Comparative Analysis of Patient Characteristics in Chronic Total Occlusion Revascularization Studies: Trials vs Real-World Registries

Impact of sex on myocardial perfusion following percutaneous coronary intervention of chronic total coronary occlusions

OBJECTIVES

We sought to investigate the impact of sex on myocardial perfusion changes following chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) as measured by [15O]H2O positron-emission tomography (PET) perfusion imaging.

BACKGROUND

CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. As such, data on the impact of sex on myocardial perfusion following CTO PCI is scarce.

METHODS

A total of 212 patients were prospectively enrolled and underwent CTO PCI combined with [15O]H2O PET perfusion imaging prior to and 3 months after PCI. Hyperemic myocardial blood flow (hMBF, mL·min-1·g-1) and coronary flow reserve (CFR) allocated to the CTO territory were quantitatively assessed.

RESULTS

This study comprised 34 (16 %) females and 178 (84 %) males. HMBF at baseline did not differ between sexes. Females showed a higher increase in hMBF than males (Δ1.34 ± 0.67 vs. Δ1.06 ± 0.74, p = 0.044), whereas post-PCI hMBF was comparable (2.59 ± 0.85 in females vs. 2.28 ± 0.84 in males, p = 0.052). Female sex was independently associated with a higher increase in hMBF after correction for clinical covariates. CFR increase after revascularization was similar in females and males (Δ1.47 ± 0.99 vs. Δ1.30 ± 1.14, p = 0.711).

CONCLUSIONS

The present study demonstrates a greater recovery of stress perfusion in females compared to males as measured by serial [15O]H2O PET imaging. In addition, a comparable increase in CFR was found in females and males. These results emphasize the benefit of performing CTO PCI in both sexes.

CLINICAL PERSPECTIVE

What is new? What are the clinical implications?

Sub-Intimal Tracking and Re-Entry and Investment Procedures: Current Applications and Future Directions

In seeking to improve upon chronic total occlusion (CTO) percutaneous coronary intervention success rates and minimize risk, CTO modification procedures (investment procedures) have been developed and utilized with increasing frequency. Two key techniques have emerged: subintimal tracking and re-entry (STAR) and subintimal plaque modification (SPM). Both require a staged approach with an index procedure for plaque modification and a second procedure weeks later for stenting. Both approaches require entry and wiring with a polymer-jacketed wire in the extra-plaque space, yet unlike SPM, which exclusively requires angioplasty of the extra-plaque space throughout the CTO segment, STAR also involves re-entry into the true luminal distal to the CTO before angioplasty. STAR and SPM, in many ways, represent a paradigm shift in our approach to CTO percutaneous coronary intervention from a 1-step to a 2-step approach in complex cases. In this review, we discuss the technical aspects of the procedures, and controversies and ongoing trials pointing to the future of these techniques. We also highlight non-device-based and intravascular ultrasound-based approaches to anterograde dissection and re-entry, which add to the CTO operator's toolkit for challenging cases.

Long-term outcomes after revascularization in chronic total and non-total occluded coronary arteries: A regionwide cohort study

BACKGROUND

Understanding the prognostic impact of percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) is crucial for patient management. Previous studies have primarily been studying prognostic impact of successful versus unsuccessful CTO PCI. This study investigated the prognostic impact of successful and unsuccessful percutaneous coronary intervention (PCI) of chronic total occluded coronary arteries (CTO) with non-CTO PCI as reference.

METHODS

Patients treated with PCI from 2009 to 2019 in the Central Region of Denmark were included in a population-based cohort study. We compared successful and unsuccessful CTO PCI with non-CTO PCI. Exclusion criteria was myocardial infarction within 30 days. Primary outcome was difference in a composite major adverse cardio- and cerebrovascular events (MACCE) encompassing all-cause death, any myocardial infarction, stroke, hospitalization for heart failure or revascularization tracked via nationwide registries.

