Simona Giubilato

Expansion of CD4+CD28null T-lymphocytes in diabetic patients: exploring new pathogenetic mechanisms of increased cardiovascular risk in diabetes mellitus

AIMS Diabetes mellitus (DM) is associated with high incidence of first and recurrent cardiovascular events, especially acute coronary syndromes (ACSs); however, the mechanisms involved are still unknown. We sought to investigate the role of CD4(+)CD28(null)T-lymphocytes, a rare long-lived subset of T-lymphocytes with proatherogenic and plaque-destabilizing properties, in the increased cardiovascular risk associated with DM. METHODS AND RESULTS CD4(+)CD28(null)T-cell frequency was analysed by flow-cytometry in 60 DM patients without overt cardiovascular disease (cDM), in 166 ACS patients with or without DM (ACS/DM+, n= 51 and ACS/DM-, n= 115), and in 60 healthy individuals. The incidence of cardiovascular events (death, myocardial infarction, unstable angina) was assessed at 36 months follow-up. CD4+CD28(null)T-cell frequency (median, range) was higher in ACS/DM+ (12.7%, 0.1-48) vs. ACS/DM- (3.9%, 0.2-35), cDM (3.1%, 0.3-22.4), and controls (1.5%, 0.1-9.1) (P< 0.001 for all comparisons). Notably, cDM patients had significantly higher CD4+CD28(null)T-cell frequency than controls (P= 0.001). Glycosylated haemoglobin A(1c) was the only parameter independently associated with CD4+CD28(null)T-cells in cDM. The 36-month event-free survival was significantly lower in cDM patients with CD4+CD28(null)T-cells ≥4% (90th percentile of normal distribution) than in those with CD4+CD28(null)T-cells <4% (P= 0.039). Among ACS patients, the 36-month event-free survival was the lowest in those with DM and CD4+CD28(null)T-cells ≥4% and highest in those without DM and CD4+CD28(null)T-cells <4% (P< 0.001), being intermediate in those with only one of these features. CONCLUSIONS In DM patients, CD4+CD28(null)T-cells are expanded and are associated with poor glycaemic control; they also correlate with the occurrence of a first cardiovascular event and with a worse outcome after an ACS.

Severity of coronary atherosclerosis in patients with a first acute coronary event: a diabetes paradox

AIMS We aimed to compare coronary artery disease (CAD) at the time of a first acute coronary syndrome (ACS) in type II diabetic and non-diabetic patients by coronary angiography and by optical coherence tomography (OCT). METHODS AND RESULTS Two different patient populations with a first ACS were enrolled for the angiographic (167 patients) and the OCT (72 patients) substudy. Angiographic CAD severity was assessed by Bogaty, Gensini, and Sullivan scores, whereas collateral development towards the culprit vessel was assessed by the Rentrop score. Optical coherence tomography plaque features were evaluated at the site of the minimum lumen area (MLA) and of culprit segment. In the angiographic substudy, at multivariate analysis, diabetes was associated with both the stenosis score and the extent index (P = 0.001). Furthermore, well-developed collateral circulation (Rentrop 2-3) towards the culprit vessel was more frequent in diabetic than in non-diabetic patients (73% vs. 16%, P = 0.001). In the OCT substudy, at MLA site lipid quadrants were less and the lipid arc was smaller in diabetic than in non-diabetic patients (2.3 ± 1.3 vs. 3.0 ± 1.2; P = 0.03 and 198° ± 121° vs. 260° ± 118°; P = 0.03). Furthermore, the most calcified cross-section along the culprit segment had a greater number of calcified quadrants and a wider calcified arc in diabetic than in non-diabetic patients (1.7 ± 1.0 vs. 1.2 ± 0.9; P = 0.03 and 126° ± 95° vs. 81° ± 80°; P = 0.03). Superficial calcified nodules were more frequently found in diabetic than in non-diabetic patients (79 vs. 54%, P = 0.04). CONCLUSIONS In spite of potent pro-inflammatory, pro-oxidant and pro-thrombotic stimuli operating in type II diabetes, diabetic patients exhibit substantially more severe coronary atherosclerosis than non-diabetic patients at the time of a first acute coronary event. Better collateral development towards the culprit vessel, a predominantly calcific plaque phenotype and, probably, yet unknown protective factors operating in diabetic patients may explain these intriguing paradoxical findings.

