Use of high‐frequency vibrational energy in the treatment of peripheral chronic total occlusions

Purpose: Peripheral chronic total occlusions (CTO) are challenging lesions to treat. The CROSSER system (FlowCardia, Sunnyvale, CA) uses high‐frequency low‐amplitude vibrations to break through the cap of the CTO and had been shown to be successful in coronary CTOs. This is a case series demonstrating the use of the CROSSER system with peripheral CTOs. Case Reports: Three patients with peripheral CTO of various lengths, locations, and complexities were treated with the CROSSER system. The device allowed placement of a guidewire across the area of occlusion, thus permitting further percutaneous intervention. The CROSSER system was effective with both ostial and distal lesions, tapered and abrupt lesion morphologies, and was used from both an ipsilateral (antegrade access) and contralateral approach. Conclusion: The CROSSER system is an additional device that may be used to treat peripheral CTOs. © 2009 Wiley‐Liss, Inc.     

Succesful antegrade subintimal bypass restenting of in‐stent chronic total occlusion

Coronary chronic total occlusions (CTOs) are known to cause significant patient morbidity. Over the past several years, the techniques and devices for treating these CTOs have advanced tremendously. The interventional management of CTOs within previously placed coronary stents, however, remains challenging. Here, we present a case of an in‐stent restenosis of the right coronary artery CTO bypassed using a controlled subintimal dissection re‐entry technique via antegrade approach creating side‐by‐side stents. © 2015 Wiley Periodicals, Inc.     

The functional reserve of collaterals supplying long-term chronic total coronary occlusions in patients without prior myocardial infarction.

AIMS: Chronic total coronary occlusions (CTOs) with angiographically well-developed collaterals may be considered to provide sufficient blood supply to the occluded segment, and the indication for revascularization may be questioned. Therefore, the collateral function and functional reserve in patients with a CTO without a prior Q-wave myocardial infarction (MI) were assessed. METHODS AND RESULTS: Invasive assessment of collateral function was done during successful percutaneous coronary intervention in 107 patients with a CTO and no prior Q-wave MI. Intracoronary Doppler flow velocity and pressure recordings were obtained distal to the occlusion before the first balloon inflation and collateral function indexes calculated. In 62 patients, additional pharmacological stress testing was done by intravenous adenosine (140 microg/kg/min) to assess the collateral flow reserve. Patients with normal and impaired regional dysfunction were compared. Collateral function was similar in patients with and without regional left ventricular (LV) dysfunction. In both groups, 78% collaterals provided a collateral pressure index at baseline > 0.3, sufficient to prevent ischaemia during a balloon occlusion, with a minimum of 0.2 in those with preserved LV function. A Doppler-derived function index showed a wider variation due to the high prevalence of microvascular dysfunction in CTOs. Only 7% of patients had an increase in collateral flow reserve > 2.0 during pharmacological stress, whereas coronary steal occurred in one-third independent of regional LV function. CONCLUSION: A limited increase in collateral flow and the high prevalence of coronary steal during stress underscore the functional limitation of collaterals in CTOs without prior Q-wave MI. Even presumably 'well-collateralized' CTOs may benefit from a revascularization.     

In-Stent CTO Percutaneous Coronary Intervention: Individual Patient Data Pooled Analysis of 4 Multicenter Registries

ObjectivesThe authors sought to examine the outcomes of percutaneous coronary intervention (PCI) for in-stent restenosis (ISR) chronic total occlusions (CTOs).BackgroundThe outcomes of PCI for ISR CTOs have received limited study.MethodsThe authors examined the clinical and angiographic characteristics and procedural outcomes of 11,961 CTO PCIs performed in 11,728 patients at 107 centers in Europe, North America, Latin America, and Asia between 2012 and 2020, pooling patient-level data from 4 multicenter registries. In-hospital major adverse cardiovascular events (MACE) included death, myocardial infarction, stroke, and tamponade. Long-term MACE were defined as the composite of all-cause death, myocardial infarction, and target vessel revascularization.ResultsISR represented 15% of the CTOs (n = 1,755). Patients with ISR CTOs had higher prevalence of diabetes (44% vs. 38%; p < 0.0001) and prior coronary artery bypass graft surgery (27% vs. 24%; p = 0.03). Mean J-CTO (Multicenter CTO Registry in Japan) score was 2.32 ± 1.27 in the ISR group and 2.22 ± 1.27 in the de novo group (p = 0.01). Technical (85% vs. 85%; p = 0.75) and procedural (84% vs. 84%; p = 0.82) success was similar for ISR and de novo CTOs, as was the incidence of in-hospital MACE (1.7% vs. 2.2%; p = 0.25). Antegrade wiring was the most common successful strategy, in 70% of ISR and 60% of de novo CTOs, followed by retrograde crossing (16% vs. 23%) and antegrade dissection and re-entry (15% vs. 16%; p < 0.0001). At 12 months, patients with ISR CTOs had a higher incidence of MACE (hazard ratio: 1.31; 95% confidence interval: 1.01 to 1.70; p = 0.04).ConclusionsISR CTOs represent 15% of all CTO PCIs and can be recanalized with similar success and in-hospital MACE as de novo CTOs.     

