Francesco Barillà

A Common Mutation of the Insulin Receptor Substrate-1 Gene Is A Risk Factor for Coronary Artery Disease

Insulin resistance is associated with increased risk of atherosclerosis. Insulin receptor substrate-1 (IRS-1) plays a key role in tissue insulin sensitivity. A common mutation (G972R) of the IRS-1 gene has been shown to impair IRS-1 function, and it has been associated with reduced insulin sensitivity and lipid abnormalities. This led us to investigate the role of the G972R mutation in predisposing individuals to coronary artery disease (CAD). The DNA of 318 subjects with angiographically documented coronary atherosclerosis (>50% stenosis) and 208 population control subjects was analyzed for the presence of the G972R mutation. This mutation was detected by nested polymerase chain reaction and BstNI restriction enzyme digestion. The frequency of the G972R mutation was significantly higher among patients with CAD than controls (18. 9% versus 6.8%, respectively; P<0.001). After controlling for other coronary risk factors, the relative risk of CAD associated with the G972R mutation was 2.93 (95% CI 1.30 to 6.60; P<0.02) in the entire cohort. This risk was found to be even higher in the subgroups of obese subjects (odds ratio [OR] 6.97, 95% CI 2.24 to 21.4; P<0.001) and subjects with clinical features of insulin resistance syndrome (OR 27.3, 95% CI 7.19 to 104.0; P<0.001). The IRS-1 gene variant was associated with a higher frequency of diabetes mellitus (14.9% among carriers versus 6.5% among noncarriers; P<0.01) and with a 60% increase of plasma total triglycerides (P<0.001). Also, plasma concentrations of total cholesterol and the ratio of total cholesterol to HDL cholesterol were significantly (P<0.001) higher among carriers than noncarriers, although to lesser a extent. These effects were independent of CAD status. The G972R mutation in the IRS-1 gene was found to be a significant independent predictor of CAD. Moreover, this mutation greatly increased the risk of CAD in obese subjects and in patients with the cluster of abnormalities of insulin resistance syndrome. Besides the increased frequency of diabetes, carriers showed a more atherogenic lipid profile, suggesting a potential role of the IRS-1 gene in the pathogenesis of lipid abnormalities associated with CAD.

Angiotensin-converting enzyme inhibitor therapy affects left ventricular mass in patients with ejection fraction > 40% after acute myocardial infarction.

OBJECTIVES We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy decreases left ventricular (LV) mass in patients with a left ventricular ejection fraction (LVEF) > 40% and no evidence of heart failure after their first acute Q wave myocardial infarction (MI). BACKGROUND Recently, ACE inhibitor therapy has been shown to have an early mortality benefit in unselected patients with acute MI, including patients without heart failure and a LVEF > 35%. However, the effects on LV mass and volume in this patient population have not been studied. METHODS Thirty-five patients with a LVEF > 40% after their first acute Q wave MI were randomized to titrated oral ramipril (n = 20) or conventional therapy (control, n = 15). Magnetic resonance imaging (MRI) performed an average of 7 days and 3 months after MI provided LV volumes and mass from summated serial short-axis slices. RESULTS Left ventricular end-diastolic volume index did not change in ramipril-treated patients (62 +/- 16 [SD] to 66 +/- 17 ml/m2) or in control patients (62 +/- 16 to 68 +/- 17 ml/m2), and stroke volume index increased significantly in both groups. However, LV mass index decreased in ramipril-treated patients (82 +/- 18 to 73 +/- 19 g/m2, p = 0.0002) but not in the control patients (77 +/- 15 to 79 +/- 23 g/m2). Systolic arterial pressure did not change in either group at 3-month follow-up. CONCLUSIONS In patients with a LVEF > 40% after acute MI, ramipril decreased LV mass, and blood pressure and LV function were unchanged after 3 months of therapy. Whether the decrease in mass represents a sustained effect that is associated with a decrease in morbid events requires further investigation.

Lower mortality rate in elderly patients with community-onset pneumonia on treatment with aspirin.

