Coronary Chronic Total Occlusion Research Articles

Chronic total occlusion revascularization: A complex piece to "complete" the puzzle.

Treatment of coronary chronic total occlusion (CTO) with percutaneous coronary intervention (PCI) has rapidly increased during the past decades. Different strategies and approach were developed in the recent past years leading to an increase in CTO-PCI procedural success. The goal to achieve an extended revascularization with a high rate of completeness is now supported by strong scientific evidences and consequently, has led to an exponential increase in the number of CTO-PCI procedures, even if are still underutilized. It has been widely demonstrated that complete coronary revascularization, achieved by either coronary artery bypass graft or PCI, is associated with prognostic improvement, in terms of increased survival and reduction of major adverse cardiovascular events. The application of “contemporary” strategies aimed to obtain a state-of-the-art revascularization by PCI allows to achieve long-term clinical benefit, even in high-risk patients or complex coronary anatomy with CTO. The increasing success of CTO-PCI, allowing a complete or reasonable incomplete coronary revascularization, is enabling to overcome the last great challenge of interventional cardiology, adding a “complex” piece to “complete” the puzzle.

Collagenase to facilitate guidewire crossing in chronic total occlusion PCI—The Total Occlusion Study in Coronary Arteries‐5 (TOSCA‐5) trial

Chronic total occlusions (CTO) are common and are associated with lower percutaneous coronary intervention (PCI) success rates, often due to failure of antegrade guidewire crossing. Local, intralesional delivery of collagenase (MZ-004) may facilitate guidewire crossing in CTO. To evaluate the effect of MZ-004 in facilitating antegrade wire crossing in CTO angioplasty. A total of 76 patients undergoing CTO PCI were enrolled at 13 international sites: 38 in the randomized training stage (collagenase [MZ-004] 900 or 1200 μg) and 38 in the placebo-controlled stage (MZ-004 900 or 1200 μg or placebo). Patients received the MZ-004 or identical volume saline (placebo group) in a double-blind design, injected via microcatheter directly into the proximal cap of the CTO. The following day patients underwent CTO PCI using antegrade wire techniques only. Patients were generally similar except for a trend for higher Japanese chronic total occlusion (J-CTO) score in the MZ-004 group (MZ-004 J-CTO score 1.9 vs. 1.4, p = 0.07). There was a numerical increase in the rates of guidewire crossing in the MZ-004 groups compared to placebo (74% vs. 63%, p = 0.52). Guidewire crossing with a soft-tip guidewire (≤1.5 g tip load) was significantly higher in the MZ-004 groups (0% in placebo, 17% in 900 μg, and 29% in 1200 μg MZ-004 group, p = 0.03). Rates of the major adverse cardiovascular event were similar between groups. Local delivery of MZ-004 into coronary CTOs appears safe and may facilitate CTO crossing, particularly with softer tipped guidewires. These data support the development of a pivotal trial to further evaluate this agent.

Drug-coated balloon for the management of coronary chronic total occlusions.

There is a higher rate of successful recanalization of patients with coronary chronic total occlusions, nevertheless, the rate of patients referred for revascularization remains low. In addition, there is a greater need to improve long-term outcomes of chronic total occlusions after percutaneous coronary intervention, and although the implantation of new-generation drug-eluting stents has been optimized with coronary imaging guidance, the rate of stenting failure remains a major issue and long-term vessel patency could be improved. We reviewed clinical data regarding the benefit of treating chronic total occlusions and the use of drug-coated balloons as an alternative therapeutic modality in this setting. Although clinical data is limited, the initial evidence and the daily clinical practice point towards a synergistic hybrid treatment strategy based on the combination of drug-coated balloons plus drug-eluting stents, reducing the total stent length and maintaining the scaffolding properties of stents where it is mandatory. Additionally, drug-coated balloons allow natural enlargement of the open vessel after percutaneous coronary intervention (PCI), which is a major limitation of stents in chronic total occlusion (CTO).

