Benefits of successful percutaneous coronary intervention in chronic total occlusion patients with diabetes

BACKGROUND

Diabetes was commonly seen in chronic total occlusion (CTO) patients but data regarding the impact of successful percutaneous coronary intervention (PCI) on clinical outcome of CTO patients with diabetes was controversial. And importantly, no studies have compared quality of life (QOL) after CTO-PCI in patients with and without diabetes.

METHODS

Consecutive patients undergoing elective CTO-PCI were prospectively enrolled from Apr. 2018 to May 2021. Patients were subdivided into 2 groups: Diabetes and No Diabetes. Detailed baseline characteristics, assessment of symptoms and QOL, angiographic and procedural details, in-hospital complications, and 1 month and 1 year follow-up data were collected. These data were analyzed accordingly for risk predictors of clinical outcome in patients who have diabetes and received successful CTO-PCI.

RESULTS

A total of 1076 patients underwent CTO-PCI attempts. Diabetes was present in 374 (34.76%) patients, who had more hypertension, previous PCI and stroke. Regarding the coronary lesions, diabetic patients suffered more LCX lesion, multivessel disease, number of lesions per patient, blunt stump, calcification and higher J-CTO score (p < 0.05). In-hospital major adverse cardiac event (MACE) (4.13% vs. 5.35%; p = 0.362) was similar in the two groups. At 1 month and 1 year follow-up after successful CTO-PCI, the incidence of MACE and all-cause mortality were also similar in the two groups (p > 0.05). Number of lesions per patient was an independent risk factor of MACE and all-cause mortality (p < 0.001) 1 year after successful CTO-PCI. Symptom and QOL were markedly improved regardless of diabetes both at 1 month and 1 year follow-up, and importantly, patients with diabetes showed similar degrees of improvement to those without diabetes (P > 0.05).

CONCLUSIONS

Successful CTO-PCI could represent an effective strategy improving clinical outcome, symptoms and QOL in CTO patients with diabetes.

Traditional Cardiovascular Risk Factors and Coronary Collateral Circulation: A Meta-Analysis

Objective: Patients with well-developed coronary collateral circulation (CC) usually have low mortality, improved cardiac function, and reduced infarct size. Currently, there is conflicting evidence on the association between traditional cardiovascular risk factors (diabetes, hypertension, and smoking habit) and CC.

Design: We performed a meta-analysis of case-control studies to better understand such associations.

Data Sources: We searched the MEDINE, EMBASE, and Science Citation Index databases to identify relevant studies.

Eligibility Criteria for Selecting Studies: Case control studies reporting data on risk factors (smoking habit, hypertension, and diabetes mellites) in comparing cases between poor CC and well-developed CC groups. Well-developed CC was the primary outcome of this meta-analysis

Data Extraction and Synthesis: Relevant data were extracted by two independent investigators. We derived pooled odds ratios (ORs) with random effects models. We performed quality assessments, publication bias, and sensitivity analysis to ensure the reliability of our results.

Results: In total, 18 studies that had 4,746 enrolled patients were analyzed. Our results showed that hypertension and smoking habit did not (OR = 0.94, 95% CI: 0.75–1.17, p = 0.564 and OR = 1.00, 95% CI: 0.84–1.18, p = 0.970, respectively), and diabetes did (OR = 0.50, 95% CI: 0.38–0.67, p = 0.00001) affect the development of CC.

Conclusion: Unlike hypertension and smoking habit, diabetes was associated with poor CC formation.

Trial Registration Number:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=87821, identifier: CRD42018087821.

