Novel predictors of late lumen enlargement in distal reference segments after successful recanalization of coronary chronic total occlusion

Long term clinical outcome after success re-attempt percutaneous coronary intervention of chronic total occlusion

BACKGROUND

To evaluate the long-term outcome after re-attempt CTO-PCI.

METHODS

This is a retrospective cohort study that included 113 re-attempt CTO-PCI patients who were consecutively registered from January 2019 to December 2020 at Beijing Anzhen Hospital's Center of Coronary Artery Disease. All patients were divided into two groups based on procedural success or failure. The primary endpoint was major adverse cardiac events (MACE), a composite of all-cause mortality, myocardial infarction and target vessel revascularization (TVR). The secondary endpoint was angina after PCI.

RESULTS

Overall, the successful re-attempt CTO-PCI was archived in 77 patients, the failed CTO-PCI was performed in 36 patients. After a median follow-up of 21.7 months (interquartile range: 10.9-26.0), the incidence of the primary outcome was significantly lower in the success group [14.2% vs. 38.9%, adjusted hazard ratio (HR) 0.351, 95% CI 0.134-0.917, P = 0.033], mainly driven by the reduction of TVR (9.1% vs. 30.6%, adjusted HR 0.238, 95% CI: 0.078-0.72, P = 0.011). Furthermore, patients who had successful re-attempt CTO-PCI had a lower risk of angina after PCI (27.3% vs.61.1%, adjusted HR 0.357, 95% CI 0.167-0.76, P = 0.008). The risk factors of TVR in the patients with successful re-attempt CTO-PCI were stent length > 100 mm (adjusted HR 21.805, 95% CI 1.765-269.368, P = 0.016) and J-CTO score > 3(adjusted HR: 9.733, 95% CI:1.533-61.797, P = 0.016).

CONCLUSIONS

For the patients with previous CTO-PCI failure, a successful re-attempt CTO-PCI was associated with significantly lower MACE, which was primarily driven by a lower TVR rate. More complex CTO lesions and longer stents were the independent predictors of TVR after successful CTO-PCI.

Recanalisation of coronary chronic total occlusions

Percutaneous treatment of coronary chronic total occlusions (CTO) has advanced greatly since its advent in the late 1970s through the development of dedicated wires and microcatheters, the improved skills of highly experienced operators and the adoption of new sophisticated strategies to guide procedural planning. The contemporary procedural success rate is 80-90% with a reduction in complications. Although there has been no improvement in prognosis in randomised trials to date, they, and other controlled registries of thousands of patients, confirm the pivotal role of CTO recanalisation in the treatment of angina and dyspnoea and an improvement in quality of life. Despite this evidence, CTO recanalisation is grossly underutilised. This review reports a detailed overview of the history, indications and treatment strategies for CTO recanalisation and hopes to increase interest among new, and especially young, operators in this demanding, rapidly evolving field of interventional cardiology.

Effects of Tirofiban and Nicorandil on Effective Reperfusion and the Levels of IL-4 and sICAM-1 After PCI for Chronic Coronary Total Occlusion

Aim: The effects of tirofiban combined with nicorandil on effective reperfusion, and the levels of interleukin-4 (IL-4)and soluble intercellular adhesion molecule-1 (sICAM-1) after percutaneous coronary intervention (PCI) for chronic coronary total occlusion (CTO) were investigated.Method: From January 1, 2017, to June 31, 2019, a total of 40 patients with CTO receiving PCI in Shandong QianfoshanHospital were randomly divided into a control group (treated with single tirofiban) and a cocktail group (treated with nicorandil combined with tirofiban). Effective reperfusion was compared between groups. In addition, differences in coronary serum IL-4 and sICAM-1 levels before and 10 min after the operation were compared between groups, and the incidence rates of adverse reactions were observed. Finally, patient follow-up occurred at 1 month and 6 months, and the total incidence rates of adverse cardiac events in both groups were assessed.Results: The levels of IL-4 and sICAM-1 in the cocktail group significantly decreased after the operation (P < 0.05).In addition, after the operation, significantly greater decreases in the IL-4 and sICAM-1 levels were observed in thecocktail group than the control group (P < 0.05). The Seattle Angina Scale (SAQ) score of the cocktail group, comparedwith the control group, showed a significant improvement after vessel opening in the patients with CTO. At the 1-month follow-up, the SAQ score of the cocktail group, compared with the control group, indicated further improvements in terms of angina attack frequency. No significant differences were observed in the incidence rates of adverse reactions between groups (P > 0.05).Conclusion: The treatment of patients with CTO undergoing PCI with nicorandil and tirofiban alleviated the inflammatoryresponse, improved the SAQ scores, and decreased the occurrence of angina pectoris in patients. Moreover, this treatment is safe and reliable, and has important clinical significance.

