Impact of coronary calcium morphology on intravascular lithotripsy

BACKGROUND

Coronary calcification negatively impacts optimal stenting. Intravascular lithotripsy (IVL) is a new calcium modification technique.

AIMS

We aimed to assess the impact of different calcium morphologies on IVL efficacy.

METHODS

This was a prospective, multicentre study (13 tertiary referral centres). Optical coherence tomography (OCT) was performed before and after IVL, and after stenting. OCT-defined calcium morphologies were concentric (mean calcium arc >180°) and eccentric (mean calcium arc ≤180°). The primary outcomes were angiographic success (residual stenosis <20%) and the presence of fracture by OCT in concentric versus eccentric lesions.

RESULTS

Ninety patients were included with a total of 95 lesions: 47 concentric and 48 eccentric. The median number of pulses was 60 (p=1.00). Following IVL, the presence of fracture was not statistically different between groups (79.0% vs 66.0% for concentric vs eccentric; p=0.165). The number of fractures/lesion (4.2±4.4 vs 2.3±2.8; p=0.018) and ≥3 fractures/lesion (57.1% vs 34.0%; p=0.029) were more common in concentric lesions. Angiographic success was numerically but not statistically higher in the concentric group (87.0% vs 76.6%; p=0.196). By OCT, no differences were noted in final minimum lumen area (5.9±2.2 mm2 vs 6.2±2.1 mm2; p=0.570), minimum stent area (5.9±2.2 mm² vs 6.25±2.4 mm2; p=0.483), minimum stent expansion (80.9±16.7% vs 78.2±19.8%), or stent expansion at the maximum calcium site (100.6±24.2% vs 95.8±27.3%) (p>0.05 for all comparisons of concentric vs eccentric, respectively). Calcified nodules were found in 29.5% of lesions; these were predominantly non-eruptive (57%). At the nodule site, dissection was more common than fracture with stent expansion of 103.6±27.2%.

CONCLUSIONS

In this prospective, multicentre study, the effectiveness of IVL followed by stenting was not significantly affected by coronary calcium morphology.

Prevalence and anatomical factors associated with stent under-expansion in non-severely calcified lesions

BACKGROUND

Stent underexpansion, typically related to lesion calcification, is the strongest predictor of adverse events after percutaneous coronary intervention (PCI). Although uncommon, underexpansion may also occur in non-severely calcified lesions.

AIM

We sought to identify the prevalence and anatomical characteristics of underexpansion in non-severely calcified lesions.

METHODS

We included 993 patients who underwent optical coherence tomography-guided PCI of 1051 de novo lesions with maximum calcium arc <180°. Negative remodeling (NR) was the smallest lesion site external elastic lamina diameter that was also smaller than the distal reference. Stent expansion was evaluated using a linear regression model accounting for vessel tapering; underexpansion required both stent expansion <70% and stent area <4.5mm2.

RESULTS

Underexpansion was observed in 3.6% of non-heavily calcified lesions (38/1051). Pre-stent maximum calcium arc and thickness were greater in lesions with versus without underexpansion (median 119° vs. 85°, p = 0.002; median 0.95 mm vs. 0.78 mm, p = 0.008). NR was also more common in lesions with underexpansion (44.7% vs. 24.5%, p = 0.007). In the multivariable logistic regression model, larger and thicker eccentric calcium, mid left anterior descending artery (LAD) location, and NR were associated with underexpansion in non-severely calcified lesions. The rate of underexpansion was especially high (30.7%) in lesions exhibiting all three morphologies. Two-year TLF tended to be higher in underexpanded versus non-underexpanded stents (9.7% vs. 3.7%, unadjusted hazard ratio [95% confidence interval] = 3.02 [0.92, 9.58], p = 0.06).

CONCLUSION

Although underexpansion in the absence of severe calcium (<180°) is uncommon, mid-LAD lesions with NR and large and thick eccentric calcium were associated with underexpansion.

Coronary intravascular lithotripsy and rotational atherectomy for severely calcified stenosis: Results from the ROTA.shock trial

BACKGROUND

Severely calcified coronary lesions present a particular challenge for percutaneous coronary intervention.

