Intravascular laser lithotripsy for calcium fracture in human coronary arteries

BACKGROUND

Electrical intravascular lithotripsy (E-IVL) uses shock waves to fracture calcified plaque.

AIMS

We aimed to demonstrate the ability of laser IVL (L-IVL) to fracture calcified plaques in ex vivo human coronary arteries and to identify and evaluate the mechanisms for increased vessel compliance.

METHODS

Shock waves were generated by a Ho:YAG (Holmium: yttrium-aluminium-garnet) laser (2 J, 5 Hz) and recorded by a high-speed camera and pressure sensor. Tests were conducted on phantoms and 19 fresh human coronary arteries. Before and after L-IVL, arterial compliance and optical coherence tomography (OCT) pullbacks were recorded, followed by histology. Additionally, microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) were performed. Finite element models (FEM) were utilised to examine the mechanism of L-IVL.

RESULTS

Phantom cracks were obtained using 230 μm and 400 μm fibres with shock-wave pressures of 84±5.0 atm and 62±0.4 atm, respectively. Post-lithotripsy, calcium plaque modifications, including fractures and debonding, were identified by OCT in 78% of the ex vivo calcified arteries (n=19). Histological analysis revealed calcium microfractures (38.7±10.4 μm width) in 57% of the arteries which were not visible by OCT. Calcium microfractures were verified by micro-CT and SEM. The lumen area increased from 2.9±0.4 to 4.3±0.8 mm2 (p<0.01). Arterial compliance increased by 2.3±0.6 atm/ml (p<0.05). FEM simulations suggest that debonding and intimal tears are additional mechanisms for increased arterial compliance.

CONCLUSIONS

L-IVL has the capability to increase calcified coronary artery compliance by multiple mechanisms.

Outcomes of Orbital Atherectomy for the Treatment of Severely Calcified Coronary Artery Lesions

Background Orbital atherectomy (OA) is used to prepare severely calcified coronary artery lesions before percutaneous coronary intervention (PCI). Intravascular ultrasound (IVUS) is used to determine the plaque volume and degree of stenosis within the arterial vessel. This study evaluated the safety and efficacy of OA for treating severely calcified coronary lesions and determined if IVUS impacted these outcomes. Methods We retrospectively collected data from a single center of patients with severe coronary artery calcification who underwent OA. The data on baseline characteristics and procedural and clinical outcomes were collected and analyzed. Results A total of 374 patients underwent OA. The mean age was 69 ± 12.7; 53.6% were Black, and 38% were female. Hypertension was present in 96% of the patients, followed by hyperlipidemia in 79.4%, diabetes mellitus in 53.7%, and chronic kidney disease (CKD) in 22.7%. More patients had presented with a non-ST-elevation myocardial infarction (NSTEMI) compared to ST-elevation myocardial infarction (STEMI) at 36.3% versus 4.3%, respectively. The radial artery was used in 35.4% of the cases, and the left anterior descending artery (LAD) was the most commonly treated vessel with OA at 61%, followed by the right coronary artery (RCA) at 30.7%. IVUS was utilized in 63.4% of cases. The most common complication of the procedure was perforation and dissection at an equal proportion of 1.3% among all patients. The no-reflow rate was 0.5%, and 0.5% developed post-procedural myocardial infarction (MI). The average length of stay was 4.7 days, while a marginal proportion, at 10.5%, had same-day discharge with no recorded complications. Conclusion In this analysis of patients with severely calcified coronary lesions, OA had low rates of major adverse cardiovascular events (MACE) and was considered a safe and effective treatment for complex coronary lesions.

Utility of coronary orbital atherectomy with guide-extension system for distally located undilatable in-stent restenosis: A case report

Orbital atherectomy (OA) may be effective in managing undilatable in‐stent restenosis (ISR) despite off‐label indications. We demonstrated that optical frequency domain imaging (OFDI)‐guided OA, with a guide‐extension system was effective even in distally located, undilatable ISR. However, OFDI revealed that inter‐struts calcified neoatherosclerosis remained a challenging issue.

