PCSK9 and Coronary Artery Plaque-New Opportunity or Red Herring?

PURPOSE OF REVIEW: Although the clinical benefit of reducing low-density lipoprotein cholesterol (LDLc) in patients with coronary artery disease (CAD) is well-established, the impact on plaque composition and stability is less clear. Our narrative review aimed to assess the clinical effects of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on coronary plaque characteristics specifically focusing from atheroma progression to regression and stabilization. RECENT FINDINGS: The combination of statin therapy and PCSK9 inhibitors (evolocumab and alirocumab) promotes plaque stability in patients following an acute coronary syndrome. The GLAGOV study highlighted the relationship between achieved LDLc levels and changes in percentage atheroma volume. Similarly, the PACMAN-AMI study concluded that the qualitative and quantitative changes in coronary plaque were associated with the levels of LDLc. Assessing the severity of coronary artery stenosis and the extent of atherosclerotic burden by means of imaging techniques (e.g., IVUS, OCT and near-infrared spectroscopic) have significantly advanced our understanding of the benefits from promoting plaque regression and achieving to features of plaque stabilization through increasingly intensive lipid-lowering strategies.

COVID-19 in Chronic Kidney Disease: The Impact of Old and Novel Cardiovascular Risk Factors.

Cardiovascular disease is a frequent complication and the most common cause of death in patients with CKD. Despite landmark medical advancements, mortality due to cardiovascular disease is still 20 times higher in CKD patients than in the general population, which is mainly due to the high prevalence of risk factors in this group. Indeed, in addition to traditional cardiovascular risk factors, CKD patients are exposed to nontraditional ones, which include metabolic, hormonal, and inflammatory alterations. The global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has brought novel challenges for both cardiologists and nephrologists alike. Emerging evidence indicates that coronavirus disease 2019 (COVID-19) increases the risk of cardiovascular events and that several aspects of the disease may synergize with pre-existing cardiovascular risk factors in CKD patients. A better understanding of these mechanisms is pivotal for the prevention and treatment of cardiovascular events in this context, and we believe that additional clinical and experimental studies are needed to improve cardiovascular outcomes in CKD patients with COVID-19. In this review, we provide a summary of traditional and nontraditional cardiovascular risk factors in CKD patients, discussing their interaction with SARS-CoV-2 infection and focusing on CO-VID-19-related cardiovascular complications that may severely affect short- and long-term outcomes in this high-risk population.

Ventricular ectopy following accessory pathway ablation in WPW syndrome.

INTRODUCTION: Many Authors already described automatic activity arising from accessory pathways, but the underlying mechanism has not been clarified yet. They may be due to embryogenetic features of myocardium or may be related to specific excitability during radiofrequency ablation. CASE: Our report shows that ventricular accelerated rhythm may transiently arise from the ventricular edge of a common myocardium made accessory pathway right after the ablation. No further action were required in our experience, since the phenomenon self extinguished in approximately hour. CONCLUSIONS: If this manifestation represents the effect of thermal injury or if it is a real intrinsic automaticity is not fully documented and may need further reporting and investigation.

Impact of metabolic syndrome on mean platelet volume and its relationship with coronary artery disease.

Platelets represent one of the main actors involved in pathogenesis of coronary artery disease (CAD). Mean platelet volume (MPV) has been proposed as marker of platelet reactivity and thrombotic risk. However, still debated is whether higher MPV constitutes an independent determinant of CAD or just the consequence of an association with several cardiovascular risk factors. Therefore, the aim of the present study was to assess the impact of metabolic syndrome (MetS), on MPV and its relationship with angiographically defined CAD. Consecutive patients undergoing coronary angiography were included. Admission samples were collected for MPV and chemistry assessment. MetS was defined according to IDF-criteria. Significant CAD was defined as at least 1 vessel stenosis > 50%, while severe CAD as left main and/or 3-vessel disease, as evaluated by quantitative coronary angiography. We included 4730 patients, among them 2167 (45.8%) had MetS. Patients with MetS were older (p < 0.001), more often females (p < 0.001), and displayed higher BMI, higher prevalence of hypercholesterolemia, renal failure, hypertension, diabetes mellitus, history of myocardial infarction (MI), previous PCI (p < 0.001, respectively), previous CABG (p = 0.002),treatment with ACE inhibitors, ARB, beta-blockers, nitrates, statins, ASA, calcium channel blockers, diuretics (p < 0.001, respectively), higher values of glycemia, HbA1c, fibrinogen (p < 0.001, respectively), creatinine (p = 0.01), uric acid (p = 0.02), and lower values of hemoglobin (p = 0.001),total-cholesterol, LDL-cholesterol, and HDL-cholesterol (p < 0.001, respectively). MetS patients showed a higher prevalence of CAD (p = 0.002) and severe CAD (p = 0.01). MPV values were slightly higher in patients with MetS (10.91 ± 1.01 vs. 10.84 ± 1.03 fL, p = 0.02), although MetS did not emerge as an independent predictor of higher MPV values (above 4th quartile; adjusted OR OR[95%CI] = 1.01[0.84-1.22], p = 0.93). When metabolic syndrome patients were analyzed according to MPV quartiles, higher MPV values did not result as an independent predictor of CAD (adjusted OR[95%CI] = 0.79[0.61-1.03], p = 0.08) and severe CAD (adjusted OR[95%CI] = 0.82 [0.65-1.03], p = 0.084). Results did not change when applying the new harmonized definition of MetS. This study shows that among patients undergoing coronary angiography MetS is not an independent predictor of higher MPV. Moreover, among MetS patients, larger-sized platelets are not associated to the prevalence and extent of CAD.