Blunt microdissection and rotational atherectomy: an effective combination for the resistant chronic total occlusion

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) has a lower success rate than nontotal occlusions. Like nontotal coronary occlusions, successful procedural outcomes of CTOs confers improvement in clinical outcomes. Reasons for unsuccessful PCI of CTOs may stem from various steps of the procedure including failure to cross the occlusion with a guidewire or a balloon, or failure to adequately dilate or modify the lesion. The Frontrunner blunt microdissection device is designed to improve the odds of guidewire passage through coronary occlusions, whereas the Rotablator rotational atherectomy device is intended for plaque modification, especially in resistant, elastic or calcific lesions. The Frontrunner and Rotablator can each facilitate the procedure at their respective junctures; the combined use of these technologies can enhance the overall PCI success rates, especially regarding difficult CTOs. This case presentation encounters two technical challenges: the inability of the balloon catheter to cross the CTO, and the inability to recross the occlusion with the less favorable RotaWire. In this case, the combined use of the Frontrunner and Rotablator devices was necessary to achieve overall procedural success. When tackling difficult CTOs, a comprehensive strategy that encompasses multiple devices and technologies can enable ultimate procedural success.     

Effect of Chronic Total Occlusion Percutaneous Coronary Intervention on Clinical Outcomes in Elderly Patients

Background

There are little published data reporting the effect of coronary artery chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on the prognosis of elderly patients with identified CTOs. We sought to evaluate the clinical effect of CTO PCI on the prognosis of elderly patients with CTOs.

“Move the cap” technique for ambiguous or impenetrable proximal cap of coronary total occlusion

Antegrade crossing remains the most commonly employed crossing strategy for coronary chronic total occlusions (CTOs) but can be challenging to perform in cases of ambiguous or impenetrable proximal cap. To successfully treat such cases, we describe a technique named “move the cap,” in which the subintimal space is entered proximal to the proximal cap using a stiff coronary guidewire or facilitated by inflating a slightly oversized balloon. Subintimal guidewire entry is followed by standard antegrade dissection and re‐entry. The “move the cap” technique can facilitate crossing of CTOs with ambiguous or impenetrable cap, while minimizing the risk of perforation. This technique is also useful for treating balloon uncrossable lesions. © 2015 Wiley Periodicals, Inc.     

Stent expansion in calcified coronary chronic total occlusions: The impact of different stent platforms

Objectives

To evaluate the stent expansion of the durable-polymer Zotarolimus-eluting stent (dp-ZES), the durable-polymer Everolimus-eluting stent (dp-EES), and the bioabsorbable-polymer Sirolimus-eluting stent (bp-SES) in calcified coronary chronic total occlusions (CTO).

Background

The newer generation stents with ultrathin struts might raise concerns regarding reduced radial strength and higher stent recoil (SR) when implanted in calcified CTOs.

Methods

Between January 2017 and June 2021 consecutive patients with CTO undergoing percutaneous coronary intervention with dp-ZES, dp-EES, or bp-SES were evaluated. The analysis was performed in calcific and in noncalcific CTOs. Quantitative coronary angiography analysis was used to assess diameter stenosis (DS), absolute and relative SR, absolute and relative focal SR, absolute and relative balloon deficit (BD), and absolute and relative focal BD. The primary endpoint was DS.

