Volumetric intravascular ultrasound imaging to illustrate the extent of coronary plaque burden in type 2 diabetic patients

Differential association of diabetes mellitus and female sex with impaired myocardial flow reserve across the spectrum of epicardial coronary disease

Aims 

Diabetes mellitus (DM) affects the macro- and microvasculature, leading to impairment in coronary vascular reactivity. Microvascular dysfunction is more prevalent in females compared to males, leading to increased cardiovascular risk in women. The purpose of this study was to quantify the association between diabetes and female sex on myocardial flow reserve (MFR) across the spectrum of epicardial coronary artery disease (CAD).

Methods and results 

In 222 patients with known or suspected CAD (63.7 ± 10.7 years, 66 females, 85 with diabetes) who had rubidium-82 positron emission tomography (PET) and invasive coronary angiography within 6 months, a multiple linear regression model was developed to predict MFR based on clinical risk factors and imaging results across a spectrum of regional epicardial disease. A significant interaction effect suggested that impairment of MFR is accelerated in diabetics with increasing severity of epicardial disease. Furthermore, female sex (−13%), decade of age (−6%), ischaemia on electrocardiogram (−10%), resting rate-pressure product (−3%), and rest end-diastolic volume (−0.2%) were associated with reductions in MFR independent of the combined extent and severity of epicardial disease.

Conclusion

In the presence of significant obstructive epicardial disease, MFR decreases more rapidly in patients with DM compared to those without. Additional patient demographics and risk factors such as female sex and older age, and stress PET functional parameters should also be considered in the clinical interpretation of MFR. This has implications for the diagnosis and management of CAD patients with these and other risk factors for microvascular disease.

Impact of prediabetic status on coronary atherosclerosis: a multivessel angioscopic study

OBJECTIVE

To determine if prediabetes is associated with atherosclerosis of coronary arteries, we evaluated the degree of coronary atherosclerosis in nondiabetic, prediabetic, and diabetic patients by using coronary angioscopy to identify plaque vulnerability based on yellow color intensity.

RESEARCH DESIGN AND METHODS

Sixty-seven patients with coronary artery disease (CAD) underwent angioscopic observation of multiple main-trunk coronary arteries. According to the American Diabetes Association guidelines, patients were divided into nondiabetic (n = 16), prediabetic (n = 28), and diabetic (n = 23) groups. Plaque color grade was defined as 1 (light yellow), 2 (yellow), or 3 (intense yellow) based on angioscopic findings. The number of yellow plaques (NYPs) per vessel and maximum yellow grade (MYG) were compared among the groups.

RESULTS

Mean NYP and MYG differed significantly between the groups (P = 0.01 and P = 0.047, respectively). These indexes were higher in prediabetic than in nondiabetic patients (P = 0.02 and P = 0.04, respectively), but similar in prediabetic and diabetic patients (P = 0.44 and P = 0.21, respectively). Diabetes and prediabetes were independent predictors of multiple yellow plaques (NYPs ≥2) in multivariate logistic regression analysis (odds ratio [OR] 10.8 [95% CI 2.09-55.6], P = 0.005; and OR 4.13 [95% CI 1.01-17.0], P = 0.049, respectively).

CONCLUSIONS

Coronary atherosclerosis and plaque vulnerability were more advanced in prediabetic than in nondiabetic patients and comparable between prediabetic and diabetic patients. Slight or mild disorders in glucose metabolism, such as prediabetes, could be a risk factor for CAD, as is diabetes itself.

[Revascularization of coronary artery disease in diabetes mellitus]

Coronary artery disease in diabetes mellitus (DM) is still associated with a poor prognosis. Especially percutaneous coronary interventions (PCI) have a higher rate of complications and restenosis, so that surgical revascularization is usually favoured in DM. The development of drug-eluting stents has improved the results of PCI significantly, however, there are still not enough prospective data comparing them to bypass surgery. The present paper summarizes the current state of coronary revascularization.

Relation of severe coronary artery narrowing to insulin or thiazolidinedione use in patients with type 2 diabetes mellitus (from the Bypass Angioplasty Revascularization Investigation 2 Diabetes Study)

Patients with diabetes continue to die of coronary artery disease (CAD) at rates 2 to 4 times higher than patients without diabetes, despite advances in treatment of cardiovascular disease. The role of glycemic control therapies, independent of their glucose-lowering effects, on cardiovascular disease is a recurring question. We examined the association of glycemic control therapies with extent of CAD as measured by coronary angiogram obtained at baseline in 1,803 subjects in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial who had type 2 diabetes mellitus, documented moderate to severe CAD, and no previous cardiac revascularization procedures. The association between glycemic control therapy use recorded at baseline and percent coronary artery stenosis and myocardial jeopardy index was analyzed by multiple regression models. Insulin use at study entry was associated with 23% fewer highly stenotic lesions (> or =70%) (p <0.001) and a significantly lower myocardial jeopardy index compared with subjects not on insulin, despite a worse cardiac risk factor profile, more unstable angina, and increased inflammatory markers in insulin users. Subjects taking thiazolidinediones (TZDs) for > or =6 months had 17% fewer highly stenotic lesions (p = 0.02) and significantly lower C-reactive protein, fibrinogen, and plasminogen activator inhibitor-1 levels compared with those not taking TZDs. In conclusion, this cross-sectional study of patients with type 2 diabetes mellitus and CAD showed that treatment with insulin or TZDs was associated with fewer highly stenotic lesions, independent of disease duration, glycemic control, and other risk factors.