RESULTS

Of 21,141 screened patients, 10,638 were enrolled: 9,065 underwent non-CTO PCI, 1,300 had successful CTO PCI, and 273 had unsuccessful CTO PCI. Median follow-up time was 5.9 [3.5;9.0] years and 4,750 MACCEs were recorded. Compared to non-CTO PCI, the adjusted MACCE rate for successful CTO PCI was equivalent (Hazard Ratio (HR): 0.98, 95% Confidence Interval (CI): 0.90-1.07, p = 0.71). In contrast, unsuccessful CTO PCI was associated with a higher MACCE rate (HR: 1.22, 95% CI: 1.04-1.43, p<0.01). HR was adjusted for age, body-mass index, previous revascularization, smoking, kidney disease, two or three-vessel disease, left ventricular ejection fraction, diabetes and comorbidities.

CONCLUSIONS

The pre-specified hypothesis was accepted. Successful CTO PCI was associated with equivalent long-term outcomes as non-CTO PCI, and unsuccessful CTO PCI was identified as a high-risk group associated to worse outcomes.

Percutaneous Coronary Intervention versus Optimal Medical Therapy in Patients with Chronic Total Occlusion: A Meta-Analysis

Background/Objectives: Chronic total occlusion (CTO) is a prevalent finding in patients with coronary artery disease and is associated with increased mortality. Prior reports on the efficacy of percutaneous coronary intervention (PCI) compared to optimal medical therapy (OMT) were controversial. Following the emergence of recently published new evidence, a meta-analysis is warranted. The current meta-analysis assessed the effects of PCI compared to OMT in the treatment of CTO. Methods: A structured literature search was performed. Randomized controlled trials (RCTs) and non-randomized controlled studies of interventions were eligible. The primary outcome was an accumulated composite of cardiac mortality, myocardial infarction and target vessel/lesion revascularization events. Results: Thirty-two studies reporting on 11260 patients were included. Of these, 5712 (50.7%) were assigned to the PCI and 5548 (49.3%) were allocated to the OMT group. The primary outcome occurred in 14.6% of the PCI and 20.1% of the OMT group (12 trials, OR 0.66, 95% CI 0.50 to 0.88, p = 0.005, I2 = 67%). Subgrouping demonstrated a consistent reduction in the primary outcome for the PCI group in RCTs (six trials, OR 0.58, 95% CI 0.33 to 0.99, p = 0.05). The primary outcome reduction was irrespective of the study design, and it was replicable in sensitivity and subgroup analyses. Advantages in other outcomes were rather related to statistical pooling effects and dominated by observational data. Conclusions: CTO-PCI was associated with improved patient-oriented primary outcome compared to OMT in a study-level meta-analysis. This composite outcome effect was mainly driven by target vessel treatment, but a significant reduction in mortality and myocardial infarction was observed, irrespectively. These findings have hypothesis-generating implications. Future RCTs with adequate statistical power are eagerly awaited.

When to Consider Coronary Revascularization for Stable Coronary Artery Disease

Revascularization is an effective adjunct to medical therapy for some patients with chronic coronary disease. Despite numerous randomized trials, there remains significant uncertainty regarding if and how to revascularize many patients. Coronary artery bypass grafting is a class I indication for patients with significant left main stenosis or multivessel disease with ejection fraction ≤ 35%. For other patients, clinicians must carefully consider the potential benefits of symptom improvement and reduction of future myocardial infarction or CV death against the risk and cost of revascularization. Although guidelines provide a framework for these decisions, each individual patient will have distinct coronary anatomy, clinical factors, and preferences.

Coronary chronic total occlusion on coronary CT angiography: what radiologists should know?

Coronary chronic total occlusion (CTO) often occurs in patients with obstructive coronary artery disease, which remains one of the greatest challenges for interventional cardiologists. Coronary computed tomography angiography (CCTA) with its emerging post-processing techniques can provide a detailed assessment of CTO lesions before percutaneous coronary intervention (PCI), playing an important role in the clinical management of CTO PCI, from early diagnosis, pre-procedural outcome prediction, the crossing algorithm planning, intraprocedural guidance, and finally post-procedural assessment and follow-up. In addition, the feasibility of CT perfusion (CTP) in patients with CTO has been validated. Combined CCTA and CTP have the great potential to be the one-stop-shop imaging modality for assessing both anatomy and function of CTO lesions. This review aims to make radiologists understand the role of CCTA in the diagnosis and assessment of CTO lesions, thus assisting interventionalists in optimizing CTO PCI crossing strategies with the expertise of radiologists.Critical relevance statement The anatomical features of CTO on CCTA can reveal the complexity of CTO lesions and are associated with CTO PCI outcome, thus helping interventionalists optimize CTO PCI crossing strategies.Key points • CTO is the common lesion in invasive coronary angiography, and CTO PCI is technically difficult and its success rate is relatively low.• Length, collaterals, and attenuation-related signs can help distinguish CTO from subtotal occlusion.• The anatomical features of CTO lesions can help grade the difficulty of CTO PCI and predict procedural outcomes and long-term outcomes of CTO PCI.• The real-time fusion of CCTA with fluoroscopic angiography can be applied in highly complicated CTO lesions.• After CTO PCI, CCTA can help guide a second CTO PCI re-entry or follow up stent patency.