Results

A total of 213 CTOs were evaluated, 115 calcific CTOs (dp-ZES:25, dp-EES:29, bp-SES:61) and 98 non-calcific CTOs (dp-ZES:41, dp-EES:11, bp-SES:46). In calcific CTOs, residual DS was lower in dp-ZES than in dp-EES and bp-SES (−1.00% [−6.50–6.50] vs. 13.00% [7.0–19.00] vs. 15.00% [5.00–20.00]; p < 0.001). Dp-ZES was also an independent predictor of residual DS ≤ 10% (OR 11.34, 95% CI 2.6–49.43, p = 0.001). Absolute and relative focal SR and absolute and relative SR were similar between dp-ZES, dp-EES, and bp-SES (p = 0.913, p = 0.890, p = 0.518, p = 0.426, respectively). In noncalcified CTOs, the residual DS was similar in the three groups (p = 0.340). High relative focal SR was less frequent in dp-ZES than in dp-EES and in bp-SES (19.5% vs. 54.5% vs. 37.0%; p < 0.048).

Conclusions

The three stent platforms demonstrated an overall low residual DS when implanted in CTOs. However, dp-ZES was associated with the lowest residual DS and identified as independent predictor of residual DS ≤ 10% in patients with calcific CTOs. Dp-ZES was associated with a lower incidence of high relative focal stent recoil, in noncalcific CTOs. Balloon deficit might be considerate as a surrogate for stent expansion in calcified CTOs.     

Treatment of in-stent chronic total occlusions with blunt microdissection

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) can be a technical challenge with an average success rate much lower than other lesion types. In-stent restenosis CTOs have inherent features that may be favorable for using the blunt microdissection catheter and may help to improve procedural success. Two successful PCI cases of in-stent restenosis CTO using the blunt microdissection device are presented here. The respective lengths and durations of occlusions are: 40 mm and 1 year, 110 mm and 3 months. Both cases failed initial crossing attempts with conventional and specialized coronary guidewires. Only one other reported case study focused on native coronary in-stent restenosis CTO and the use of the blunt microdissection catheter. This current study presents the use of the blunt microdissection technique in both native coronary and bypass graft in-stent restenosis CTOs. This report adds to the overall experience with this promising approach to a subpopulation of CTO patients with in-stent restenosis.     

Long-term clinical outcomes of percutaneous coronary intervention for chronic total occlusions in patients with versus without diabetes mellitus

There is a paucity of data on long-term outcomes after percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) in the high-risk group of patients with diabetes mellitus (DM). The aim of this study was to evaluate long-term clinical outcomes after PCI of CTOs in patients with and without DM. A total of 1,742 patients with known DM status underwent PCI of CTOs at 3 tertiary care centers in the United States, South Korea, and Italy from 1998 to 2007. Five-year clinical outcomes were evaluated in patients with successful versus failed CTO PCI and the use of drug-eluting stents (DES) versus bare-metal stents (BMS) stratified according to DM status. A total of 395 patients (23%) had DM (42% of whom had insulin-dependent DM). Procedural success was similar in patients with versus without DM (69.6% vs 67.9%, p = 0.53). After successful CTO PCI, stents were implanted in 96.4% of patients with DM (BMS in 23.8%, DES in 76.2%) and in 94.0% of patients without DM (BMS in 38.6%, DES in 61.4%). Median follow-up was 3.0 years. In patients with DM, successful CTO PCI was associated with reduced long-term mortality (10.4% vs 13.0%, p <0.05) and a reduced need for coronary artery bypass grafting (2.4% vs 15.7%, p <0.01). The use of DES was associated with a reduction in target vessel revascularization in patients with DM (14.8% vs 54.1%, p <0.01) and in those without DM (17.6% vs 26.5%, p <0.01). Multivariate analysis identified insulin-dependent DM as an independent predictor of mortality in the DM cohort. In conclusion, successful CTO PCI in patients with DM was associated with a reduction in mortality and the need for coronary artery bypass grafting. Compared to non-insulin-dependent DM, patients with insulin-dependent DM had an increased risk for long-term mortality. The use of DES rather than BMS was associated with a reduction in target vessel revascularization in patients with and without DM.     

Coronary septal collaterals as an access for the retrograde approach in the percutaneous treatment of coronary chronic total occlusions.

