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.

Mid-Term Angiographic and Intracoronary Imaging Results Following Intracoronary Lithotripsy in Calcified Coronary Artery Disease: Results From Two Tertiary Referral Centres.

BACKGROUND: Intracoronary lithotripsy (IVL) is a safe and effective treatment for coronary calcification. Angiographic and intracoronary imaging follow-up have not yet been described. We aimed to describe the mid-term angiographic outcomes following IVL. METHODS: Patients successfully treated with IVL in two tertiary referral hospitals were included. Repeat angiography and intracoronary imaging was performed. Quantitative coronary angiography (QCA) and optical coherence tomography (OCT) analyses were performed using dedicated workstations. RESULTS: Twenty patients were included; mean age 67.1 years, left anterior descending artery 55 %. Median IVL balloon size was 3.0 mm and a median of 60 pulses were delivered per vessel. Percentage stenosis by QCA was 60 % [IQR 51-70] reducing to 20 % post stenting (p < 0.001). On OCT, 88.9 % had circumferential calcium. IVL resulted in fractures in 88.9 %. Resulting minimum stent expansion was 91.75 % [IQR 81.5-108]. Follow-up was at a median of 22.7 months [IQR16.4-25.5]. Percentage stenosis by QCA was 22.5 % [IQR 14-30] and not significantly different from the index procedure (p > 0.05). Minimum stent expansion by OCT was 85 % [IQR 72-97]. Late luminal loss was 0.15 mm [IQR -0.25 to 0.69]. Binary angiographic instent restenosis (ISR) was 10 % (2 of 20 patients). OCT demonstrated a predominantly homogenous neointimal pattern with high backscatter. CONCLUSION: Following successful IVL treatment, repeat angiography demonstrated preserved stent parameters in the majority of patients with favorable vascular healing properties by OCT. A binary restenosis rate of 10 % was observed. These results suggest durable results following IVL treatment of severe coronary calcification however larger studies are warranted.

Vascular healing responses to paclitaxel coated balloons or everolimus eluting stents for the treatment of in-stent restenosis. Insights from optical coherence tomography.

BACKGROUND: Treatment of in-stent restenosis (ISR) remains a significant challenge. Current options include repeat stenting or drug-coated balloons. However, there is a paucity of data regarding vascular healing after these strategies. We, aimed to compare optical coherence tomography (OCT)-based vessel healing after treatment with paclitaxel-coated balloons (PCB) or everolimus-eluting stents (EES). METHODS: An OCT substudy (baseline and 6-9 months) of patients from RIBS IV and RIBS V, two prospective multicenter, randomized controlled clinical trials comparing PCB vs. EES in patients with ISR was performed. RESULTS: Sixty-four patients were included (30 PCB and 34 EES). There were no differences in the baseline or angiographic characteristics between groups. Both groups had the same proportion of drug-eluting and bare-metal stent (BMS) ISR. Baseline OCT analysis did not show differences in the qualitative characteristics of the ISR nor the restenotic tissue burden. Follow-up OCT showed a larger mean lumen area in the EES group (6.03 ± 1.5 vs. 5.24 ± 1.3 mm 2 ; P = 0.043) but no difference in angiographic restenosis ( P = 0.66). Percentage tissue coverage was higher with PCB vs. EES (26 ± 13 vs. 19 ± 11%; P = 0.031). EES-treated ISR more frequently had uncovered struts at follow-up [21 (72%) vs. 12 (44%); P = 0.034]. Tissue covering struts more frequently had a high backscatter structure after PCB [21 (78%) vs. 16 (55%); P = 0.07]. CONCLUSIONS: Compared with EES, ISR treated with PCB demonstrated more strut coverage with mainly high backscattering tissue. Larger OCT-defined neointimal proliferation in PCB-treated ISR did not translate into higher angiographic restenosis rates.

Invasive evaluation of coronary microvascular dysfunction.

Coronary microvascular dysfunction (CMD) is a prevalent cause of ischemic heart disease and is associated with poorer quality of life and worse patient outcomes. Both functional and structural abnormalities of the microcirculation can generate ischemia in the absence of epicardial stenosis or worsen concomitant obstructive coronary artery disease (CAD). The invasive assessment of CMD allows for the evaluation of the entirety of the coronary vascular tree, from the large epicardial vessels to the microcirculation, and enables the study of vasomotor function through vasoreactivity testing. The standard evaluation of CMD includes vasomotor assessment with acetylcholine, as well as flow- and resistance-derived indices calculated with either thermodilution or Doppler guidewires. Tailored treatment based upon the information gathered from the invasive evaluation of CMD has been demonstrated to reduce the burden of angina; therefore, a thorough understanding of these procedures is warranted with the aim of improving the quality of life of the patient. This review summarizes the most widespread approaches for the invasive evaluation of CMD, with a focus on patients with ischemia and non-obstructive CAD.

Safety of coronary revascularization deferral based on fractional flow reserve and instantaneous wave-free ratio in patients with chronic kidney disease.

BACKGROUND: The safety of revascularization deferral according to pressure wire examination in patients with chronic kidney disease (CKD) has not been fully established. METHODS: From a retrospective cohort of 439 patients in whom revascularization was deferred after physiological assessment, we examined the incidence of patient-oriented composite endpoint (POCE: all-cause death, myocardial infarction [MI] and unplanned revascularization) in patients with CKD (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m²) and without it. RESULTS: At 4 years of follow-up, the primary endpoint was met by 25.0% of patients with CKD and by 14.4% of patients without CKD (hazard ratio [HR] 1.56, 95% confidence interval [CI] 0.96-2.53, p = 0.071). The incidence of POCE was even higher in patients with an eGFR < 30 mL/min/1.73 m²: 43.8% (HR 3.10, 95% CI 1.08-8.92, p = 0.036). However, no differences were observed in the incidence of MI (4.2% vs. 4.4% in non-CKD), target vessel revascularization (5.8% vs. 5.9%), and target vessel MI (0.8% vs. 4.6%). CONCLUSIONS: Patients with CKD in whom pressure-wire evaluation led to deferral of coronary revascularization develop more POCE in the long term, compared to patients with normal renal function. However, the increase in POCE in patients with CKD was seldom related to deferred vessels, thus suggesting an epiphenomenon of an intrinsically higher cardiovascular risk of CKD patients.