Plasma levels of thromboxane A2 on admission are associated with no-reflow after primary percutaneous coronary intervention

AIMS Thromboxane A2 (TXA2) is a key mediator of platelet activation and aggregation, and an important mediator of platelet-induced coronary artery constriction. We sought to investigate whether baseline plasma levels of TXA2 are associated with coronary no-reflow after primary percutaneous coronary intervention (PPCI). METHODS AND RESULTS A total of 47 consecutive patients (age, 62.5 +/- 12.7; male sex, 76.6%) admitted to our hospital for a first ST-segment elevation myocardial infarction and undergoing PPCI within 12 h of onset of symptoms were enrolled. Admission TXA2 plasma levels were measured by enzyme-linked immunosorbent assay (ELISA). Angiographic no-reflow was defined as a final TIMI flow of <or=2 or final TIMI flow of 3 with a myocardial blush grade of <2, whereas ST-segment resolution from baseline value of <or=50% was used as ECG index of no-reflow. At multivariable analysis TXA2 plasma levels, endothelin-1 (ET-1) plasma levels, and left anterior descending coronary artery (LAD) as culprit vessel were significant predictors of angiographic no-reflow (P = 0.04), whereas TXA2 and ET-1 plasma levels were the only independent predictors of lack of ST-segment resolution (P = 0.013 and 0.04, respectively). Of note, TXA2 tertiles were independent predictors of both angiographic no-reflow and lack of ST-segment resolution (OR, 3.5; 95% CI, 1.1-11; P = 0.03 and OR, 3; 95% CI, 1.3-7; P = 0.01, respectively). CONCLUSION TXA2 is an independent indicator of no-reflow that occurs after PPCI. This observation may open new therapeutic opportunity in the setting of PPCI.

Combined atherogenic effects of celiac disease and type 1 diabetes mellitus

OBJECTIVE Previous studies have shown a high cardiovascular risk in patients with autoimmune diseases, such as type 1 diabetes mellitus (T1DM). Conversely, few data are available about patients with celiac disease (CD). The aim of our study was to assess carotid intima-media thickness (c-IMT), in patients with T1DM, CD or both (T1DM+CD) as compared with age- and sex-matched healthy individuals (H). METHODS We enrolled 120 patients, 30 with T1DM, 30 with CD, 30 with T1DM+CD and 30 H. Clinical, metabolic and anthropometric data were collected. All T1DM patients were on insulin while all CD patients were on a gluten-free diet. c-IMT was evaluated by high frequency linear digital ultrasound. RESULTS c-IMT was significantly greater in patients with T1DM+CD than in patients with T1DM or CD (P<0.001 for both), while no difference was found between T1DM and CD. Moreover, c-IMT was greater in CD than in H (P<0.001). Glycemic control and disease duration were similar between T1DM+CD and T1DM. Lipid and anthropometric parameters were similar among groups. Furthermore, in a pooled multivariate analysis, only age and disease type were significantly correlated with c-IMT (P<0.001 for both). CONCLUSION Our study demonstrates that celiac patients have greater c-IMT as compared with healthy individuals. Thus, non-invasive monitoring of c-IMT in CD might be useful in preventing cardiovascular disease. Moreover, patients with T1DM+CD show more severe subclinical atherosclerosis as compared with those presenting T1DM or CD only, suggesting that the association of these autoimmune diseases might accelerate the atherosclerotic process.

Adaptive immunity, inflammation, and cardiovascular complications in type 1 and type 2 diabetes mellitus.

Diabetes mellitus (DM) is a pandemics that affects more than 170 million people worldwide, associated with increased mortality and morbidity due to coronary artery disease (CAD). In type 1 (T1) DM, the main pathogenic mechanism seems to be the destruction of pancreatic β-cells mediated by autoreactive T-cells resulting in chronic insulitis, while in type 2 (T2) DM primary insulin resistance, rather than defective insulin production due to β-cell destruction, seems to be the triggering alteration. In our study, we investigated the role of systemic inflammation and T-cell subsets in T1- and T2DM and the possible mechanisms underlying the increased cardiovascular risk associated with these diseases.