OBJECTIVES: To investigate the feasibility and safety of the percutaneous dilatation of coronary septal collaterals and to allow its use as an access for retrograde approach to percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs). BACKGROUND: Despite improvements in percutaneous techniques and materials, CTO recanalization success rate is still suboptimal. The retrograde approach allows to significantly increase this success rate. However, its application via a bypass graft or epicardial collateral can potentially result in severe complications. A safer retrograde access is desired and would allow broadening the application of the retrograde approach in the percutaneous treatment of CTOs. METHODS: After a failed antegrade CTO recanalization attempt, a retrograde approach via septal collaterals was tried in 21 patients (19 males, 2 females). The septal collateral was accessed via the contralateral patent coronary artery and was crossed with a hydrophilic floppy wire. After successful wire crossing of the septal collateral, sequential low pressure dilatation was performed with a 1.25 or 1.5 mm balloon to allow the delivery of a balloon catheter up to the distal CTO site. RESULTS: Successful wire crossing and balloon dilatation of septal collaterals was achieved in 19 cases and in 17 cases, respectively. Postdilatation septal collateral diameter increased significantly reaching a mean diameter of 1.46 +/- 0.38 mm. Retrograde CTO recanalization was successfully performed in 71% of the cases. No major complications occurred. CONCLUSIONS: Coronary septal collaterals can be used as an access for the retrograde approach in the percutaneous treatment of CTOs.     

Prevention of lesion recurrence in chronic total coronary occlusions by paclitaxel-eluting stents

OBJECTIVES: The aim of this research was to assess the efficacy of paclitaxel-eluting stents in chronic total coronary occlusions (CTO). BACKGROUND: Percutaneous coronary interventions for CTOs are characterized by a high target vessel failure rate. METHODS: In 48 consecutive patients, paclitaxel-eluting stents (Taxus, Boston Scientific Corp., Natick, Massachusetts) were implanted after successful recanalization of a CTO (duration >2 weeks). Patients underwent an angiography after 6 months and were followed clinically for 12 months. They were compared with 48 lesion- and risk-matched patients with CTOs treated with bare metal stents (BMS). Primary clinical end point was the one-year incidence of major adverse cardiac events (MACE) (death, myocardial infarction, repeat revascularization); secondary end points were the rate of restenosis and re-occlusion. RESULTS: In-hospital MACE was 4.2% with Taxus, and 2.1% with BMS (p = NS). The one-year MACE rate was 12.5% in the Taxus group, and 47.9% in the BMS group (p < 0.001), which was due to a reduced need for repeat revascularization. The angiographic restenosis rate was 8.3% with Taxus versus 51.1% with BMS (p < 0.001). There was only one late re-occlusion with Taxus (2.1%) as compared with 23.4% with BMS (p < 0.005). The late loss was reduced in the Taxus group by 84% as compared with BMS. All nonocclusive restenoses in the Taxus group were focal and successfully treated by implanting an additional Taxus stent. CONCLUSIONS: The treatment of CTOs with a paclitaxel-eluting stent drastically reduces MACE and restenosis, and almost eliminates re-occlusion, which is typically frequent with BMS in CTOs. Chronic total coronary occlusion should be a preferred indication for drug-eluting stents.     

Novel approaches for the treatment of chronic total coronary occlusions

Despite major advancements in the technology used for the percutaneous treatment of coronary artery disease, chronic total occlusions (CTOs) persist as a major challenge to the interventional cardiologist with relatively low success rates. CTOs are evident in 20% of patients undergoing cardiac catheterization and are responsible for the majority of cases that are referred to bypass surgery. There is growing evidence that patients may benefit from recanalization of a CTO by alleviation of angina, improving left ventricular function, and potentially long-term survival. The major obstacle to percutaneous recanalization of CTOs is the inability to cross the occlusion with coronary guidewires. Even when crossed, the operator has to deal with the exact location of the distal wire (e.g., dissection or true lumen) and the existence of relatively long lesion requiring multiple stents with high restenosis rates. New technologies for CTO revascularization have been focused mainly on a mechanical approach including specialized guidewires and more recently, specific devices using highly sophisticated technology such as laser guidewire, optical coherence reflectometry, and a blunt microdissection catheter. An alternate biological approach involves the local administration of enzymes such as plasminogen activators (urokinase) or collagenase, which can act locally to specifically degrade the collagen content of the CTO, thereby "softening" the occlusion and allowing easier guidewire crossing. In conclusion, CTOs emerge as a great technical challenge and are the focus of novel series of mechanical and biological approaches.     

Successful use of the frontrunner catheter in the treatment of in-stent coronary chronic total occlusions.