AIMS

The aim of this randomized study was to determine whether coronary intravascular lithotripsy (IVL) is non-inferior to rotational atherectomy (RA) regarding minimal stent area (MSA).

METHODS

The randomized, prospective non-inferiority ROTA.shock trial enrolled 70 patients between July 2019 and November 2021. Patients were randomly (1:1) assigned to undergo either IVL or RA before percutaneous coronary intervention of severely calcified coronary lesions. Optical coherence tomography was performed at the end of the procedure for primary endpoint analysis.

RESULTS

The primary endpoint MSA was lower but non-inferior after IVL (mean: 6.10 mm2 , 95% confidence interval [95% CI]: 5.32-6.87 mm2 ) versus RA (6.60 mm2 , 95% CI: 5.66-7.54 mm2 ; difference in MSA: -0.50 mm2 , 95% CI: -1.52-0.52 mm2 ; non-inferiority margin: -1.60 mm2 ). Stent expansion was similar (RA: 0.83 ± 0.10 vs. IVL: 0.82 ± 0.11; p = 0.79). There were no significant differences regarding contrast media consumption (RA: 183.1 ± 68.8 vs. IVL: 163.3 ± 55.0 mL; p = 0.47), radiation dose (RA: 7269 ± 11288 vs. IVL: 5010 ± 4140 cGy cm2 ; p = 0.68), and procedure time (RA: 79.5 ± 34.5 vs. IVL: 66.0 ± 19.4 min; p = 0.18).

CONCLUSION

IVL is non-inferior regarding MSA and results in a similar stent expansion in a random comparison with RA. Procedure time, contrast volume, and dose-area product do not differ significantly.

Comparison of Coronary Intravascular Lithotripsy and Rotational Atherectomy in the Modification of Severely Calcified Stenoses

Debulking techniques are often necessary for successful lesion preparation in percutaneous coronary intervention. The aim of this study was to compare plaque modification of severely calcified lesions by coronary intravascular lithotripsy (IVL) with that of rotational atherectomy (RA) using optical coherence tomography (OCT). ROTA.shock was a 1:1 randomized, prospective, double-arm, multicenter noninferiority trial designed to compare final minimal stent area after IVL with RA for lesion preparation in percutaneous coronary interventional treatment of severely calcified lesions. On the basis of OCT acquired before and immediately after IVL or RA in 21 of the 70 patients included, we performed a detailed analysis of the modification of the calcified plaque. After RA and IVL, calcified plaque fractures were present in 14 of the patients (67%), with a significantly greater number of fractures after IVL (3.23 ± 0.49) than after RA (1.67 ± 0.52; p < 0.001). Plaque fractures after IVL were longer than after RA (IVL: 1.67 ± 0.43 mm vs RA: 0.57 ± 0.55 mm; p = 0.01), resulting in a greater total volume of the fractures (IVL: 1.47 ± 0.40 mm³ vs RA: 0.48 ± 0.27 mm³; p = 0.003). Use of RA was associated with a greater acute lumen gain than was use of IVL (RA: 0.46 ± 0.16 mm² vs IVL: 0.17 ± 0.14 mm²; p = 0.03). In conclusion, we were able to show differences in plaque modification of calcified coronary lesions by OCT: although RA leads to a greater acute lumen gain, IVL induces more and longer fractures of the calcified plaque.

Rotational Atherectomy or Balloon-Based Techniques to Prepare Severely Calcified Coronary Lesions

BACKGROUND

The comparative efficacy of percutaneous techniques for the preparation of calcified lesions before stenting remains poorly studied.

OBJECTIVES

This study sought to compare the performance of up-front rotational atherectomy (RA) or balloon-based techniques before drug-eluting stent implantation in severely calcified coronary lesions as assessed by angiography and optical coherence tomography (OCT).

METHODS

Patient-level data from the PREPARE-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) and ISAR-CALC (Comparison of Strategies to Prepare Severely Calcified Coronary Lesions) randomized trials were pooled. The primary endpoint was stent expansion as assessed by OCT imaging. The secondary endpoints included stent eccentricity, stent asymmetry, angiographic acute lumen gain, strategy success and in-hospital occurrence of cardiac death, target vessel myocardial infarction, and repeat revascularization.