Background Pneumonia is complicated by high rate of mortality and cardiovascular events (CVEs). The potential benefit of aspirin, which lowers platelet aggregation by inhibition of thromboxane A2 production, is still unclear. The aim of the study was to assess the impact of aspirin on mortality in patients with pneumonia. Methods and Results Consecutive patients admitted to the University‐Hospital Policlinico Umberto I (Rome, Italy) with community‐onset pneumonia were recruited and prospectively followed up until discharge or death. The primary end point was the occurrence of death up to 30 days after admission; the secondary end point was the intrahospital incidence of nonfatal myocardial infarction and ischemic stroke. One thousand and five patients (age, 74.7±15.1 years) were included in the study: 390 were receiving aspirin (100 mg/day) at the time of hospitalization, whereas 615 patients were aspirin free. During the follow‐up, 16.2% of patients died; among these, 19 (4.9%) were aspirin users and 144 (23.4%; P<0.001) were aspirin nonusers. Overall, nonfatal CVEs occurred in 7% of patients, 8.3% in nonaspirin users, and 4.9% in aspirin users (odds ratio, 1.77; 95% confidence interval, 1.03 to 3.04; P=0.040). The Cox regression analysis showed that pneumonia severity index (PSI), severe sepsis, pleural effusion, and PaO2/FiO2 ratio <300 negatively influenced survival, whereas aspirin therapy was associated with improved survival. Compared to patients receiving aspirin, the propensity score adjusted analysis confirmed that patients not taking aspirin had a hazard ratio of 2.07 (1.08 to 3.98; P=0.029) for total mortality. Conclusions This study shows that chronic aspirin use is associated with lower mortality rate within 30 days after hospital admission in a large cohort of patients with pneumonia.

Inadequate anticoagulation by Vitamin K Antagonists is associated with Major Adverse Cardiovascular Events in patients with atrial fibrillation

BACKGROUND Time in therapeutic range (TTR) reflects the quality of anticoagulation and is inversely correlated with ischemic stroke in atrial fibrillation (AF) patients. Few data on the relationship between TTR and myocardial infarction (MI) are available. We investigated the association between TTR and Major Adverse Cardiovascular Events (MACE) in a cohort of anticoagulated AF patients. METHODS We calculated TTR for 627 AF patients on vitamin K antagonists, who were followed for a median of 30.8 months (1755 patients/year). The primary outcome was a combined endpoint of MACE including fatal/nonfatal MI and cardiovascular death. RESULTS Mean age was 73.3 (±8.2) years, and 40.2% were women. During follow-up, we recorded 67 events: 19 stroke/TIA (1.1%/year) and 48 MACE (2.9%/year): 24 MI and 24 cardiovascular deaths. The cohort was categorized according to tertiles of TTR values: TTR 13-58%, 59-74%, and 75-100%. There was a significant increased rate of MACE across tertiles of TTR (Log-Rank test: p<0.001). On Cox proportion hazard analysis, the 2nd vs. 1st tertile of TTR (p=0.002, hazard ratio [HR] 0.347, confidence interval [CI] 95% 0.177-0.680), 3rd vs. 1st tertile of TTR (p<0.001, HR 0.164, CI 95% 0.067-0.402), age (p<0.001, HR 1.094, CI 95% 1.042-1.148), history of stroke/TIA (p=0.015, HR 2.294, CI 95% 1.172-4.490) and smoking (p=0.003, HR 3.450, CI 95% 1.532-7.769) predicted MACE. CONCLUSION TTR was an independent predictor of MACE in our cohort of AF patients. Our findings suggest that a good anticoagulation control is necessary to reduce not only the risk of stroke but also that of MACE.

Effectiveness of Two-Year Clopidogrel Aspirin in Abolishing the Risk of Very Late Thrombosis After Drug-Eluting Stent Implantation (from the TYCOON (Two-Year ClOpidOgrel Need) Study)