Impact of adenosine A2a receptor polymorphism rs5751876 on platelet reactivity in ticagrelor treated patients.

Dual antiplatelet therapy constitutes a key point in the management of patients with acute coronary syndromes. In particular, ticagrelor, an ADP-antagonist, can provide a more potent and predictable platelet inhibition as compared to clopidogrel, and adenosine-mediated pathways have been involved in its beneficial effects on mortality and myocardial perfusion. However, a quote of patients still displays a suboptimal platelet inhibition on ticagrelor, and, while the role of genetics in conditioning clopidogrel resistance is well established, few data have been reported for ticagrelor. We investigated the impact of rs5751876 C > T polymorphism of adenosine A2a receptor (ADORA2a) on platelet reactivity in patients during chronic treatment with ticagrelor. We included patients treated with ASA and ticagrelor for a recent ACS or elective coronary revascularization. Platelet reactivity was assessed at 30-90 days post-discharge by multiple-electrode aggregometry. HRPR for ticagrelor was defined as ADP-test results >417 AU*min. Genetic analysis was performed to assess the presence of rs5751876 C > T polymorphism of ADORA2a receptor. We included 244 patients in our study, 174 (71.3%) patients carried the polymorphism (T allele), 51 (20.9%) of them in homozygosis (T/T). C-allele carriers (homozygotes C/C and heterozygotes C/T) showed no difference in baseline characteristics but for lower HDL-cholesterol (p = 0.01). An absolute lower rate of HRPR on ticagrelor was observed in homozygotes T/T (p = 0.03). At multivariate analysis, C allele carriage was independently associated with the rate of HRPR on ticagrelor (adjusted OR[95%CI] = 4.63[1.02-21.01], p = 0.048). Our study results showed a significant independent association between rs5751876 allele C carriage and a higher rate of high residual platelet reactivity in patients on ticagrelor after a recent ACS or PCI.

Impact of anticoagulation strategy with bivalirudin or heparin on nonaccess site bleeding in percutaneous coronary interventions: A meta-analysis of randomized trials.

BACKGROUND: Transradial approach has significantly decreased the rate of access site bleeding in patients undergoing percutaneous coronary interventions (PCI), therefore potentially mitigating the benefits offered by bivalirudin in lowering major bleeding complications as compared to heparin. However, nonaccess site bleeding, that represent the majority of hemorrhagic complications, still carry negative prognostic consequences for these patients and no study has so far defined the exact impact of bivalirudin on nonaccess site bleeding, that was therefore the aim of present meta-analysis. METHODS AND STUDY OUTCOMES: Literature archives (Pubmed, EMBASE, Cochrane) and main scientific sessions were scanned comparing bivalirudin vs. heparin in patients undergoing PCI. Primary endpoint was the occurrence of nonaccess site bleeding within 30 days. Secondary endpoints were 30 days mortality and the occurrence of access-site bleeding. RESULTS: A total of nine randomized clinical trials were finally included, involving 32,587 patients, 55.8% randomized to bivalirudin. Bivalirudin significantly reduced the rate of nonaccess site bleeding (2.6 vs. 3.8%, OR [95% CI] = 0.68 [0.60-0.77], P < 0.00001, Phet = 0.10). However, the reduction of hemorrhagic events was more pronounced when bivalirudin was compared to heparin plus glycoprotein IIbIIIa inhibitors than when it was compared to heparin alone (r = -0.01 (-0.02; -0.001), P = 0.02). Similar results were observed for access-site bleeding (OR [95% CI] = 0.67 [0.57-0.79], P < 0.000001, Phet = 0.10), with a significant role of glycoprotein IIbIIIa inhibitors use (r = -0.02 (-0.04; -0.004), P = 0.017). Moreover, the observed benefits in hemorrhagic complications did not translate into mortality benefits (OR [95% CI] = 0.89 [0.76-1.05], P = 0.18; Phet = 0.12; r = 0.21 (-1.12; 1.53), P = 0.76). CONCLUSIONS: The present meta-analysis shows that bivalirudin can provide a significant reduction of both access and nonaccess site bleeding in patients undergoing PCI. However, these hemorrhagic benefits did not impact on survival, and moreover, were significantly conditioned by the association of heparin with potent antithrombotic strategies, such as glycoprotein IIbIIIa inhibitors, rather than by heparin or bivalirudin alone. Therefore, we could not provide any clinical evidence for the routine use of bivalirudin as preferred anticoagulation strategy for PCI. © 2017 Wiley Periodicals, Inc.

