Vascular remodeling and plaque composition between focal and diffuse coronary lesions assessed by intravascular ultrasound

Plasma Trimethylamine N-Oxide, a Gut Microbe-Generated Phosphatidylcholine Metabolite, Is Associated With Atherosclerotic Burden

BACKGROUND

Trimethylamine N-oxide (TMAO), a gut microbiota metabolite from dietary phosphatidylcholine, has mechanistic links to atherosclerotic coronary artery disease (CAD) pathogenesis and is associated with adverse outcomes.

OBJECTIVES

This study sought to examine the relationship between plasma TMAO levels and the complexity and burden of CAD and degree of subclinical myonecrosis.

METHODS

We studied 353 consecutive stable patients with evidence of atherosclerotic CAD detected by elective coronary angiography between 2012 and 2014. Their high-sensitivity cardiac troponin T (hs-cTnT) levels were measured. SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) scores and lesion characteristics were used to quantify atherosclerotic burden. Fasting plasma TMAO was measured by mass spectrometry.

RESULTS

In this prospective cohort study, the median TMAO level was 5.5 μM (interquartile range [IQR]: 3.4 to 9.8 μM), the median SYNTAX score was 11.0 (IQR: 4.0 to 18.5), and 289 (81.9%), 40 (11.3%), and 24 (6.8%) patients had low (0 to 22), intermediate (23 to 32), and high (≥33) SYNTAX scores, respectively. Plasma TMAO levels correlated (all p < 0.0001) with the SYNTAX score (r = 0.61), SYNTAX score II (r = 0.62), and hs-cTnT (r = 0.29). Adjusting for traditional risk factors, body mass index, medications, lesion characteristic, renal function, and high-sensitivity C-reactive protein, elevated TMAO levels remained independently associated with a higher SYNTAX score (odds ratio [OR]: 4.82; p < 0.0001), SYNTAX score II (OR: 1.88; p = 0.0001), but were not associated with subclinical myonecrosis (OR: 1.14; p = 0.3147). Elevated TMAO level was an independent predictor of the presence of diffuse lesions, even after adjustments for traditional risk factors and for hs-cTnT (OR: 2.05; 95% confidence interval: 1.45 to 2.90; p = 0.0001).

CONCLUSIONS

Fasting plasma TMAO levels are an independent predictor of a high atherosclerotic burden in patients with CAD.

Associations between Genetic Variants and Angiographic Characteristics in Patients with Coronary Artery Disease

AIM

In this study, we investigated the genetic determinants of lesion characteristics and the severity of coronary artery disease (CAD) using a genome-wide association study (GWAS) and replication genotyping.

METHODS

The discovery set for GWAS consisted of 667 patients exhibiting angiographically diagnosed CAD with symptoms. For replication genotyping, 837 age- and sex-matched CAD patients were selected. Genetic determinants of lesion characteristics (diffuse vs. non-diffuse lesions), the number of diseased vessels (multi-vessel vs. single vessel disease) and the modified Duke score (high vs. low), which indicates the severity of CAD, were analyzed after adjusting for confounding factors.

RESULTS

Single nucleotide polymorphisms (SNPs) rs12917449, rs10152898 and rs231150 were associated with diffuse lesions, while rs1225006 and rs6745588 were associated with multi-vessel disease. However, on replication genotyping, no significant associations were found between any of these five SNPs and the lesion characteristics or CAD severity. In contrast, in the combined population of both the discovery and replication sets, genotypes rs125006 of CPNE4 and rs231150 of TRPS1 were found to be significantly associated with the modified Duke score. The addition of rs1225006 to conventional risk factors had significant incremental value in the model of the score.

CONCLUSIONS

The associations between five SNPs identified using GWAS and angiographic characteristics were not significant in the current replication study. However, two variants, particularly rs1225006, were found to be associated with the severity of CAD in the combined set. These results indicate the potential clinical implication of these variants with respect to the risk of CAD.