5-Year Clinical Outcomes of Successful Recanalisation for Coronary Chronic Total Occlusions in Patients With or Without Type 2 Diabetes Mellitus

Background: Despite substantial improvement in chronic total occlusions (CTO) revascularization technique, the long-term clinical outcomes in diabetic patients with revascularized CTO remain controversial. Our study aimed to investigate the 5-year cardiovascular survival for patients with or without type 2 diabetes mellitus (DM) who underwent successful percutaneous coronary intervention (PCI) for CTO. Methods: Data of the current analysis derived from a large single-center, prospective and observational cohort study, including 10,724 patients who underwent PCI in 2013 at Fuwai Hospital. Baseline, angiographic and follow-up data were collected. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), which consisted of death, recurrent myocardial infarction (MI), stroke and target vessel revascularization (TVR). The secondary endpoint was all-cause mortality. Cox regression analysis and propensity-score matching was performed to balance the baseline confounders. Results: A total of 719 consecutive patients with ≥1 successful CTO-PCI were stratified into diabetic (n = 316, 43.9%) and non-diabetic (n = 403, 56.1%) group. During a median follow-up of 5 years, the risk of MACCE (adjusted hazard ratio [HR] 1.47, 95% confidence interval [CI] 1.08-2.00, P = 0.013) was significantly higher in the diabetic group than in the non-diabetic group, whereas the adjusted risk of all-cause mortality (HR 2.37, 95% CI 0.94-5.98, P = 0.068) was similar. In the propensity score matched population, there were no significant differences in the risk of MACCE (HR 1.27, 95% CI 0.92-1.75, P = 0.155) and all-cause mortality (HR 2.56, 95% CI 0.91-7.24, P = 0.076) between groups. Subgroup analysis and stratification analysis revealed consistent effects on 5-year MACCE across various subgroups. Conclusions: In patients who received successful CTO-PCI, non-diabetic patients were related to better long-term survival benefit in terms of MACCE. The risk of 5-year MACCE appeared to be similar in less-controlled and controlled diabetic patients after successful recanalization of CTO. Further randomized studies are warranted to confirm these findings.

Impact of diabetes mellitus on outcomes of percutaneous coronary intervention in chronic total occlusions: A systematic review and meta-analysis

BACKGROUND

Patients with diabetes mellitus (DM) have a high prevalence of coronary chronic total occlusions (CTOs). We conducted a systematic review and meta-analysis to characterize outcomes after CTO percutaneous coronary intervention (PCI) in patients without or with DM.

METHODS

PubMed, EMBASE, Cochrane, and Google Scholar were queried for studies comparing non-DM vs. DM patients undergoing attempted CTO PCI. The primary outcome was all-cause mortality at longest follow-up (at least 6 months). Secondary outcomes were major adverse cardiovascular events (MACE) which is a composite endpoint including myocardial infarction, cardiac or all-cause mortality and any revascularization in patients after CTO PCI, target vessel revascularization (TVR), myocardial infarction (MI), Japanese chronic total occlusion (J-CTO) score and prevalence of multivessel (MV) CTO disease. We used a random effects model to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Sixteen studies, including 2 randomized control trials and 14 observational studies, met inclusion criteria. At longest follow-up, all-cause mortality (OR 0.54 [95% CI 0.37-0.80], p < 0.0001) and MACE (OR 0.82 [95% CI 0.72-0.93], p < 0.00001) were significantly lower in non-DM CTO patients. MV CTO disease was less prevalent in patients without DM (OR 0.80 [95% CI 0.69-0.93], p = 0.004). However, there were no differences in MI, TVR and J-CTO score.

CONCLUSIONS

Non-diabetics undergoing CTO PCI have lower all-cause mortality and MACE than diabetics. Future research may determine if DM control improves diabetics' CTO PCI outcomes.

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.

Long-term prognosis of chronic total occlusion treated by successful percutaneous coronary intervention in patients with or without diabetes mellitus: a systematic review and meta-analysis

Background

Diabetes mellitus (DM) is highly prevalent among patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). Therefore, the purpose of our study was to investigate the clinical outcomes of CTO-PCI in patients with or without DM.