Randomized evaluation of short-term dual antiplatelet therapy in patients with acute coronary syndrome treated with the COMBO dual therapy stent: rationale and design of the REDUCE trial.

BACKGROUND: The optimal duration of dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS) patients treated with drug eluting stents (DES) is still under debate. Recent meta-analyses on ≤6months versus 12months DAPT suggest that bleeding rates can be reduced, without a higher rate of thrombotic complications. In particular, the COMBO dual therapy stent, being associated with early re-endothelialization, may allow for a reduction of the duration of DAPT without increasing the thrombotic risk, while reducing the risk of bleeding complications. AIM: The aim of the REDUCE trial is to demonstrate the non-inferiority of a combined efficacy and safety endpoint of a short-term 3months DAPT strategy as compared to standard 12-month DAPT strategy in ACS patients treated with the COMBO stent. DESIGN: A prospective, multicenter, randomized study designed to enroll 1500 patients with ACS treated with the COMBO stent. Patients will be randomized before discharge in a 1:1 fashion to either 3 or 12months of DAPT. A clinical follow-up is scheduled at 3, 6, 12, and 24months. The primary endpoint is the time to event as defined by the occurrence of one of the following: all cause mortality, myocardial infarction, stent thrombosis, stroke, target vessel revascularization or bleeding (Bleeding Academic Research Council type II, III and V) within 12months. The study has recruited patients since July 2014, and the results are expected in 2017. SUMMARY: A reduction of the DAPT duration in ACS patients after PCI without affecting the thrombotic risk is an attractive option with regard to the associated bleeding risk. The REDUCE trial will be the first to investigate the efficacy and safety of a 3-month DAPT strategy compared to a 12-month DAPT strategy in an ACS only population treated with the COMBO stent.

Risk and Benefits of Triple Therapy in Patients Undergoing Coronary Stent Implantation Requiring Oral Anticoagulation: A Meta-Analysis of 16 Studies.

BACKGROUND: Patients with coronary artery disease who undergo stent implantation and have concomitant indication for long-term oral anticoagulation represent a considerable proportion of the overall population. To date there is still no consensus about the optimal antithrombotic strategy to choose in this kind of patients, due to the difficult balance between an increased risk of bleeding and thromboembolic complications. Therefore, the aim of this study was to perform a meta-analysis to evaluate the risk and benefits of triple antithrombotic therapy versus dual antithrombotic therapy in patients undergoing coronary stent implantation, requiring long-term oral anticoagulation. METHODS: We performed formal searches of PubMed, EMBASE, Cochrane central register of controlled trials and major international scientific session abstracts from January 1990 to September 2015 regarding the use of triple antithrombotic therapy (TT) versus dual therapy (DT) in patients undergoing percutaneous coronary stent implantation that required chronic oral anticoagulation. Data regarding study design, inclusion/exclusion criteria, number of patients, and selected endpoints was extracted by 2 investigators. Disagreements were resolved by consensus. RESULTS: Sixteen trials with a total of 21716 patients undergoing coronary stent implantation with indication to long term oral anticoagulation, were finally included. A total of 6950 received TT, whereas 14766 received DT alone. The follow-up period ranged from 180 to 730 days. Data regarding mortality were available in 21658 patients (99.7 %). All cause mortality was observed in 10.4 % patients in TT versus 16.3 % in DT (OR [95 % CI] =0.73 [0.66-0.80], p <0.001; p het <0.001). In addition, TT was associated with a reduced incidence of MI (6.4 versus 9.8 %, OR [95 % CI] = 0.74 [0.65-0.84], p < 0.001; phet < 0.001) and ischemic stroke (1.8 versus 3.9 %, OR [95 % CI] = 0.55 [0.45-0.68], p < 0.001; p het = 0.07). As expected, TT was associated with a significant increase in major bleeding events (10.8 versus 8.5 %, OR [95 % CI] = 1.38 [1.25-1.53], p < 0.001; p het = 0.02). By meta regression analysis we found that benefits in mortality with TT were inversely related with the risk of bleedings (beta [95 % CI] = 2.25 (1.55; 2.95), p < 0.00001). The benefits with TT regarding overall mortality, recurrent MI and ischemic stroke were also confirmed in a pre-specified analysis versus DAPT or oral anticoagulation in association with a single antiplatelet agent. CONCLUSION: This meta-analysis showed that among patients undergoing coronary stent implantation, requiring chronic OAC, the use of a TT is associated with a significant reduction in overall mortality, recurrent MI and ischemic stroke. As expected, we found a higher incidence of bleedings in patients treated with triple therapy. The benefits in mortality were lost in patients at high-risk for bleedings.

Gender Differences in Platelet Reactivity in Patients Receiving Dual Antiplatelet Therapy.