Outcomes of chronic total occlusion percutaneous coronary intervention in patients with reduced left ventricular ejection fraction.

The relationship between left ventricular ejection fraction (LVEF) and the success and safety of coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We examined the clinical characteristics and outcomes of CTO PCI in the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO) after stratifying patients by LVEF (≤35%, 36%-49%, and ≥50%). A total of 7827 CTO PCI procedures with LVEF data were included. Mean age was 64 ± 10 years, 81% were men, 43% had diabetes mellitus, 61% had prior PCI, 45% had prior myocardial infarction, and 29% had prior coronary artery bypass graft surgery. Technical success was similar in the three LVEF strata: 85%, 86%, and 87%, p = 0.391 for LVEF ≤35%, 36%-49%, and ≥50%, respectively. In-hospital mortality was higher in lower LVEF patients (1.1%, 0.4%, and 0.3%, respectively, p = 0.001). In-hospital major adverse cardiovascular events (MACE) were numerically higher in lower EF patients (2.7%, 2.1%, and 1.9%, p = 0.271). At a median follow-up of 2 months (interquartile range: 19-350 days), patients with lower LVEF continued to have higher mortality (4.9%, 3.2%, and 1.4%, p < 0.001) while the MACE rates were similar (9.3%, 9.6%, and 7.4%, p = 0.172). CTO PCI can be performed with high technical success in patients with reduced LVEF but is associated with higher in-hospital and post-discharge mortality.

Validation of the newly introduced CASTLE Score for predicting successful CTO recanalization.

BackgroundThe new EuroCTO CASTLE Score was validated against the widely adopted Japanese Multicenter CTO Registry (J-CTO) score in predicting technical success in percutaneous coronary intervention (PCI) for coronary chronic total occlusions (CTO).MethodsA total of 463 patients treated by CTO PCI were included in a retrospective analysis. Result: The mean CASTLE score was 2.23 ± 1.1 and J-CTO score was 2.84 ± 1.0. The overall technical success rate was 83.2%. At 30 days follow up, a primary composite safety endpoint showed a low proportion of stent thrombosis (0.2%) and re-hospitalization (0.4%). Moreover, an improvement of clinical symptoms was found in 83% of patients. Receiver operating characteristic analysis (ROC) demonstrated a comparable overall discriminatory performance in predicting technical outcome: CASTLE score, area under the ROC curve (AUC) 0.668, 95% CI: 0.606–0.730; J-CTO score AUC 0.692, 95% CI: 0.631–0.752; Comparison of AUCs: p = 0.324. Those findings were even consistent in more complex procedures CASTLE Score ≥ 4 and J-CTO score ≥ 3: CASTLE Score AUC 0.514, 95% CI: 0.409–0.619; J-CTO score, AUC 0.617, 95% CI: 0.493–0.741; Comparison of AUCs: p = 0.211. Furthermore, increasing score values are accompanied by a longer examination and fluoroscopy time, more contrast medium and a higher dose area product.ConclusionCompared to the widely accepted J-CTO score, the new introduced EuroCTO CASTLE score demonstrated a comparable overall discriminatory performance in predicting technical outcomes in CTO PCI.

Safety and efficacy of the transradial access when performing percutaneous coronary interventions to treat chronic total coronary occlusions

Safety and efficacy of the transradial access when performing percutaneous coronary interventions to treat chronic total coronary occlusions

The Comparison of Long-Term Outcome Between Patients with Single and Multiple Coronary Chronic Total Occlusions After Percutaneous Coronary Intervention.

