Percutaneous coronary intervention of ostial lesions

Coronary lithotripsy for the treatment of underexpanded stents: the international & multicentre CRUNCH registry

BACKGROUND

Stent underexpansion increases the risk of cardiac adverse events. At present, there are limited options to treat refractory stent underexpansion. In this context, the intravascular lithotripsy (IVL) system might be a safe and effective strategy.

AIMS

We aimed to evaluate the safety and efficacy of IVL in addressing resistant stent underexpansion due to heavy underlying calcification.

METHODS

This was an international multicentre registry including patients receiving IVL therapy to treat stent underexpansion from December 2017 to August 2020. Angiographic and intracoronary imaging data were collected. The efficacy endpoint was device success (technical success with a final percentage diameter stenosis <50%). The safety endpoint was in-hospital major adverse cardiac events (MACE).

RESULTS

Seventy patients were included, the mean age was 73±9.2 years and 76% were male. The median time from stent implantation to IVL therapy was 49 days (0-2,537). Adjuvant treatment with non-compliant balloon dilatations pre- and post-IVL was performed in 72.3% and 76.8% of patients, respectively, and additional stenting was performed in 22.4%. Device success was 92.3%. Minimum lumen diameter increased from 1.49±0.73 mm to 2.41±0.67 mm (p<0.001) and stent expansion increased by 124.93±138.19% (p=0.016). No IVL-related procedural complications or MACE were observed. The use of bailout IVL therapy directly after stenting and the presence of ostial underexpanded lesions negatively predicted lumen diameter gain.

CONCLUSIONS

Coronary lithotripsy is safe and effective in increasing lumen and stent dimensions in underexpanded stents secondary to heavily calcified lesions.

Power Flush, a novel bail-out technique for stumpless aorto-ostial CTOs. A case-based approach

BACKGROUND

Aorto-ostial coronary artery flush chronic total occlusions are a challenging subset of lesion with peculiar characteristic: the near complete lack of guiding catheter support, the presence of a thicker layer of muscular fibers and a greater collagen and calcium content, responsible for balloon dilatation's resistance and greater recoil tendency. We introduce a novel bailout technique to overcome retrograde wire failure in accessing aorta, a variation of the Carlino technique which we named Power Flush.

MATERIALS AND METHODS

Power Flush consists in a forceful injection of contrast dye directly through the guiding catheter positioned against the aortic wall in correspondence to the coronary ostium location, to gain access to the extra-plaque space and proceed with the vessel's recanalization. In one case we used a further iteration named Nick And Flush, in which a preliminary nicking of the aortic wall with a penetrative wire was done before the Power Flush.

RESULTS

We hereby present three cases of aorto-ostial right coronary artery flush chronic total occlusions. In two of them we utilized the Power Flush technique, in one case we employed its variant Nick And Flush. We were successful in all cases and no complication occurred.

CONCLUSIONS

In this kind of lesions Power Flush and Nick And Flush are effective bailout techniques to overcome retrograde wire failure to reach aorta.

Long-Term Follow-Up of Patients With Isolated Side Branch Coronary Artery Disease

The data with respect to stable coronary artery disease (SCAD) are mainly confined to main vessel disease. However, there is a lack of information and long-term outcomes regarding isolated side branch disease. This study aimed to evaluate long-term major adverse cardiac and cerebrovascular events (MACCEs) in patients with isolated side branch coronary artery disease (CAD). A total of 437 patients with isolated side branch SCAD were included. After a median follow-up of 38 months, the overall MACCE and all-cause mortality rates were 14.6% and 5.9%, respectively. Among angiographic features, 68.2% of patients had diagonal artery and 82.2% had ostial lesions. In 28.8% of patients, the vessel diameter was ≥2.75 mm. According to the American College of Cardiology lesion classification, 84.2% of patients had either class B or C lesions. Age, ostial lesions, glycated hemoglobin A1c, and neutrophil levels were independent predictors of MACCE. On the other hand, side branch location, vessel diameter, and lesion complexity did not affect outcomes. Clinical risk factors seem to have a greater impact on MACCE rather than lesion morphology. Therefore, the treatment of clinical risk factors is of paramount importance in these patients.

Determination of optimal fluoroscopic angulations for aorto-coronary ostial interventions from coronary computed tomography angiography

BACKGROUND

An optimal aorto-coronary angiographic projection, characterized by an orthogonal visualization of the proximal coronary artery, is crucial for interventional success. We determined the distribution of optimal C-arm positions and assessed their feasibility by invasive coronary angiography.

METHODS

Orthogonal aorto-coronary ostial angulations were determined in 310 CT data sets. In 100 patients undergoing subsequent invasive angiography, we assessed if the CT-predicted angulations were achievable by the C-arm system. If the predicted projection was not achievable due to mechanical constraints of the C-arm system, the most close, achievable angulation was determined. Patient characteristics were analyzed regarding the distribution of optimal angulations and its feasibility by the C-arm system.