BACKGROUND: Cardiovascular risk is still underestimated in women, experiencing higher mortality and worse prognosis after acute cardiovascular events. Gender differences have been reported in thrombotic and hemorrhagic risk during dual antiplatelet therapy (DAPT), thus suggesting a potential variability in platelet reactivity according to sex. The aim of the present study was to assess the role of gender on platelet function and the prevalence of high-on treatment residual platelet reactivity (HRPR) during DAPT in patients with recent acute coronary syndrome or percutaneous coronary revascularization. METHODS: Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30-90 days post-discharge. By whole blood impedance aggregometry, HRPR was considered for ASPI test >862 AU*min (for ASA) and ADP test values ≥417 AU*min (for ADP-antagonists). RESULTS: We included 541 patients on DAPT, 122 (22.6 %) of whom were females. Females were older (p < 0.001), displayed more frequently hypercholesterolemia (p = 0.003), renal failure (p = 0.04), acute presentation (p < 0.001), higher cholesterol levels and platelets count (p < 0.001). Inverse association was demonstrated with smoking (p < 0.001), previous PCI (p = 0.04) and statin use (p = 0.03), creatinine and haemoglobin (p < 0.001). Female gender did not influence mean platelet reactivity or the prevalence of HRPR for ASA (1.7 % vs 1.4 %, OR[95%CI] = 1.14[0.17-4.36], p = 0.99, adjusted OR[95%CI] = 1.54[0.20-11.6], p = 0.68) or ADP-antagonists (26.3 % vs 22.8 %, OR[95%CI] = 1.17[0.52-1.34], p = 0.45, adjusted OR[95%CI] = 1.05[0.59-1.86], p = 0.87). Results did not change when considering separately the 309 patients treated with clopidogrel (34 % vs 31.3 %, OR[95%CI] = 1.13[0.62-2.07], p = 0.76, adjusted OR[95%CI] = 1.35[0.63-2.9], p = 0.44 for females vs males), or patients (n = 232) on ticagrelor (20.4 % vs 11.1 %, OR[95%CI] = 2.27[0.99-5.17], p = 0.06 for females vs males), confirmed after correction for baseline differences (adjusted OR[95%CI] = 1.21[0.28-2.29], p = 0.68). CONCLUSION: In patients receiving dual antiplatelet therapy, gender does not impact on the prevalence of high-on treatment residual platelet reactivity (HRPR) with the major antiplatelet agents ASA, clopidogrel or ticagrelor.

Impact of diabetes on immature platelets fraction and its relationship with platelet reactivity in patients receiving dual antiplatelet therapy.

Contrasting data have been reported so far on the role of reticulated platelets in suboptimal response to antiplatelet therapies. In particular, still unexplored is whether they may contribute to explain the higher risk of thrombotic complications observed in diabetic patients. Aim of the present study was to evaluate the impact of diabetes on the levels of reticulated platelets and its relationship with high residual on-treatment platelet reactivity (HRPR) in patients receiving dual antiplatelet therapy. In patients treated with ASA (100-160 mg) and clopidogrel (75 mg daily) or ticagrelor (90 mg twice a day) platelet reactivity and the reticulated platelets fraction (immature platelets fraction, IPF) were assessed at 30-90 days post-discharge for an acute coronary syndrome or elective PCI. Aggregation was assessed by multiple-electrode aggregometry. We included 386 patients, 158 (40.9 %) diabetics. The percentage of IPF was similar in diabetic and non diabetic patients, both at baseline (3.5 ± 2.5 vs 3.6 ± 2.7 %, p = 0.91) and at 30-90 days re-assessment (3.3 ± 2.1 vs 3.5 ± 2.5 %, p = 0.30), with diabetes not emerging as an independent predictor of IPF above III tertile (adjusted OR [95 %CI] = 0.58 [0.30-1.09], p = 0.10). Diabetic patients displayed an enhanced platelet reactivity and a higher rate of HRPR with ADP antagonists (32.8 vs 22.5 %, p = 0.009). However, no association was found between the percentage of IPF and platelet function (r = -0.004; p = 0.95 for ASPI test, r = -0.04; p = 0.59 for ADP-mediated aggregation), or the rate of HRPR for ADP antagonsist across IPF tertiles. Results were similar for diabetics both receiving clopidogrel and ticagrelor. Diabetic patients display a higher platelet reactivity and suboptimal response to ADP-antagonists. However, the rate of reticulated platelets is neither influenced by diabetic status nor associated with an increased platelet reactivity among diabetic patients receiving dual antiplatelet therapy for a recent acute coronary syndrome or PCI.

Immature platelet fraction and high-on treatment platelet reactivity with ticagrelor in patients with acute coronary syndromes.