BackgroundRapid advancements in percutaneous coronary intervention (PCI) have improved the outcome of chronic coronary total occlusions (CTOs); however, data regarding the difference in long-term outcomes in stable coronary artery disease (CAD) patients with single and multiple CTOs who underwent PCI are scarce. This study aimed to compare the long-term outcomes of patients with multiple CTOs and single CTO after PCI.MethodsThis study cohort included stable CAD patients who were diagnosed with CTO and treated with PCI from a single center. The primary endpoint was all-cause death.ResultsWe retrospectively reviewed 670 consecutive patients with CTO-PCI. Among them, 539 patients had a single CTO, and 131 (19.7%) patients had multiple (at least two) CTOs. CTO revascularization was achieved in 470 (70.1%) patients. After a median follow-up duration of 33.7 months, the cumulative all-cause mortality (p = 0.037) and cardiac mortality (p = 0.003) were higher in patients with multiple CTOs than in those with a single CTO. In the multivariable model, multiple CTOs and left ventricular ejection fraction (LVEF) less than 40% were independent predictors for cardiac death (adjusted hazard ratio (HR) 2.53; P = 0.013 and adjusted HR 3.95; P < 0.001), while age older than 65 and LVEF less than 40% were independent predictors for all-cause death in CTO-PCI patients (adjusted hazard ratio (HR) 1.84; P = 0.035 and adjusted HR 2.54; P = 0.001).ConclusionIn CTO-PCI patients, long-term survival was associated with multiple CTOs, age and LVEF, but not with CTO revascularization.

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 Qianfoshan Hospital 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&lt;0.05). In addition, after the operation, significantly greater decreases in the IL-4 and sICAM-1 levels were observed in the cocktail group than the control group (P&lt;0.05). The Seattle Angina Scale (SAQ) score of the cocktail group, compared with 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&gt;0.05). Conclusion: The treatment of patients with CTO undergoing PCI with nicorandil and tirofiban alleviated the inflammatory response, 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.

Lesion characteristics and procedural complications of chronic total occlusion percutaneous coronary intervention in patients with prior bypass surgery: A meta‐analysis

Coronary artery bypass graft (CABG) accelerates the prevalence of native coronary chronic total occlusion (CTO), and this kind of CTO shows extensive challenging and complex atherosclerotic pathology. As a result, the procedural success rate of percutaneous coronary intervention (PCI) is inferior to another kind of lesions. The present meta‐analysis aims to compare the lesion characteristics and procedural complications of CTO‐PCI in patients with or without prior CABG. A total of 8 studies, comprising of 13439 patients, published from inception to August 2021 were included in this meta‐analysis. Results were pooled using random effects model and are presented as odds ratio (OR) with 95% confidence intervals (95% CIs). From the 13439 patients enrolled, 3349 (24.9%) patients had previous CABG and 10090 (75.1%) formed the control group in our analysis. For the clinical characteristic, compared to the non‐CABG patients, prior CABG patients were older (OR, 3.98; 95% CI, 3.19–4.78; p < .001; I 2 = 72%), had more male (OR, 1.30; 95% CI, 1.14–1.49; p < .001; I 2 = 6%), diabetes mellitus (OR, 1.54; 95% CI, 1.36–1.73; p < .001; I 2 = 37%), dyslipidemia (OR, 1.89; 95% CI, 1.33–2.69; p < .001; I 2 = 81%), hypertension (OR, 1.88; 95% CI, 1.46–2.41; p < .001; I 2 = 71%), previous myocardial infarction (OR, 1.94; 95% CI, 1.48–2.56; p < .001; I 2 = 85%), and previous PCI (OR, 1.74; 95% CI, 1.52–1.98; p < .001; I 2 = 22%). Non‐CABG patents had more current smoker (OR, .45; 95% CI, 0.27–0.74; p < .001; I 2 = 91%). BMI (OR, −0.01; 95% CI, −0.07–0.06; p = .85; I 2 = 36%) were similar in both groups. For lesions location, the right coronary artery (RCA) was predominant target vessel in both groups (50.5% vs 48.7%; p＝.49), although, the left circumflex (LCX) was more frequently CTO in the prior CABG group (27.3% vs 18.9%; p＜.01), while left anterior descending artery (LAD) in non‐CABG ones (16.0% vs 29.1%; p＜0.01). For lesions characteristics, prior CABG patients had more blunt stump (OR, 1.71; 95% CI, 1.46–2.00; p < .001; I 2 = 40%), proximal cap ambiguity (OR, 1.45; 95% CI, 1.28–1.64; p < .001; I 2 = 0.0%), severe calcifications (OR, 2.91; 95% CI, 2.19–3.86; p < .001; I 2 = 83%), more bending (OR, 3.07; 95% CI, 2.61–3.62; p < .001; I 2 = 0%), lesion length > 20 mm (OR, 1.59; 95% CI, 1.10–2.29; p = .01; I 2 = 83%), inadequate distal landing zone (OR, 1.95; 95% CI, 1.75–2.18; p＜.001; I 2 = 0.0%), distal cap at bifurcation (OR, 1.65; 95% CI, 1.46–1.88; p < .001; I 2 = 0.0%), and higher J‐CTO score (SMD, 0.52; 95% CI, 0.42–0.63; p < .001; I 2 = 65%). But side branch at proximal entry (OR, 0.88; 95% CI, 0.72–1.07; p = .21; I 2 = 45%), in‐stent CTO (OR, 0.99; 95% CI, 0.86–1.14; p = .88; I 2 = 0.0%), lack of interventional collaterals (OR, 0.80; 95% CI, 0.55–1.15; p = .23; I 2 = 78%), and previously failed attempt (OR, 0.73; 95% CI, 0.48–1.11; p = .14; I 2 = 89%) were similar in both groups. For complication, prior CABG patients had more perforation with need for intervention (OR, 1.91; 95% CI, 1.36–2.69; p < 0.001; I 2 = 34%), contrast‐induced nephropathy (OR, 3.40; 95% CI, 1.31–8.78; p = .01; I 2 = 0.0%). Non‐CABG patents had more tamponade (OR, 0.25; 95% CI, 0.09–0.72; p = .01; I 2 = 0.0%), and the major bleeding complication (OR, 1.18; 95% CI, 0.57–2.44; p = .65; I 2 = 0%) were no significant difference in both groups. In conclusion, Patients with prior CABG undergoing CTO‐PCI have more complex lesion characteristics, though procedural complication rates were comparable.