Incidence, treatment, and in-hospital outcome of bifurcation lesions in patients undergoing percutaneous coronary interventions for chronic total occlusions.

Background Bifurcation lesions represent a distinct lesion subset associated with an increased risk of procedural complications. Data on the incidence, treatment, and outcome of bifurcation lesions associated with chronic total occlusions are limited. Methods Among chronic total occlusion procedures performed by a single experienced operator, patients with a bifurcation lesion within the chronic total occlusion vessel and a side branch reference diameter greater than or equal to 2.0 mm were enrolled. Results A total of 905 patients (mean age 61.1±9.5 years, men 89.4%) were treated for 922 chronic total occlusion lesions. Among these, 244 bifurcation lesions were observed (26.5%). The procedural time was significantly longer in bifurcation lesions (139±67 vs. 124±68 min; P=0.003), with greater use of contrast load (470±193 vs. 436±227 ml; P=0.04) and higher number of stents (3.1±1.5 vs. 2.9±1.4; P=0.035). Overall, an angiographic success was achieved in 91.1% of cases with a higher rate in nonbifurcation lesions (92.5 vs. 87.3%; P=0.04). Coronary perforations were more often observed in bifurcation lesions (4.9 vs. 1.7%; P<0.001), resulting in more tamponades (2.4 vs. 0.2%; P<0.001). True bifurcations were encountered in the majority of cases (86.8%) and required more two-stent techniques than false bifurcations (50 vs. 18.8%; P=0.001). Conclusion The incidence of bifurcation lesions in chronic total occlusions is higher than that reported in continuous lesions. The presence of a bifurcation lesion increases the complexity of the procedure and may lead to less angiographic success and more periprocedural complications.

Delayed neutrophil apoptosis in patients with unstable angina: relation to C-reactive protein and recurrence of instability

AIMS To investigate spontaneous polymorphonuclear neutrophils (PMNs) apoptosis in unstable angina (UA) and its association with recurrence of instability. METHODS AND RESULTS We compared PMNs apoptotic rate at 4 and 24 h in patients with UA, stable angina (SA), and controls (H) with two different protocols by flow cytometry. We measured apoptotic rate of isolated PMNs (Protocol 1) in 30 UA patients, 13 SA patients, and 34 H; and apoptosis of PMNs in whole blood culture (Protocol 2) in further 10 UA patients, 7 SA patients, and 6 H. Serum high-sensitivity C-reactive protein was also measured. Polymorphonuclear neutrophils of UA patients showed a decreased apoptotic rate compared with SA patients and H at 4 h in Protocol 1 (both P < 0.01), and at 24 h in Protocol 2 (P < 0.05 and <0.01, respectively). In overall population, a negative correlation was found between apoptotic rate at 4 h and high-sensitivity C-reactive protein levels (P < 0.01). Six among 40 patients with UA had early recurrence of symptoms and their apoptotic rate was significantly reduced compared with UA patients without recurrence of symptoms (P = 0.024). CONCLUSIONS Our study demonstrates delayed PMN apoptosis in UA. This alteration might be involved in the persistence of inflammatory activation and affects recurrence of instability.

Different Apparent Prognostic Value of hsCRP in Type 2 Diabetic and Nondiabetic Patients with Acute Coronary Syndromes