Application of Intravascular Ultrasound in the Emergency Diagnosis and Treatment of Patients with ST-Segment Elevation Myocardial Infarction

PURPOSE

This study aimed to examine the application of intravascular ultrasound (IVUS) in ST-segment elevation myocardial infarction (STEMI) patients with high thrombus burden (thrombus grade ≥3) undergoing emergency diagnosis and primary percutaneous coronary intervention.

METHODS

Eighty STEMI patients were enrolled and randomly assigned to the IVUS-guided group (38 patients) or non-IVUS group (42 patients). Stent implantation was performed in non-IVUS group patients. IVUS group patients were further divided into low-risk and high-risk patients on the basis of IVUS evaluation for determining whether stenting should be performed. Major adverse cardiac event (MACE) rates, changes in the left ventricular end-diastolic diameter (LVEDD) and ejection fraction (EF) values, and stent numbers were examined during hospitalization, and follow-up was performed at 1, 3, 6, and 12 months postoperatively.

RESULTS

During hospitalization, there were no significant differences in the MACE rates, LVEDD, and EF values and in the follow-up outcomes at 1, 3, 6, and 12 months postoperatively among the patients in the 2 groups (P > 0.05). A significantly lower number of stents were implanted in the IVUS group than in the non-IVUS group patients (P < 0.05).

CONCLUSION

During the IVUS-guided emergency intervention, enhanced antithrombotic therapy and best medical care for low-risk STEMI patients may be feasible.

In-vivo assessment of the natural history of coronary atherosclerosis: vascular remodeling and endothelial shear stress determine the complexity of atherosclerotic disease progression

PURPOSE OF REVIEW

Atherosclerotic disease progression is determined by localized plaque growth, which is induced by systemic and local hemodynamic factors, and the nature of the wall remodeling response. The purpose of this review is to summarize the processes underlying the heterogeneity of coronary atherosclerosis progression in relation to the local hemodynamic and arterial remodeling environment.

RECENT FINDINGS

Multiple competing biological processes in the extracellular matrix define the extent of vascular remodeling and disease progression. The remodeling phenomenon is not consistent but is characterized by great phenotypical heterogeneity which reflects the complex effect of systemic, genetic and hemodynamic factors on the arterial wall response to plaque formation and progression. The exaggeration of expansive remodeling (i.e., excessive expansive remodeling) likely contributes to the transformation of an initially favorable action into an excessive course of vessel expansion, continued disease progression and plaque instability. Extremely low endothelial shear stress and excessive expansive remodeling establish a vicious cycle which leads to the formation of severe plaques with high-risk characteristics.

SUMMARY

The dynamic interplay between the local hemodynamic environment and the wall remodeling behavior determines the complexity of the natural history of atherosclerosis and explains the development of localized plaque vulnerability.

Association of angiotensin-converting enzyme inhibitors and serum lipids with plaque regression in cardiac allograft vasculopathy

We assessed clinical predictors of the process of cardiac allograft vasculopathy (CAV) in 39 consecutive patients (mean 49 years old) using three-dimensional intravascular ultrasound (3-D IVUS) examination of the left anterior descending coronary artery at 36 +/- 38 months and 47 +/- 40 months after cardiac allotransplantation (TX). Compared with 17 patients with plaque progression, 22 patients with plaque regression were more likely to be male (P < .01), to have a higher use of angiotensin-converting enzyme inhibitors (ACEI, P < .05), and to have a lower volumetric remodeling index (P < .001). The changes in plaque volume correlated with the changes in total cholesterol (P < .005) and low-density lipoprotein cholesterol (P < .02). Plaque progression of CAV was independently associated with time after TX, hypertension, nonuse of ACEI, donor age, and changes in total cholesterol and triglycerides. In conclusion, plaque progression is associated with positive vascular remodeling and plaque regression is associated with lower serum lipids and ACEI in patients after TX.