Percutaneous intervention of coronary chronic total occlusion (CTO) from in-stent restenosis (ISR) is hindered by difficulty to cross the lesion with conventional guidewires. This study describes the successful treatment of five cases of CTOs from ISR using the Frontrunner controlled blunt microdissection catheter. Four of the five cases had failed previous attempts of percutaneous intervention with conventional guidewires. The Frontrunner catheter successfully facilitated the placement of guidewire into the distal true lumen in all five cases. The median crossing time was 10 min. No subintimal delivery of guidewire or vascular perforation was observed. TIMI 3 flow was achieved in all target vessels after further balloon angioplasty or stenting. The Frontrunner device is a safe and effective tool in the treatment of CTOs from ISR.     

Preliminary experience with the Frontrunner coronary catheter: novel device dedicated to mechanical revascularization of chronic total occlusions.

The novel device Frontrunner coronary catheter (FCC), dedicated to recanalization of chronic total occlusions (CTOs), relies on blunt microdissections inside the plaque, allowing passage of guidewire through the lesion and adjunctive angioplasty. In order to evaluate efficacy and safety of recanalization using the FCC device, we included patients with de novo or restenotic CTOs in a native coronary artery with prior failure using a guidewire or considered unsuitable for guidewire attempt in which the FCC was attempted first. Between October 2000 and June 2003, 50 patients with 50 CTOs were included in the study. Thirty-two patients had prior failure with a mechanical wire. Device and angiographic success were obtained in 25 (50%) occlusions: 53% in lesions with prior guidewire failure and 44% when FCCs were attempted first (P = 0.8). During the first year of experience, angiographic success was 42% (5 occlusions) and in the third year 75% (12 occlusions; P = 0.12). Coronary perforation occurred in nine (18.0%) patients, leading to tamponade in two (4%) patients. Perforations occurred in 5 out of 12 attempted patients during the first year and in 4 out of 38 patients in the following period (41.7% vs. 10.5%; P = 0.04). Serious adverse events occurred in five (10%) patients within 30-day follow-up. Four non-Q-wave myocardial infarctions occurred in hospital (clinical success 42%) and one death 7 days after the index procedure. The use of FCC increases the success to open chronic total occlusions refractory to mechanical guidewires or that were considered unsuitable for an attempt with a guidewire. The risk of coronary perforation due to FCC use is relatively high and it can decrease with experience.     

Improvement of regional ischemia after successful percutaneous intervention of bypassed native coronary chronic total occlusion: an application of the CART technique

Myocardial ischemia has been associated with patent saphenous vein grafts (SVG) for reasons that may be attributable to graft-related endothelial dysfunction. Recanalization of the bypassed native coronary arteries may relieve the regional ischemia. In this clinical scenario, percutaneous coronary intervention (PCI) of the challenging chronic total occlusions (CTO) can be facilitated by a retrograde approach utilizing the SVGs as access conduits. Controlled antegrade and retrograde subintimal tracking (CART) is a technique developed to facilitate the recanalization of CTOs by aggressive wire manipulation from both ends of the lesions. Success rates of CART are high in experienced hands with few complications. We discuss 2 patients who presented with anginal symptoms, ischemia on stress nuclear scintigraphy and patent SVGs on angiography. After the corresponding native CTOs in the bypassed coronary arteries were successfully recanalized using the CART technique, both patients' symptoms and reversible scintigraphic defects resolved. The CART technique is highlighted utilizing SVGs as access conduits for the retrograde approach.     

Percutaneous Intervention of Circumflex Chronic Total Occlusions Is Associated With Worse Procedural Outcomes: Insights From a Multicentre US Registry