BACKGROUND C-reactive protein (CRP) is an established prognostic marker in acute coronary syndromes (ACS); however, no study has specifically addressed its prognostic role in type 2 diabetes with ACS. We evaluated the prognostic role of CRP separately in diabetic and nondiabetic patients with ACS. METHODS We enrolled 251 patients with unstable angina and measured serum concentrations of high sensitivity (hs)CRP. Ninety-seven patients underwent coronary angiography with evaluation of atherosclerotic disease severity and extent by Bogaty score. Assessed endpoint was the combined occurrence of myocardial infarction (MI) and death at 1 year. RESULTS No significant differences were found in hs-CRP between patients with and without diabetes. By Cox regression, hsCRP was not associated with 1-year follow-up events in diabetic patients but was strongly associated with events in nondiabetic patients (P = 0.0012). Coronary angiography exhibited a higher extent index in patients with diabetes than in those without (P = 0.04). hsCRP concentrations were not associated with angiographic atherosclerotic burden. By Cox analysis, hsCRP and extent score were associated with events in patients who underwent coronary angiography (P < 0.001 and P = 0.034, respectively). In nondiabetic patients, hsCRP was the only predictor of events at 1-year follow-up (P < 0.001), whereas in diabetic patients, hsCRP was not associated with events and a weak association was observed for extent score (P = 0.06). CONCLUSIONS Our study suggests that different pathophysiological mechanisms may be responsible for MI and death in unstable angina patients with or without diabetes and that severity of coronary artery disease plays a major role in diabetes (and inflammation in the absence of diabetes).

Thromboxane production in morbidly obese subjects

Postmortem studies have demonstrated that morbidly obese subjects, surprisingly, have less coronary atherosclerosis than obese subjects. However, the reasons for this apparent protection from atherosclerosis are not yet clear. Thromboxane A2, a marker of platelet activation, is greater in obese subjects than in lean subjects, and this might be a clue to their increased cardiovascular risk. However, data on thromboxane A2 in morbidly obese subjects are lacking; therefore, we hypothesized that lower levels of thromboxane A2 in morbidly obese subjects might play a role in their lower atherothrombotic burden. We measured the serum levels of thromboxane B2 (TxB2), a stable metabolite of thromboxane A2, high-sensitivity C-reactive protein (hs-CRP) and leptin in 17 lean subjects (body mass index [BMI] 22.9 ± 1.6 kg/m(2)), 25 obese subjects (BMI 32.6 ± 2.4 kg/m(2)), and 23 morbidly obese subjects (BMI 48.6 ± 7.1 kg/m(2)), without insulin resistance, diabetes, or overt cardiovascular disease. The serum TxB2 levels were lower in the lean subjects than in the obese subjects (p = 0.046) and in the morbidly obese subjects than in the lean and obese subjects (p = 0.015 and p <0.001, respectively). In contrast, the hs-CRP and leptin levels were greater in the obese than in the lean subjects (hs-CRP, p <0.001; leptin, p <0.001) and in the morbidly obese subjects than in the lean subjects (p <0.001 for both). Leptin was also higher in the morbidly obese subjects than in the obese subjects (p <0.001). TxB2 negatively correlated with leptin and BMI. hs-CRP correlated with leptin, and both also correlated with waist circumference, BMI, and homeostasis model assessment of insulin-resistance. In conclusion, insulin-sensitive morbidly obese subjects had lower levels of TxB2 than the obese subjects and lean subjects, suggesting that reduced platelet activation could play a role in the paradoxical protection of morbidly obese subjects from atherosclerosis, despite the greater levels of leptin.

Platelet P2Y12 receptor inhibition by thienopyridines: status and future

Thienopyridines have a well-established role in the treatment of coronary artery disease, especially in the setting of acute coronary syndromes and percutaneous coronary interventions. Ticlopidine, the first FDA-approved thienopyridine, was shown to be effective in reducing coronary events in high risk patients, but the original enthusiasm was hampered by concerns about its serious bone marrow toxicity. Clopidogrel a second generation thienopyridine with lesser side effects, is not only at least as effective as ticlopidine, but in combination with a low dose of aspirin, has been demonstrated to reduce the risk of major cardiovascular events in acute coronary syndrome patients in large-scale, randomised trials. Recent studies have highlighted major flaws in clopidogrel pharmacokinetics due to its delayed onset of action, and much attention has been devoted to the phenomenon of clopidogrel ‘resistance’. Among the novel, third generation thienopyridines, prasugrel as compared to clopidogrel has demonstrated lower inter-patient response variability and a reduced incidence of ischaemic events, but at an increased risk of major bleeding. Currently, several studies are continuing to test new direct P2Y12 receptor antagonists, such as cangrelor and AZD6140, characterised by a faster reversal of platelet inhibition.