RESULTS

For the left ostium, CT revealed a mean angulation of LAO 23 ​± ​21°/cranial 25 ​± ​23° (90% of patients with a LAO/cranial angulation, 3% LAO/caudal, 4% RAO/cranial, 3% RAO/caudal) and were achievable by the C-arm system in 87% of patients. For the right ostium, the mean CT-predicted orthogonal angulation was LAO 36 ​± ​37°/cranial 36 ​± ​51° (84% LAO/cranial, 2% LAO/caudal, 14% RAO/caudal) and achievable by the C-arm system in 45% of patients. For the left ostium, a higher body weight was associated with a steeper LAO/cranial angulation being less feasible by the C-arm system due to mechanical constraints.

CONCLUSIONS

Orthogonal aorto-left coronary angulations show a relative narrow distribution predominately in LAO/cranial position whereas a wider range of angulations was found for the right coronary ostium. The feasibility of CT-predicted angulations by the C-arm system is more restricted for the right than the left coronary ostium.

The role of intravascular ultrasound in percutaneous coronary intervention of complex coronary lesions

Intravascular ultrasound (IVUS) is a catheter-based coronary imaging technique. It utilises the emission & subsequent detection of reflected high frequency (30-60 MHz) sound waves to create high resolution, cross-sectional images of the coronary artery. IVUS has been the cornerstone of intracoronary imaging for more than two decades. When compared to the invasive coronary angiogram which studies only the silhouette of the contrast-filled artery lumen, IVUS also crucially images the vessel wall. Because of this capability, IVUS has greatly facilitated understanding of the coronary atherosclerosis process. Such insights from IVUS reveal how commonly and extensively plain angiography underestimates the true extent of coronary plaque, the characteristics of plaques prone to rupture and cause acute coronary syndromes (lipid rich, thin cap atheroma), and a realisation of the widespread occurrence of vessel remodelling in response to atherosclerosis. Similarly, IVUS has historically provided salutary mechanistic insights that have guided many of the incremental advances in the techniques of percutaneous coronary intervention (PCI). Examples include mechanisms of in-stent restenosis, and the importance of high-pressure post-dilatation of stents to ensure adequate stent apposition and thereby reduce the occurrence of stent thrombosis. IVUS also greatly facilitates the choice of correct diameter and length of stent to implant. Overall, a compelling body of evidence indicates that use of intravascular ultrasound in PCI helps to achieve optimal technical results and to mitigate the risk of adverse cardiac events. In this review, the role of intravascular ultrasound as an adjunct to PCI in complex coronary lesions is explored. The complex coronary situations discussed are the left main stem, ostial stenoses, bifurcation stenoses, thrombotic lesions, the chronically occluded coronary artery, and calcified coronary artery disease. By thorough review of the available evidence, we establish that the advantages of IVUS guidance are particularly evident in each of these complex CAD subsets. In particular, some consider the use of IVUS to be almost mandatory in left main PCI. A comparison with other intracoronary imaging techniques is also explored.

In-Hospital Outcomes After Recanalization of Ostial Chronic Total Occlusions

BACKGROUND

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) still remains a major challenge in interventional cardiology. Recanalization of ostial lesions is challenging and complex. This present study aims to evaluate the outcome of patients with ostial and non-ostial CTO-PCI with regard to acute, in-hospital outcome.

METHODS

Between 2012 and 2018 we included 600 patients. Ostial lesions (OL) were defined as a coronary arterial stenosis within 3 mm of the vessel origin. Antegrade and retrograde CTO-PCI techniques were used and a composite safety endpoint comprising in-hospital death, vascular complications, cardiac tamponade, stroke and acute myocardial infarction.

RESULTS

The majority of the patients were male (82.3%) and the mean age was 62.1 years (±10.3 years). The right coronary artery (RCA) was the most frequent target vessel in 58.5%, followed by the left circumflex artery (LCX) (15.4%) and the left anterior descending artery (LAD) (26.2%). The success (p = .439) and complication rates (p = .169) were independent of the target vessel. We determined that examination and fluoroscopy time were longer in patients with OL (120.7 min vs. 99.0 min, p < .001 and 44.9 min vs. 34.5 min, p < .001) and that in this group of patients the retrograde approach was used more frequent (38.8% vs. 18.2%, p < .001). Overall success rates were lower in OL than compared to NOL (74.6% vs. 86.5%, p = .016).

CONCLUSIONS

Our retrospective study suggests that recanalization of ostial CTO lesions is associated with reduced PCI success rates as well as long examination and high fluoroscopy times.

Performing and Interpreting Fractional Flow Reserve Measurements in Clinical Practice: An Expert Consensus Document

Fractional flow reserve (FFR) measurements can determine the haemodynamic relevance of coronary artery stenoses. Current guidelines recommend their use in lesions in the absence of non-invasive proof of ischaemia. The prognostic impact of FFR has been evaluated in randomised trials, and it has been shown that revascularisation can be safely deferred if FFR is >0.80, while revascularisation of stenoses with FFR values ≤0.80 results in significantly lower event rates compared to medical treatment. Left main stenoses, aorto-ostial lesions, as well as patients with left ventricular hypertrophy and severely-impaired ejection fraction, have been excluded from large, randomised trials. While FFR measurements are relatively straightforward to perform, uncertainty about procedural logistics, as well as data acquisition and interpretation in specific situations, could explain why they are not widely used in clinical practice. We summarise the clinical data in support of FFR measurements, and provide recommendations for performing and interpreting the procedure.