Relevance of hemostatic risk factors on coronary morphology in patients with diabetes mellitus type 2

Objective

The influence hemostatitc parameters on the morphological extent and severity of coronary artery disease were studied in patients with and without DM type 2.

Background

It is known that patients with diabetes (DM) have abnormal metabolic and hemostatic parameters

Methods

Of 150 consecutive patients with angiographically proven coronary artery disease 29 presented with DM. Additionally to parameters of lipid-metabolism fibrinogen, tissue-plasminogenactivator (t-PA), plasminogen-activator-inhibitor (PAI), plasmin-a-antiplasmin (PAP), prothrombin-fragment 1+2 (F1+2), thrombin-antithrombin (TAT), von-willebrand-factor (vWF), platelet factor 4 (PF4), glykomembranproteine 140 (GMP140) and the rheologic parameters plasma viscosity and red blood cell aggregation were evaluated. The extent and severity of CAD was evaluated according to the criteria of the American Heart Association.

Results

Patients with DM presented with a higher number of conventional risk factors as compared to non-diabetic patients. Additionally there were significant differences for F1+2, red blood cell aggregation and PAI. Diabetic patients showed a more severe extent of coronary arteriosclerosis, which also could be found more distally. A significant relationship between blood-glucose, thrombocyte-activation (vWF), endogenous fibrinolysis (PAI) and the severity of CAD and a more distal location of stenoses could be found (r = 0.6, p < 0.001).

Conclusion

Patients with coronary artery disease and DM type 2 showed marked alterations of metabolic, hemostatic, fibrinolytic and rheologic parameters, which can produce a prothrombogenic state. A direct association of thrombogenic factors on coronary morphology could be shown. This can be the pathophysiologic mechanism of more severe and distal pronounced coronary atherosclerosis in these patients.

Effect of diabetes on progression of coronary atherosclerosis and arterial remodeling: a pooled analysis of 5 intravascular ultrasound trials

OBJECTIVES

Our goal was to characterize coronary atherosclerosis progression and arterial remodeling in diabetic patients.

BACKGROUND

The mechanisms that underlie adverse cardiovascular outcomes in diabetic patients have not been well characterized.

METHODS

A systematic analysis was performed in 2,237 subjects in randomized controlled studies of atherosclerosis progression. The pattern of arterial remodeling, extent of coronary atherosclerosis, and disease progression was compared in subjects with and without diabetes.

RESULTS

In association with more risk factors, diabetic patients demonstrated a greater percent atheroma volume (PAV) (40.2 +/- 0.9% vs. 37.5 +/- 0.8%, p < 0.0001) and total atheroma volume (TAV) (199.4 +/- 7.9 mm(3) vs. 189.4 +/- 7.1 mm(3), p = 0.03) on multivariate analysis. A stronger correlation was observed between PAV and glycated hemoglobin (r = 0.22, p = 0.0003) than fasting glucose (r = 0.09, p < 0.0001), although the difference just failed to meet statistical significance after controlling for study. Diabetic patients exhibited a smaller lumen (291.1 +/- 104.8 mm(3) vs. 306.5 +/- 108.2 mm(3), p = 0.005) but no difference in external elastic membrane (494.9 +/- 166.9 mm(3) vs. 498.8 +/- 167.2 mm(3), p = 0.61) volumes. More rapid progression of PAV (0.6 +/- 0.4% vs. 0.05 +/- 0.3%, p = 0.0001) and TAV (-0.6 +/- 2.5 mm(3) vs. -2.7 +/- 2.4 mm(3), p = 0.03) was observed in diabetic patients on multivariate analysis. Smaller external elastic membrane (482.5 +/- 160.7 mm(3) vs. 519.9 +/- 166.9 mm(3), p = 0.03) and lumen (276.0 +/- 100.3 mm(3) vs. 310.1 +/- 105.6 mm(3), p = 0.001) volumes were observed in diabetic patients treated with insulin despite the presence of a similar TAV (206.5 +/- 88.6 mm(3) vs. 209.9 +/- 90.2 mm(3), p = 0.84). Intensive low-density lipoprotein cholesterol lowering in patients improved the rate of plaque progression, but only to the level observed in nondiabetic patients with suboptimal lipid control.

CONCLUSIONS

Diabetes is accompanied by more extensive atherosclerosis and inadequate compensatory remodeling. Accelerated plaque progression, despite use of medical therapies, supports the need to develop new antiatherosclerotic strategies in diabetic patients.