Antonio Rizza

Genetic polymorphisms in folate and homocysteine metabolism as risk factors for DNA damage

Epidemiological studies indicated a role for polymorphisms in genes of folate and homocysteine (Hcy) metabolism in the etiology of neurodegenerative disease, congenital defects and coronary artery disease (CAD). This study investigated the effect of several polymorphisms [C677 T, A1298C of methylenetetrahydrofolate reductase (MTHFR) and A66G of methionine synthase reductase (MTRR) genes] on Hcy levels and DNA damage in 68 patients who underwent coronary angiography. Plasma Hcy concentrations were higher in patients with multivessel disease with respect to monovessel disease and no-CAD patients (19.4±2.6 vs 11.6±1.2 and 13.7±1.4 μmol/l, respectively; P=0.03). 677TT patients had higher Hcy levels than those with 677CC or 677CT genotypes (26.2±4.3 vs 13.1±1.4 and 13.0±1.4 μmol/l, respectively; P=0.0006). No significant associations were found between A1298C and A66G polymorphisms and plasma Hcy levels. Among patients with 677CC genotype, 66GG individuals tended to have higher levels of Hcy than 66AA homozygotes (14.5±1.9 vs 8.9±0.7 μmol/l, P=0.06). Multivessel disease patients showed an increased frequency of DNA damage, measured by the micronucleus (MN) frequency, as compared to monovessel disease and no-CAD subjects (12.5±1.1 vs 8.5±0.8 and 8.2±0.9, respectively; P=0.006). The MN were positively correlated with Hcy levels (r=0.33, P=0.006) and were significantly higher in subjects with the 677TT genotype compared with the 677CC or 677CT genotypes (14.4±2.0 vs 8.8±1.2 and 9.5±0.7, respectively; P=0.006). A1298C and A66G polymorphisms had no effect on MN frequency. However, among 677TT patients, 66GG subjects tended to have higher levels of MN than those 66AG and 66AA (18.2±3.6 vs 13.8±4.0 and 10.3±1.7, respectively; P=NS). Our results indicate that genetic instability may be associated with increased risk for multiple Hcy-related diseases.

Interactive effect of the glutathione S-transferase genes and cigarette smoking on occurrence and severity of coronary artery risk

Cardiovascular diseases and cancer are the main causes of death in developed countries. Mortality trends for these diseases suggest that they share common pathogenetic mechanisms. Glutathione S-transferase (GST) is a family of enzymes that detoxify reactive electrophiles, particularly present in tobacco smoke. Glutathione S-transferase null M1 and T1 (GSTM1 and GSTT1) genotypes have often been associated with increased risk of developing cancer. Our hypothesis was that the polymorphic GSTM1 and GSTT1 genes modulate the risk of smoking-coronary artery disease (CAD). We evaluated the distribution of GST genotypes in 430 angiographically defined patients (308 CAD and 122 non-CAD). The frequencies of GST null genotypes did not differ significantly between patients with CAD and without CAD. However, smokers with GSTM1 and GSTT1 null genotypes had a significantly higher risk of CAD than never-smokers with these genotypes present (OR 2.2 and 3.4 for smokers with null GSTM1 and GSTT1 genes, respectively). There was also evidence of multiple interaction between GSTM1 and GSTT1 deleted genotypes and smoking. In nonsmokers carrying both null genotypes the risk of CAD was 0.66. In smokers with both present genotypes the OR was 1.5 and was significantly increased in smokers with concurrent lack for GSTM1 and GSTT1 genes (OR=4.0). Moreover, smokers lacking GST genes had both more stenosed vessels and a higher Duke score than smokers expressing the genes. We also examined the levels of DNA damage in 66 men patients using the micronucleus test, a sensitive assay for evaluating chromosome damage. Micronucleus levels were higher in smokers with null genes than in smokers with present genes. These observations suggest that GST-null genotypes strengthen the effect of smoking on CAD risk by modulating the detoxification of genotoxic atherogens.

Deoxyribonucleic Acid Damage in Human Lymphocytes After Percutaneous Transluminal Coronary Angioplasty