Impact of intravascular ultrasound on the long-term clinical outcomes in the treatment of coronary ostial lesions

OBJECTIVES

To evaluate the long-term outcomes of patients with ostial lesions who underwent percutaneous coronary intervention (PCI) with and without the use of intravascular ultrasound (IVUS).

BACKGROUND

A higher rate of adverse cardiac events is associated with PCI of ostial lesions as compared with nonostial disease.

METHODS

From 7/2002 to 8/2010, 225 patients with 233 coronary ostial lesions underwent PCI with (n = 82) and without (n = 143) IVUS guidance. Ostial lesions included both native aorto-ostial or major coronary vessel (left anterior descending, left circumflex, and ramus intermedius) lesions. Clinical outcomes [cardiovascular death, myocardial infarction (MI), and target lesion revascularization (TLR)] at a mean follow-up of 4.2 ± 2.5 years were compared between patients undergoing PCI of an ostial lesion with and without use of IVUS using univariate and propensity score adjusted analyses.

RESULTS

Aorto-ostial lesions (n = 109) comprised 47% of lesions, whereas the remaining lesions (53%) involved major coronary vessels. After propensity score adjustment, IVUS use was associated with lower rates of the composite of cardiovascular death, MI, or TLR (HR 0.54, 95% CI 0.29-0.99; P = 0.04), composite MI or TLR (HR 0.39, 95% CI 0.18-0.83; P = 0.01), and MI (HR 0.31, 95% CI 0.11-0.85; P = 0.02) as compared with no IVUS. The use of IVUS was also associated with a trend towards a lower rate of TLR (HR 0.42, 95% CI 0.17-1.02; P = 0.06).

CONCLUSIONS

PCI of coronary ostial lesions with the use of IVUS was associated with significantly lower rates of adverse cardiac events.

Stent boost subtract imaging for the assessment of optimal stent deployment in coronary ostial lesion intervention: comparison with intravascular ultrasound

Percutaneous coronary intervention (PCI) of ostial lesions is complex and is technically very demanding. Intravascular ultrasound (IVUS) is considered the gold standard method to guide PCI but has several limitations. Stent boost subtract (SBS) imaging is an enhancement of the radiologic edge of the stent by digital management of regular X-ray images. The purpose of this study was to determine the availability of stent enhancement with SBS during ostial PCI by comparison with IVUS.We investigated SBS and IVUS after stent implantation in 58 ostial lesions in 55 patients. SBS and IVUS were performed in all patients to obtain improved stent location and to detect optimal release and deployment. We defined the SBS and IVUS criteria for accuracy of stent location and adequate stent deployment. IVUS findings showed that stent location was generally good. The location was accurate in 48 (82.8%) and inadequate stent deployment was observed in 10 of 58 (17.2%). Eight SBS images showed inadequate stent expansion. SBS predicted inadequate findings of IVUS with 100% specificity and 80% sensitivity, while a significant positive correlation was observed between SBS-MSA and MSA by IVUS with a regression coefficient of 0.95.Imaging techniques have a primary role during ostial PCI. SBS is a simple and quick method that offers several advantages, enabling improved stent location, adequate stent expansion, and optimal apposition of the struts to the wall. SBS imaging could be conventionally used during ostial PCI, especially in centers where IVUS is not used routinely.

Causes of failure with Szabo technique - an analysis of nine cases

OBJECTIVE

The objective of this case series is to identify and define causes of failure of Szabo technique in rapid-exchange monorail system for ostial lesions.

METHODS AND RESULTS

From March 2009 to March 2011, 42 patients with an ostial lesion were treated percutaneously at our institution using Szabo technique in a monorail stent system. All patients received unfractionated heparin during intervention. Loading dose of clopidogrel, followed by clopidogrel and aspirin was administered. In 57% of patients, drug-eluting stents were used and in 42.8% patients bare metal stents. The stent was advanced over both wires, the target wire and the anchor wire. The anchor wire, which was passed through the proximal trailing strut of the stent helps to achieve precise stenting. The procedure was considered to be successful if stent was placed precisely covering the lesion and without stent loss or anchor wire prolapsing. Of the total 42 patients, the procedure was successful in 33, while failed in 9. Majority of failures were due to wire entanglement, which was fixed successfully in 3 cases by removing and reinserting the anchor wire. Out of other three failures, in one stent dislodgment occurred, stent could not cross the lesion in one and in another anchor wire got looped and prolapsed into target vessel.

CONCLUSION

This case series shows that the Szabo technique, in spite of some difficulties like wire entanglement, stent dislodgement and resistance during stent advancement, is a simple and feasible method for treating variety of ostial lesions precisely compared to conventional angioplasty.