RESULTS

Among 274 patients originally randomized, 200 participants with available OCT data after lesion preparation with RA (n = 63), a modified balloon (MB, n = 103), or a super high-pressure balloon (n = 34) before stenting were analyzed. The use of RA versus MB or a super high-pressure balloon led to comparable stent expansion (73.2% ± 11.6% vs 70.8% ± 13.6% vs 71.8% ± 12.2%, P = 0.49) and stent asymmetry (P = 0.83). Compared with RA or MB, a super high-pressure balloon was associated with less stent eccentricity (P = 0.03) with a numerically higher acute lumen gain, albeit not significantly different (P = 0.08). Strategy success was more frequent with RA versus MB (P = 0.002) and numerically more frequent with RA versus a super high-pressure balloon (P = 0.06). Clinical outcomes did not differ between groups.

CONCLUSIONS

In patients with severely calcified lesions undergoing drug-eluting stent implantation, lesion preparation with RA, MB, or a super high-pressure balloon was associated with comparable stent expansion. A super high-pressure balloon is associated with less stent eccentricity, whereas strategy success is more frequent with RA.

Optical Coherence Tomography Assessment in Patients Treated With Rotational Atherectomy Versus Modified Balloons: PREPARE-CALC OCT

[Figure: see text].

Multimodality intravascular imaging of bioresorbable vascular scaffolds implanted in vein grafts

Introduction

There are no data presenting a serial assessment of vein graft healing after bioresorbable vascular scaffold (BVS) implantation at long-term follow-up.

Aim

To describe ABSORB BVS healing in vein grafts by optical coherence tomography (OCT) and high-definition intravascular imaging (HD-IVUS) at long-term follow-up.

Material and methods: The study group consisted of 6 patients. The first patient had serial OCT assessment of BVS implanted in the saphenous vein grafts (SVG) at baseline and at 3-, 6-, 18-month follow-up and the second patient had OCT assessment of BVS implanted in the SVG at baseline and 24-, 48-month follow-up. The second and the third patients had OCT and HD-IVUS imaging at baseline and 48-month follow-up. The last 3 patients had OCT imaging of BVS implanted in the native coronary artery at 48-month follow-up.

Results

There were no differences in neointimal hyperplasia after BVS implantation between each time point. However, complete scaffold coverage was observed only 48 months after implantation. Out of 202 analyzed scaffold struts, there were 67 (33%) black boxes detectable at 48-month follow-up. HD-IVUS presented plaque burden up to 67% at the segment of BVS implantation at 48-months follow-up. There was a difference in neointimal hyperplasia thickness (1.27 (0.953–1.696) vs. 0.757 (0.633–0.848), p < 0.001) between a native coronary artery and BVS scaffolds at 48-month follow-up.

Conclusions

Bioresorbable vascular scaffold implanted in SVG characterized moderate neointimal hyperplasia as excessive as compared to native coronary arteries at long-term follow-up. The complete scaffold coverage was observed only 48 months after implantation.

Neoatherosclerosis 5 Years After Bioresorbable Vascular Scaffold Implantation

BACKGROUND

Data regarding neoatherosclerosis after everolimus-eluting bioresorbable vascular scaffold (BVS) (ABSORB BVS Rev. 1.1, Abbott Vascular, Santa Clara, California) implantation are limited.

OBJECTIVES

This study investigated the findings of neoatherosclerosis at 5 years after BVS 1.1 implantation by using multi-imaging modalities, including optical coherence tomography (OCT).

METHODS

Patients included in the ABSORB EXTEND (ABSORB EXTEND Clinical Investigation) trial at Shonan Kamakura General Hospital underwent OCT at baseline after the index procedure and at 1 and 5 years. Intimal plaque distributions in the in-scaffold and out-scaffold segments were analyzed.