Visfatin and 25-Hydroxyvitamin D3 Levels Affect Coronary Collateral Circulation Development in Patients with Chronic Coronary Total Occlusion

Background: Coronary collateral circulation (CCC) plays a vital role in the myocardial blood supply, especially for ischemic myocardium. Evidence suggests that the visfatin and 25-hydroxyvitamin D3 [25(OH)D3] levels are related to the degree and incidence of vascular stenosis associated with coronary artery disease; however, few studies have evaluated the effect of visfatin and 25(OH)D3 on CCC development in patients with chronic total occlusion (CTO). This study aimed to evaluate the relationship between the serum visfatin and 25(OH)D3 levels and CCC in patients with CTO. Methods: A total of 189 patients with CTO confirmed by coronary angiography were included. CCC was graded from 0 to 3 according to the Rentrop-Cohen classification. Patients with grade 0 or grade 1 collateral development were included in the poor CCC group (n=82), whereas patients with grade 2 or grade 3 collateral development were included in the good CCC group (n=107). The serum visfatin and 25(OH)D3 levels were measured by ELISA. Results: The visfatin level was significantly higher in the poor CCC group than in the good CCC group, and the 25(OH)D3 level was significantly lower in the poor CCC group than in the good CCC group (P=0.000). Correlation analysis showed that the Rentrop grade was negatively correlated with the visfatin level (r=−0.692, P=0.000) but positively correlated with the 25(OH)D3 level (r=0.635, P=0.000). Logistic regression analysis showed that the visfatin and 25(OH)D3 levels were independent risk factors for CCC (odds ratio 1.597, 95% confidence interval 1.300–1.961, P=0.000 and odds ratio 0.566, 95% confidence interval 0.444–0.722, P=0.000, respectively). The visfatin and 25(OH)D3 levels can effectively predict the CCC status. Conclusion: Serum visfatin and 25(OH)D3 levels are related to CCC development and are independent predictors of poor CCC.