Residual high-on treatment platelet reactivity (HRPR) has been associated with a 2-9 fold increased risk of acute ischemic events in patients with acute coronary syndromes or coronary stenting. However, the mechanism of suboptimal platelet inhibition are still poorly understood. Aim of present study was to evaluate the role of the percentage of reticulated platelets on HRPR with ticagrelor. In patients treated with ASA (100-160 mg) and ticagrelor (90 mg twice a day) platelet reactivity and the reticulated platelets fraction (immature platelets fraction, IPF) were assessed at 30-90 days after acute coronary syndrome. Aggregation was assessed by multiple-electrode aggregometry. HRPR was defined as ADP test >417 AU*min. Our population is represented by 190 patients, divided according to tertiles values of IPF (<2.5; 2.5-3.99; ≥4 %). Higher IPF was associated to a larger platelet volume and lower platelets count (p < 0.001), and inversely related with a history of previous coronary revascularization (p = 0.03). Twenty-one out of 190 (11.0 %) patients displayed HRPR. No difference in the levels of circulating IPF was found in patients with or without HRPR (p = 0.25), with no correlation between the rate of reticulated platelets and platelet reactivity at ADP test (r = -0.084, p = 0.26). In fact no association was observed between high levels of IPF and the occurrence of HRPR (adjusted OR[95 % CI] = 0.69[0.34-1,37], p = 0.28), even after correction for baseline differences. In patients treated with ticagrelor, the levels of circulating reticulated platelets assessed at 30-90 days post-ACS are not associated with platelet reactivity or the occurrence of HRPR.

Switching from Clopidogrel to Prasugrel in patients undergoing PCI: A meta-analytic overview.

Despite the demonstrated benefits of Prasugrel, a new generation thienopyridine, in the prevention of thrombotic complications after percutaneous coronary interventions (PCI) for Acute Coronary Syndromes (ACS), its use is still precluded to those many patients arriving to the cath lab pre-treated with Clopidogrel. Conclusive data on the strategy of switching from Clopidogrel to Prasugrel are still missing, therefore we aimed to perform a meta-analysis of current studies evaluating the safety and efficacy of switching from Clopidogrel to Prasugrel (PS) as compared to a standard thienopyridine therapy with Clopidogrel or Prasugrel in patients undergoing PCI. Literature archives and main scientific sessions' abstracts were scanned for studies comparing a switching strategy from Clopidogrel to Prasugrel vs. Prasugrel or Clopidogrel. Primary efficacy endpoint was overall mortality. Secondary endpoints were: non-fatal myocardial infarction and definite/probable stent thrombosis. Safety endpoint was the rate of major bleedings according to a per-protocol definition. A total of 12 studies, involving 3956 patients, were included. Among them, 1396 patients (35.3%), received Prasugrel after a Clopidogrel treatment (PS), while 2560 (64.7%) received either Prasugrel or Clopidogrel. The switch from Clopidogrel to Prasugrel was in the majority of the studies periprocedural. The mortality was numerically lower, but not statistically significant, in the PS group as compared with patients who did not switch (1.7% vs. 3.8%, OR [95% CI] = 0.68 [0.40,1.15], p = 0.15, phet = 0.61), without any relationship with patients' risk profile (r = -0.68 [-2.09, 0.73], p = 0.35). Similar results were obtained for secondary efficacy endpoints and at sensitivity analysis in the majority of subgroups evaluated. Moreover, the PS strategy did not increase major bleedings as compared with standard therapy (1.4% vs. 2.5%, OR [95% CI = 0.70 [0.39, 1.25], p = 0.23, phet = 0.6). The present meta-analysis confirms that, among patients undergoing PCI, switching from Clopidogrel to Prasugrel may be safely performed and therefore should be encouraged among patients eligible to Prasugrel.

Vitamin D levels and high-residual platelet reactivity in patients receiving dual antiplatelet therapy with clopidogrel or ticagrelor.

BACKGROUND: Suboptimal platelet inhibition still represents an important challenge, especially for patients undergoing percutaneous coronary interventions (PCIs). However, very few are known so far on the predictors of high-residual platelet reactivity (HRPR) despite antiplatelet strategies. Increasing attention has been paid in the last years to the role of vitamin D in atherothrombosis. Therefore, the aim of our study was to evaluate the impact of vitamin D levels on platelet function in patients treated with dual antiplatelet therapy (DAPT). Patients treated with DAPT (ASA and clopidogrel or ticagrelor) after a recent acute coronary syndrome (ACS) or elective PCI were scheduled for platelet function assessment at 30-90 days post-discharge. Platelet function was assessed by whole blood impedance aggregometry (Multiplate®-Roche Diagnostics AG), HRPR was considered for ASPI test values > 862 AU*min (for ASA) and adenosine diphosphate (ADP) test values ≥417 AU*min (for ADP-antagonists). Fasting samples were obtained for main chemistry parameters and vitamin D level assessment. Our population is represented by 503 patients, who were divided according to vitamin D quartiles (≤9.1; 9.2-14.4; 14.5-21.7; >21.7 ng/ml). Lower vitamin D levels related with age (p = 0.04), diabetic status (p = 0.05), and previous coronary surgery (p = 0.007), therapy with beta-blockers and statins (p = 0.01 and p = 0.02). Vitamin D inversely related to the levels of total cholesterol (p = 0.01), triglycerides (p < 0.001), hemoglobin (p = 0.05), and HbA1c (p < 0.001). Significantly higher platelet reactivity was observed after platelet stimulation with ADP (p = 0.01), but not with other platelet activators. The prevalence of HRPR for ASA was low (1.2%) and not conditioned by Vitamin D levels (adjusted OR[95%CI] = 1.56[0.71-3.5], p = 0.27). HRPR with ADP-antagonists was observed in 26% of patients, and the rate increased with lower vitamin D quartiles (37.3% vs 22.2% vs 24.4% vs 20.2%, p = 0.005, adjusted OR[95%CI] = 1.23[1.02-1.49], p = 0.04). An absolute increase in HRPR with lower vitamin D levels was similarly observed among patients receiving ticagrelor (adjusted OR[95% CI] = 1.40[0.95-2.06], p = 0.08), and those on clopidogrel (adjusted OR[95%CI] = 1.31[0.99-1.75], p = 0.06). Thus, lower vitamin D levels are associated with higher platelet reactivity and impaired effectiveness of ADP-antagonists, while not influencing the effectiveness of ASA. Future studies will tell whether vitamin D supplementation can reduce platelet reactivity, overcoming the phenomenon of resistance to antiplatelet agents.