Clinical Characteristics and Outcomes Among Patients Undergoing High-Risk Percutaneous Coronary Interventions by Single or Multiple Operators: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Background High-risk percutaneous coronary intervention (HR-PCI) is increasingly common among contemporary patients with coronary artery disease. Experts have advocated for a collaborative 2-operator approach to support intraprocedural decision-making for these complex interventions. The impact of a second operator on patient and procedural outcomes is unknown. Methods and Results Patients who underwent HR-PCI from 2015 to 2018 within the Veterans Affairs Healthcare System were identified. Propensity-matched cohorts were generated to compare the outcomes following HR-PCI performed by a single or multiple (≥2) operators. The primary end point was the 12-month rate of major adverse cardiovascular events. We identified 6672 patients who underwent HR-PCI during the study period; 6211 (93%) were treated by a single operator, and 461 (7%) were treated by multiple operators, with a nonsignificant trend toward increased multioperator procedures over time. A higher proportion of patients treated by multiple operators underwent left main (10% versus 7%, P=0.045) or chronic total occlusion intervention (11% versus 5%, P<0.001). Lead interventionalists participating in multioperator procedures practiced at centers with higher annual HR-PCI volumes (124±71.3 versus 111±69.2; standardized mean difference, 0.197; P<0.001) but otherwise performed a similar number of HR-PCI procedures per year (34.4±35.3 versus 34.7±30.7; standardized mean difference, 0.388; P=0.841) compared with their peers performing single-operator interventions. In a propensity-matched cohort, there was no significant difference in major adverse cardiovascular events (32% versus 30%, P=0.444) between patients who underwent single-operator versus multioperator HR-PCI. Adjusted analyses accounting for site-level variance showed no significant differences in outcomes. Conclusions Patients who underwent multioperator HR-PCI had similar outcomes compared with single-operator procedures. Further studies are needed to determine if the addition of a second operator offers clinical benefits to a subset of HR-PCI patients undergoing left main or chronic total occlusion intervention.

Outcomes of rotational atherectomy versus orbital atherectomy for the treatment of heavily calcified coronary stenosis: A systematic review and meta-analysis

INTRODUCTION

The optimal approach to deal with severe coronary artery calcification (CAC) during percutaneous coronary intervention (PCI) remains ill-defined.

METHODS

We conducted an electronic database search of all published studies comparing Orbital versus Rotational Atherectomy in patients undergoing PCI.

RESULTS

Eight observational studies were included in the analysis. Overall, there were no significant differences in Major-adverse-cardiac-events/MACE (OR: 0.81, CI: 0.63-1.05, p = .11), myocardial-infarction/MI (OR: 0.75, CI: 0.56-1.00, p = .05), all-cause mortality (OR: 0.82, CI: 0.25-2.64, p = .73) or Target-vessel-revascularization/TVR (OR: 0.72, CI: 0.38-1.36, p = .31). However, OA was associated with lower long-term MACE (1-year), (OR: 0.66, CI: 0.44-0.99, p = .04), long-term TVR (OR: 0.40, CI: 0.18-0.89, p = .03), and short-term MI (in-hospital and 30-day) (OR: 0.64, CI: 0.44-0.94, p = .02). OA was associated with more coronary artery dissections (OR: 2.61, CI: 1.38-4.92, p = .003) and device-related coronary perforations (OR: 2.79, CI: 1.08-7.19, p = .03). There were no differences in cardiac tamponade (OR: 1.78, CI: 0.37-8.69, p = .47). OA was noted to have significantly lower fluoroscopy time (MD: -3.96 min, CI: -7.67, -0.25; p = .04) compared to RA. No significant difference was noted in terms of contrast volume between the two groups (OR: -4.35 ml, CI: -14.52, 23.22; p = .65).

CONCLUSION

Although there was no difference in overall MACE, MI, all-cause mortality and TVR, OA was associated with lower long-term MACE and short-term MI. OA is associated with lower fluoroscopy time but higher rates of coronary artery dissection and coronary perforation.

Short term outcomes of rotational atherectomy versus orbital atherectomy in patients undergoing complex percutaneous coronary intervention: a systematic review and meta-analysis

OBJECTIVE

Coronary artery calcification (CAC) is one of the paramount hurdles for percutaneous coronary intervention (PCI) since it impedes stent delivery and complete expansion. This study intended to evaluate the short-term clinical and procedural outcomes comparing rotational atherectomy (RA) and orbital atherectomy (OA) in patients with heavily calcified coronary lesions undergoing PCI. Design: This systematic review and meta-analysis included all head-to-head published comparisons of coronary RA versus OA. Procedural endpoints and post-procedural clinical outcomes (30 days/in-hospital), were compared. RevMan 5.3 software was used for data analysis. Results: Seven retrospective observational investigations with a total of 4623 patients, including 3203 patients in the RA group and 1420 patients in the OA group, were incorporated. Compared with OA, the RA group was associated with a higher incidence of myocardial infarction at short-term follow-up (OR: 1.56, 95% CI: 1.07-2.29, p = .02, I² = 0%). No difference was noted among other short-term post-procedural clinical outcomes including all-cause mortality, target vessel revascularization, or major adverse cardiac events. Among procedural complications, RA was associated with reduced coronary artery dissection and arterial perforation. Increased fluoroscopy time was observed in the RA cohort as compared with OA (MD: 4.78, 95% CI: 2.25-7.30, p = .0002, I² = 80%). Conclusion: RA was associated with fewer vascular complications, but at a cost of higher incidence of myocardial infarction and higher fluoroscopy time compared with OA, at short term follow-up. OA is a safe and effective alternative for the management of CAC.