 1.797; 95% CI 1.133-2.850; p = 0.013). Less developed collaterals (i.e., either ipsi- or contralateral compared to bilateral) and a J-CTO score ≥ 3 were strongest predictors of recurrences in CTO patients at 5 years.

CONCLUSION

A coronary CTO even in the presence of less developed collaterals and more complex CTO category is associated with increasing risk of recurrent ventricular tachyarrhythmias at 5 years in consecutive ICD recipients.

Percutaneous Coronary Intervention for Chronic Total Occlusion

Treatment of coronary chronic total occlusions represents one of the major challenges in the field of interventional cardiology. This is due to the complexity of these procedures and to the relatively higher risk of complications. In recent years, the development of innovative techniques and the evolution of materials have produced significant progress in this field. Better procedural outcomes have been achieved, with fewer complications. This article highlights the most recent scientific evidence and techniques, with the intention to guide interventional cardiologists in optimal patient selection and procedure choice.

Differential clinical impact of chronic total occlusion revascularization based on left ventricular systolic function

Background

The effect of chronic total occlusion (CTO) revascularization on survival remains controversial. Furthermore, data regarding outcome differences for CTO revascularization based on left ventricular systolic function (LVSF) are limited.

The differential outcomes from CTO revascularization in patients with preserved LVSF (PLVSF) versus reduced LVSF (RLVSF) were assessed.

Methods

A total of 2,173 CTO patients were divided into either a PLVSF (n = 1661, Ejection fraction ≥ 50%) or RLVSF (n = 512, < 50%) group. Clinical outcomes were compared between successful CTO revascularization (SCR) versus optimal medical therapy (OMT) within each group. The primary endpoint was a composite of all-cause death or non-fatal myocardial infarction. Inverse probability of treatment weighting for endpoint analysis and a contrast test for comparison of survival probability differences according to LVSF were used.

Results

Patients with RLVSF had a mean 37% ejection fraction (EF) and 19% had EF < 30%. The median follow-up duration was 1,138 days. Regardless of LVSF, the primary endpoint incidence was significantly lower in patients treated with SCR [RLVSF: 29.7% vs. 49.7%, hazard ratio (HR) = 0.46, 95% confidence interval (CI): 0.36–0.62, p < 0.0001; PLVSF 7.3% vs. 16.9%, HR = 0.68, 95% CI: 0.54–0.93, p = 0.0019], which was mainly driven by a reduction in cardiac death. The difference in survival probability was greater and became more pronounced over time in patients with RLVSF than with PLVSF (1-year, p = 0.197; 3-years, p = 0.048; 5-years, p = 0.036).

Conclusions

SCR was associated with better survival benefit than OMT regardless of LVSF. The benefit was greater and became more significant over time in patients with RLVSF versus PLVSF.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01738-2) 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.

Prognosis of Patients With Reduced Left Ventricular Ejection Fraction and Chronic Total Occlusion According to Treatment Applied

BACKGROUND

Chronic total occlusion (CTO) is common among patients with coronary artery disease. Very few studies have focused on outcomes of patients with CTO and reduced left ventricular ejection fraction (LVEF), according to treatment applied. The aim of our study was to determine the potential influence of the selected treatment on the prognosis in patients with CTO associated with reduced LVEF.

METHODS

Between June 2010 and October 2013, all consecutive patients with at least one CTO and reduced LVEF (<40%) were enrolled. Major adverse cardiac events (MACE), defined as the composite of cardiac mortality or myocardial infarction (MI) and its individual components, were compared between three treatment groups: medical therapy (MT), percutaneous coronary intervention (PCI), and coronary bypass graft (CABG).

RESULTS

In 256 included patients, the follow-up was 1129 ± 556 days. The incidence of MACE was 40% in the MT group, compared with PCI (20.3%) and CABG (16.7%); p < 0.001. All-cause and cardiac mortality were also higher in the MT group (40.7% and 33.3%, respectively) versus the PCI (21.9% and 15.6%) and CABG (11.9% and 9.5%) groups (p < 0.001 for both endpoints); MI rate did not differ among groups. In the adjusted multivariate analysis, CABG had lower MACE risk, compared with MT (HR = 0.39, 0.17-0.91; p = 0.029); successful PCI also trended toward lower risk of MACE, compared with MT.