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.

Three-year outcomes of A Randomized Multicentre Trial Comparing Revascularization and Optimal Medical Therapy for Chronic Total Coronary Occlusions (EuroCTO)

BACKGROUND

Percutaneous coronary intervention (PCI) for chronic total coronary occlusions (CTO) improves clinical symptoms and quality of life. The longer-term safety of PCI compared to optimal medical therapy (OMT) remains uncertain.

AIMS

We sought to evaluate the long-term safety of PCI for CTO in a randomised trial as compared to OMT.

METHODS

A total of 396 patients with a symptomatic CTO were enrolled into a randomised, multicentre clinical trial comparing PCI and OMT. Half of the patients had a single CTO; the others had multivessel disease. Non-CTO lesions were treated prior to randomisation (2:1 ratio). During follow-up, crossover from OMT to PCI occurred in 7.3% (1 year) and 17.5% (3 years) of patients.

RESULTS

At 3 years, the incidence of cardiovascular death or nonfatal myocardial infarction was not significantly different between the groups (OMT 3.7% vs PCI 6.2%; p=0.29). By per-protocol analysis, the difference remained non-significant (OMT 5.7% vs PCI 4.7%; p=0.67). Overall, major adverse cardiovascular events (MACE) were more frequent with OMT (OMT 21.2% vs PCI 11.2%), largely because of ischaemia-driven revascularisation. The rates of stroke or hospitalisation for bleeding were not different between the groups.

CONCLUSIONS

At 3 years there was no difference in the rate of cardiovascular death or myocardial infarction between PCI or OMT among patients with a remaining single coronary CTO. The MACE rate was higher in the OMT group due largely to ischaemia-driven revascularisation. CTO PCI appears to be a safe option for patients with a single remaining significant coronary CTO. CinicalTrials.gov: NCT01760083.

PCI or CABG for left main coronary artery disease: the SWEDEHEART registry

AIMS

An observational nationwide all-comers prospective register study to analyse outcomes after coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) in unprotected left main coronary artery (LMCA) disease.

METHODS AND RESULTS

All patients undergoing coronary angiography in Sweden are registered in the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registry. Between 01/01/2005 and 12/31/2015, 11 137 patients with LMCA disease underwent CABG (n = 9364) or PCI (n = 1773). Patients with previous CABG, ST-elevation myocardial infarction (MI) or cardiac shock were excluded. Death, MI, stroke, and new revascularization during follow-up until 12/31/2015 were identified using national registries. Cox regression with inverse probability weighting (IPW) and an instrumental variable (IV), administrative region, were used. Patients undergoing PCI were older, had higher prevalence of comorbidity but lower prevalence of three-vessel disease. PCI patients had higher mortality than CABG patients after adjustments for known cofounders with IPW analysis (hazard ratio [HR] 2.0 [95% confidence interval (CI) 1.5-2.7]) and known/unknown confounders with IV analysis (HR 1.5 [95% CI 1.1-2.0]). PCI was associated with higher incidence of major adverse cardiovascular and cerebrovascular events (MACCE; death, MI, stroke, or new revascularization) than CABG, with IV analysis (HR 2.8 [95% CI 1.8-4.5]). There was a quantitative interaction for diabetic status regarding mortality (P = 0.014) translating into 3.6 years (95% CI 3.3-4.0) longer median survival time favouring CABG in patients with diabetes.

CONCLUSION

In this non-randomized study, CABG in patients with LMCA disease was associated with lower mortality and fewer MACCE compared to PCI after multivariable adjustment for known and unknown confounders.

