Chronic total coronary occlusion: treatment results

Overview of Contemporary Chronic Total Occlusion Percutaneous Coronary Intervention Techniques: A Narrative Systematic Review

BACKGROUND

Despite the abundance of coronary chronic total occlusions (CTO) percutaneous coronary intervention (PCI) studies, the literature is not easy to digest for both general PCI operators and CTO PCI specialists because of the many varied terms used for approaches and inconsistency in terminology. This inconsistency makes it challenging to understand the advantages and disadvantages of these different approaches and, most importantly, their downstream clinical outcomes. Accordingly, we conducted a systematic review of all published studies on CTO PCI to describe techniques and algorithms used in the last decade to provide an overview on the efficacy and safety of contemporary CTO PCI techniques.

METHODS

We performed a comprehensive search of the PubMed, EMBASE, and the Cochrane library databases for manuscripts about PCI of CTOs. We included studies published between the years 2005 and 2019. We categorized studies into those using a single approach (antegrade, retrograde) and those with a prespecified algorithm (ie, hybrid approach).

RESULTS

Fifty-five observational studies including 28,907 patients who underwent CTO were included in this review. CTO PCI generally carries low risk of major procedural complications, with angiographic success rates being higher in studies that used an algorithmic vs single technical approach.

CONCLUSIONS

This systematic review highlights the wide variation in definitions and practices in CTO PCI and calls for standardization in terminology and practice.

Efficacy of Coronary Sinus Reducer in Patients With Non-revascularized Chronic Total Occlusions

The coronary sinus reducer (CSR) has been introduced as therapy for patients with refractory angina with no other treatment options. Aim of this study is to investigate the efficacy of the CSR in patients with refractory angina and presence of coronary chronic total occlusions (CTO). In this multicentre, international retrospective study, patients undergoing CSR implantation were screened and divided in 2 groups according to the presence/absence of CTO lesions. Baseline and clinical characteristics were analyzed in the 2 groups. Primary-outcome consisted of the variation in Canadian Cardiovascular Society (CCS) class at 6-month follow-up. Between January 2014 and December 2018, 205 patients with refractory angina were consecutively treated with the study device in the participating centers, 103 (50.2%) of which had a CTO lesion at coronary angiogram and formed the CTO-group. Baseline characteristics of the study population were well balanced between the 2 groups. CSR was successfully implanted in all cases. Baseline CCS class was 3  ±  0.5 in the CTO-group versus 3.1  ±  0.6 in the non-CTO group (p = 0.45), and improved at follow-up to 1.6  ±  0.9 versus 2  ±  1.1 respectively (p <0.01), with a significantly higher improvement in CCS class in the CTO-group (1.4  ±  0.9 vs 1.1  ±  1 respectively, p = 0.01). Any improvement in CCS class was registered in 79 (80.6%) CTO-patients, while a significantly lower percentage (65 patients, 66.3%) of the non-CTO patients reported benefits in CCS class (p = 0.03). In conclusions, patients suffering from refractory angina with non-revascularized CTO lesions have a better response to CSR implantation than patients without CTOs. CSR implantation should be considered a valid complementary therapy to CTO-PCI in these patients.

Comparison of long-term outcomes of medical therapy and successful recanalisation for coronary chronic total occlusions in elderly patients: a report of 1,294 patients

Background

Little is known about the long-term outcomes of medical therapy (MT) versus successful percutaneous coronary intervention (PCI) in elderly patients with coronary chronic total occlusions (CTOs).

Methods

There were 1,294 consecutive patients with 1,520 CTOs included (2007 to 2016) and were divided into the younger group (age <65 years; n=664, 51.3%) and the older group (age ≥65 years; n=630, 48.7%). In the older group, 630 patients were divided into MT group (n=421) and successful CTO-PCI group (n=209) according to the initial treatment strategy. In the younger group, they were divided into two groups: 379 patients in the MT group and 285 patients in the successful CTO-PCI group. We performed propensity score matching to minimize any selection bias. The primary end point was cardiac mortality. The secondary end point was major adverse cardiac event (MACE).

