The Value of Intracoronary Imaging and Coronary Physiology When Treating Calcified Lesions

Consensus of National Heart Center and the Saudi Arabian Cardiac Interventional Society on the Current Landscape of the Management of Intracoronary Calcification in Saudi Arabia

Objectives

We aimed to develop a streamlined algorithm for the management of intracoronary calcification that includes guidance on intracoronary imaging and the appropriate selection of atherectomy devices.

Methods

National experts representing both the National Heart Center (NHC) and the Saudi Arabian Cardiac Interventional Society (SACIS) met to develop a consensus document on the assessment and management of intracoronary calcification in Saudi Arabia. The nominal group technique was utilized; a number of statements on the assessment and management of coronary artery calcification were developed based on a systematic review of the literature. The authors discussed the developed statements until a consensus was reached.

Results

Twenty statements were discussed and agreed upon. Invasive and non-invasive imaging modalities in the assessment of coronary artery calcification, and management of intracoronary calcification using calcium ablation techniques, excimer laser coronary atherectomy, ballon-based techniques, and shockwave lithotripsy; were all thoroughly discussed in light of scientific evidence and the experts' clinical practice.

Conclusions

We present a national consensus on the assessment and the multifaceted management of intracoronary calcification in Saudi Arabia.

Coronary intravascular lithotripsy in contemporary practice: challenges and opportunities in coronary intervention

Percutaneous coronary intervention (PCI) of calcified coronary arteries is associated with poor outcomes. Poorly modified calcified lesion hinders the stent delivery, disrupts drug-carrying polymer, impairs drug elution kinetics and results in under-expanded stent (UES). UES is the most common cause of acute stent thrombosis and in-stent restenosis after PCI of calcified lesions. Angiography has poor sensitivity for recognition and quantification of coronary calcium, thereby mandating the use of intravascular imaging. Intravascular imaging, like intravascular ultrasound and optical coherence tomography, has the potential to accurately identify and quantify the coronary calcium and to guide appropriate modification device before stent placement. Available options for the modification of calcified plaque include modified balloons (cutting balloon, scoring balloon and high-pressure balloon), atherectomy devices (rotational atherectomy and orbital atherectomy) and laser atherectomy. Coronary intravascular lithotripsy (IVL) is the newest addition to the tool box for calcified plaque modification. It produces the acoustic shockwaves, which interact with the coronary calcium to cause multiplanar fractures. These calcium fractures increase the vessel compliance and result in desirable minimum stent areas. Coronary IVL has established its safety and efficacy for calcified lesion in series of Disrupt CAD trials. Its advantages over atherectomy devices include ease of use on workhorse wire, ability to modify deep calcium, no debris embolization causing slow flow or no-flow and minimal thermal injury. It is showing promising results in modification of difficult calcified lesion subsets such as calcified nodule, calcified left main bifurcation lesions and chronic total occlusion. In this review, authors will summarize the mechanism of action for IVL, its role in contemporary practice, evidence available for its use, its advantages over atherectomy devices and its imaging insight in different calcified lesion scenarios.

Interobserver Variability Between Expert, Experienced, and Novice Operator Affects Interpretation of Optical Coherence Tomography and 20 MHz Intravascular Ultrasound Imaging

BACKGROUND

Vessel sizing and calcium detection by intracoronary imaging informs optimal strategy during coronary interventions, but image interpretation and analysis software vary considerably between platforms. We compared the interobserver variability of clinicians with a range of experience in assessing co-registered optical coherence tomography (OCT) and 20 MHz solid state intravascular ultrasound (IVUS) vessel/ lumen geometry and quantitative plaque data.

METHODS

Co-registered OCT and IVUS frames at the minimum lumen area (MLA) and 5 frames at 2 mm intervals upstream and downstream were read blinded by an expert, consultant, interventional fellow and registrar to define vessel and lumen sizes, plaque characteristics (arc of calcium and lipid) and presence of OCT-defined thin-capped fibroatheroma (TCFA).