CONCLUSIONS

Patients with CTO and reduced LVEF treated with MT had a worse prognosis than those treated with revascularization (either CABG or PCI). Patients with an indication for CABG appeared to perform best during long-term follow-up.

Vulnerability for ventricular arrhythmias in patients with chronic coronary total occlusion

INTRODUCTION

The presence of a chronic total occlusion (CTO) is associated with an increased risk of ventricular arrhythmias.

AREAS COVERED

This review provides an overview of the relationship between CTO and ventricular arrhythmias, arrhythmogenic mechanisms, and the effect of revascularization.

EXPERT OPINION

Studies in recipients of an implantable cardioverter-defibrillator (ICD) have shown that a CTO is an independent predictor of appropriate ICD therapy. The myocardial territory supplied by a CTO is a pro-arrhythmogenic milieu characterized by scar tissue, large scar border zone, hibernating myocardium, residual ischemia despite collaterals, areas of slow conduction, and heterogeneity in repolarization. Restoring coronary flow by revascularization might be associated with electrical homogenization as reflected by a decrease in QT(c) dispersion, decrease in T wave peak-to-end interval, reduction of late potentials, and decrease in scar border zone area. Future research should explore whether CTO revascularization results in a lower burden of ventricular arrhythmias. Furthermore, risk stratification of CTO patients without severe LV dysfunction is interesting to identify potential ICD candidates. Potential tools for risk stratification are the use of electrocardiographic parameters, body surface mapping, electrophysiological study, and close rhythm monitoring using an insertable cardiac monitor.

Periprocedural and clinical outcomes of percutaneous coronary intervention of chronic total occlusions in patients with low- and mid-range ejection fractions

Background

The benefit and safety of percutaneous coronary intervention (PCI) to chronic total occlusions (CTO) in patients with low and mid-range left ventricular ejection fraction (LVEF) continue to be evidence limited. The aim of our study was to investigate the impact of LVEF in patients undergoing CTO PCI and to evaluate the mid-term clinical outcome of those with low and mid-range LVEF. We assessed the periprocedural and mid-term outcomes of 75 patients undergoing CTO PCIs according to pre-procedural LVEF: group (N), ≥ 50% (normal, nom.= 25); group (M), 40-49% (mid-range, nom.= 25); and group (L), < 40% (low, nom.= 25); within 6 months of follow-up.

Results

The prevalence of DM and chronic kidney disease (CKD) was significantly higher in low LVEF group (60%, p = 0.04 and 48%, p = 0.01 respectively). Apart from significantly lower contrast volume in patients with low LVEF (p = 0.04), there was no significant difference between the three groups regarding the procedural time, SYNTAX score and J-CTO score. We noticed similar procedural success in the three groups (88% vs. 84% vs. 76%, p = 0.521). LVEF category failed to predict procedural success (OR = 0.652, p = 0.268). There was a highly significant improvement in angina 6 months following intervention in normal LVEF group (p value < 0.001). Grade of dyspnea significantly improved 6 months following intervention in mid-range LVEF and low LVEF groups (p value = 0.04 and 0.031 respectively). There was no significant difference between the three groups regarding the reported MACCEs (12% vs. 16% vs. 28%, p = 0.268).

Conclusion

CTO PCI represents an efficient and safe strategy in patients with low and mid-range LVEFs. Mid-term outcomes in these patients were significantly improved following successful CTO PCI, without higher risk of MACCE at 6 months follow-up.

Incidence and characteristics of ventricular tachycardia in patients after percutaneous coronary revascularization of chronic total occlusions

Objectives

This study sought to investigate the prevalence of ventricular tachycardia after percutaneous coronary intervention (PCI) of chronic total occlusion (CTO).

Background

PCI of a CTO is associated with improvement of the left ventricular ejection fraction and possibly associated with reduced mortality. However, benefits of CTO-PCI must be weighed against a higher risk of procedure-related complications. The incidence of new-onset ventricular tachycardia after a successful CTO-PCI has not been investigated so far. In this retrospective registry we seek to describe characteristics and predictors of occurrence of post-procedural ventricular tachycardias.