Impact of Diabetes on Homocysteine Levels and Its Relationship with Coronary Artery Disease: A Single-Centre Cohort Study.

BACKGROUND/AIMS: Coronary artery disease (CAD) is a major cause of mortality worldwide. Hyperhomocysteinemia has been identified as a risk factor for CAD due to increased thrombogenicity, oxidative stress status and endothelial dysfunction. Few data have been provided on the impact of diabetes on homocysteine and its relationship with the prevalence and extent of CAD in this high-risk subset of patients and therefore, this is the aim of this study. METHODS: Our population is represented by a consecutive cohort of patients undergoing coronary angiography at Azienda Ospedaliera-Universitaria, 'Maggiore della Carità', Novara, Italy from March 2007 to October 2012. RESULTS: Diabetes was observed in a total of 1,125 out of 3,534 patients. Diabetes was associated with more advanced age, hypercholesterolemia, arterial hypertension, renal failure, previous myocardial infarction, coronary revascularization (p < 0.001, respectively) and smoking (p = 0.001). Patients with diabetes were more frequently on angiotensin-converting-enzyme inhibitors, angiotensin receptor blockers, beta-blockers, calcium-antagonists, diuretics, statins (p < 0.001, respectively), and acetylsalicylic acid (p = 0.004). Patients with diabetes displayed higher creatinine and triglycerides (p < 0.001), but lower total and high-density lipoprotein-cholesterol (p < 0.001) and haemoglobin (p < 0.001). Diabetes was associated with a significantly higher prevalence and extent of CAD and more complex lesions at angiography, including calcified lesion, total occlusions, in-stent restenosis. No significant difference was found in total homocysteine (tHcy) levels between diabetic and non-diabetic patients (p = 0.2). No difference in the percentage of patients with tHcy above the third tertile (≥18.2 nmol/ml) was observed between patients with or without diabetes (32.8 vs. 35%, p = 0.18; adjusted OR 0.88, 95% CI 0.73-1.05, p = 0.14). Among patients with diabetes, no significant association was found between tHcy, CAD (82.4 vs. 83.6 vs. 78.6%, p = 0.19) or severe CAD (33.2 vs. 33.1 vs. 36.9%, p = 0.18). Same results were observed after correction for baseline differences (adjusted OR 0.78, 95% CI 0.61-1.02, p = 0.11) for CAD and severe CAD (adjusted OR 0.92, 95% CI 0.76-1.13, p = 0.46). CONCLUSIONS: In our study, diabetes was not associated with higher tHcy levels. Furthermore, elevated tHcy is not a risk factor for CAD among patients with diabetes.

Effect of diabetes mellitus on periprocedural myocardial infarction in patients undergoing coronary stent implantation.

BACKGROUND: Diabetic patients undergoing percutaneous coronary interventions are still regarded as a very high risk category because of an increased platelet reactivity and risk of complications, especially in patients with inadequate glycaemic control. However, although its prognostic effect on long-term outcome is well-defined, still unclear is the effect of diabetes on the risk of periprocedural myocardial infarction in patients undergoing percutaneous coronary interventions, which was therefore the aim of our study. METHODS: Myonecrosis biomarkers were dosed at intervals from 6 to 48 h after nonemergent percutaneous coronary interventions. Periprocedural myocardial infarction was defined as creatine kinase-MB increase by three times the upper limit normal or by 50% of an elevated baseline value, whereas periprocedural myonecrosis as troponin I increase by three times the upper limit normal or 50% of baseline. RESULTS: Of 1311 patients, diabetes mellitus was found in 458 patients (34.9%) and associated with age (p = 0.03), hypertension (p < 0.001), renal failure (p = 0.01), previous MI (p = 0.03), previous coronary revascularization (p < 0.001), higher fasting glycaemia and lower haemoglobin (p < 0.001), more severe coronary disease (p < 0.001), multivessel percutaneous coronary interventions (p = 0.03), coronary calcification (p = 0.003) and in-stent restenosis (p < 0.001) but lower presence of thrombus (p = 0.03). Diabetic patients were receiving significantly more frequent specific pharmacological treatment at admission. Diabetic status did not influence the risk of periprocedural myocardial infarction or periprocedural myonecrosis [adjusted OR(95%CI) = 0.90(0.64-1.27), p = 0.57 and adjusted OR(95%CI) = 0.92(0.70-1.21), p = 0.55]. Amongst diabetic patients, we did not observe any effect of chronic glycaemic control on periprocedural myocardial infarction. CONCLUSIONS: Diabetic status, independent of chronic glycaemic control, is not associated with increased risk of periprocedural myocardial infarction and myonecrosis in patients undergoing percutaneous coronary interventions.