It remains unclear whether dual antiplatelet therapy >12 months might carry a better prognosis after percutaneous coronary intervention (PCI) with drug-eluting stents (DESs). To address the hypothesis that in the real world the risk of very late thrombosis after PCI with DESs can be decreased by an extended use of clopidogrel, we set up the Two-Year ClOpidOgrel Need (TYCOON) registry and prospectively investigated the impact on very late thrombosis of 12- versus 24-month dual antiplatelet regimens in an unselected population. The registry enrolled 897 consecutive patients who underwent PCI with stenting from January 1, 2003, to December 31, 2004, and had dual antiplatelet therapy. All patients had a 4-year clinical follow-up. In the 447 patients with DES implantation, the dual antiplatelet regimen after PCI was given for 12 months in the 173 patients treated in 2003 (12-month group) and for 24 months in the 274 patients treated in 2004 (24-month group). Comparison between groups did not reveal any significant difference in baseline clinical characteristics, angiographic and procedural features, and major adverse cardiac events. During follow-up, there were 5 cases of stent thrombosis after PCI in the 12-month DES group and 1 case in the 24-month DES group (p = 0.02). Specifically, there were 2 cases of subacute thrombosis (1 in each group), no case of late thrombosis, and 4 cases of very late thrombosis occurring at 13, 15, 17, and 23 months after DES implantation in the 12-month group only. In conclusion, a 2-year dual antiplatelet regimen with aspirin and clopidogrel can prevent the occurrence of very late stent thrombosis after PCI with DESs.

C242T Polymorphism of NADPH Oxidase p22phox and Recurrence of Cardiovascular Events in Coronary Artery Disease

Objectives—The common C242T polymorphism in the gene for the p22phox subunit of NADPH oxidase has been reported to be negatively associated with oxidative stress, but whether it confers prognostic information is not yet clear. Methods and Results—The incidence of major adverse cardiovascular events (MACE) were determined in 237 patients with coronary stenosis during a median follow-up of 7.8 years. The p22phox genotypes were evaluated in 213 patients (89.9%) by polymerase chain reaction and RsaI. digestion. Plasma levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative stress, were also measured. In the univariate analysis, patients with CT/TT genotypes showed reduced recurrence of cardiovascular deaths, nonfatal MI, and revascularization procedures compared with homozygous carriers of the C allele. After controlling for confounders, a significantly lower risk of new revascularization procedures (HR=0.31, 95% CI 0.12 to 0.70; P=0.014) remained associated with the T allele. The Kaplan–Meier analysis showed a longer survival free from fatal and nonfatal MI in carriers of T allele (P<0.001). The presence of the 242T allele was associated with significantly reduced plasma concentrations of 8-OHdG. Conclusions—The 242T allele was a predictor of lower risk of recurrence of cardiovascular events in high-risk patients and was associated with reduced systemic oxidative stress.

Right ventricular function in acute pulmonary embolism: a combined assessment by three-dimensional and speckle-tracking echocardiography.

BACKGROUND The aim of this study was to assess changes in right ventricular (RV) parameters determined by three-dimensional (3D) echocardiography and speckle-tracking echocardiography in patients with acute pulmonary embolism and RV dysfunction without systemic hypotension (submassive pulmonary embolism). METHODS Sixty-six patients were prospectively studied at the onset of the acute episode and after median follow-up periods of 30 days and 6 months. Sixty-six controls were selected. RV fractional area change, tricuspid annular plane systolic excursion, and myocardial performance index were determined. RV systolic pressure was assessed using continuous-wave Doppler echocardiography. Three-dimensional RV ejection fraction (RVEF) was calculated. Two-dimensional peak systolic RV longitudinal strain (RVLS) was measured in the basal free wall, mid free wall (MFW), and apical free wall and the septum. RESULTS Tricuspid annular plane systolic excursion and fractional area change were smaller and myocardial performance index was larger compared with controls (P < .05). Global RVLS (P < .05), MFW RVLS (P < .001), and 3D RVEF (P < .001) were lower in patients with pulmonary embolism than in controls. There was earlier reversal of MFW RVLS values on 30-day follow-up and longer reversal of 3D RVEF and RV systolic pressure values at 6-month follow-up. Receiver operating characteristic curve analysis showed that changes in 3D RVEF and MFW RVLS were the most sensitive predictors of adverse events. By multivariate analysis, RV systolic pressure (P = .007), MFW RVLS (P = .002), and 3D RVEF (P = .001) were independently associated with adverse outcomes. CONCLUSIONS Acute submassive pulmonary embolism has a significant impact on RV function as assessed by 3D echocardiography and speckle-tracking echocardiography. Decreases in MFW RVLS and 3D RVEF may persist during short-term and long-term follow-up and correlate with unfavorable outcomes.