Methods and results

Between 2010 and 2015, 485 patients underwent successful CTO-PCI at Heart Center Leipzig. Of them, 342 had complete follow-up and were further analyzed. Ventricular tachycardias were detected in 9 (2.6%) patients. All of them were monomorphic ventricular tachycardias occurring in median 1 day (interquartile range [IQR] 0.25–4.75 days) after PCI and caused prolongation of the hospital stay. Patients with ventricular tachycardia were older, had worse left ventricular ejection fraction (mean 33.1%, SD 5.9%) and more frequently a CTO of an infarct-related artery. The target vessel was not associated with the occurrence of ventricular arrhythmias. In multivariable analysis, only impaired left ventricular systolic function was an independent predictor for procedure-related ventricular tachycardia. Mortality rates were not different between patients with or without ventricular tachycardia.

Conclusion

Ventricular tachycardia can occur early after CTO-PCI as possible reperfusion arrhythmia and poorer left ventricular ejection fraction is the only independent predictor for onset. Although the occurrence of ventricular tachycardia after CTO-PCI seems not to influence mortality, awareness of this possible complication and longer monitoring may be recommended.

Impact of chronic total occlusion on ventricular arrhythmia and mortality in ischaemic cardiomyopathy patient with implantable cardiac defibrillator: a meta-analysis

Background: Recent studies suggested that chronic total occlusion of the coronary artery increased risk of ventricular arrhythmia (VA) and all-cause mortality in ischaemic cardiomyopathy (ICM) patient who underwent implantable cardiac defibrillator (ICD) implantation. We aim to demonstrate an association between a presence of CTO and poor cardiovascular outcome in ICD implanted ICM patients. Objective: To examine the association between the presence of CTO and all-cause mortality in ICM with ICD implantation Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to February 2018. The studies that reported appropriated shock and all-cause mortality in ICD implanted ICM patients, compared between patients with and without CTO of the coronary artery, were included for meta-analysis. Results: Five studies from 2015 to 2018 were included in this meta-analysis involving 1,095 subjects (505 CTO and 590 non-CTO). The presence of CTO was associated with increased incidence of VA (pooled risk ratio = 1.75, 95% confidence interval: 1.10-2.77, p = 0.01) and all-cause mortality (pooled risk ratio = 1.63, 95% confidence interval: 1.10-2.41, p = 0.001) in ICD implanted ICM patients. Conclusions: Presence of CTO of the coronary artery increased risk of VA and all-cause mortality in ICD implanted ICM patients up to 75% and 63%, respectively. Our study suggested that CTO is an independent predictor of unfavourable outcome and revascularised option should be considered in ICM patients with ICD.

Prognostic impact of recanalizing chronic total occlusion in non-infarct related arteries on long-term clinical outcomes in acute myocardial infarction patients undergoing primary percutaneous coronary intervention

Although chronic total occlusion (CTO) in non-infarct-related arteries (non-IRAs) negatively affects long-term mortality in patients with acute myocardial infarction (AMI) who are undergoing primary percutaneous coronary intervention (PCI), the prognostic impact of successful CTO-PCI has not been completely addressed. Among 1855 consecutive patients with AMI who underwent primary PCI, those who were treated for CTO with either PCI or medical therapy were included. We evaluated the association between recanalization of CTO and long-term cardiac mortality. Of the 172 included patients, 88 underwent CTO-PCI, and the procedures were successful in 65 patients. Thus, the successfully recanalized CTO (SR-CTO) group included 65 patients; and the no recanalized CTO (NR-CTO) group, 107 patients. During the follow-up, 72 patients died, and of whom 56 (77.8%) died because of cardiac causes. The cumulative 10-year, 30-day, and 30-day to 10-year incidences of cardiac mortality were lower in the SR-CTO group than in the NR-CTO group (19.0% vs. 51.9% p = 0.004; 4.6% vs. 14.0%, p = 0.05; 15.0% vs. 44.1%, p = 0.003, respectively). After adjusting for confounding factors, the benefits of SR-CTO for the 10-year cardiac mortality remained significant compared with those of NR-CTO (hazard ratio 0.37; 95% confidence interval 0.17-0.75; p = 0.004). In conclusion, patients with SR-CTO in non-IRAs after AMI was associated with reduced long-term cardiac mortality compared with those with NR-CTO.