Results

After 3.6 (IQR, 2.1-5.0) years follow-up, no significant difference was observed between the MT and successful CTO-PCI groups in terms of cardiac mortality (MT vs. successful CTO-PCI: 9.3% vs. 5.0%, P=0.378) and MACE (28.3% vs. 15.1%, P=0.070) in the older group. After propensity score matching analysis (120 pairs), the risk of cardiac mortality (6.7% vs. 8.3%, P=0.624) was found to be comparable between the two groups. In the younger group, the occurrence of cardiac death (MT vs. successful CTO-PCI: 3.7% vs. 1.4%, P=0.072) was similar, whereas the MACE rate (27.7% vs. 17.9%, P=0.003) was significantly higher in MT group. After multivariate analysis, previous myocardial infarction (MI) [hazard ratio (HR) 1.70, 95% confidence interval (CI): 1.16-2.49, P=0.006], CTO in right coronary artery (HR 1.55, 95% CI: 1.07-2.25, P=0.020), multivessel disease (HR 2.02, 95% CI: 1.10-3.72, P=0.024) and calcification (HR 1.61, 95% CI: 1.07-2.42, P=0.023) were independent predictors of MACE in elderly.

Conclusions

In the treatment of elderly patients with CTOs, successful CTO-PCI compared with MT alone didn't reduce the risk of cardiac death or MACE.

Evaluation of the impact of percutaneous coronary intervention of chronic total occlusion on regional myocardial function using strain echocardiography

BACKGROUND

Successful revascularization of chronic total occlusions has been associated with potential effects on left ventricular (LV) function. Strain and strain rate are more sensitive measures of LV mechanics than LV ejection fraction (LVEF). This study was conducted to investigate the impact of revascularization of chronic total occlusion (CTO) on LV function using tissue Doppler (TDI) strain echocardiography.

RESULTS

This study included 60 patients divided into two main groups: the percutaneous coronary intervention (PCI) group including patients who had a successful PCI of CTO on left anterior descending (LAD) artery and was presented for elective PCI with symptomatic angina and/or positive functional ischemic study. They included 18 males with a mean age of 57 ± 5 years. The optimum medical treatment (OMT) group, including 30 patients, had non-revascularized CTO-LAD and was kept on OMT alone; 20 of them were males with a mean age of 58 ± 4 years. In the PCI group, there was a significant improvement in all the TDI strain parameters of the LAD territory segments. Six months after PCI, the peak systolic strain rate improved from - 0.65 ± 0.21 to 1.05 ± 0.31 1/s (p value < 0.01), the peak systolic strain improved from 6.54 ± 2.48 to 11.51 ± 3.33% ( p value < 0.001 ), and the end systolic strain improved from 7.88 ± 2.77 to 10.51 ± 3.14% (p value < 0.01 ). There was no significant improvement in the mean LVEF (60.70 ± 8.33 vs 61.91 ± 8.16% (p value = 0.6)). In the OMT group, there was no improvement in all the strain parameters and there was no change in the mean LVEF. In the PCI group, there was a significant improvement in the angina class (p value = 0.03) while, in the OMT group, there was no significant improvement (p value = 0.835).

CONCLUSIONS

Successful PCI for CTO improved regional LV myocardial function assessed by TDI strain echocardiography. This improvement was associated with improvement in the angina class.

Successful recanalisation of coronary chronic total occlusions is not associated with improved cardiovascular survival compared with initial medical therapy

Objective. To compare the clinical outcomes associated with successful percutaneous coronary intervention (PCI) versus initial medical therapy (MT) in patients with coronary chronic total occlusions (CTOs). Methods. Between January 2007 and December 2016, a total of 1702 patients with ≥1 CTO were enrolled. Patients who had a failed CTO-PCI were excluded. After exclusion, 1294 patients with 1520 CTOs were divided into the MT group initially (did not undergo a CTO-PCI attempt) (n = 800) and successful PCI group (n = 494). Propensity-score matching was also performed to adjust for baseline characteristics. The primary outcome was cardiac death. Results. The median overall follow-up duration was 3.6 (IQR, 2.1-5.0) years, there was no significant difference between the two groups with respect to the prevalence of cardiac death (MT vs. successful PCI: 6.6 vs. 3.8%, adjusted hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.41-2.14, p = .867). In the propensity-matched population (286 pairs), there were no significant differences in the prevalence of cardiac death (MT vs. successful PCI: 5.9% vs. 3.1%, HR 0.51, 95% CI 0.23-1.15, p = .104) and major adverse cardiovascular events (MACE) (HR 0.76, 95% CI 0.53-1.09, p = .130) between the two groups. Conclusion. In the treatment of patients with CTOs, successful PCI is not associated with improved long-term cardiovascular survival or reduced the risk of MACE compared with MT alone initially.