Intravascular ultrasound-guided versus angiography-guided percutaneous coronary intervention in unprotected left main coronary artery disease: A systematic review

BACKGROUND

Significant unprotected left main coronary artery (ULMCA) disease is encountered in approximately 5 % of patients undergoing diagnostic coronary angiography. Intravascular ultrasound (IVUS) overcomes many of the known limitations of angiography and improves outcomes of patients undergoing percutaneous coronary interventions (PCI) in stable or complex coronary artery disease. The aim of this systematic review is to evaluate the evidence on IVUS-guidance versus angiography-guidance in ULMCA PCI, highlighting the chronological frequencies of event rates in line with the maturation of PCI technique and devices over time.

METHODS

A comprehensive systematic search in Medline was performed to identify all studies that had assessed the effect of IVUS-guided versus angiography-guided ULMCA PCI on various primary and secondary endpoints.

RESULTS

Seventeen studies (2 randomized, 10 non-randomized and 5 meta-analyses) were included in this systematic review.

CONCLUSIONS

This systematic review on IVUS-guided versus angiography-guided PCI in patients with significant ULMCA disease strongly supports the hypothesis that IVUS-guided PCI is associated with a significant reduction in major adverse cardiac events composites, all-cause death, cardiac death, myocardial infarction and stent thrombosis. Ongoing, adequately powered trials will contribute significantly to the level of evidence.

Echocardiography Core Laboratory Validation of a Novel Vendor-Independent Web-Based Software for the Assessment of Left Ventricular Global Longitudinal Strain

BACKGROUND

Global longitudinal strain (GLS) is an accurate and reproducible parameter of left ventricular (LV) systolic function which has shown meaningful prognostic value. Fast, user-friendly, and accurate tools are required for its widespread implementation. We aim to compare a novel web-based tool with two established algorithms for strain analysis and test its reproducibility.

METHODS

Thirty echocardiographic datasets with focused LV acquisitions were analyzed using three different semi-automated endocardial GLS algorithms by two readers. Analyses were repeated by one reader for the purpose of intra-observer variability. CAAS Qardia (Pie Medical Imaging) was compared with 2DCPA and AutoLV (TomTec).

RESULTS

Mean GLS values were -15.0 ± 3.5% from Qardia, -15.3 ± 4.0% from 2DCPA, and -15.2 ± 3.8% from AutoLV. Mean GLS between Qardia and 2DCPA were not statistically different (p = 0.359), with a bias of -0.3%, limits of agreement (LOA) of 3.7%, and an intra-class correlation coefficient (ICC) of 0.88. Mean GLS between Qardia and AutoLV were not statistically different (p = 0.637), with a bias of -0.2%, LOA of 3.4%, and an ICC of 0.89. The coefficient of variation (CV) for intra-observer variability was 4.4% for Qardia, 8.4% 2DCPA, and 7.7% AutoLV. The CV for inter-observer variability was 4.5%, 8.1%, and 8.0%, respectively.

CONCLUSIONS

In echocardiographic datasets of good image quality analyzed at an independent core laboratory using a standardized annotation method, a novel web-based tool for GLS analysis showed consistent results when compared with two algorithms of an established platform. Moreover, inter- and intra-observer reproducibility results were excellent.

[Optical coherence tomography of coronary arteries--a novel intravascular imaging modality]

Optical coherence tomography (OCT) is the latest intravascular imaging modality for the investigation of coronary arteries. It can be used in patients with stable coronary artery disease as well as in patients with acute coronary syndrome. Its almost microscope-like resolution of 10-20 μm (10-times greater than intravascular ultrasound) gives us the most detailed insight into the coronary artery wall in vivo so far.Optical coherence tomography can be used for accurate qualitative and quantitative assessment of stenoses in stable coronary artery disease and accurate guidance of percutaneous coronary interventions as well as accurate postprocedural control. In patients with acute coronary syndrome it can be used for the detection of culprit of the culprit lesion (vulnerable plaque) which allows the operator to cover not only angiographically tightest stenosis (angiographic culprit lesion, caused in most cases by thrombus only) but most importantly the vulnerable plaque, which led to the acute event, as well. Furthermore, optical coherence tomography allows accurate assessment of thrombotic burden, stent apposition/malapposition, edge dissections and tissue prolaps or thrombus protrusions throught stent struts, etc.

Radiofrequency-intravascular ultrasound assessment of lesion coverage after angiography-guided emergent percutaneous coronary intervention in patients with non-ST elevation myocardial infarction

Using radiofrequency-intravascular ultrasound (VH-IVUS), we have previously demonstrated that in 50% of patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention with optimal angiographic result, the stent does not fully cover the whole VH-IVUS-derived thin-cap fibroatheroma (VH-TCFA) related to the culprit lesion. Presently, we set out to extend these findings to 20 patients with non-STEMI with Thrombolysis In Myocardial Infarction flow 3 in the infarct-related artery before intervention who were then treated with angiography-guided direct stent implantation. The lesion was imaged with VH-IVUS before and after intervention, but the results were blinded to the operator. Plaque rupture site was identified in 8 lesions (40%), all proximal to the minimum lumen area (MLA) site. The maximum necrotic core site was found proximal to MLA in 18 lesions and at the MLA in 2 lesions. Although the plaque rupture site was fully covered with the stent in all lesions, an uncovered VH-TCFA was found in 7 lesions (35%), 4 in the proximal reference segment, 1 in the distal reference segment, and 2 in both the proximal and distal reference segments. In conclusion, in 35% of patients with non-STEMI undergoing angiography-guided emergent percutaneous coronary intervention, the stent does not fully cover a VH-TCFA related to the culprit lesion.

Virtual histology-intravascular ultrasound assessment of lesion coverage after angiographically-guided stent implantation in patients with ST Elevation myocardial infarction undergoing primary percutaneous coronary intervention

An occlusion or severe stenosis (angiographic culprit lesion) of the infarct-related artery is frequently located at the site of the maximum thrombus burden, whereas the origin of the plaque rupture (the true culprit) can be situated proximal or distal to it. The aim of this study was to examine stent coverage of true culprit lesions in 20 patients who underwent primary percutaneous coronary intervention and had Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow restored in the infarct-related artery by angiographically guided direct stenting. Images of lesions were obtained using virtual histology-intravascular ultrasound before and after intervention (blinded to the operator). Plaque rupture sites were identified by intravascular ultrasound in 12 lesions (60%), 11 proximal and 1 distal to the minimum luminal area (MLA). Maximum necrotic core sites were found proximal to the MLA in 16 lesions, at the MLA in 3 lesions, and distal to the MLA in 1 lesion. Plaque rupture sites were fully covered by stents in 11 lesions. Virtual histology-intravascular ultrasound-derived thin-cap fibroatheroma longitudinal geographic misses were found in 10 lesions, 7 in the proximal reference segment and in 3 patients in the proximal and distal reference segments. In conclusion, in about 50% of patients who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction with optimal angiographic results, the stent does not fully cover the maximum necrotic core site related to the culprit lesion.