Methods

All relevant articles published in electronic databases (PubMed, Embase, and the Cochrane Library) from inception to August 7, 2020 were identified with a comprehensive literature search. Additionally, we defined major adverse cardiac events (MACEs) as the primary endpoint and used risk ratios (RRs) with 95% confidence intervals (CIs) to express the pooled effects in this meta-analysis.

Results

Eleven studies consisting of 4238 DM patients and 5609 non-DM patients were included in our meta-analysis. For DM patients, successful CTO-PCI was associated with a significantly lower risk of MACEs (RR = 0.67, 95% CI 0.55–0.82, p = 0.0001), all-cause death (RR = 0.46, 95% CI 0.38–0.56, p < 0.00001), and cardiac death (RR = 0.35, 95% CI 0.26–0.48, p < 0.00001) than CTO-medical treatment (MT) alone; however, this does not apply to non-DM patients. Subsequently, the subgroup analysis also obtained consistent conclusions. In addition, our study also revealed that non-DM patients may suffer less risk from MACEs (RR = 1.26, 95% CI 1.02–1.56, p = 0.03) than DM patients after successful CTO-PCI, especially in the subgroup with a follow-up period of less than 3 years (RR = 1.43, 95% CI 1.22–1.67, p < 0.0001).

Conclusions

Compared with CTO-MT alone, successful CTO-PCI was found to be related to a better long-term prognosis in DM patients but not in non-DM patients. However, compared with non-DM patients, the risk of MACEs may be higher in DM patients after successful CTO-PCI in the drug-eluting stent era, especially during a follow-up period shorter than 3 years.

Derivation and validation of the J-CTO extension score for pre-procedural prediction of major adverse cardiac and cerebrovascular events in patients with chronic total occlusions

We developed a prediction model of long-term risk after percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) based on pre-procedural clinical information. A total of 4,139 eligible patients, who underwent CTO-PCI at 52 Japanese centers were included. Specifically, 1,909 patients with 1-year data were randomly divided into the derivation (n = 1,273) and validation (n = 636) groups. Major adverse cardiac and cardiovascular event (MACCE) was the primary endpoint, including death, stroke, revascularization, and non-fatal myocardial infarction. We assessed the performance of our model using the area under the receiver operating characteristic curve (AUC) and assigned a simplified point-scoring system. One-hundred-thirty-eight (10.8%) patients experienced MACCE in the derivation cohort with hemodialysis (HD: odds ratio [OR] = 2.55), left ventricular ejection fractions (LVEF) <35% (OR = 2.23), in-stent occlusions (ISO: OR = 2.27), and diabetes mellitus (DM: OR = 1.72). The AUC of the derivation model was 0.650. The model’s performance was similar in the validation cohort (AUC, 0.610). When assigned a point for each associated factor (HD = 3, LVEF <35%, ISO = 2, and DM = 1 point), the average predicted versus the observed MACCE probability using the Japan-CTO extension score for the low, moderate, high, and very high risk groups was 8.1% vs. 7.3%, 16.9% vs. 15.9%, 22.0% vs. 26.1%, and 56.2% vs. 44.4%, respectively. This novel risk model may allow for the estimation of long-term risk and be useful in disseminating appropriate revascularization procedures.

Long term clinical impact of successful recanalization of chronic total occlusion in patients with and without type 2 diabetes mellitus

BACKGROUND

Diabetes mellitus is one of the risk factors for coronary artery disease and frequently associated with multivessels disease and poor clinical outcomes. Long term outcome of successful revascularization of chronic total occlusions (CTO) in diabetes patients remains controversial.