Successful revascularization versus medical therapy in diabetic patients with stable right coronary artery chronic total occlusion: a retrospective cohort study

Background

The territory of the right coronary artery (RCA) is smaller than that of the left anterior descending artery. Previous studies have reported conflicting results when considering whether stable RCA-chronic total occlusion (CTO) should be reopened. The coexistence of diabetic and coronary artery diseases represents a severe situation. Therefore, we aimed to determine if stable RCA-CTO in diabetic patients was necessary to be reopened. To our knowledge, no studies have focused on this topic to date.

Methods

We enrolled diabetic patients with RCA-CTO who had clinical presentations of symptomatic stable angina or silent ischemia. RCA-CTO was treated with either successful revascularization (the CTO-SR group) or medical therapy (the CTO-MT group). The primary endpoint was all-cause death. Both Cox regression and propensity score matching analyses were used. Sensitivity analysis was performed based on subgroup populations and relevant baseline variables.

Results

A total of 943 patients were included: 443 (46.98%) patients in the CTO-MT group and 500 (53.02%) patients in the CTO-SR group. After a mid-term follow-up (CTO-SR: 48 months; CTO-MT: 42 months), we found that CTO-SR was superior to CTO-MT in terms of all-cause death (adjusted hazard ratio [HR] [model 1]: 0.429, 95% conference interval [CI] 0.269–0.682; adjusted HR [model 2]: 0.445, 95% CI 0.278–0.714). The superiority of CTO-SR was consistent for cardiac death, possible/definite cardiac death, repeat revascularization, target vessel revascularization (TVR) and repeat nonfatal myocardial infarction. Subgroup analysis confirmed the mortality benefit of CTO-SR by percutaneous coronary intervention (the successful CTO-PCI subgroup, 309 patients in total). While CTO-SR by coronary artery bypass grafting (the CTO-CABG subgroup, 191 patients in total) offered patients more benefit from repeat revascularization and TVR than that offered by successful CTO-PCI.

Conclusions

For stable RCA-CTO patients with diabetes, successful revascularization offered patients more clinical benefits than medical therapy. CTO-CABG might be a more recommended way to accomplish revascularization.

Trial registration This study was not registered in an open access database

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0911-4) contains supplementary material, which is available to authorized users.

Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention

Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI.  1. Ischemic symptom improvement is the primary indication for CTO-PCI.  2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI.  3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges.  4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs.  5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use.  6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation.  7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training.

Surgical Revascularization of Chronically Occluded Coronary Arteries—What You See Is What You Get?

Background Revascularization strategy in coronary artery bypass grafting (CABG) surgery usually depends on coronary dimension and stenosis severity. Little is known about the relation of preoperative evaluation of scarcely or invisibly chronic occluded coronary arteries (chronic total occlusion [CTO]) and revascularization rate or anastomosis quality. We aimed to evaluate the success rates of CTO revascularization in CABG surgery and determine the influence of coronary lumen visibility and collateralization in preoperative angiograms on revascularization rates, bypass blood flow, and target vessel diameter.

Method Preoperative coronary angiograms were evaluated for 938 consecutive patients who underwent isolated CABG surgery between 2014 and 2016 and screened for occluded coronary arteries. The occluded vessels were scored for visibility using the Rentrop grading of collateral filling. Intraoperatively, dimensions of the occluded arteries were measured using conventional vessel probes, and anastomosis quality was assessed by transit time flow measurement.

Results A total of 404 (43.1%) patients were identified with at least one CTO. Revascularization rates differed from 96.2% in the left anterior descending artery, to 85.0% in left circumflex artery-dependent vessels, and 78.8% in right coronary artery territory. Coronary visibility and grade of collateralization in the preoperative angiogram had no influence on intraoperatively measured coronary diameter. Bypass blood flow in grafts revascularizing CTOs lacking collateralization were not significantly lower than those grafts leading to CTOs with higher Rentrop scores.

Conclusion Preoperative coronary assessment often differs from intraoperative findings. Our study confirms that even patients with scarcely collateralized CTOs and impaired visibility in the coronary angiogram have a high chance of complete revascularization during CABG surgery.

Electrical storm - still an extremely poor prognosis. Do these acute states of life-threatening arrhythmias require a multidirectional approach from the start?