BackgroundWe sought to determine whether outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) vary according to CTO target vessel: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA).MethodsWe evaluated the clinical and angiographic characteristics and procedural outcomes of 636 patients who underwent CTO PCI at 6 high-volume centres in the United States between January 2012 and March 2014.ResultsThe CTO target vessel was the RCA in 387 cases (61%), LAD in 132 (21%), and LCX in 117 (18%). LCX lesions were more tortuous and RCA lesions had greater occlusion length and Japanese Chronic Total Occlusion (J-CTO) score, but were less likely to have a side branch at the proximal cap and had more developed collateral circulation. The rate of procedural success was lower in LCX CTOs (84.6%), followed by RCA (91.7%), and LAD (94.7%) CTOs (P = 0.016). Major complications tended to occur more frequently in LCX PCI (4.3% vs 1.0% for RCA vs 2.3% for LAD; P = 0.07). LCX and RCA CTO PCI required longer fluoroscopy times (45 [interquartile range (IQR), 30-74] minutes vs 45 [IQR, 21-69] minutes for RCA vs 34 [IQR, 20-60] minutes for LAD; P = 0.018) and LCX CTOs required more contrast administration (280 [IQR, 210-370] mL vs 250 [IQR, 184-350] mL for RCA and 280 [IQR, 200-400] mL for LAD).ConclusionsIn a contemporary, multicentre CTO PCI registry, LCX was the least common target vessel. Compared with LAD and RCA, PCI of LCX CTOs was associated with a lower rate of procedural success, less efficiency, and a nonsignificant trend for higher rates of complications.     

Comparison of safety, efficacy, and outcome of successful versus unsuccessful percutaneous coronary intervention in "true" chronic total occlusions

Despite improving techniques for opening chronic total occlusions (CTOs), the benefit of successful recanalization of the artery remains unclear. The aims of this study were to investigate the safety and efficacy of percutaneous coronary intervention for "true" CTO, defined by Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 and duration > or =3 months, and to compare the outcome of successful versus failed procedures. A cohort of 172 consecutive patients with de novo CTOs of native vessels confirmed by angiographic review in which percutaneous coronary interventions were attempted was studied. End points included angiographic success, in-hospital complications, and long-term major adverse cardiac events. Technical success was obtained in 73.8% of CTO lesions (127 of 172). No deaths or nonfatal Q-wave myocardial infarctions occurred in the hospital. Repeat percutaneous coronary interventions in the hospital were required in 1.6% of patients (2 of 127) in whom the CTOs were initially opened. Perforation during the initial failed attempts occurred in 6.7% of patients (3 of 45). One patient required operative repair. After an average follow-up period of 2 years, patients with successful procedures experienced similar incidences of cardiac death and nonfatal Q-wave myocardial infarctions as did patients with failed procedures (5.3% and 4.9%, respectively, p = 0.3). Patients with successfully opened arteries required target vessel revascularization more frequently, but this did not reach statistical significance (18.8% vs 0%, p = 0.06). In conclusion, attempts to open CTOs with the devices available at the time of this registry were accompanied by a significant risk for perforation. Furthermore, successful recanalization did not translate into a reduction in 2-year mortality or nonfatal Q-wave myocardial infarctions compared with patients with failed procedures.     

Survival benefit after percutaneous treatment of chronic total coronary occlusions

In their recently published paper, Valenti et al.¹ report howsuccessful percutaneous coronary intervention (PCI) of chronictotal coronary occlusions (CTOs) was associated with a significant2-year survival benefit in a large series of 486     

磁导航引导下冠状动脉介入治疗的临床研究

目的 探讨应用磁导航引导进行冠状动脉介入治疗的有效性和安全性.方法 入选在磁导航室经冠状动脉造影确诊并符合介入治疗适应证的冠状动脉病变.经股动脉或桡动脉径路,采用磁导航引导进行冠状动脉介入治疗,记录靶病变特征、手术过程、X线暴露时间、X线暴露量和相关并发症.用Stata 9.2软件进行数据分析.结果 自2006年4月至2008年6月共入选冠心病患者121例,治疗靶病变138处,其中A型病变30处、B1型病变50处、B2型病变36处、C型病变22处(包括闭塞病变7处).靶病变平均狭窄程度(85.3±10.0)%、平均长度(21.1±10.0)mm.在磁导航引导下,磁导丝通过病变134处,病变通过率为97.1%.磁导丝置入过程中X线暴露时间(55.9±35.4)s、X线暴露量(98.0±86.1)mGy/(490.0±422.2)μGym2、对比剂用量(8.0±5.4)ml.在磁导丝通过的靶病变处共置人支架164枚.未发生与磁导航系统相关的并发症.磁导丝未能通过的靶病变共4处,其中2处为慢性完全闭塞(CTO)病变,另2处为伴有钙化的次全闭塞病变.结论 应用磁导航引导进行常规的冠状动脉介入治疗是可行的,磁导丝病变通过率高,安全性好.CTO病变和伴有钙化的次全闭塞病变不适宜应用磁导航系统进行介入治疗.