METHODS AND RESULTS

From January 2005 to December 2015, 739 patients who underwent revascularization for CTO in Taipei Veterans General Hospital were included in this study, of which 313 (42%) patients were diabetes patients. Overall successful rate of revascularization was 619 (84%) patients whereas that in diabetics and non-diabetics were 265 (84%) and 354 (83%) respectively. Median follow up was 1095 days (median: 5 years, interquartile range: 1-10 years). During 3 years follow-up period, 59 (10%) in successful group and 18 (15%) patients in failure group died. Although successful revascularization of CTO was non-significantly associated with better outcome in total cohort (hazard ratio (HR): 0.593, 95% confidence interval (CI) 0.349-0.008, P: 0.054), it might be associated with lower risk of all-cause mortality (HR: 0.307, 95% CI 0.156-0.604, P: 0.001) and CV mortality (HR: 0.266, 95% CI 0.095-0.748, P: 0.012) in diabetics (P: 0.512). In contrast, successful CTO revascularization didn't improve outcomes in non-diabetics (all P > 0.05). In multivariate cox regression analysis, successful CTO revascularization remained an independent predictor for 3-years survival in diabetic subgroup (HR: 0.289, 95% CI 0.125-0.667, P: 0.004). The multivariate analysis result was similar after propensity score matching (all-cause mortality, HR: 0.348, 95% CI 0.142-0.851, P: 0.021).

CONCLUSIONS

Successful CTO revascularization in diabetes may be related to better long term survival benefit but not in non-diabetic population.

Long-term outcomes of medical therapy versus successful recanalisation for coronary chronic total occlusions in patients with and without type 2 diabetes mellitus

Background

In this study, we compared the outcomes of medical therapy (MT) with successful percutaneous coronary intervention (PCI) in chronic total occlusions (CTO) patients with and without type 2 diabetes mellitus.

Methods

A total of 2015 patients with CTOs were stratified. Diabetic patients (n = 755, 37.5%) and non-diabetic patients (n = 1260, 62.5%) were subjected to medical therapy or successful CTO-PCI. We performed a propensity score matching (PSM) to balance the baseline characteristics. A comparison of the major adverse cardiac events (MACE) was done to evaluate long-term outcomes.

Results

The median follow-up duration was 2.6 years. Through multivariate analysis, the incidence of MACE was significantly higher among diabetic patients compared to the non-diabetic patients (adjusted hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.09–1.61, p = 0.005). Among the diabetic group, the rate of MACE (adjusted HR 0.61, 95% CI 0.42–0.87, p = 0.006) was significantly lower in the successful CTO-PCI group than in the MT group. Besides, in the non-diabetic group, the prevalence of MACE (adjusted HR 0.85, 95% CI 0.64–1.15, p = 0.294) and cardiac death (adjusted HR 0.94, 95% CI 0.51–1.70, p = 0.825) were comparable between the two groups. Similar results as with the early detection were obtained in propensity-matched diabetic and non-diabetic patients. Notably, there was a significant interaction between diabetic or non-diabetic with the therapeutic strategy on MACE (p for interaction = 0.036).

Conclusions

For treatment of CTO, successful CTO-PCI highly reduces the risk of MACE in diabetic patients when compared with medical therapy. However, this does not apply to non-diabetic patients.

Scoring System for Identification of "Survival Advantage" after Successful Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion

Background: Percutaneous coronary intervention (PCI) is widely used in patients with chronic total occlusion (CTO), but its benefit in improving long-term outcomes is controversial. We aimed to develop a prediction score for grading “survival advantage” conferred by successful results of CTO-PCI and a scoring system for prediction of the influence of CTO-PCI results on major adverse cardiac and cerebrovascular events (MACCEs). Methods: Follow-up data of 2625 patients who underwent CTO-PCI at 65 Japanese centers were analyzed. An integer scoring system was developed by including statistical effect modifiers on the association between successful CTO-PCI and one-year mortality. Results: Follow-up at 12 months was completed in 2034 patients. During follow-up, 76 deaths (3.7%) occurred. Patients with successful CTO-PCI had a better one-year survival than patients with failed CTO-PCI (log rank P = 0.016). Effect modifiers for the association between successful procedure and one-year mortality included diabetes (P interaction = 0.043), multivessel disease (P interaction = 0.175), Canadian Cardiovascular Society class ≥2 (P interaction = 0.088), and prior myocardial infarction (MI) (P interaction = 0.117). Each component was assigned a single point and summed to develop the scoring system. The patients were then categorized to specify the prediction of survival advantage by successful PCI: ≤2 (normal) and ≥3 (distinct). The differences in one-year mortality between patients with successful and failed treatment were −0.7% and 11.3% for normal and distinct score categories, respectively. In the scoring system for MACCE, score components were prior MI (P interaction = 0.19), left anterior descending artery (LAD)-CTO (P interaction = 0.079), and reattempt of CTO-PCI (P interaction = 0.18). The differences in one-year MACCEs between successful and failed patients for each score category (0, 1, and ≥2) were −1.7%, 7.5%, and 15.1%, respectively. Conclusions: The novel scoring system assessing the advantage of successful PCI can be easily applied in patients with CTO. It is a valid instrument for clinical decision-making while assessing the survival advantage of CTO-PCI and the influence of procedural results on MACCEs.