Electrical storm (ES) is a state of electrical instability of the heart manifesting as multiple and potentially lethal recurring ventricular arrhythmias such as ventricular tachycardia or ventricular fibrillation. This definition is not related to the condition of each patient, who can present from asymptomatic to unconscious and in deep cardiogenic shock. Most patients affected by ES have heart failure (HF) of ischaemic origin. Ischaemia, exacerbation of HF, low ejection fraction, previous ventricular arrhythmias, infection or electrolyte disturbances together with other factors, or a few factors combined, may result in ES. The prognosis of ES survivors is very poor, with 1-year mortality exceeding 40%, which should draw attention to this group of patients as one of extremely high risk. The number of patients with cardioverter-defibrillators is increasing and so is the number of patients suffering from ES. Therefore, each patient should be supported with tailored therapy, and not only restricted to pharmacotherapy or ablation procedures. This paper was written to analyse the most frequent causes of ES and prompt the most appropriate clinical pathways and possibilities, underlining the need for a comprehensive invasive approach to diagnosis, treatment and circulatory stabilization in addition to adequate pharmacotherapy. This approach might help to reduce the mortality rate in this group of patients and improve the prognosis.

Impact of recanalization of chronic total occlusion on left ventricular electrical remodeling

Background

Successful percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is associated with reduction of cardiac mortality, as well as reducing fatal ventricular arrhythmias. The aim of this study was to evaluate the effect of recanalization of CTO on endocardial left ventricular voltages by paired electrophysiological studies.

Methods

Sixteen consecutive patients who underwent PCI for de novo CTO lesions were included. High‐density mapping was performed during sinus rhythm before and 8 months after PCI. According to the amplitude of bipolar electrograms, the left ventricular endocardium was classified into a preserved normal voltage (>1.5 mV), border zone (0.5–1.5 mV), and dense scar areas (<0.5 mV).

Results

The border zone area had a significant positive correlation with CTO length, as well as a significant negative correlation observed in the preserved voltage region. In the successful PCI patient, the median dense scar area did not change significantly (reported as [median difference: 95% confidence interval]) between baseline and after PCI (0.1 cm²: –2.8 to 2.9). However, the area of the border zone decreased (–10.5 cm²: –16.8 to –4.1) and the preserved voltage area increased significantly (19.2 cm²: 7.7–30.6). In addition, successful PCI was related to slight, but significant, increase in the amplitude of unipolar and bipolar voltage (1.55 mV: 0.88–3.33, 0.23 mV: 0.08–0.36).

Conclusions

Recanalization of CTO may promote reverse electrical remodeling in the border zone of the left ventricle, without affecting the dense scar tissue.

Current Evidence and Rationale of Percutaneous Therapy for Chronic Total Coronary Occlusions

The prevalence of chronic total occlusion (CTO) lesions in coronary arteries is notably high in patients with significant coronary artery disease. However, only a relatively small fraction of observed CTOs classically go for revascularization. Recent advances in techniques and equipment has greatly improved the success rates of CTO revascularization while reducing complications. There has also been an increasing body of evidence regarding clinical benefit of CTO revascularization. However, until recently majority of the evidence was observational and based on data from large multicenter registries. Recent randomized studies have reported on clinical benefits of CTO revascularization particularly with relief of angina. However, there is heterogeneity of results among different studies and the magnitude of benefit is not consistently seen in all studies. This article reviews the existing literature on the current evidence regarding clinical benefits and other rationale for CTO revascularization.

Risk of cardiac and sudden death with and without revascularisation of a coronary chronic total occlusion

Objective

The aim of this study is to evaluate the long-term risk of cardiac death and sudden cardiac death (SCD) and/or sustained ventricular arrhythmias (SVAs) in patients with coronary chronic total occlusions (CTO) revascularised versus those with CTO not revascularised by percutaneous coronary intervention (PCI).

Methods

From a cohort of 1357 CTO-PCI patients, 1162 patients who underwent CTO PCI attempt were included in this long-term analysis: 837 patients were revascularised by PCI (CTO-R group) and 325 were not revascularised (CTO-NR group). Primary adverse endpoint was the incidence of cardiac death; secondary endpoint was the cumulative incidence of SCD/SVAs.