The common mutations in the lipoprotein lipase gene in Italy: effects on plasma lipids and angiographically assessed coronary atherosclerosis.

The present study evaluated the role of the common lipoprotein lipase (LPL) mutations on the risk of dyslipidemia and coronary atherosclerosis in an Italian population. Cohorts of 632 patients undergoing coronary angiography, as well as 191 healthy controls, were screened by a combination of PCR and restriction enzyme digestion. In the pooled population, the frequencies of LPL D9N and N291S were 4.1%, with no homozygous carriers, whereas that of LPL S447X was 21% with 19.6% heterozygous and 1.4% homozygous carriers. Compared to non‐carriers, LPL N291S carriers showed higher plasma triglycerides (TG) (p<0.03) and increased risk of high TG phenotype (odds ratio [OR] 2.49, 95% CI 1.06–5.81; p<0.03). When this LPL mutation was associated with high body mass index (BMI) (>25 Kg/m2) or fasting, plasma insulin (>10.6 mU ml−1) significantly reduced HDL‐C levels were also observed. Carriers of the S447X mutation presented with higher HDL‐C concentrations (p<0.05) as compared to non‐carriers; they also showed a significantly reduced risk of high TG/low HDL‐C dyslipidemia (OR 0.34, 95% CI 0.12–0.99; p<0.05). The favourable effect of the LPL S447X variant was even more pronounced in lean subjects and in those with low insulin levels. No significant influence on plasma lipids by the LPL D9N was observed. None of LPL variants was a significant predictor of angiographically assessed coronary atherosclerosis. At most, the risk was borderline, increased in N291S carriers and possibly decreased in S447X carriers.

Circulating miR-33a and miR-33b are up-regulated in familial hypercholesterolaemia in paediatric age

Hypercholesterolaemia is one of the major causes of CVD (cardiovascular disease). It is associated with enhanced oxidative stress, leading to increased lipid peroxidation which in turn determines endothelial dysfunction and susceptibility to coronary vasoconstriction and atherosclerosis. Different miRNAs are involved in the pathogenesis of CVD and play an important role in inflammatory process control, therefore, together with atherogenic factors, they can stimulate atherosclerotic degeneration of the vessel walls of arteries. miR-33a and miR-33b play a pivotal role in a variety of biological processes including cholesterol homoeostasis, HDL (high-density lipoprotein)-cholesterol formation, fatty acid oxidation and insulin signalling. Our study aimed to determine whether circulating miR-33a and miR-33b expression was altered in familial hypercholesterolaemic children. Total RNA was extracted from plasma, and miR-33a and miR-33b were measured by quantitative real-time PCR. We found that miR-33a and miR-33b were significantly up-regulated in the plasma of 28 hypercholesterolaemic children compared with 25 healthy subjects (4.49±0.27-fold increase, P<0.001, and 3.21±0.39-fold increase, P<0.05 respectively), and for both miRNAs, a positive correlation with total cholesterol, LDL (low-density lipoprotein)-cholesterol, LDL-cholesterol/HDL-cholesterol ratio, apolipoprotein B, CRP (C-reactive protein) and glycaemia was found. OLS (ordinary least squares) regression analysis revealed that miR-33a was significantly affected by the presence of FH (familial hypercholesterolaemia), glycaemia and CRP (P<0.001, P<0.05 and P<0.05 respectively). The same analysis showed that miR-33b was significantly related to FH and CRP (P<0.05 and P<0.05 respectively). Although it is only explorative, the present study could be the first to point to the use of miR-33a and miR-33b as early biomarkers for cholesterol levels in childhood, once validated in independent larger cohorts.

Antitissue transglutaminase antibodies in acute coronary syndrome: an alert signal of myocardial tissue lesion?

Background and aim.  Antitransglutaminase, previously considered identical to antiendomysial in coeliac sprue (CS), have been reported in end‐stage heart failure. To clarify the above‐mentioned data, we evaluated these antibodies in a cohort of cardiological patients with respect to troponin I, creatine kinase (CK), MB fraction creatine kinase (CK‐MB mass) and myoglobin.