Impact of myocardial bridge on late lumen enlargement in distal reference segments after recanalization of coronary chronic total occlusion

Successful recanalization of coronary chronic total occlusion (CTO) can induce subsequent positive vascular remodeling. Although myocardial bridge (MB) is known to alter endothelial function and wall shear stress, the impact of MB on late lumen enlargement in the distal segment is unclear. A total of 59 patients who underwent successful percutaneous coronary intervention (PCI) for CTO in the left anterior descending artery (LAD) under intravascular ultrasound (IVUS) guidance and follow-up angiography at 8-12 months were included. Gray-scale IVUS images were analyzed and MB was detected. Lumen diameter (LD) at distal reference at post-PCI was quantitatively compared with corresponding LD at follow-up coronary angiography to assess late lumen enlargement. MB on IVUS was detected in 17 patients (29%). The length from LAD ostium to the entry of CTO was shorter (11.7 ± 13.9 vs. 22.8 ± 13.4 mm, p = 0.006) and LD at distal reference at post-PCI was smaller (1.65 ± 0.54 vs. 1.97 ± 0.56 mm, p = 0.049) in patients with MB than those without. At the mean follow-up of 10.4 ± 2.4 months, LD at distal reference was significantly increased by 25% from baseline to follow-up in the overall population (1.88 ± 0.57 vs. 2.21 ± 0.41 mm, p < 0.001), with a greater increase in patients with MB compared to those without (46 ± 31% vs. 17 ± 29%, p < 0.001). Multivariable analysis indicated MB as an independent predictor of late lumen enlargement. In patients with MB on IVUS, CTO was located in more proximal segment of LAD than those without. Late lumen enlargement at follow-up was greater in patients with MB compared to the counterpart.

iFR uncovers profound but mostly reversible ischemia in CTOs and helps to optimize PCI results

OBJECTIVES

The study aimed to demonstrate through instant wave-free ratio (iFR) measurements that myocardium distal to a chronic total occlusion (CTO) is ischemic, that ischemia is reversible by PCI, and that iFR assessment after PCI can be used to optimize PCI results.

BACKGROUND

The greatest benefit of revascularization is found in patients with low fractional flow reserve. In patients with CTOs, iFR measurement may be more appropriate to evaluate ischemia as it does not require maximal microvascular vasodilation, which may be hampered by microvascular dysfunction.

METHODS

The iFR was measured in 81 CTO patients, both pre- and post-PCI in 63 patients, and only post-PCI in the following 18 patients. A pressure wire pullback was performed post-PCI if iFR ≤0.89.

RESULTS

The first 63 patients all had significant ischemia distal to the CTO with a median iFR of 0.33 [0.22; 0.44], improving significantly post-PCI to a median iFR of 0.93 [0.89;0.96] (p < .001). In the complete cohort, the median iFR post-PCI was 0.93 [0.86;0.96] but still ≤0.89 in 23 patients (30%). 12 of these patients had further PCI optimization because of a residual focal pressure gradient on pullback, after which only two had a final iFR ≤0.89.

CONCLUSIONS

In CTO patients with an indication for PCI, iFR consistently demonstrated profound myocardial ischemia. Successful PCI immediately relieved ischemia in 70% of patients. In the remaining 30% of cases, a manual iFR pullback proved helpful in guiding further optimization of the PCI result.