Cost Change of Elective Percutaneous Coronary Artery Intervention for Chronic Coronary Syndrome in Japan From 2010 to 2019

BACKGROUND

Because of revisions to insurance reimbursement costs, medical fees have changed for investigations and percutaneous coronary intervention (PCI) treatment of chronic coronary syndrome (CCS). In this retrospective study, we investigated these changes and their effects on mortality and cardiovascular events.

METHODS AND RESULTS

We included 1,483 patients who underwent elective PCI for CCS between April 2010 and September 2019. The primary outcomes were changes in PCI procedure fees and all included hospitalization fees due to the biennial revisions of reimbursement costs across 5 time periods (~2 years each). Secondary outcomes were rates of survival and freedom from major adverse cerebral and cardiovascular events (MACCE) in each time period. Patient characteristics were generally unchanged over the study period; however, treatment procedures changed significantly, with changes in the approach site (from transfemoral to transradial access; P<0.0001) and final device (from bare-metal stents to drug-eluting stents; P<0.0001), and an increase in the use of imaging modalities (P<0.0001). Medical fee parameters (primary outcomes) decreased significantly from 2010 to 2019 (P<0.001): PCI procedure fees decreased by 25%, whereas all included hospitalization fees decreased by 20%. There were no significant differences in survival or freedom-from-MACCE rates between periods.

CONCLUSIONS

Because of revisions to reimbursement prices, there were rapid and significant decreases in PCI procedure and hospitalization fees for CCS. These changes had no effect on mortality or cardiovascular events.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention of the Left Anterior Descending Artery

The left anterior descending artery (LAD) subtends a large myocardial territory. The outcomes of LAD chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have received limited study. We performed a retrospective analysis of all patients who underwent LAD CTO PCI at a high-volume single center. Outcomes included in-hospital and long-term major adverse cardiovascular events (MACEs) and changes in left ventricular ejection fraction (LVEF). We performed a subgroup analysis of patients with ischemic cardiomyopathy, defined as an LVEF of 40% or less. From December 2014 to February 2021, 237 patients underwent LAD CTO PCI. The technical success rate was 97.4%, and the in-hospital MACE rate was 5.4%, A landmark analysis after hospital discharge showed an overall survival of 92% and 85% MACE-free survival at 2 years. There was no difference in overall survival or MACE-free survival between those who had ischemic cardiomyopathy versus those who did not. In patients with ischemic cardiomyopathy, LAD CTO PCI was associated with significant improvement in LVEF (10.9% at 9 months), which was further pronounced when these patients had a proximal LAD CTO and were on optimal medical therapy (14% at 6 months). In a single high-volume center, LAD CTO PCI was associated with 92% overall survival at 2 years, with no difference in survival between patients with or without ischemic cardiomyopathy. LAD CTO PCI was associated with an absolute 10% increase in LVEF at 9 months in patients with ischemic cardiomyopathy.

Leveraging Machine Learning Techniques to Forecast Chronic Total Occlusion before Coronary Angiography

BACKGROUND

Chronic total occlusion (CTO) remains the most challenging procedure in coronary artery disease (CAD) for interventional cardiology. Although some clinical risk factors for CAD have been identified, there is no personalized prognosis test available to confidently identify patients at high or low risk for CTO CAD. This investigation aimed to use a machine learning algorithm for clinical features from clinical routine to develop a precision medicine tool to predict CTO before CAG.

METHODS

Data from 1473 CAD patients were obtained, including 1105 in the training cohort and 368 in the testing cohort. The baseline clinical characteristics were collected. Univariate and multivariate logistic regression analyses were conducted to identify independent risk factors that impact the diagnosis of CTO. A CTO predicting model was established and validated based on the independent predictors using a machine learning algorithm. The area under the curve (AUC) was used to evaluate the model.

RESULTS

The CTO prediction model was developed with the training cohort using the machine learning algorithm. Eight variables were confirmed as 'important': gender (male), neutrophil percentage (NE%), hematocrit (HCT), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), ejection fraction (EF), troponin I (TnI), and N-terminal pro-B-type natriuretic peptide (NT-proBNP). The model achieved good concordance indices of 0.724 and 0.719 in the training and testing cohorts, respectively.

CONCLUSIONS

An easy-to-use tool to predict CTO in patients with CAD was developed and validated. More research with larger cohorts are warranted to improve the prediction model, which can support clinician decisions on the early discerning CTO in CAD patients.