The Prognostic Importance of Nonsignificant Left Main Coronary Artery Disease in Patients Undergoing Percutaneous Coronary Intervention

Revascularization Options for Left Main Disease: What Clinicians Need to Know

PURPOSE OF REVIEW

Left main disease represents the highest-risk lesion subset of coronary artery disease and is associated with adverse cardiovascular events. Accordingly, we aim to understand how the significance of left main disease is assessed by different modalities, followed by a review of management options in current era.

RECENT FINDINGS

Invasive coronary angiogram remains the gold standard for assessment of left main disease, but intracoronary imaging or physiological testing is indicated for angiographically equivocal disease. Revascularization by either coronary artery bypass surgery or percutaneous coronary intervention is strongly recommended, which have been compared by six randomized trials, as well as recent meta-analyses. Surgical revascularization remains the preferred mode of revascularization, especially in patients with high lesion complexity and left ventricular dysfunction. Randomized studies are needed to understand if current-generation stents with the use of intracoronary imaging and improved medical therapy could match outcomes with surgical revascularization.

Assessment of left main coronary artery disease: a comparison between invasive and noninvasive

Left main coronary artery disease has significant therapeutic as well as prognostic implications. The presence of left main coronary artery stenosis is strongly associated with poor short- and long-term prognoses. Accurate identification of left main stenosis is extremely important since it would be the main factor to guide management. There are several modalities used to determine the presence of atherosclerosis and the degree of stenosis in a left main coronary artery. Newer modalities allow for an accurate evaluation of left main stenosis and atherosclerosis. In this review, we go through different invasive and noninvasive modalities to diagnose left main stenosis, shedding more light into coronary computed tomography angiography, and its accuracy in this specific diagnosis.

Coronary Artery Dominance and Long-term Prognosis in Patients With ST-segment Elevation Myocardial Infarction Treated With Primary Angioplasty

INTRODUCTION AND OBJECTIVES

The long-term prognostic significance of coronary artery dominance pattern in patients with ST-segment elevation myocardial infarction is poorly characterized. We investigated the prognosis of such patients according to whether they had right dominance, left dominance, or codominance.

METHODS

This was a retrospective study of 767 patients, who were admitted to hospital between 2007 and 2012 with ST-segment elevation myocardial infarction and treated with primary percutaneous coronary intervention. We determined the effect of the coronary dominance pattern on all-cause mortality and readmission for infarction, adjusting for mortality as a competing event.

RESULTS

A total of 80.9% of patients had right coronary dominance, and 8.6% had left coronary dominance. Over 40.8 months' [interquartile range, 21.9-58.3 months] follow-up, 118 (15.4%) deaths were recorded, of which 39 (5.1%) were in hospital. Mortality for right dominance, left dominance, and codominance was 7.1%, 36.4%, and 13.8% (P ˂ .001), respectively. Cause of death was cardiovascular in 7.1%, 21.2%, and 2.4%. On Cox multivariate analysis, left dominance was significantly associated with mortality (hazard ratio = 1.76; P = .02). Taking "coronary dominance" into account in prediction of risk of death improved the discrimination and calibration capacity of GRACE (Global Registry of Acute Coronary Events) scoring. At follow-up, 9.3% (71 patients) had reinfarction. On multivariate analysis, left dominance was an independent predictor of reinfarction (subhazard ratio = 2.06; P = .01).

CONCLUSIONS

In ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention, left coronary artery dominance confers a higher risk of death and reinfarction than right coronary artery dominance, and should be included in prognostic stratification.

Remodeling is a more important determinant of lumen size than atheroma burden in left main coronary artery disease

BACKGROUND

Left main coronary artery (LMCA) disease influences survival; however, the predictors of LMCA changes over time are incompletely understood.

METHODS

Paired intravascular ultrasound (IVUS) and core laboratory analyses were performed in a standardized fashion in 207 subjects (mean +/- SD age 58 +/- 10 years, 80% men). The average follow-up duration was 18 months (range 12-24 months). The IVUS measurements were first obtained at the smallest lumen area and the largest plaque area at follow-up and the corresponding positions in the LMCA were then measured at baseline.

RESULTS

The LMCA percentage of atheroma area at baseline was 38.2% +/- 11.8%, and 133 patients (64%) experienced an increase in percentage of atheroma area. Change in lumen area correlated positively with change in total vessel area (R = 0.85, P < .0001) and negatively with change in percentage of atheroma area (R = -0.58, P < .0001). Change in plaque area correlated well with change in total vessel area (R = 0.64, P < .0001) but only weakly with change in lumen area (r = 0.14, P = .039). Although LMCA length correlated negatively with baseline lumen area and total vessel area, it did not correlate with their changes over time. On multivariable analyses, current smoking predicted an increase in percentage of atheroma area (P = .0013) and plaque area (P = .0041). Height negatively predicted change in percentage of atheroma area (P = .001).

CONCLUSIONS

The LMCA lumen dimensions are more tightly linked with remodeling than with atheroma progression/regression.

Ostial Lesions of Left Main and Right Coronary Arteries: Demographic and Angiographic Features

In 258 patients with left main tract disease, the atherosclerotic risk factors were compared between patients with ostial and nonostial lesions of the left main coronary artery. Also, it was done for patients with ostial right coronary artery. Women were more likely to have ostial left main coronary artery and/or ostial right coronary artery. A multivariate logistic regression analysis revealed that the female sex (odds ratio: 2.336) and hypertriglyceridemia (odds ratio: 1.004) were independent risk factors of ostial left main coronary artery lesion. For ostial right coronary artery lesion, the female sex and family history of coronary artery disease were independent predictors. Ostial left main coronary artery and right coronary artery lesions were strongly correlated. The demographic and clinical profiles of ostial stenosis suggest that this group may represent a distinct entity, different from the more common atherosclerotic left main trunk stenosis (LMTD). The female sex and serum triglyceride level can be considered as independent predictors of ostial left main tract disease.

Coronary dominance and prognosis of patients with acute coronary syndrome

BACKGROUND

A number of studies have identified the number of diseased vessels to be an important determinant of survival in patients with acute coronary syndrome (ACS). It is unknown if coronary dominance has an impact on prognosis of these patients. We hypothesized that the prognosis of patients with ACS with left dominance (LD) would be worse than that of patients with right or mixed dominance.

METHODS

The study population consisted of 27,289 patients whose primary indication for cardiac catheterization was ACS. The patients were divided into 3 groups according to coronary dominance. The mean duration of follow-up was 3.5 years (range 1-6.5 years). A Cox proportional hazards analysis was used to compare survival by dominance, adjusting for age, sex, diagnosis, comorbidities, severity of coronary disease, and ejection fraction.

RESULTS

The rates and patterns of revascularization among patients with significant coronary disease were similar between the groups. At the end of follow-up, patients with LD had a significantly higher mortality (hazard ratio 1.18, 95% CI 1.05-1.34; adjusted hazard ratio 1.13, CI 1.00-1.28). The mortality of patients with mixed and right dominance was similar.

CONCLUSION

In patients with ACS, LD is a significant and independent predictor of increased long-term mortality. Further research is needed to determine mechanisms of increased mortality in patients with LD and measures that can be taken to improve the outcome of patients with left-dominant circulation.