Survival benefit of revascularization versus optimal medical therapy alone for chronic total occlusion management in patients with diabetes

BACKGROUND

Chronic total occlusion (CTO) is common in patients with diabetes mellitus. Data on the long-term outcomes after treatment of CTOs in this high-risk population are scarce.

AIM

To compare the long-term clinical outcomes of CTO revascularization either by coronary artery bypass graft (CABG) or successful percutaneous coronary intervention (PCI) versus optimal medical treatment (MT) alone in patients with diabetes.

METHODS AND RESULTS

A total of 538 consecutive patients with diabetes and at least one CTO were identified from 2010 to 2014 in our center. In the present analysis, patients were stratified according to the CTO treatment strategy that was selected. MT was selected in 61% of patients whereas revascularization in the remaining 39%. Patients undergoing revascularization were younger, had higher left ventricular ejection fraction (LVEF), lower ACEF score, and more positive myocardial ischemia detection results compared to the MT group (p < .001).Patients referred for CABG had higher rates of left main disease compared to the PCI and MT groups (32% vs. 3% and 11%, respectively; p < .001). Complete revascularization was more often achieved in the CABG group, compared to the PCI group (62% vs. 32% p < .001). Multivariable analysis showed that revascularization with CABG was associated with lower rates of all-cause and cardiac mortality rates compared to MT, [hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.25-0.70, p < .001 and HR 0.40, 95% CI 0.20-81, p = .011, respectively]. Successful CTO-PCI showed a trend towards benefit in all-cause mortality (HR 0.58, 95% CI 0.33-1.04, p = .06).

CONCLUSION

In our registry, CTO revascularization in diabetic patients, especially with CABG, was associated with lower long-term mortality rates as compared to MT alone.

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.

Relation of Chronic Total Occlusion to In-Hospital Mortality in the Patients With Sudden Cardiac Arrest Due to Acute Coronary Syndrome

Although the presence of chronic total occlusion (CTO) has been associated with long-term mortality in the patients with ST-segment elevation myocardial infarction, the influence of having CTO on in-hospital mortality in sudden cardiac arrest (SCA)-acute coronary syndrome (ACS) patients has not been reported. Therefore, we examined the association between the presence of CTO and in-hospital mortality in those patients. Consecutive 106 SCA-ACS patients who received coronary angiography were retrospectively included. The factors associated with in-hospital mortality were analyzed. Among 106 patients, 40 (38%) patients died during hospitalization. Multivariate analysis revealed presence of CTO dependent on infarct-related artery (IRA-dependent-CTO) (hazard ratio [HR] = 2.88, p = 0.004), diabetes mellitus (HR = 2.04, p = 0.044), percutaneous cardiopulmonary support use (HR = 2.22, p = 0.045), successful recanalization (HR = 0.31, p = 0.004), and peak creatine kinase muscle-brain fraction (HR = 1.11, p < 0.001) were significantly associated with mortality. In conclusion, presence of IRA-dependent-CTO was significantly associated with in-hospital mortality in SCA-ACS patients.

