Fatih Uzun

Hypertension as a Risk Factor for Aspirin and Clopidogrel Resistance in Patients With Stable Coronary Artery Disease

Background: Platelets play an important role in the pathogenesis of coronary artery disease (CAD). The importance of dual antiplatelet therapy to prevent recurrent ischemic events in patients who have acute coronary syndrome and who will undergo percutaneous coronary intervention (PCI) is well known and widely accepted as a gold standard. However, despite this apparently effective therapy, incidence of adverse ischemic events could not be decreased enough. Resistance to aspirin/clopidogrel is an important risk factor for adverse ischemic clinical events. Up-to-date studies revealed many risk factors for antiplatelet resistance, one of which is hypertension (HT). Currently, there is no sufficient number of studies evaluating the association between HT and antiplatelet resistance, which is the aim of this study. Methods: We enrolled 145 consecutive patients (19 female [13.1%], 126 male [86.9%], mean age 55 ± 10) with stable CAD receiving regular antiplatelet therapy composed of 100 mg/d aspirin and 75 mg/d clopidogrel. All patients had been implanted nondrug-eluting coronary stent and/or stents at least 1 month ago. The HT was diagnosed by 24-hour blood pressure (BP) monitoring. Clopidogrel and aspirin resistance was measured by impedance aggregometry method. Results: We included 49 patients with HT and 96 nonhypertensive patients with stable CAD. Aspirin resistance was detected in 22 (16.4%) of 134 patients who received aspirin. Clopidogrel resistance was detected in 55 (37.9%) of 145 patients who received clopidogrel. Prevalance of aspirin and clopidogrel resistance was significantly higher in the hypertensive group than in the nonhypertensive group (P = .030 and P = .007, respectively). Correlation analysis revealed weak but significantly positive correlation between clopidogrel resistance and serum uric acid levels, mean platelet volume, platelet count, and 24-hour mean systolic BP (r = −.180, P = .030; r = .189, P = .016; r = .226, P = .006; and r = .200, P = .016, respectively). Conclusion: We demonstrated higher incidence of antiplatelet resistance in patients with HT. Upon this finding, which is emerged from an actual group of patients with HT, cardioprotective effect of antiplatelet therapy in patients with HT should be argued.

Utility of the Logistic Clinical Syntax Score in the Prediction of Contrast-Induced Nephropathy After Primary Percutaneous Coronary Intervention.

BACKGROUND The Logistic Clinical Syntax Score (log CSS) is a combined risk scoring system that includes clinical and anatomic parameters; it has been found to be effective for the prediction of mortality in patients with ST-elevation myocardial infarction (STEMI). The aim of the present study was to assess whether the log CSS was associated with the development of contrast-induced nephropathy (CIN) in patients who underwent primary percutaneous coronary intervention (pPCI). METHODS A total of 930 patients with STEMI undergoing pPCI between January 2012 and August 2013 were included prospectively. The patients were grouped according to the development of CIN. Either an absolute serum creatinine level ≥ 0.5 mg/dL or a 25% increase in the serum creatinine level compared with the baseline level within 48 hours after the administration of contrast medium was defined as CIN. RESULTS The Synergy Between Percutaneous Coronary Interventions With Taxus and Cardiac Surgery score (SYNTAX [SS]) and log CSS were higher in patients with CIN than in those without. In the multivariate analysis, log CSS (odds ratio, 1.405, 95% confidence interval, 1.318-1.497; P < 0.001), hemoglobin, and contrast volume were found to be independent predictors of CIN. In the receiver operating characteristic analysis, a log CSS > 9.5 had a 74.5% sensitivity and a 90.5% specificity for predicting CIN, with an area under the curve (AUC) of 0.892, whereas an SS > 18.5 had a 64% sensitivity, a 58.1% specificity, and an AUC of 0.625 (0.892 vs 0.625; P < 0.001). A log CSS > 9.5 was associated with in-hospital and long-term mortality, reinfarction, revascularization, and in-hospital hemodialysis (P < 0.001 for each). CONCLUSIONS The log CSS may improve the accuracy of risk stratification for the development of CIN in patients undergoing pPCI.