RESULTS

Overall, 143 paired frames of OCT and IVUS were analysed. Excellent consistency was seen for all OCT measures of vessel/luminal geometry irrespective of experience (all intraclass correlation coefficients (ICC) >0.89). Inexperience compromised ICC for IVUS (lumen area ICC 0.56; vessel size ICC 0.65) and overestimated lumen size compared to expert (p < 0.001). Calcium arc agreement for OCT and IVUS was equally strong for all but the most inexperienced reader (ICC >0.84). OCT lipid arc agreement was moderate for experienced readers but poor for all grades of reader with IVUS (ICC 0.24-0.43). OCT-TCFA agreement was moderate between expert and consultant (κ = 0.55) and poor for less experienced readers.

CONCLUSION

OCT dimensions are minimally affected by observer experience and more consistent than IVUS. Inexperienced readers oversize with IVUS. Calcium arc is dependably assessed by IVUS and OCT by all but the most inexperienced reader.

The Impact of Intracoronary Imaging on PCI Outcomes in Cases Utilising Rotational Atherectomy: An Analysis of 8,417 Rotational Atherectomy Cases from the British Cardiovascular Intervention Society Database

Introduction

There is increasing evidence supporting the use of intracoronary imaging to optimize the outcomes of percutaneous coronary intervention (PCI). However, there are no studies examining the impact of imaging on PCI outcomes in cases utilising rotational atherectomy (RA-PCI). Our study examines the determinants and outcomes of using intracoronary imaging in RA-PCI cases including 12-month mortality.

Methods

Using the British Cardiac Intervention Society database, data were analysed on all RA-PCI procedures in the UK between 2007 and 2014. Descriptive statistics and multivariate logistic regressions were used to examine baseline, procedural, and outcome associations with intravascular imaging.

Results

Intracoronary imaging was used in 1,279 out of 8,417 RA-PCI cases (15.2%). Baseline covariates associated with significantly more imaging use were number of stents used, smoking history, previous CABG, pressure wire use, proximal LAD disease, laser use, glycoprotein inhibitor use, cutting balloons, number of restenosis attempted, off-site surgery, and unprotected left main stem (uLMS) PCI. Adjusted rates of in-hospital major adverse cardiac/cerebrovascular events (IH-MACCE), its individual components (death, peri-procedural MI, stroke, and major bleed), or 12-month mortality were not significantly altered by the use of imaging in RA-PCI. However, subgroup analysis demonstrated a signal towards reduction in 12-month mortality in uLMS RA-PCI cases utilising intracoronary imaging (OR 0.67, 95% CI 0.44–1.03).

Conclusions

Intracoronary imaging use during RA-PCI is associated with higher risk of baseline and procedural characteristics. There were no differences observed in IH-MACCE or 12-month mortality with intracoronary imaging in RA-PCI.

Safety and procedural outcomes of intravascular lithotripsy in calcified coronaries in Indian patients

OBJECTIVE

Calcified coronaries still remain a major challenge for interventional cardiologist. This study aims to evaluate safety and efficacy of intravascular lithotripsy (IVL) in management of coronary artery calcification.

METHODS

This was a retrospective single centre study regarding the utility of IVL in management of calcified coronaries. Patients with hemodynamically stable acute coronary syndrome or symptomatic chronic coronary syndrome (CCS) and calcified coronaries on angiography and who underwent IVL were enrolled. Intravascular imaging was performed wherever feasible. The primary endpoint was procedural success. In addition, data regarding procedural complications were collected.