Expanding indications: hybrid surgicalpercutaneous coronary intervention (PCI) coronary revascularization of chronic total occlusions in patients with multivessel coronary artery disease (CAD)

Hybrid revascularization of multivessel coronary artery disease by combining coronary artery bypass grafting (CABG) and chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is a relatively novel concept. Hybrid CABG-CTO PCI aims to combine the durable clinical benefits of a left internal mammary artery graft (ideally minimally invasively) with the durability of CTO PCI in non-left anterior descending vessels. This review assesses the current evidence for performing hybrid CTO PCI-CABG and pre-procedural planning considerations.

ЭКОНОМИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ИСПОЛЬЗОВАНИЯ РАЗЛИЧНЫХ ТИПОВ СТЕНТОВ ПРИ КОРРЕКЦИИ ХРОНИЧЕСКИХ ОККЛЮЗИЙ КОРОНАРНЫХ АРТЕРИЙ

Aim. To study cost-effectiveness of different types of stents in the correction of chronic total occlusion (CTO). Methods. The study included 119 patients after successful coronary artery CTO recanalization in 2009–2012. After 6.1±0.9 months and 12.7±1.6 months a control examination was performed (coronary angiography, intravascular ultrasound, optical coherence tomography). Negative events (in-stent restenosis and thrombosis) were analyzed. Taking into account the obtained data, direct costs were calculated including the cost of implants, and the cost of restenosis and thrombosis treatment. Results. The highest frequency of in-stent restenosis (p &lt; 0.05) was registered after IntrepideTM (in 57.1% cases) and Prolim® (in 47.4% cases) stent implantation while the similar events in cases of Taxus® Express 2, Xience V®/Xience Prime® LL, Endeavor® Resolute, Nobori® stent implantation were registered in 0-11.1% of cases. There weren’t differences in the thrombosis incidence between studied types of implants (p &gt; 0.05). Based on the data obtained, the stents were classified as devices with low rate of adverse events (Taxus® Express 2, Xience V®/Xience Prime® LL, Endeavor® Resolute, Nobori® – LRAE group), and those with a high rate of restenosis and thrombosis (IntrepideTM and Prolim® – HRAE group). The average cost of stents in the LRAE group was 2155.1 US dollars. Endovascular correction of in-stent restenosis were performed in 6.3% of cases, thrombosis – in 1.3%, the average direct treatment cost per patient over 12.7±1.6 months totaled 3906.4 US dollars. In the HRAE group the cheaper devices were implanted (median cost was $1650.8). Repeated PCIs due to restenosis were performed in 52.5% of cases, one patient (2.5%) with verified thrombosis underwent CABG. The average direct treatment cost per patient over 12.7±1.6 months period was 4993.5 US dollars, which was $1,087.1 more than in the LRAE group. Conclusion. The obtained data indicate higher financial cost during 12.7±1.6 months follow-up period after IntrepideTM and Prolim® stent implantation in the recanalized CTO areas. This emphasizes the impotance of using coronary stents with proven minimal risks of in-trastent restenosis and thrombosis in CTO cases.

Impact of Left Ventricular Ejection Fraction on the 10-Year Mortality of Patients Following Coronary Chronic Total Occlusion Intervention

Impact of Left Ventricular Ejection Fraction on the 10-Year Mortality of Patients Following Coronary Chronic Total Occlusion Intervention

Commentary on: Angiographic scoring system for predicting successful percutaneous coronary intervention of uneasy in-stent chronic total occlusion

As the Percutaneous Coronary Intervention (PCI) is prevalent in the recent decades, In-Stent Coronary chronic Total Occlusion (IS-CTO) has become a frequently met lesion in daily PCI procedure. It is estimated IS-CTO PCI accounts for 5-25% of all CTO