Percutaneous Coronary Intervention of Chronic Total Occlusions in Patients with Diabetes Mellitus: a Treatment-Risk Paradox

PURPOSE OF REVIEW

Diabetes mellitus (DM) is highly prevalent among patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs). This review aims to summarize the available evidence on CTO recanalization in patients with DM.

RECENT FINDINGS

Coronary artery bypass grafting (CABG) surgery is the recommended revascularization modality for patients with DM and multivessel coronary artery disease (CAD). However, the optimal management strategy in diabetic patients with CTO and single-vessel disease or prior CABG remains a clinical dilemma. Contemporary, large-scale, observational registries support the notion that CTO PCI, if performed at high-volume CTO PCI centers by highly experienced operators, conveys similar high procedural success and low complication rates in patients with and without DM. Although DM patients have more frequently CTOs and may derive greater benefit from complete revascularization, they are less frequently exposed to CTO PCI than non-DM patients (treatment-risk paradox). CTO PCI performed by highly experienced operators constitutes a safe and effective treatment option for selected diabetic CTO patients who are not candidates for CABG. Randomized studies are warranted to compare long-term outcomes of CTO PCI and medical therapy in this high-risk subset.

What the surgeon needs to know about percutaneous coronary intervention treatment of chronic total occlusions

Chronic total occlusion (CTO) accounts for 10-20% of lesions identified in coronary artery disease (CAD) patients. CTO percutaneous coronary intervention (PCI) is one of the most challenging of lesion subsets due to its technical difficulty, requiring specific operator expertise and equipment. There has been increased interest on CTO PCI evolving with the development of novel techniques and dedicated devices. Furthermore, in order to effectively and systematically utilize these techniques and devices, CTO PCI algorithms have been established. All of these developments have resulted in procedural success rates increasing to approximately 90%. In this review, we outline the evidence base for CTO PCI, conventional and contemporary CTO PCI techniques, CTO algorithms and outline integrated management strategies between cardiac surgeons and interventional cardiologists.

Reduced coronary collateralization in type 2 diabetic patients with chronic total occlusion

BACKGROUND

The extent of coronary collateral formation is a primary determinant of the severity of myocardial damage and mortality after coronary artery occlusion. Type 2 diabetes mellitus (T2DM) represents an important risk factor for impaired collateral vessel growth. However, the mechanism of reduced coronary collateralization in type 2 diabetic patients remains unclear.

METHODS

With the reference to the recent researches, this review article describes the pathogenic effects of T2DM on collateral development and outlines possible clinical and biochemical markers associated with reduced coronary collateralization in type 2 diabetic patients with chronic total occlusion (CTO).

RESULTS

Diffuse coronary atherosclerosis in T2DM reduces pressure gradient between collateral donor artery and collateral recipient one, limiting collateral vessel growth and function. An interaction between advanced glycation end-products and their receptor activates several intracellular signaling pathways, enhances oxidative stress and aggravates inflammatory process. Diabetic condition decreases pro-angiogenic factors especially vascular endothelial growth factor and other collateral vessel growth related parameters. Numerous clinical and biochemical factors that could possibly attenuate the development of coronary collaterals have been reported. Increased serum levels of glycated albumin, cystatin C, and adipokine C1q tumor necrosis factor related protein 1 were associated with poor coronary collateralization in type 2 diabetic patients with stable coronary artery disease and CTO. Diastolic blood pressure and stenosis severity of the predominant collateral donor artery also play a role in coronary collateral formation.

CONCLUSIONS

T2DM impairs collateral vessel growth through multiple mechanisms involving arteriogenesis and angiogenesis, and coronary collateral formation in patients with T2DM and CTO is influenced by various clinical, biochemical and angiographic factors. This information provides insights into the understanding of coronary pathophysiology and searching for potential new therapeutic targets in T2DM.