UNLABELLED OBJECTIVES; We investigated the presence of oxidative deoxyribonucleic acid (DNA) damage in the peripheral lymphocytes of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) by using the micronucleus test and comet assay, which are sensitive biomarkers of DNA damage. BACKGROUND; Although it has recognized that ischemia-reperfusion can induce oxidative DNA damage, its occurrence in patients undergoing PTCA has not yet been demonstrated. METHODS Three groups of patients were enrolled: 30 patients with documented coronary heart disease who underwent elective PTCA (group I); 25 patients who underwent elective coronary angiography for diagnostic purpose (group II); and 27 healthy, age- and gender-matched subjects (group III). For each subject, the frequency of micronucleated binucleated (MNBN) cells, DNA single-strand breaks (SSBs), endonuclease III-sensitive sites, and sites sensitive to formamidopyrimidine glycosylase (FPG) were analyzed before and after diagnostic procedures. RESULTS The mean basal values of MNBN cells (p = 0.04), DNA-SSBs (p = 0.001), endonuclease III-sensitive sites (p = 0.002), and FPG sites (p < 0.0001) were significantly higher in groups I and II than in group III. A high significant increase of MNBN cell frequency was observed in group I after the PTCA procedure (11.0 +/- 1.3 vs. 19.8 +/- 1.6, p < 0.0001), whereas no significant difference was observed in group II (10.2 +/- 1.3 vs. 12.9 +/- 1.4, p = 0.18). A significant positive correlation was observed between the increase in the MNBN cell rate and total inflation time during PTCA (R = 0.549, p = 0.0017). The levels of DNA-SSBs (11.7 +/- 1.4 vs. 26.5 +/- 3.0, p = 0.0003) and FPG sites (13.8 +/- 1.8 vs. 22.5 +/- 2.4, p = 0.01) were also higher after PTCA. CONCLUSIONS Our results provide evidence for oxidative DNA damage after PTCA, likely related to ischemia-reperfusion injury.

Relation of increased chromosomal damage to future adverse cardiac events in patients with known coronary artery disease.

Somatic deoxyribonucleic acid (DNA) damage has been associated with early-phase and/or acute complications of atherosclerosis. However, it remains unclear whether circulating levels of DNA damage have prognostic value in patients with coronary artery disease (CAD). The aim of this study was to assess the prognostic significance of chromosomal DNA damage in human lymphocytes on the rate of major adverse cardiovascular events in patients with CAD. A follow-up prospective cohort study was carried out of 178 patients (153 men, mean age 61.9 +/- 9.7 years) with angiographically proved CAD who underwent micronucleus assay, a sensitive biomarker of chromosomal damage and genetic instability, from March 1999 and June 2001. During a mean follow-up period of 51.4 +/- 23.8 months, 58 patients had major adverse cardiovascular events (cardiac death, myocardial infarction, stroke, congestive heart failure, unstable angina, or coronary and peripheral revascularization). The overall event-free survival rates were 77.5%, 70.4%, and 49.0% in patients in the lower, middle, and upper tertiles of micronucleus level, respectively (log rank = 11.5, p = 0.003). In a multivariate Cox regression model, only the upper tertiles were significantly associated with a higher risk for major adverse cardiovascular events (hazard ratio 2.2, 95% confidence interval 1.1 to 4.7, p = 0.03). In conclusion, levels of peripheral chromosomal DNA damage may be a new sensitive biomarker of prognostic stratification in patients with known CAD.

Relationships Between Optical Aggregometry (Type Born) and Flow Cytometry in Evaluating ADP-Induced Platelet Activation

Platelet response to activating agents is used to monitor the efficacy of anti‐aggregation therapies. The aim of our study has been to demonstrate the existence of relationships between early events of ADP‐induced platelet activation, measured by flow cytometry and platelet‐rich plasma aggregation, quantified by optical aggregometry.

Plasma N-e-(carboxymethyl)lysine levels are associated with the extent of vessel injury after coronary arterial stenting

ObjectiveIn animal models, increased tissue receptor for advanced glycation end products and its ligands, including N-ϵ-(carboxymethyl)lysine (CML), are critically implicated in postprocedural intimal hyperplasia after balloon injury. In patients undergoing percutaneous coronary interventions with stenting, we investigated whether plasma levels of CML and the soluble form of receptor for advanced glycation end products (sRAGE) changed during poststenting follow-up. MethodsWe studied 81 patients with coronary artery disease who underwent successful percutaneous coronary interventions. Plasma levels of CML and sRAGE were measured before intervention, and at 1 day and 180 days of follow-up. ResultsCML levels increased significantly at day 1 after stenting and persisted at an elevated level at 180 days (P=0.013), whereas sRAGE levels increased significantly at 180 days (P=0.011). CML levels were significantly higher in multivessel-treated patients than in single-vessel-treated patients both at 1 day and 180 days of follow-up. In addition, CML values were positively associated with the extent of stent area at 1 day and 180 days of follow-up (r=0.278, P=0.022 and r=0.315, P=0.012, respectively). In logistic regression analysis, only the extent of stent area predicted adverse clinical events at 180-day follow-up (P=0.03, odds ratio=14.25, confidence interval=1.25–162.2). ConclusionThis study supports the hypothesis that increased circulating levels of CML occurred in the presence of vascular injury. This persistent rise of CML could amplify an inflammatory phenomenon triggered by stent placement and thus contributes to coronary artery disease progression.