Results

Up to 12-year follow-up (median 6 year), compared with CTO-R patients, those with CTO-NR had significantly higher rate of cardiac death (13%[43/325]vs6%[48/837]; p<0.001) and SCD/SVAs (7.5%[24/325]vs2.5%[20/837]; p<0.001). The risk of cardiac death and SCD/SVAs was mainly driven by the subgroup of infarct-related artery (IRA) CTO patients and was significantly higher only in IRA CTO-NR patients (18%vs7%, p<0.001, 14%vs5%, p=0.001; IRA CTO-NR vs IRA CTO-R, respectively). At multivariable Cox hazards regression analysis, CTO-NR remains one of the strongest independent predictors of higher risk of cardiac death and of SCD/SVAs in the overall population and in IRA CTO patients.

Conclusions

At long-term follow-up, patients with CTO not revascularised by PCI had worse outcomes compared with those with CTO revascularised, with >2-fold risk of cardiac death and threefold risk of SCD/SVAs. The presence of an infarct-related artery (IRA CTO) not revascularised identified the category of patients with the highest rate of adverse events .

Beta-blocker therapy reduces mortality in patients with coronary artery disease treated with percutaneous revascularization: a meta-analysis of adjusted results

AIMS

The long-term impact of beta blockers on prognosis in patients treated with contemporary therapies for coronary artery disease remains to be defined.

METHODS AND RESULTS

All observational studies evaluating the impact of beta blockers in patients treated with coronary revascularization and contemporary therapies and adjusted with multivariate analysis were included. All-cause death was the primary endpoint, while Major Adverse Cardiac Events (MACE) (composite endpoint of all-cause death or myocardial infarction, MI) and MI were secondary endpoints. A total of 26 studies were included, with 863 335 patients. After 3 (1-4.3) years, long-term risk of all-cause death was lower in patients on beta blockers [odds ratio, OR 0.69 (0.66-0.72)], both for Acute Coronary Syndrome (ACS) [OR 0.60 (0.56-0.65)], and stable angina patients [OR 0.84 (0.78-0.91)], independently from ejection fraction [OR 0.64 (0.42-0.98) for reduced ejection fraction and OR 0.79 (0.69-0.91) for preserved ejection fraction]. The risk of long-term MACE was lower but NS for ACS patients treated with beta blockers [OR 0.83 (0.69-1.00)], as in stable angina. Similarly, risk of MI did not differ between patients treated with beta blockers or without beta blockers [OR 0.99 (0.89-1.09), all 95% confidence intervals]. Using meta-regression analysis, the benefit of beta blockers was increased for those with longer follow-up. The number needed to treat was 52 to avoid one event of all-cause death for ACS patients and 111 for stable patients.

CONCLUSION

Even in percutaneous coronary intervention era, beta blockers reduce mortality in patients with coronary artery disease, confirming their protective effect, which was consistent for both ACS and stable patients indifferently of preserved or reduced ejection fraction.

Completeness of Revascularization as a Determinant of Outcome: A Contemporary Review and Clinical Perspectives

It has been debated whether patients with multivessel coronary artery disease should undergo complete revascularization (CR). The benefit of CR is biologically plausible, and numerous studies and large meta-analyses suggested that CR achievement was associated with a substantial reduction of mortality and future coronary events. In patients with multivessel coronary artery disease, the aim of myocardial revascularization is to minimize residual ischemia. Therefore, CR of all significant coronary lesions has been proposed as the first priority in decision-making for myocardial revascularization between coronary artery bypass grafting and percutaneous coronary intervention (PCI). Reflecting the contemporary practice of ischemia-based revascularization, a physiological/functional approach, such as measurement of fractional flow reserve or instantaneous wave-free ratio, is considered more reasonable and should be encouraged for appropriate CR. In patients who present with acute ST-elevation myocardial infarction, current evidence suggests that an immediate or staged CR strategy might be equivalent or superior to culprit-only revascularization. There is still uncertainty on when and how to perform CR in ST-elevation myocardial infarction patients; comprehensive studies dedicated to this issue are required. Hybrid coronary revascularization includes the advantages of minimally invasive bypass grafting for the left anterior descending artery and PCI for non-left anterior descending arteries and has been proposed as a viable alternative for coronary artery bypass grafting or PCI only for achieving CR. In clinical practice, the extent of revascularization and strategy for CR should be individualized, taking account of different aspects of the patients, lesions, and treating physicians. Collaboration of coronary heart teams would confer balanced decision-making and advanced therapeutic capabilities.