Body Mass Index and Platelet Reactivity During Dual Antiplatelet Therapy With Clopidogrel or Ticagrelor.

INTRODUCTION: Dual antiplatelet therapy (DAPT) is considered essential in clinical management of patients undergoing percutaneous coronary revascularization or acute coronary syndromes. However, the optimal platelet inhibition is not always obtained, with high residual platelet reactivity (HRPR) increasing stent thrombosis and recurrent ischemic events. Aim of this study was to investigate the impact of body mass index (BMI) on platelet reactivity in patients on DAPT. METHODS: We included patients treated with acetylsalycilic acid (ASA) (100-160 mg) and clopidogrel (75 mg) or ticagrelor (90 mg twice a day) for acute coronary syndromes or drug-eluting stent implantation. Platelet reactivity was assessed at 30-90 days postdischarge by multiple-electrode aggregometry. HRPR for adenosine diphosphate (ADP) antagonists was defined as ADP test results >417 AU*min. HRPR for ASA was considered for ASPI test >862 AU*min. RESULTS: Our population is represented by 498 patients, 308 (61.8%) were treated with clopidogrel and 190 (38.2%) with ticagrelor. Overall, higher BMI was related with younger age (P = 0.003), higher prevalence of diabetes mellitus (P < 0.001), hypercholesterolemia (P = 0.017), hypertension (P < 0.001), chronic therapy with angiotensin-receptor blockers (P = 0.019), calcium channel blockers (P = 0.003). Higher values of BMI directly related with hemoglobin (P = 0.02), triglycerides (P < 0.001), glycemia (P = 0.035), HbA1c (P < 0.001), and inversely related with high-density lipoprotein cholesterol (P = 0.01). BMI did not influence the effectiveness of ASA, whereas it was associated to a nonsignificant trend for higher platelet reactivity (r = 0.08, P = 0.08) for ADP antagonists. In fact, 111 patients (22.3%) displayed HRPR at ADP test (>417 AU*min) with no statistically significant difference according to BMI {20.3% vs. 27.1% vs. 25.7%, P = 0.28; adjusted odds ratio [OR] [95% confidence interval (CI)] = 1.19 [0.86-1.64], P = 0.30}. However, results were different when considering separately patients receiving clopidogrel or ticagrelor. In the clopidogrel-treated subgroup, significantly higher ADP-mediated aggregation values were found in patients with higher BMI (r = 0.14, P = 0.023) that emerged as an independent predictor of HRPR with clopidogrel [OR (95% CI), 1.45 (1.01-2.12), P = 0.049]. On the contrary, no impact of BMI was observed in the ticagrelor-treated subgroup for platelet reactivity (r = -0.036, P = 0.62) or the prevalence of HRPR [adjusted OR (95% CI), 0.73 (0.39-1.36), P = 0.32]. CONCLUSIONS: This study shows that among patients treated with DAPT for coronary artery disease, higher BMI is related to increased platelet reactivity and a higher prevalence of HRPR in clopidogrel-treated patients while not significantly influencing the effectiveness of ticagrelor or ASA.

Homocysteine Levels Influence Platelet Reactivity in Coronary Artery Disease Patients Treated With Acetylsalicylic Acid.

BACKGROUND: Suboptimal platelet inhibition with antiplatelet treatments is associated with a severe prognosis in patients with coronary artery disease (CAD), and the identification of its determinants is still challenging. Homocysteine elevation has emerged as a prothrombotic factor, influencing coagulative status and endothelial function and potentially modulating platelet aggregation. We therefore aimed to evaluate the effects of homocysteine (Hcy) levels on platelet reactivity in patients receiving acetylsalicylic acid (ASA) with or without ADP antagonists. METHODS: Patients undergoing coronary angiography and receiving ASA (100-160 mg daily) for >7 days, with or without ADP antagonists, were included. Aggregation tests were performed by multiple electrode aggregometry. Suboptimal platelet inhibition was defined as on-treatment aggregation above the lower limit of normality. RESULTS: Our population is represented by 508 ASA-treated patients, 406 (80.1%) of whom on dual antiplatelet therapy (ASA and ADP antagonists). Hcy levels above the median (15.1 nmol/mL) were associated with male gender (P = 0.04), hypertension (P = 0.004), hypercholesterolemia (P = 0.03), aging, renal failure (P < 0.001, respectively), previous coronary bypass grafting (P = 0.04), therapy with calcium antagonists (P = 0.04) and diuretics (P = 0.001), and multivessel CAD (P = 0.03). Higher Hcy is directly related with serum creatinine and uric acid (P < 0.001). Suboptimal platelet inhibition was found in 16 patients (3.2%) for ASA and for ADP antagonists in 80 patients (19.7%). Hcy levels significantly affected suboptimal response to ASA, but not to ADP-mediated aggregation. In fact, a linear relationship was found between homocysteine and platelet reactivity after stimulation with arachidonic acid (r = 0.14, P = 0.004) and collagen (r = 0.12, P = 0.02), but not with ADP (r = 0.02, P = 0.77). Moreover, after correction for baseline differences, Hcy above the median was confirmed as an independent predictor of impaired ASA response [adjusted odds ratio (95% confidence interval) = 3.7 (1.08-12.4), P = 0.04]. CONCLUSIONS: Among patients with CAD, elevated homocysteine is an independent predictor of suboptimal response to ASA, but not to ADP antagonists.

