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.

Reducing stray radiation with a novel detachable lead arm support in percutaneous coronary intervention

Background

Placing radioprotective devices near patients reduces stray radiation during percutaneous coronary intervention (PCI), a promising technique for treating coronary artery disease. Therefore, lead arm support may effectively reduce occupational radiation dose to cardiologists.

Purpose

We aimed to estimate the reduction of stray radiation using a novel detachable lead arm support (DLAS) in PCI.

Materials and methods

A dedicated cardiovascular angiography system was equipped with the conventional 0.5‐mm lead curtain suspended from the table side rail. The DLAS was developed using an L‐shaped acrylic board and detachable water‐resistant covers encasing the 0.5‐, 0.75‐, or 1.0‐mm lead. The DLAS was placed adjacent to a female anthropomorphic phantom lying on the examination tabletop at the patient entrance reference point. An ionization chamber survey meter was placed 100 cm away from the isocenter to emulate the cardiologist's position. Dose reduction using the L‐shaped acrylic board, DLAS, lead curtain, and their combination each was measured at five heights (80–160 cm in 20‐cm increments) when acquiring cardiac images of the patient phantom with 10 gantry angulations, typical for PCI.

Results

Median dose reductions of stray radiation using the L‐shaped acrylic board were 9.0%, 8.8%, 12.4%, 12.3%, and 6.4% at 80‐, 100‐, 120‐, 140‐, and 160‐cm heights, respectively. Dose reduction using DLAS with a 0.5‐mm lead was almost identical to that using DLAS with 0.75‐ and 1.0‐mm leads; mean dose reductions using these three DLASs increased to 16.2%, 45.1%, 66.0%, 64.2%, and 43.0%, respectively. Similarly, dose reductions using the conventional lead curtain were 95.9%, 95.5%, 83.7%, 26.0%, and 19.6%, respectively. The combination of DLAS with 0.5‐mm lead and lead curtain could increase dose reductions to 96.0%, 95.8%, 93.8%, 71.1%, and 47.1%, respectively.

Conclusions

DLAS reduces stray radiation at 120‐, 140‐, and 160‐cm heights, where the conventional lead curtain provides insufficient protection.

On-line estimated peak skin dose during percutaneous coronary intervention for chronic total occlusion using new patient dose mapping technology

BACKGROUND

X-ray exposure during complex percutaneous coronary intervention is a very important issue.

AIM

To reduce patient peak skin dose during percutaneous coronary intervention procedures for chronic total occlusion using on-line estimated peak skin dose software (Dose Map).

METHODS

Throughout the procedure, Dose Map provided a map of local cumulative peak skin dose. This map was displayed in-room from 1Gy cumulative air kerma, and was updated every 0.5Gy. The operator's actions to minimize deterministic risks following map notification were collected. Skin reaction was evaluated 3 months after the procedure. A comparison with our historical X-ray exposure data (207 patients from January 2013 to July 2014) was performed.

RESULTS

From November 2015 to October 2016, 97 patients (Japanese chronic total occlusion score 2.1±1.1; 100 percutaneous coronary intervention procedures for chronic total occlusion) were prospectively enrolled. Fluoroscopy time was 40.8 (21.6-60.3) minutes, cumulative air kerma 1884 (1144-3231) mGy, estimated peak skin dose 962 (604-1474) mGy and kerma area product 115.8 (71.5-206.7) Gy.cm². Cumulative air kerma was>3Gy in 28% of cases, and>5Gy in 11% of cases. In 68% of cases, at least one action was taken by the operator after map notification to optimize skin dose distribution. Main changes included: gantry angulation (52%); field of view (25%); and collimation (13%). No skin injuries were observed at follow-up. In comparison with our chronic total occlusion historical radiation data, median cumulative air kerma and kerma area product were reduced by 31% and 33%, respectively (P<0.005.

CONCLUSION

Online skin dose mapping software allows the distribution of patient skin dose during complex percutaneous coronary intervention procedures, and may minimize X-ray exposure.

Impact of dose reducing software on patient and staff temple dose during fluoroscopically guided pacemaker insertion, closure devices implantation and coronary angiography procedures

The aim of this study is to investigate the effectiveness of dose reducing software (ClarityIQ) on patient and staff dose during fluoroscopically guided cardiac procedures. Dose measurements were collected in a room without dose reducing software (n = 157) and compared with similar procedures performed in two rooms with the software (n = 1141). Procedures included diagnostic coronary angiography, percutaneous coronary intervention, deployment of cardiac closure devices (for occlusion of atrial septal defect, patent foramen ovale, and atrial appendage) and insertion of permanent pacemakers. The dose reducing software was found to be effective in reducing patient and staff dose by approximately 50%. This study has added to the limited literature reporting on the capability of dose reducing software to decrease radiation exposure during the implantation of cardiac closure devices, as well as demonstrating a reduction in dose to the cardiologist and nursing staff. Administrators should ensure timely upgrades to angiographic equipment to safeguard patients and staff against the potentially adverse effects of radiation exposure. Regardless of the use of dose reducing software, the mean occupational dose during closure devices was in descending order scout > scrub > cardiologist. Scrub nurse dose was found to be higher than the cardiologist during closure devices (0.98/0.26 μSv) and diagnostic coronary angiograms (1.51/0.82 μSv). Nursing staff should be aware that their levels of radiation dose during some cardiac procedures may come close to or even exceed that of the cardiologist.