RESULTS

A total of 29 patients underwent IVL with a majority being males and having comorbidities such as hypertension and diabetes. A procedural success rate of 93.1% was achieved with no patient having >50% residual stenosis. IVL catheter was successfully delivered in all patients. The mean catheter diameter was 3.3 ± 0.4 mm and mean number of delivered pulses was 70.3 ± 16.4. The arteries most commonly intervened were the left main coronary and the left anterior descending artery. Intracoronary imaging revealed a significant increase in minimum luminal cross-sectional area (MLA) post IVL (pre-MLA: 5.1 ± 2.5 mm2; post-MLA: 10.7 ± 2.9 mm2; P<0.001). Two patients had in-hospital MACE in form of peri-procedural non Q-wave MI. No patient had arrhythmias, stent thrombosis, coronary perforation, or slow flow/no-reflow. Two patients had a rupture of IVL balloon while four had coronary artery dissection.

CONCLUSIONS

IVL is a safe and highly effective modality with high procedural success rate in management of calcified coronaries.

Improving PCI Outcomes Using Postprocedural Physiology and Intravascular Imaging

Although clinical outcomes after percutaneous coronary intervention (PCI) are improving, the long-term risk for target vessel failure remains concerning. Although the application of intravascular imaging and physiological indexes significantly improves outcomes, their routine use in practice remains limited. Nevertheless, merely using these modalities is not enough, and to truly improve patient outcomes, optimal intravascular dimensions with minimal vascular injury should be targeted. When assessing post-PCI results using either type of physiological or imaging technology, a broad spectrum of stent- and vessel-related anomalies can be expected. As not all of these issues warrant treatment, a profound knowledge of what to expect and how to recognize and when to treat these intraluminal problems is needed. Additionally, promising new modalities such as angiography-derived coronary physiology and hybrid imaging catheters are becoming available. The authors provide an overview of the currently available tools and techniques to define suboptimal PCI and when to apply these technologies to improve outcomes.

Successful off-label use of rotational atherectomy in ST-segment elevation myocardial infarction: A case report

Rotational atherectomy (RA) in ST-segment elevation myocardial infarction (STEMI) is uncommon and its use in a thrombotic lesion is labelled a contraindication by its manufacturer due to the concern for further increase in platelet activation and aggregation by the spinning burr or distal embolization of the thrombotic material promoting no-reflow (NR). However, thrombus burden varies significantly in the STEMI setting and can be classified according to the thrombolysis in myocardial infarction (TIMI) thrombus grade (TG). This case demonstrates the successful off-label use of RA-assisted primary percutaneous coronary intervention to facilitate treatment of a heavily calcified ostial right coronary artery lesion with low thrombotic burden (TIMI TG 0) in an octogenarian STEMI patient. Atherectomy drug cocktails, intracoronary vasodilators, short burr runs and avoidance of rotating the burr at slower than minimum approved rotational speed contribute to atherectomy success and decrease the chances of NR.

Super high-pressure balloon versus scoring balloon to prepare severely calcified coronary lesions: the ISAR-CALC randomised trial

BACKGROUND

The comparative efficacy of balloon-based techniques to prepare severely calcified coronary lesions before stenting remains poorly studied.

AIMS

We sought to compare stent expansion following preparation of severely calcified coronary lesions with either a super high-pressure balloon or a scoring balloon.

METHODS

In this randomised, open-label trial, patients with severely calcified coronary lesions were enrolled at five centres in Germany and Switzerland. After unsuccessful lesion preparation with a standard non-compliant balloon (<30% reduction of baseline diameter stenosis), participants were randomised to predilation with either a super high-pressure balloon or a scoring balloon before drug-eluting stent (DES) implantation. The primary endpoint of the study was stent expansion index as assessed by optical coherence tomography (OCT). The key secondary endpoints included angiographic, strategy and procedural success.

RESULTS

OCT data after DES implantation were available for 70 out of 74 patients (94.6%) enrolled. Lesion preparation with a super high-pressure balloon versus a scoring balloon led to a comparable stent expansion index (0.72±0.12 vs 0.68±0.13; p=0.22). Compared with the scoring balloon, the super high-pressure balloon increased the minimum lumen diameter (2.83±0.34 mm vs 2.65±0.36 mm; p=0.03) and reduced the diameter stenosis (11.6±4.8% vs 14.4±5.6%; p=0.02) without difference in terms of angiographic success (100% vs 97.3%; p>0.99). Strategy success (91.9% vs 83.8%; p=0.48) and procedural success (100% vs 89.2%; p=0.12) were numerically more frequent with the super high-pressure balloon versus the scoring balloon.