Left atrial appendage occlusion in high-risk patients with non-valvular atrial fibrillation

Objective Percutaneous left atrial appendage (LAA) occlusion has been developed as a viable option for stroke and thromboembolism prevention in patients with non-valvular atrial fibrillation (NVAF) and at high risk for cerebral cardioembolic events. Data on device implantation and long-term follow-up from large cohorts are limited. Methods 110 consecutive patients with NVAF and contraindications to oral anticoagulants (OACs) underwent LAA occlusion procedures and achieved a longer than 1 year follow-up. All patients were enrolled in a prospective registry. Procedures were performed using the Amplatzer Cardiac Plug or Amulet guided by fluoroscopy and intracardiac echocardiography. Results Mean age of the population was 77±6 years old; 68 were men. Atrial fibrillation was paroxysmal in 20%, persistent in 15.5% and permanent in 64.5% of cases, respectively. Mean CHA2DS2-VASc and HAS-BLED scores were 4.3±1.3 and 3.4±1, respectively. Technical success (successful deployment and implantation of device) was achieved in 100% of procedures. Procedural success (technical success without major procedure-related complications) was achieved in 96.4%, with a 3.6% rate of major procedural complications (three cases of pericardial tamponade requiring drainage and one case of major bleeding). Mean follow-up was 30±12 months (264 patient-years). Annual rates for ischaemic stroke and for other thromboembolic events were respectively 2.2% and 0%, and annual rate for major bleeding was 1.1%. Conclusions Our data suggest LAA occlusion in high-risk patients with NVAF not suitable for OACs is feasible and associated with low complication rates as well as low rates of stroke and major bleeding at long-term follow-up.

Predictive value of less than moderate residual mitral regurgitation as assessed by transesophageal echocardiography for the short-term outcomes of patients with mitral regurgitation treated with mitral valve repair

BackgroundTraditionally, in patients with mitral regurgitation (MR) a successful mitral valve repair is considered when residual MR by post-pump transesophageal echocardiography (TEE) is less than moderate or absent. Little is known about the prognostic value of less than moderate (mild or mild-to-moderate) residual MR for the early outcome of patients treated with mitral valve repair.MethodsEligible for this study were patients undergoing isolated mitral valve repair. Patients with moderate or severe residual MR after valve repair were excluded. The primary endpoint of the study was the composite of death or need of reintervention.ResultsA total of 98 patients (54 with no residual MR-Group 1, and 44 with less than moderate residual MR-Group 2) were analyzed. Of these, 72% presented with New York Heart Association (NYHA) 3/4, and 38% were women. The primary endpoint of the study occurred in 3 (5.5%) patients in Group 1 and 6 (13.6%) patients in Group 2 MR (P = 0.31). There was a trend toward a higher incidence of use of inotropic drugs post-interventional (P = 0.12), and a longer hospital stay among patients with less than moderate residual MR (P = 0.18).ConclusionIn our study population, patients with less than moderate residual MR had a trend toward a higher risk of early adverse outcomes as compared with patients with no residual MR by post-pump TEE. Studies with a larger patient population and longer follow-up data may be useful to better define the clinical significance of residual mild MR after mitral vale repair.

Self-expanding stent for complex percutaneous coronary interventions: A real life experience

AIM Self-expanding stents represent a re-emerging option for percutaneous coronary interventions. Their application covers a wide spectrum of angiographic situations, i.e., coronary bifurcations, acute coronary syndromes with large thrombotic burden and stenosis of ectatic coronaries. We review our experience with self-expanding stents for different clinical and angiographic indications, with long clinical follow-up. METHODS From 2011 to 2013 we used self-expanding STENTYS® stents in 40 consecutive patients followed-up for death from any cause and from cardiovascular cause, myocardial infarction, target lesion revascularization (TLR), stent thrombosis (mean 21±13months). We also revised rate of procedural outcomes, acute stent thrombosis and TLR in patients treated with conventional stents for similar clinical/angiographic situations, in the same period at our institution. RESULTS We identified three anatomical settings of STENTYS® use: coronary bifurcations with proximal/distal main branch diameter discrepancy (55% of cases), massive thrombotic burden in the setting of acute coronary syndrome (35% of cases) and stenosis of ectatic coronaries (15%). We observed one death related to acute heart failure and 1 case (2.5%) of acute stent thrombosis (2.5% in the control group). During follow-up 2 cases of stent restenosis leading to TLR (5%) occurred (6.25% in the control group). CONCLUSIONS According to our real life experience, self-expanding STENTYS® stents appear to be an effective tool for different angiographic situations in which they may be preferable to balloon-expandable stents, showing a low rate of complications and good results at long term follow-up.

Development and validation of a risk stratification score for new-onset atrial fibrillation in STEMI patients undergoing primary percutaneous coronary intervention

New‐onset atrial fibrillation (NOAF) is a complication not infrequent in patients with acute ST‐segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) and has been associated with worse in‐hospital and long‐term prognosis. We aimed to develop and validate a risk score based on common clinical risk factors and routine blood biomarkers to assess the early incidence of NOAF post‐pPCI, before discharge.