The last resort during complex retrograde percutaneous coronary chronic total occlusion intervention: Extraplaque intracoronary lithotripsy to externally crush a heavy calcified occluded stent

Chronic total occlusions (CTO) due to in-stent restenosis represent a challenging lesion subset for percutaneous coronary intervention in particular when associated with coronary calcification. Sometimes CTO lesions require antegrade or retrograde dissection-re-entry techniques with extraplaque dilation. Recently intravascular lithotripsy (IVL) emerged as a therapeutic option for the treatment of severely calcified coronary lesions but its role in extraplaque dilation is not described. In this report, we present a case of retrograde complex percutaneous coronary chronic total occlusion revascularization accomplished by the use of extraplaque IVL necessary to externally crush a heavy calcified previous implanted stent.

401 Myocardial viability and ischaemia assessment in chronic coronary total occlusions according to collaterals distribution: a retrospective analysis

Abstract Aims Whether CTO-PCI (chronic total occlusions—percutaneous coronary intervention) offers clinical benefit over optimal medical therapy is still a matter of debate. Viability and ischaemia assessment could improve selection of candidates to PCI. Traditionally, well-developed collaterals are considered a marker of myocardial viability in CTO territory. Current literature offers few data concerning the relationship between viability/ischaemia and collaterals distribution. Methods and results We retrospectively analysed the Cardiovascular Magnetic Resonance (CMR) studies and coronary angiographies of patients with at least one CTO referred at Humanitas Research Hospital between June 2009 and September 2020. We included 131 patients who underwent CMR with LGE assessment; of them, 111 (85%) underwent stress-CMR with adenosine. AHA segments (16 segment/patient for a total of 2096 segment assessed) were assessed on three short axis projection and scored for WMSI on cine images, for the presence of ischaemia on first pass perfusion, and for viability on LGE images. Viability was defined as LGE transmurality ≤50% and WMSI (wall motion score index) &amp;gt;1. Patients were divided in three groups according to collaterals distribution at coronary angiography: Patients with TD collaterals were more likely to have viable segments in the CTO-territory (90% of the segments in TD, 76% in WD, and 71% in PD, coeff. 0.107, P &amp;lt; 0.001). No statistically significant differences were found between groups as regard the amount of ischaemic segments (61% of the segments in TD, 65% in WD, and 60% in PD, P = 0.189). Conclusions The presence of myocardial viability is slightly associated with the degree of coronary collateralization at coronary angiography while the amount of ischaemia is not. Stress CMR should be considered in CTO patients before a reopening attempt.

Contemporary Strategies and Outcomes of Dedicated Chronic Total Occlusion Percutaneous Coronary Intervention Programs: A Prospective Multicentre Registry.

Background The field of CTO PCI is expanding, but successful and safe percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTO) requires a substantial resource and experience investment. We aimed to assess temporal trends in strategies and outcomes of 2 dedicated programs for CTO PCI. Methods Between 2011 and 2020, 920 CTO PCI procedures were prospectively included at 2 referral centres in Belgium. Temporal trends were assessed, and logistic regression models were built to identify predictors of outcome. Results Despite an increase in lesion complexity (the J-CTO score increased from 1.3 in year 1 to 1.7–2.0 in years 8-9, p < 0.001), technical success improved from 70.0% to 85.6% in year 9 (p value for trend <0.001). We observed the most significant improvement starting at years 3-4 (OR 2.3 in year 4 versus year 1, p=0.018). Together with an increase in success rates and lesions complexity, there was an increase in the use of dual injections, retrograde approaches, the number of balloons and stents, and the use of microcatheters. Conversely, there was a decrease in large bore access, an increase in radial approach, and a shift towards contemporary dissection/reentry techniques. This strategy resulted in a stable major complication rate of 4.7% (p value for trend 0.33). The rate of coronary procedure-related myocardial injury was high (71.0%) and was associated with the use of more intracoronary devices. Conclusions Three to four years after initiation of a dedicated CTO PCI program with 50 CTO PCIs per year, consistent high technical success and low complication rates are achieved using contemporary strategies.

