Tissue responses to everolimus-eluting stents implanted in severely calcified lesions following atherectomy

Histopathological examination has revealed that stents on severely calcified plaques were associated with delayed vascular healing. Although atherectomy devices can increase the number of malapposed struts, tissue responses to implanted drug eluting stents in atherectomy patients remain largely unknown. This retrospective observational study included 30 patients who underwent atherectomy and everolimus-eluting stent (EES) deployment for severely calcified coronary lesions (biodegradable polymer EES (BP-EES), n = 15; durable polymer EES (DP-EES), n  = 15). Optical coherence tomography was carried out at baseline and follow-up, and struts with acute stent malapposition (ASM) were categorized as struts on modified calcium (mod-Ca), non-modified calcium (non-mod-Ca), or non-calcium (non-Ca). Adequate vascular healing, defined as ASM resolution with neointimal coverage, was compared between the BP-EES and DP-EES groups. Multivariate linear regression analysis using a generalized estimated equation revealed that BP-EES use was associated with significantly better adequate vascular healing compared with DP-EES (odds ratio [OR]: 3.691, 95% confidence interval [CI] 1.175-11.592, P = 0.025). adequate vascular healing was associated with the underlying plaque morphology (mod-Ca vs non-mod-Ca: OR 2.833, 95% CI 1.491-5.384, P = 0.001; non-Ca vs non-mod-Ca: OR 1.248, 95% CI 0.440-3.543, P = 0.677). This study demonstrates that drug-eluting stent selection and calcium modification are possible factors affecting vascular healing of malapposed struts in severely calcified lesions.

Safety and efficacy of frequency-domain optical coherence tomography in evaluating and treating intermediate coronary lesions

AIM

To establish whether frequency-domain optical coherence tomography (FD-OCT) is safe and effective in the evaluation and treatment of angiographically-intermediate coronary lesions (ICL)

METHODS

Sixty-four patients with 2-dimensional quantitative coronary angiography (2D-QCA) demonstrating ICL were included. OCT imaging was performed. According to predetermined OCT criteria, patients were assigned to either of 2 groups: OCT-guided percutaneous coronary intervention (PCI) or OCT-guided optimal medical therapy (OMT). The primary efficacy endpoint was to demonstrate the superiority and higher accuracy of FD-OCT compared to 2D-QCA in evaluating stenosis severity in patients with ICL. The primary safety endpoint was the incidence of 30-d major adverse cardiac events (MACE). Secondary endpoints included MACE at 12 mo and other clinical events.

RESULTS

Analysis of the primary efficacy endpoint demonstrates that 2D-QCA overestimates the stenosis severity of ICL in both the OCT-guided PCI and OMT groups, proving FD-OCT to be superior to and more precise than 2D-QCA in treating this subset of lesions. The primary safety endpoint was fully met with the incidence of 30-d MACE being nil in both the OCT-guided PCI and OCT-guided OMT groups. Incidences of secondary endpoints were found to be low in both arms, the only exception being the relatively high incidence of recurrent episodes of angina which was, however, very similar in the 2 groups.

CONCLUSION

FD-OCT is safe and effective in the evaluation and treatment of ICL. Larger studies are needed to firmly establish the efficacy and safety of FD-OCT in treating ICL across all coronary artery disease population subgroups.

Difference in plaque characteristics of coronary culprit lesions in a cohort of Egyptian patients presented with acute coronary syndrome and stable coronary artery disease: An optical coherence tomography study

Aims

This study was designed to utilize frequency-domain optical coherence tomography (FD-OCT) for assessment of plaque characteristics and vulnerability in patients with acute coronary syndrome (ACS) compared to stable coronary artery disease (SCAD).

Methods and results

We enrolled 48 patients; divided into an ACS-group (27 patients) and SCAD-group (21 patients) according to their clinical presentation. Hypertension and diabetes mellitus were more prevalent in SCAD group. Patients with ACS showed higher frequency of lipid-rich plaques (96.3% vs. 66.7%, P = .015), lower frequency of calcium plaques (7.4% vs. 57.1%, P < .001), and fibrous plaques (14.8% vs. 81%, P < .001) when compared with SCAD patients. The TCFA (defined as lipid-rich plaque with cap thickness <65 μm) identified more frequently (33.3% vs. 14.3%, P = .185), with a trend towards thinner median fibrous cap thickness (70 (50–180) µm vs. 100 (50–220) µm, P = .064) in ACS group. Rupture plaque (52% vs. 14.3%, P = .014), plaque erosion (18.5% vs. 0%, P = .059) and intracoronary thrombus (92.6% vs. 14.3%, P < .001) were observed more frequently in ACS group, while cholesterol crystals were identified frequently in patients with SCAD (0.0% vs. 33.3%, P = .002).

Conclusion

The current FD-OCT study demonstrated the differences of plaque morphology and identified distinct lesion characteristics between patients with ACS and those with SCAD. These findings could explain the clinical presentation of patients in both groups.

Plaque microstructures in patients with coronary artery disease who achieved very low low-density lipoprotein cholesterol levels

OBJECTIVE

Lowering low-density lipoprotein cholesterol (LDL-C) with statins reduces cardiovascular events and slows plaque progression. While this therapeutic approach has been reported to favorably modify plaque composition, this is not well characterized in humans. Also, the benefit of achieving LDL-C levels below current recommended targets remains unknown. Frequency-domain optical coherence tomography (FD-OCT) enables visualization of plaque microstructures associated with plaque instability. We investigated plaque morphologies in patients with low LDL-C levels by using FD-OCT.

METHODS

293 and 122 non-obstructive lipid and fibrous plaques in 280 stable statin-treated CAD patients were evaluated by FD-OCT imaging in vessels requiring percutaneous coronary intervention. Study subjects were stratified according to achieved LDL-C levels (<50, 50-70, 70-100, <100 mg/dL). FD-OCT derived plaque microstructures were compared.

RESULTS

LDL-C levels <50 mg/dL and <70 mg/dL were observed in 13.9% (39/280) and 29.2% (82/280) of patients, respectively. Patients with LDL-C <50 mg/dL were more likely to be older (p < 0.001) and receive a high-dose statin (p = 0.01). On FD-OCT imaging, patients with LDL-C <50 mg/dL were more likely to have fibrous plaque (51.7, 43.2, 22.2 and 12.3%, p = 0.01) and less likely to have lipid plaques (48.2, 56.7, 77.7 and 87.6%, p = 0.01). In addition, LDL-C level was significantly associated with lipid arc (173 ± 76, 175 ± 88, 196 ± 102 and 234 ± 85°, p = 0.01) and fibrous cap thickness (139.9 ± 93.9, 103.1 ± 66.4, 92.5 ± 48.5 and 92.1 ± 47.8 um, p = 0.001). In particular, the smallest lipid arc and thickest fibrous cap were observed in patients who achieved LDL-C <50 mg/dL. Multivariable analysis revealed LDL-C levels (beta coefficient -0.254, p = 0.009) and high-dose statin use (beta coefficient 1.814, p = 0.003) to independently associate with fibrous cap thickness.

CONCLUSIONS

More stable plaque features were observed within non-obstructive atheromas in patients with very low LDL-C levels. These findings underscore LDL-C level to stabilize plaques in patients with CAD and high residual atherosclerotic risk.