Platelet Larger Cell Ratio and High-on Treatment Platelet Reactivity During Dual Antiplatelet Therapy.

BACKGROUND: Low response to antiplatelet agents has been associated to an increased risk of thrombotic complications and recurrent ischemic events. Platelet size has been proposed as a potential marker of platelet reactivity. Therefore, the aim of the present study was to evaluate the impact of platelet Larger Cell Ratio (p-LCR) on platelet aggregation and the prevalence of residual high-on treatment platelet reactivity (HRPR) in patients receiving dual antiplatelet therapy (DAPT) after a recent acute coronary syndrome or coronary revascularization. METHODS: Patients treated with DAPT (ASA and clopidogrel or ticagrelor) were scheduled for platelet function assessment at 30-90 days post-discharge. HRPR was considered for ASPI test >862 AU*min (for ASA) or ADP test values ≥417 AU*min (for ADP-antagonists) using impedance aggregometry. RESULTS: Our population consisted of 530 patients receiving DAPT, who were divided in tertiles according to values of p-LCR (< 27.6; 27.6-34.7; ≥34.7 l). p-LCR was related with use of beta-blockers (p = 0.02) and statins (p = 0.002), and inversely with acute presentation (p = 0.05). Higher platelet count (p < 0.001) and haemoglobin levels (p = 0.001) were observed in higher p-LCR tertiles. The prevalence of HRPR for ASA was low and not significantly different across tertiles of p-LCR (1.1 vs 1.1 vs 1.7%, p = 0.66; adjusted OR[95%CI] = 1.68[0.66-4.29], p = 0.27). Moreover, p-LCR did not influence the occurrence of HRPR for ADP-antagonists (24.4% vs 20.9% vs 25.6 %%, p = 0.80, adjusted OR[95%CI] = 0.88[0.67-1.17], p = 0.38) and similar results were obtained when considering separately patients receiving clopidogrel (adjusted OR[95%CI] = 1.21[0.86-1.69], p = 0.29) or ticagrelor (adjusted OR[95%CI] = 1.17[0.69-2], p = 0.56). CONCLUSION: In patients receiving DAPT for coronary artery disease, p-LCR does not impact platelet reactivity. Larger platelets did not influence the prevalence of high-on treatment platelet reactivity with the antiplatelet agents ASA, clopidogrel or ticagrelor.

Impact of red blood cells count on the relationship between high density lipoproteins and the prevalence and extent of coronary artery disease: a single centre study [corrected].

We have hypothesized that high red blood cells (RBC) count can potentially play an atheroprotective role in patients with coronary atherosclerosis. We, therefore, have investigated the relationship between high density lipoproteins cholesterol (HDL-C) and RBC levels in patients undergoing coronary angiography. Coronary artery disease (CAD) is a major cause of mortality. Impaired lipid profile represents a major risk factor for atherosclerosis. High density lipoprotein (HDL) is a key factor in atherosclerosis disease development. RBC can mimic HDL's reverse cholesterol transportation with a potential atheroprotective role. Coronary angiography has been evaluated in 3,534 patients. Fasting samples were collected for haematology and lipids levels assessment. Coronary disease was defined for at least 1 vessel stenosis >50 %. Patients were divided according to HDL-C and RBC tertiles. Lower HDL-C was significantly associated to the prevalence of CAD (84.8 vs 78.5 vs 67.3 %, p ≤ 0.001; adjusted OR [95 % CI] = 1.55 [1.3-1.8], p < 0.001) and severe CAD (30 % vs 30 % vs 24.4 %, p = 0.002; adjusted OR [95 % CI] = 1.08 [1.01-1.16], p = 0.02), this relationship was maintained even dividing our population according to RBC tertiles (p < 0.001).In conclusion, HDL-C levels are directly related to RBC count and inversely to the prevalence and extent of coronary disease. Higher RBC levels can reduce the risk of CAD in patients with lower HDL-C levels, suggesting an important atheroprotective role.