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

Comparison of intravascular lithotripsy and rotational atherectomy for the treatment of heavily calcified coronary lesions: the STIFF ( S tenoses with calcificaTIon treated with angioplasty e FF ected with dedicated interventional tools) study

BACKGROUND

Percutaneous coronary interventions in heavily calcified coronary lesions are associated with technical difficulties and the worse prognosis. Lesion preparation is important to reduce complications and improve outcomes. The aim of this study is to compare the results of rotational atherectomy (RA) and intravascular lithotripsy (IVL) at achieving optimal stent implantation using intravascular ultrasound criteria.

METHODS

Retrospective, single-center study comparing patients with heavily calcified coronary lesions that underwent percutaneous coronary interventions using RA or IVL.

RESULTS IN TOTAL

25 patients (13 in the RA group and 12 in the IVL group) were included. Reference vessel diameter was similar between the groups [2.59 (2.51-3.63) mm in the RA group vs. 2.79 (2.59-3.16) mm in the IVL group; P  = 0.89], as were minimal lumen area [1.02 (0.80-1.23) mm vs. 1.40 (1.01-1.40) mm; P  = 0.43] and diameter stenosis [60.4% (52.3-72.3) vs. 56.1% (47.8-61.3); P  = 0.56). The final minimal lumen area was significantly larger in the IVL group [7.6 mm 2 (5.8-8.6) vs. 5.4 mm 2 (4.5-6.2); P  = 0.01] as were lumen area gain [4.1 mm 2 (2.6-5.9) vs. 2.3 mm 2 (1.4-3.6); P  = 0.01] and final stent volume [491.2 mm 3 (372.2-729.8) vs. 326.2 mm 3 (257.1-435.4); P  = 0.03]. In the RA group, 69.2% of the patients achieved the preestablished intravascular ultrasound-based criteria for successful stent implantation, vs. 100% of the patients in the IVL group ( P  = 0.04).

CONCLUSION

Patients in the IVL group achieved the Intravascular Ultrasound Versus Angiography-Guided Drug-Eluting Stent Implantation trial criteria of successful stent implantation more frequently than those treated with RA.

Coronary Artery Calcium and Aging: Physiological Basis, Assessment, and Treatment Options in Percutaneous Coronary Intervention

Coronary artery calcification is a complex anatomical and histological pathology with different pathways that contribute to calcium deposit and calcification progression. As part of the atherosclerotic process, extensive calcifications are becoming more common and are associated with poorer PCI outcomes if not properly addressed. Since no drug has shown to be effective in changing this process once it is started, proper knowledge of the underlying pathogenesis and how to diagnose and manage it is essential in contemporary coronary intervention. Atherosclerosis is a pandemic disease, quickly spreading across the world and not limited anymore to the industrialized Western world. In this paper, we review the role of intracoronary imaging and the main technologies available and propose a simple and rational algorithm for the choice of a preferential first strategy in the treatment of severely calcified coronary atherosclerosis, followed by three emblematic cases on how we successively applied it.

Feasibility of in vitro calcification plaque disruption using ultrasound-induced microbubble inertial cavitation

Percutaneous transluminal coronary angioplasty (PTCA) is a clinical method in which plaque-narrowed arteries are widened by inflating an intravascular balloon catheter. However, PTCA remains challenging to apply in calcified plaques since the high pressure required for achieving a therapeutic outcome can result in balloon rupture, vessel rupture, and intimal dissection. To address the problem with PTCA, we hypothesized that a calcified plaque can be disrupted by microbubbles (MBs) inertial cavitation induced by ultrasound (US). This study proposed a columnar US transducer with a novel design to generate inertial cavitation at the lesion site. Experiments were carried out using tubular calcification phantom to mimic calcified plaques. After different parameters of US + MBs treatment (four types of MBs concentration, five types of cycle number, and three types of insonication duration; n = 4 in each group), inflation experiments were performed to examine the efficacy of cavitation for a clinically used balloon catheter. Finally, micro-CT was used to investigate changes in the internal structure of the tubular plaster phantoms. The inflation threshold of the untreated tubular plaster phantoms was > 11 atm, and this was significantly reduced to 7.4 ± 0.7 atm (p = 5.2E-08) using US-induced MBs inertial cavitation at a treatment duration of 20 min with an acoustic pressure of 214 kPa, an MBs concentration of 4.0 × 108 MBs/mL, a cycle number of 100 cycles, and a pulse repetition frequency of 100 Hz. Moreover, micro-CT revealed internal damage in the tubular calcification phantom, demonstrating that US-induced MBs inertial cavitation can effectively disrupt calcified plaques and reduce the inflation threshold of PTCA. The ex vivo histopathology results showed that the endothelium of pig blood vessels remained intact after the treatment. In summary, the results show that US-induced MBs inertial cavitation can markedly reduce the inflation threshold in PTCA without damaging blood vessel endothelia, indicating the potential of the proposed treatment method.

Intravascular lithotripsy during percutaneous coronary intervention: current concepts

INTRODUCTION

Coronary artery calcification (CAC) is commonly encountered by interventional cardiologists. Severe CAC may impair stent delivery or result in stent underexpansion, stent thrombosis and/or in-stent restenosis (ISR). Multiple tools have been developed to help overcome the challenges associated with CAC and improve outcomes for these patients. Intravascular shockwave lithotripsy (IVL) is a novel therapy that uses acoustic pressure waves for the modification of CAC.

AREAS COVERED

This review discusses the growing body of evidence to support the safety and efficacy of IVL in the setting of de novo severely calcified coronary arteries prior to stenting. We also discuss international real world experience with the coronary IVL system. This includes the use of IVL in the setting of acute coronary syndrome (ACS), ISR and in combination with other tools for calcium modification.

EXPERT OPINION

IVL is a safe and effective therapy that results in the fracture of coronary calcium and facilitates optimal stent delivery and expansion. Longer term follow up is essential to shed light on the durability and late outcomes of an IVL strategy. Randomised control trials are warranted to compare IVL to alternative methods of calcium modification and to explore further the use of IVL for ACS.

Coronary lithotripsy - a state of the art review

Lesion calcification is frequently encountered during percutaneous coronary intervention and has been directly linked to procedural complications and future cardiac events. Intravascular lithotripsy is a novel balloon-based modality that does not rely on barotrauma or debulking, but converts electrical energy into mechanical energy creating sonic pressure waves that selectively disrupt calcium. The present review provides an overview of its mechanism of action, the available evidence on its safety and efficacy and indications for use.