RESULTS

Twenty patients (22 lesions) with stable angina pectoris were enrolled. The median follow-up duration was 67 months (interquartile range: 65 to 69 months), and the mean age was 69 ± 8 years. Patients with diabetes mellitus (25%) were included. Based on the baseline angiogram, 10 (46%) lesions were type B2/C lesions. At 1 and 5 years of follow-up, significant differences in the prevalence of in-scaffold lipid-laden neointima (17% vs. 61%; p = 0.04), calcification (28% vs. 94%; p < 0.01), neovascularization (6% vs. 78%; p < 0.01), and thin-cap fibroatheroma (0% vs. 22%; p = 0.02) were found. In the out-scaffold segments, no significant difference in the plaque prevalence between 1 and 5 years was noted.

CONCLUSIONS

The occurrence and progression of in-scaffold neoatherosclerosis with luminal narrowing was observed at 5 years after BVS 1.1 implantation. The small size of the current study warrants confirmation in larger study. (ABSORB EXTEND Clinical Investigation [ABSORB EXTEND]; NCT01023789).

Predictors of bioresorbable scaffold failure in STEMI patients at 3 years follow-up

BACKGROUND

Little data are available on the long-term outcomes of bioresorbable scaffold (BRS) in the setting of ST-segment elevation myocardial infarction (STEMI). The aim of this study is to investigate three-years outcomes and predictors of BRS failure in patients presenting with STEMI.

METHODS AND RESULTS

Two prospective, single-arm registries were pooled. Incidence and predictors of clinical outcome were assessed with Kaplan-Meier and Cox regression analyses. From May-2012 to January-2015, 183 STEMI patients (58 ± 13 years, 77% males, 29% diabetics) who received a total of 256 BRS (1.4 ± 0.8 per patient) were included. 248 patients (65 ± 11 years, 74% males, 27% diabetics) treated for stable coronary artery disease (SCAD) served as control. 3-years follow-up was available in 386 (90%) patients. Device-oriented composite endpoint and scaffold thrombosis (ScT) rates were similar in the two groups (STEMI: 11.5% vs SCAD: 12.9%, P = 0.84; STEMI: 3.6% vs SCAD: 3.3%, P = 0.90). While early ScT was more frequent in SCAD patients, late/very late ScT was a feature of STEMI. While in STEMI patients the incidence of ScT was higher in vessels with RVD > 3.5 mm, a RVD < 2.5 mm was a predictor of events in stable patients. Similarly, BRS undersizing predicted events in STEMI patients, while oversizing was a predictor in stable ones. Finally, the incidence of ScT was reduced in both STEMI and stable patients (from 6.3% to 0% and from 5.80% to 0.9%) when an optimized implantation technique was used.

CONCLUSIONS

The incidence of events for three years follow-up was similar in STEMI and SCAD patients, although different timing and features underlie ScT in the two groups.

Serial Optical Coherence Tomography at Baseline, 7 Days, and 1, 3, 6 and 12 Months After Bioresorbable Scaffold Implantation in a Growing Porcine Model

BACKGROUND

Little is known about serial changes in lumen and device dimensions after bioresorbable scaffold implantation in a growing animal model. Methods and Results: ABSORB (n=14) or bare metal stents (ICROS amg [Abbott Vascular, Santa Clara, CA, USA], Winsen-Luhe, Germany; n=15) were implanted in the coronary arteries of domestic swine (a hybrid of Finnish-Norwegian Landrace swine) weighing 30-35 kg. Angiography and optical coherence tomography (OCT) were performed immediately after implantation and repeated at 7 days, 1, 3, 6 and 12 months after the index procedure. One month after implantation, mean lumen area decreased relative to baseline in both groups (relative area change from baseline, -41.4±15.6% for ABSORB vs. -20.9±18.6% for ICROS) while mean device area decreased only in the ABSORB group (relative area change: -11.1±9.4% vs. +0.14±7.95%, respectively). At 12 months, mean lumen area increased relative to baseline in both groups (relative area change from baseline, +55.6±22.4% vs. +32.3±83.6%, respectively) in accordance with the swine growth weighing up to 260-300 kg. Mean device area in the ICROS group remained stable whereas that in the ABSORB group began to increase between 3 and 6 months along with the vessel growth (relative area change: +107.8±25.7% vs. +0.14±7.95%).

CONCLUSIONS

In the growing porcine model, ABSORB was associated with greater extent of recoil 1 month after implantation compared with ICROS but demonstrated substantial adaptability to vessel growth in late phase.