Assessment of late gadolinium enhancement-negative chronic total occlusion by longitudinal strain analysis using cardiac magnetic resonance imaging

Strain analysis has become commonly used in clinical practice in various heart diseases. To explore whether late gadolinium enhancement (LGE)-negative areas with coronary artery chronic total occlusion (CTO) appear normal when analyzed for longitudinal strain using cardiac magnetic resonance (CMR) imaging. A total of 16 patients and 31 healthy controls who underwent 1.5-T MR at our hospital between January 2015 and July 2017 were included in the study. The LGE-CMR of patients with CTO was negative. Left ventricular functional parameters, segmental longitudinal strain/strain rate, and perfusion parameters were measured using CVI42 software. For myocardial segments supplied by CTO vessels, systolic longitudinal strain rate (SLSR)was significantly lower than that of healthy controls, and diastolic longitudinal strain rate (DLSR) was significantly higher (1.19 1/s vs. 1.02 1/s; P = 0.018). Moreover, longitudinal strain (LS), SLSR, and DLSR did not differ between good and poor collateral circulation. Perfusion index of CTO territory segments was lower than non-CTO territory segments (0.20 vs. 0.22; P = 0.027). No correlation was found between longitudinal strain parameters and perfusion parameters. Although LGE-CMR was negative in patients with CTO, the myocardial SLSR of CTO territory segments was significantly lower than that of healthy controls.

Further advancement in the percutaneous revascularization of coronary chronic total occlusions: the redefined "minimalistic hybrid approach" algorithm.

A careful angiographic assessment of a chronic total occlusion (CTO) is essential for optimal procedural planning. In the classic hybrid approach, the insertion of two guiding catheters at the beginning of the intervention is recommended. This is fundamental to perform simultaneous double injection, to achieve complete visualization of the coronary circulation and to choose the best starting strategy between antegrade wire escalation (AWE), antegrade dissection and re-entry (ADR) and the retrograde techniques (retrograde wire escalation [RWE] and retrograde dissection and re-entry [RDR]). In the hybrid algorithm the set-up is the same, regardless of the chosen first strategy, and therefore routinely uses double access. Because revascularizations of CTOs commonly require large bore catheters (7-8 French) to ensure high back-up support, the femoral arterial access is preferred by most of the operators. However, the use of a double access, large introducer sheaths and femoral approach are associated with a greater risk of access-related complications and even the occurrence of major adverse cardiovascular events. We have previously proposed an algorithm, called "minimalistic hybrid approach," which aims to limit the routine use of dual injection, and to favor the use of trans-radial access and smaller (6-7 French) guiding catheters. In this algorithm the chosen starting strategy depends on the complexity of the lesion assessed by J-CTO Score and on the presence of favorable contralateral interventional collateral circulation. However, this novel algorithm proved to have some limitations, such as the non-specific evaluation of CTOs with ipsilateral collateral circulation and the too arbitrary choice of the starting strategy based on a J-CTO Score cut-off. These considerations led to the development of an "updated" minimalistic hybrid approach algorithm that considers the type of collaterals (ipsilateral or contralateral) and the a-priori choice of the hybrid technique, with the highest chance of success in that specific CTO lesion (independently from the J-CTO Score). One important aspect that makes this algorithm unique is its "dynamicity:" not only for the technique to be used, as in the classic hybrid algorithm (shifting between AWE, ADR, RWE and RDR), but also for the set-up, with access site and French size to be adapted during the PCI to the technique adopted. We believe that this novel approach could further improve the safety of CTO-PCI without losing its current efficacy.

Evaluation of left ventricular function by global longitudinal strain (GLS) after percutaneous recanalization of chronic coronary total occlusion

Evaluation of left ventricular function by global longitudinal strain (GLS) after percutaneous recanalization of chronic coronary total occlusion