Impact of plaque composition on long-term clinical outcomes in patients with coronary artery occlusive disease

Ten-year clinical outcomes of an intermediate coronary lesion; prognosis and predictors of major adverse cardiovascular events

AIMS

The natural history of intermediate coronary lesions (30 to 70% angiographic stenosis) and the prognostic predictors in predicting very long-term clinical outcomes is unknown.

METHODS

Patients (n = 82, mean 60 years old) with intermediate non-culprit coronary lesions (NCL, n = 86), evaluated by virtual histology-intravascular ultrasound (VH-IVUS), were followed for 10 years. Major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, stroke, and revascularization) were collected over follow-up period and stratified by culprit lesion (CL)-related, NCL-related and indeterminate/unrelated to CL or NCL lesions. NCL-related MACE was further stratified into intermediate and minimal NCL-related events.

RESULTS

Twenty two (25.6%) out of 86 intermediate NCL were associated with MACE in 20/82 (24.4%) study patients. Ten-year cumulative intermediate NCL-related MACE rate was twice (25.6% vs. 12.8%) compared to treated culprit lesion (CL)-related MACE. Ten-year cumulative revascularization rate of the intermediate NCL lesions was similar (17.4% vs. 15.1%) to those of CL, but higher than that of minimal (stenosed <30% at baseline) NCL (8.1%). Important intermediate NCL VH-IVUS predictor for MACE was area stenosis ≥50%, and for revascularization were percent diameter stenosis, plaque burden ≥70%, and fibrofatty area.

CONCLUSIONS

Ten-year MACE rate of intermediate NCL was double that of CL and ten-year revascularization rate of intermediate NCL was similar or slightly higher than that of CL. VH-IVUS may play an important role in determining the very long-term clinical outcomes in patients with intermediate NCL. This study suggests that Intermediate NCL can be safely followed up in terms of revascularization risk.

Role of Intravascular Ultrasound in Patients with Acute Myocardial Infarction

Rupture of a vulnerable plaque and subsequent thrombus formation are important mechanisms leading to the development of an acute myocardial infarction (AMI). Typical intravascular ultrasound (IVUS) features of AMI include plaque rupture, thrombus, positive remodeling, attenuated plaque, spotty calcification, and thin-cap fibroatheroma. No-reflow phenomenon was attributable to the embolization of thrombus and plaque debris that results from mechanical fragmentation of the vulnerable plaque by percutaneous coronary intervention (PCI). Several grayscale IVUS features including plaque rupture, thrombus, positive remodeling, greater plaque burden, decreased post-PCI plaque volume, and tissue prolapse, and virtual histology-IVUS features such as large necrotic corecontaining lesion and thin-cap fibroatheroma were the independent predictors of no-reflow phenomenon in AMI patients. Non-culprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of ≥70%, a minimal luminal area of ≤4.0 mm(2), or to be classified as thin-cap fibroatheromas.

Impact of spotty calcification on long-term prediction of future revascularization: a prospective three-vessel intravascular ultrasound study

To date, there are no prospective studies on the relationship between plaque characteristics identified by 40 MHz IVUS and future adverse events. This prospective study evaluated the relationship between plaque morphology in nonculprit nonsignificant lesions, determined by 40 MHz IVUS, and long-term clinical outcomes. Consecutively, 45 patients who underwent 3-vessel intravascular ultrasound (IVUS) examinations were prospectively enrolled. Qualitative and quantitative IVUS analyses including scoring of echogenicity for assessment of plaque characterization were performed for each nonsignificant nonculprit lesion. The number, the length, the location (superficial or deep), and maximum arc were measured for each calcium deposit within plaques. Spotty calcification was defined as calcium deposits <90° and <6 mm in length. Primary end point was defined as nonsignificant nonculprit lesion-related revascularization (NNLR) during 6 years of follow-up. A total of 163 nonsignificant nonculprit lesions with mild to moderate stenosis were identified on baseline 3-vessel IVUS. Of those 163 lesions, six lesions required NNLR during the follow-up period. There were no differences in quantitative IVUS parameters including remodeling index, plaque burden, and echogenicity between lesions requiring and not requiring NNLR. However, deep spotty calcification was more frequently identified in lesions requiring NNLR than in those not requiring NNLR (33 vs. 8 %, P = 0.02). Spotty calcium deposits identified by 40 MHz IVUS predicted the need for NNLR during a 6-year follow-up period. This finding suggests that deep spotty calcium may be a surrogate marker for plaque progression and the subsequent need for revascularization in the future.

Safety and Efficacy of a Novel Technique in the Use of Fractional Flow Reserve in Complex Coronary Artery Lesions

Background:

Fractional flow reserve (FFR) has become an increasingly important index when making decisions with respect to revascularization of coronary artery stenosis. However, the pressure guidewire used in obtaining FFR measurements is difficult to control and manipulate in certain complex coronary artery lesions, resulting in increased fluoroscopy time and contrast dye usage. This study examined a novel (NOV) technique for obtaining FFR measurements in hope of easing the difficulties associated with evaluating and treating complex coronary artery lesions.

Methods:

Fifty-six patients with complex coronary artery lesions were assigned to a conventional (CON) FFR technique group or a NOV FFR technique group. The NOV technique involved the use of a balloon and wire exchange within the coronary artery. The fluoroscopy time, contrast dye usage, and FFR-related complications were assessed after completing the FFR measurement procedure for each patient.

Results:

The median time required for fluoroscopy in the NOV technique group was significantly less than that in the CON technique group; additionally, lesser amounts of contrast dye were used in the NOV technique group (both P < 0.05). The NOV technique was successfully performed in thirty patients, without any FFR-related complications. However, the CON technique failed in three patients, including two who experienced coronary artery spasms (P > 0.05).

Conclusions:

Compared to the CON technique used for measuring FFR, the new technique reduced the fluoroscopy time and amount of contrast dye used when evaluating complex coronary artery lesions. The new technique did not increase the risk of operation or decrease the success rate.

Biochemical and clinical correlation of intraplaque neovascularization using contrast-enhanced ultrasound of the carotid artery

OBJECTIVE

Several biomarkers reflecting inflammatory or proteolytic activity have been known to represent plaque vulnerability. Moreover, a recent study confirmed that contrast-enhanced ultrasound (CEUS) can visualize intraplaque neovascularization (IPN) and demonstrate plaque vulnerability. In this study, we tried to demonstrate that IPN detected by CEUS was correlated with several well-known biomarkers and clinical outcome in patients with coronary artery disease (CAD).

METHODS

Patients with stable CAD were screened by conventional carotid ultrasound and patients with carotid plaque thickness more than 2 mm were performed by CEUS for the presence of IPN. Plasma levels of biomarkers and clinical outcomes were evaluated.

RESULTS

Among consecutive 89 patients fulfilled the inclusion criteria, 30 patients without IPN (group 1) and 59 patients with IPN (group 2) were analyzed. There were no significant difference in baseline characteristics except for mean age (62.9±10.1 yrs versus 68.4±9.6 yrs, p=0.015). On multivariate analysis, only MMP-9 (p=0.021, 95% CI 1.002-1.027) showed a significant association with IPN. But patients with IPN showed only trend for a history of cardiovascular disease (CVD) (44% versus 30%, p=0.19) and one-year cardiovascular events (CVE) (6.8% versus 3.3%, p=0.50) compared to group 1. Maximum plaque thickness (p=0.04, 95% CI 1.230-6.322) showed a significant correlation with the clinical outcome including CVD or CVE.

CONCLUSION

MMP-9 correlated with IPN on CEUS. For clinical implication, however, large prospective studies are needed.