Update on chronic total occlusion percutaneous coronary intervention

Chronic total occlusion (CTO) percutaneous coronary interventions (PCI) can be challenging to perform. The main indication for CTO PCI is to improve symptoms. Several contemporary studies have reported high CTO PCI success rates at experienced centers but success rates in all-comer registries remain low. Several scores can estimate the difficulty and the likelihood of success of CTO PCI. Dual arterial access and use of CTO crossing algorithms can improve the success and safety of CTO PCI. Intracoronary imaging can optimize stent expansion and minimize adverse cardiovascular events. While complications are more common in CTO PCI, careful planning and prompt diagnosis and treatment can prevent them or minimize their adverse consequences. In this article, we review contemporary data on the indications, safety and efficacy of CTO PCI.

Predictors and trends of contrast use and radiation exposure in a large cohort of patients treated with percutaneous coronary interventions: Chronic total occlusion analysis based on a national registry

BACKGROUND

The aim herein, was to assess predictors and current trends of radiation exposure and total contrast amount use in patients treated with percutaneous coronary intervention within chronic total occlusion (CTO PCI) and non-CTO PCI.

METHODS

Based on a nationwide registry (ORPKI), 535,857 patients treated with PCI between 2014 and 2018 were analysed. The study included 12,572 (2.34%) patients treated with CTO PCI. The CTO PCI and non-CTO PCI groups were compared before and after propensity score matching (PSM). Multifactorial mixed regression models were used to assess predictors of contrast amount use and radiation exposure.

RESULTS

The mean total contrast dose and radiation exposure decrease reached statistical significance in following years for the CTO PCI (p = 0.002 and p < 0.001) and non-CTO PCI groups (p < 0.001 and p < 0.001). Multifactorial analysis revealed that non-CTO PCI was a strong independent predictor of lower total contrast dose (estimate: -17.41; 95% confidence interval [CI]: -18.45 to -16.49, p < 0.001) and radiation exposure (estimate: -264.28; 95% CI: -273.75 to -254.81, p < 0.001). After PSM, it was confirmed that CTO PCI was an independent predictor of greater radiation exposure (estimate: 328.6; 95% CI: 289.1-368.1; p < 0.001) and total contrast dose (estimate: 30.5; 95% CI: 27.28-33.74; p < 0.001).

CONCLUSIONS

Contrast dose and radiation exposure have decreased in previous years with regard to the CTO PCI and non-CTO PCI groups. CTO PCI was found to be an independent predictor of greater total contrast dose and radiation exposure in the overall group of patients treated with PCI.

Complications during chronic total occlusion percutaneous coronary intervention: a sign- and symptom-based approach to early diagnosis and treatment

Coronary chronic total occlusions (CTO) are frequently found in patients undergoing coronary angiography. Despite their high prevalence and indication for revascularization in a relevant proportion of cases, CTO recanalization is attempted only in a minority of cases. This is due to higher risk of procedural complications compared to non-CTO interventions and because the CTO-PCIs are the most complex procedures in interventional cardiology. In particular, the perceived higher risk of complications during CTO intervention might discourage new operators from engaging in this challenging field. The aim of this work is to review the potential complications of CTO percutaneous coronary intervention, and to provide an algorithmic, sign- and symptom-based approach to facilitate early recognition and effective management.

Current challenges and prevention strategies for chronic total occlusion (CTO) complications

Introduction: Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) can be challenging, but high success rates (85-90%) are currently achieved at experienced centers with approximately 3% risk for a major periprocedural complication.Areas covered: CTO PCI complications can be categorized according to location such as cardiac and non-cardiac (vascular access complications, thromboembolic complications, contrast-related and radiation injury) complications. Cardiac complications are further subdivided into coronary (acute closure, perforation, and equipment loss or entrapment) and non-coronary (hypotension, myocardial infarction, tamponade, arrhythmias).Expert opinion: In this article, we review strategies to prevent and treat CTO PCI complications. Careful monitoring throughout the case enables prevention and early detection of a complication. If a complication occurs, rapid implementation of treatment using an algorithmic approach can minimize its adverse impact.

Reducing fluoroscopic and cineangiographic contribution to radiation exposure for chronic total coronary occlusion interventions

BACKGROUND

The treatment of chronic total coronary occlusions (CTO) carries the highest radiation exposure among percutaneous coronary interventions (PCI). In order to minimize radiation damage, we need to understand and optimize the contribution of all components of radiation exposure.

METHODS

A total of 1000 CTO procedures performed between 2011 and 2020 were compared according to implemented radiation modifications. Group 1 used the original set-up of the X-ray equipment (Artis Zee, Siemens). In group 2 a modified protocol aimed at reducing the fluoroscopy exposure, in group 3 further modifications aimed at reducing cineangiographic exposure.

RESULTS

Despite an increased lesion complexity, Air Kerma (AK) was reduced from 2619 mGy (1653-4574) in group 1 to 2178 mGy (1332-3500; p < 0.001) in group 2 by mainly reducing fluoroscopic contribution by 54.1%, the cineangiographic contribution was lowered by only 6.6%. In group 3 AK dropped drastically to 746 mGy (480-1225; p < 0.001) mainly by reducing the cineangiographic contribution by 53.4%, still there was a further reduction of fluoroscopy contribution of 8.2%. This also led to a reduction of the skin entry dose from 1038 mGy (690-1589) in group 2 to 359 mGy (204-591; p < 0.001) in group 3. This was achieved both in normal weight and obese patients, and both in antegrade and retrograde procedures.

CONCLUSIONS

The present study demonstrates that by modifying both the fluoroscopic and cineangiographic contribution to radiation exposure a drastic reduction of radiation risk can be achieved, even in obese patients. Currently accepted radiation thresholds may no longer be a limit for CTO PCI.