Invasive coronary imaging: any role in primary and secondary prevention?

Evaluation of coronary plaques and atherosclerosis using optical coherence tomography

Introduction: Coronary angiography (CAG) is the standard modality for assessing coronary stenosis; however, it has limitations in assessing coronary plaque morphology. Optical coherence tomography (OCT) is a high-resolution (10-20 μm) light-based intravascular imaging technique that can identify more detailed coronary plaque morphology compared to other intravascular imaging modalities. OCT is remarkable for characterizing fibrous, fibrocalcific, and lipid-rich plaques. The capabilities of OCT are well suited for discriminating three types of unstable plaque morphologies underlying coronary thrombosis, such as plaque rupture, erosion, and calcified nodules. The high resolution of OCT makes it possible to identify important features of vulnerable plaques, such as thin-cap (<65 μm thick) fibroatheroma, macrophages, vasa vasorum, and cholesterol crystals.Areas covered: This review summarizes the clinical impact of OCT and its efficacy in identifying plaque components and morphological features associated with plaque vulnerability.Expertopinion: The unique properties of OCT as a tool for investigating high-risk lesions have greatly contributed to a better understanding of plaque vulnerability. Consequently, OCT has led to significant changes in medical treatment and percutaneous coronary intervention strategies for acute coronary syndrome. Further development and investigation of OCT are necessary to better predict and manage acute coronary events in the future.

Prognostic Value of Left Ventricular Global Strain Analysis by Two-Dimensional Speckle-Tracking Echocardiography in Non-Hemodynamically Significant Intermediate Coronary Lesions

Intermediate coronary lesions represent a major challenge for the invasive and noninvasive cardiologist. Left ventricular strain calculation by speckle tracking echocardiography has the capacity to analyze the motion of the cardiac tissue. This study aimed to evaluate its usefulness and prognostic significance in nonhemodynamically significant intermediate coronary lesions. We studied 247 patients who underwent a clinically indicated coronary angiogram. Each of the patients had a single nonrevascularized nonhemodynamically significant intermediate severity coronary lesion (ISCL) with a fractional flow reserve greater than 0.80. The left ventricular global longitudinal strain (GLS) was calculated using speckle-tracking echocardiography with TomTec 2D Cardiac Performance Analysis (Unterschleissheim, Germany). An abnormal GLS was defined as less than -20%. The primary endpoints were revascularization of the target lesion, admissions for major adverse cardiac events (MACE), and cardiac-related mortality, all within 2 years. On multivariate logistic regression data analysis, we found that patients with an ISCL and abnormal GLS had an increased risk for admissions due to MACE (odds ratio [OR] 1.06, P < 0.05, confidence interval [CI] 95%, 1.005-1.120], and an increased risk of cardiac-related death (OR 1.12, P < 0.05, CI 95% 1.012-1.275). There was no difference in the need for target lesion revascularization among individuals with normal and abnormal GLS (1.00, P 0.88, CI 95% .950-1.061). Left ventricular strain analysis by speckle-tracking echocardiography showed an independent prognostic value in patients with nonrevascularized nonhemodynamically significant coronary lesions.

Intra-coronary Imaging for the Evaluation of Plaque Modifications Induced by Drug Therapies for Secondary Prevention

PURPOSE OF REVIEW

Patients diagnosed with coronary artery disease are at a high risk of subsequent cardiovascular events; therefore, secondary prevention in the form of therapeutic lifestyle changes, and drug therapies is vital. This article aims to review potential application of intra-coronary imaging for the evaluation of plaque modifications, induced by medications for secondary prevention for CAD.

RECENT FINDINGS

Intra-coronary imaging provides detailed information on the atherosclerotic plaque which is the primary pathological substrate for the recurrent ischemic cardiovascular events. These modalities can detect features associated with high risk and allow serial in vivo imaging of lesions. Therefore, intravascular imaging tools have been used in landmark studies and played a role in improving our understanding of the disease processes. Changes in size and plaque composition over time can be evaluated by these tools and may help understanding the impact of a treatment. Moreover, surrogate imaging end points can be used when testing new drugs for secondary prevention.

SYNTAX score-0 patients: risk stratification in nonobstructive coronary artery disease

BACKGROUND

The complexity of coronary artery disease (CAD) is a predictor of cardiovascular events in patients with >50 % diameter stenosis as determined by SYNTAX score. Here, we compare the Gensini score to SYNTAX in patients with CAD as well as apply the Gensini score in patients with nonobstructive CAD (NOB-CAD), defined by ≤50 % diameter stenosis, were the SYNTAX score cannot be utilized to define future risk.

METHODS

The AtheroGene study enrolled 2316 patients [861/37.2 % with acute cardiovascular syndrome (ACS) and 1500/62.8 % with stable CAD (SCAD)]. Of these, 1966 had obstructive CAD (OB-CAD) with SYNTAX and Gensini scores available and 291 events with either cardiovascular mortality or non-fatal myocardial infarction were recorded. Furthermore, 350 patients had NOB-CAD with only Gensini score and 36 events. Median follow-up time was 4.9 years.

RESULTS

In the OB-CAD cohort the SYNTAX and the Gensini score predicted outcome. Kaplan-Meier curve analysis with the dichotomized Gensini score showed a significant result (p = 0.04) in the NOB-CAD cohort. Cox Regression analysis after adjustment showed a hazard ratio (HR) of 1.33 and p = 0.04 for the Gensini score in the NOB-CAD cohort. Receiver operating characteristic curve (ROC) analysis provided the highest area under the curve (AUC) regarding the outcome for the Gensini score with 0.65 (p = 0.004). Comparing the SYNTAX and Gensini score in this cohort showed improved discrimination of patients with events by the Gensini score (p = 0.02).

CONCLUSION

The Gensini score predicted events in patients with ≤50 % diameter lesions. Utilization of this score is useful to define risk in NOB-CAD patients.