CONCLUSIONS

In patients with severely calcified coronary artery lesions, preparation with a super high-pressure balloon versus a scoring balloon was associated with comparable stent expansion on intravascular imaging and a trend towards improved angiographic performance. Visual summary. A ComparIson of Strategies to PrepAre SeveRely CALCified Coronary Lesions: the ISAR-CALC randomised trial.

Shockwave coronary intravascular lithotripsy system for heavily calcified de novo lesions and the need for a cost-effectiveness analysis

The optimal management for severely calcified coronary artery disease is multi-adjunctive. Different strategies with dedicated devices should be available in the cardiac catheterization laboratory with their selection depending on the nature of the calcific disease and its anatomical distribution. Shockwave Intravascular Lithotripsy (S-IVL) system offers a novel option for lesion preparation of heavily calcified plaques in coronary and peripheral vessels. S-IVL is based on the fundamental principles of lithotripsy, a technology that has been used to modify renal stones for over 30 years. Pulsatile mechanical energy is used to fragment selectively amorphous calcium, sparing soft tissue. S-IVL has the potential of more widespread adoption because of its proven safety, efficacy and operational simplicity, but cost-effectiveness of such advanced technology will need to be analyzed.

Optical coherence tomography-guided management of underexpanded stent in calcified coronary lesion

Calcified lesions often result in undilatable lesions, balloon dog-boning, poor device delivery as well as underexpanded stents (UES). This leads to an increased risk of acute and chronic stent failure. A 49-year-old man was admitted with anterior wall myocardial infarction and angiogram showed a diffuse calcific left anterior descending artery/diagonal lesion, which was stented with two overlapping drug-eluting stents. Angiogram after post-dilatation showed UES. Optical coherence tomography (OCT) confirmed UES with 58% expansion, minimum stent area (MSA) of 2.91 mm² and 360° calcium arc around the stent. This UES was dilated with a ultra high-pressure balloon (UHPB) at 40 atmosphere, that led to calcium fracture and increased MSA to 7.42 mm² and stent expansion to 97%. While OCT-guided lesion modification prior to stenting is ideal, OCT-guided assessment and management is also invaluable post-percutaneous coronary intervention. In the event of stent underexpansion, UHPB may be used as an initial management strategy.

Percutaneous Coronary Revascularization in Patients With Single Coronary Artery

INTRODUCTION

Single coronary artery (SCA) is a rare congenital coronary anomaly. Its incidence in various angiographic series is from 0.024% to 0.066%. Percutaneous coronary intervention (PCI) of coronary artery disease (CAD) in these patients is technically challenging.

METHODS

We retrospective analyzed the cardiac catheterization procedures of last 15 years and found 12 cases of SCA (incidence 0.084%). To determine the course of anomalous coronaries, angiographic "dot and eye" method and computed tomography (CT) were used. The course of the SCA was classified as per the modified Lipton criteria. PCI was performed as per the standard protocol for a significant epicardial coronary artery stenosis.

RESULTS

Out of total 12 patients of SCA, 9 patients had PCI of significant CAD. The mean age of 9 PCI patients was 63.8 ± 8.2 years (5 males, 4 females). The origin of the SCA was from the right sinus of Valsalva in 6 cases and from left sinus of Valsalva in 3 cases. Eleven successful PCI procedures were performed, which included PCI of left main, coronary bifurcation lesion, chronic total occlusion, and multi-vessel disease. Four patients had intravascular imaging and 3 patients had rotablation of calcified lesions.

CONCLUSION

PCI of SCA is technically challenging, which requires considerable expertise and experience. An appropriate selection of hardware along with technical expertise can make the procedure simpler with optimal end results.