Ultrasonic tissue characterization of carotid plaque improves the prediction of cardiovascular events in diabetic patients: a pilot study

OBJECTIVE

The aim of this study is to evaluate whether noninvasive ultrasonic tissue characterization of carotid plaque using integrated backscatter (IBS) analysis can be a predictor of future cardiovascular events (CVE) in asymptomatic type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

We prospectively evaluated the association between Calibrated-IBS value, an ultrasonic marker for tissue characteristics of carotid plaque, and CVE in 85 asymptomatic type 2 diabetic patients with carotid plaque.

RESULTS

The median follow-up period was 7.9 years, and there were 20 new CVE. The risk of CVE was significantly higher in the subjects with low Calibrated-IBS values (<-17.1 dB; n = 42) as compared with those with high values (≥-17.1 dB; n = 43) (P = 0.004, log-rank test). Cox proportional hazards regression analysis revealed that both Calibrated-IBS value (hazard ratio [HR] 0.802 [95% CI 0.710-0.906]; P < 0.0001) and plaque thickness (1.938 [1.170-3.213]; P = 0.010) were independently associated with CVE, even after adjustment for the 10-year risk for a general cardiovascular disease estimated by Framingham risk scoring (FRS). Time-dependent receiver operating characteristic curve analysis for CVE at 10 years after the baseline examinations revealed that area under the curve for Calibrated-IBS was 0.76 (0.60-0.90) and substantially higher than those for plaque thickness (0.60 [0.45-0.79]) and FRS (0.60 [0.40-0.78]). These analyses also revealed that the addition of both plaque thickness and Calibrated-IBS value to conventional risk factors significantly improved the event prediction.

CONCLUSIONS

Calibrated-IBS value could improve the risk prediction of CVE in asymptomatic type 2 diabetic patients with carotid plaque.

Interplay between statins and PPARs in improving cardiovascular outcomes: a double-edged sword?

Statins are best-selling medications in the management of high cholesterol and associated cardiovascular complications. They inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA)-reductase in order to prevent disproportionate cholesterol synthesis. Statins slow the progression of atherosclerosis, prevent the secondary cardiovascular events and improve the cardiovascular outcomes in patients with elevated cholesterol levels. The underlying mechanisms pertaining to the cardioprotective role of statins are linked with numerous pleiotropic actions including inhibition of inflammatory events and improvement of endothelial function, besides an effective cholesterol-lowering ability. Intriguingly, recent studies suggest possible interplay between statins and nuclear transcription factors like PPARs, which should also be taken into consideration while analysing the potential of statins in the management of cardiovascular complications. It could be suggested that statins have two major roles: (i) a well-established cholesterol-lowering effect through inhibition of HMG-CoA-reductase; (ii) a newly explored PPAR-activating property, which could mediate most of cardiovascular protective pleiotropic effects of statins including anti-inflammatory, antioxidant and anti-fibrotic properties. The present review addressed the underlying principles pertaining to the modulatory role of statins on PPARs.

Aleglitazar, a balanced PPARα/γ agonist, has no clinically relevant pharmacokinetic interaction with high-dose atorvastatin or rosuvastatin

BACKGROUND

Aleglitazar, a dual PPAR-α/γ agonist, combines the lipid benefits of fibrates and the insulin-sensitizing benefits of thiazolidinediones.

OBJECTIVE

To investigate the pharmacokinetic effects of co-administration of atorvastatin or rosuvastatin with aleglitazar.

RESEARCH DESIGN AND METHODS

In a two-cohort, open-label, randomised, three-period crossover study, 44 healthy subjects received once-daily oral doses of aleglitazar 300 μg, statin (atorvastatin 80 mg or rosuvastatin 40 mg) and aleglitazar co-administered with each statin for 7 days. Plasma concentrations of each drug were measured and pharmacokinetic parameters determined on day 7 in each period.

MAIN OUTCOME MEASURES

Peak observed plasma concentration (C(max)) and total exposures (AUC(0 - 24)) of aleglitazar, atorvastatin and rosuvastatin.

RESULTS

C(max) and AUC(0 - 24) to aleglitazar were similar, whether administered alone or in combination with a statin. Total exposure to either statin was unaffected by co-administration with aleglitazar. C(max) treatment ratios for both statins exceeded the conventional no-effect boundary (1.25) when administered with aleglitazar.

CONCLUSIONS

Co-administration of aleglitazar with a statin does not alter the pharmacokinetic profile of either drug.

Pleiotropic effects of statins. - Basic research and clinical perspectives -

Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, which are widely used to lower serum cholesterol levels in the primary and secondary prevention of cardiovascular disease. Recent experimental and clinical evidence suggests that the beneficial effects of statins may extend beyond their cholesterol-lowering effects, to include so-called pleiotropic effects. These cholesterol-independent effects include improving endothelial function, attenuating vascular and myocardial remodeling, inhibiting vascular inflammation and oxidation, and stabilizing atherosclerotic plaques. The mechanism underlying some of these pleiotropic effects is the inhibition of isoprenoid synthesis by statins, which leads to the inhibition of intracellular signaling molecules Rho, Rac and Cdc42. In particular, inhibition of Rho and one of its downstream targets, Rho kinase, may be a predominant mechanism contributing to the pleiotropic effects of statins. The aim of the present review is to provide an update on the non-cholesterol-dependent statin effects in the cardiovascular system and highlight some of the recent findings from bench to bedside to support the concept of statin pleiotropy.

Pioglitazone reduces the necrotic-core component in coronary plaque in association with enhanced plasma adiponectin in patients with type 2 diabetes mellitus

BACKGROUND

Pioglitazone has a preventive effect on cardiovascular disease, but its ability to stabilize coronary plaque is unknown.

METHODS AND RESULTS

A prospective, randomized trial was conducted in 54 patients with type 2 diabetes and stable angina pectoris, randomly assigned to either a pioglitazone group or control group. Non-culprit, angiographically mild-to-moderate obstructive lesions were examined with virtual histology intravascular ultrasound (VH-IVUS) at coronary intervention and 6 months later. In total, 42 lesions of 22 patients in the pioglitazone group and 44 lesions of 24 patients in the control group were analyzed. After 6 months, patients in the pioglitazone group had significantly improved blood sugar, high-sensitivity C-reactive protein, and plasma adiponectin levels. VH-IVUS analysis revealed that, although the total plaque-to-vessel volume was not changed in either group, the necrotic-core area had significantly decreased in the pioglitazone group (-4.6+/-5.9% vs 1.1+/-9.3%, P=0.001). There was a significant inverse correlation between the change in plasma adiponectin levels and the change in necrotic-core area (r=-0.46, P<0.0001).

CONCLUSIONS

Pioglitazone may stabilize coronary plaque by reducing the necrotic-core component, in association with enhanced plasma adiponectin levels.