Evaluation of the effect of mitral stenosis severity on the left ventricular systolic function using isovolumic myocardial acceleration

BACKGROUND Isovolumic acceleration (IVA) is a new tissue Doppler parameter in the assessment of systolic function of both left and right ventricles. It remains unaffected with the changes in pre- and after-load within the physiological range. The aim of our study was to assess the effect of mitral stenosis degree, which is determined by echocardiography, on the left ventricular (LV) function using IVA. METHODS A total number of 62 patients with mitral stenosis (MS) and 32 healthy controls were examined. The severity of MS (mild, moderate, and severe) was determined on the basis of mitral valve area (MVA) and the mean diastolic mitral gradient findings. The peak myocardial velocities during isovolumic contraction, systole, early diastole and late diastole were measured by using tissue Doppler imaging (TDI). RESULTS All TDI-derived global LV basal wall systolic (peak myocardial isovolumic contraction velocity, peak myocardial systolic velocity and IVA), and diastolic velocities (peak early and late diastolic velocities) were significantly decreased in the patients with MS, compared to the healthy patients (p < 0.001, for all). However, IVA was not different when the degree of MS was evaluated (p = 0.114). In addition, IVA was not correlated with the MVA (r = 0.185, p = 0.150). CONCLUSIONS Left ventricular function is impaired in patients with MS regardless of the severity of the disease.

Antiplatelet resistance and the role of associated variables in stable patients treated with stenting

Introduction Nowadays, clopidogrel and acetylsalicylic acid (ASA) have become routinely applied therapies in percutaneous coronary interventions (PCI) with stenting. Aim Numerous variables can interfere with antiplatelet responsiveness, so we aimed to investigate the role of different variables associated with ASA or clopidogrel resistance in stable coronary artery disease. Material and methods A total of 207 patients undergoing elective PCI were included in the analysis. All patients received a loading dose of clopidogrel and ASA during PCI procedure and followed by dual antiplatelet therapy. Clopidogrel and ASA resistance were measured by impedance aggregometry method. Results Of the patients, 19.8% had clopidogrel resistance, 18.8% had ASA resistance, 9.2% had both clopidogrel and ASA resistance, and 71.5% were responsive to both drugs. In multivariate analysis, platelet count, angiotensin receptor blocker (ARB) use, and ASA resistance were independent variables associated with clopidogrel resistance, and clopidogrel resistance was the only variable associated with ASA resistance. In differentiating whether clopidogrel resistance exists or not, optimum ASA aggregometry response cut-off values were specified, and in differentiating whether ASA resistance exists or not, optimum clopidogrel aggregometry response cut-off values were specified. Conclusions In this study, there was a higher incidence of low responsiveness to ASA when there was a low response to clopidogrel, and vice versa. Angiotensin receptor blocker use, platelet count, and ASA resistance were independent variables associated with clopidogrel resistance. Clopidogrel resistance was the only independent variable associated with ASA resistance. Angiotensin receptor blocker use seems to an independent risk factor for clopidogrel resistance in this study, but this result needs to be verified in other studies.

Comparison of subclinical left and right ventricular systolic dysfunction in non-dipper and dipper hypertensives: impact of isovolumic acceleration

Abstract Objectives: To evaluate subclinical left ventricular and right ventricular systolic impairment in dipper and non-dipper hypertensives by using isovolumic acceleration. Methods: About 45 normotensive healthy volunteers (20 men, mean age 43 ± 9 years), 45 dipper (27 men, mean age 45 ± 9 years) and 45 non-dipper (25 men, 47 ± 7 years) hypertensives were enrolled. Isovolumic acceleration was measured by dividing the peak myocardial isovolumic contraction velocity by isovolumic acceleration time. Results: Non-dippers indicated lower left ventricular (2.2 ± 0.4 m/s2 versus 2.8 ± 1.0 m/s2, p < 0.01) and right ventricular isovolumic acceleration values (2.8 ± 0.8 m/s2 versus 3.5 ± 1.0 m/s2, p = 0.012) compared with dippers. Left ventricular mass index (p = 0.001), interventricular septal thickness (p = 0.002) and myocardial performance index (p < 0.001) were negatively correlated with left ventricular isovolumic acceleration. Left ventricular septal thickness (p = 0.002), mass index (p = 0.001) and right ventricular myocardial performance index (p < 0.001) were negatively correlated with right ventricular isovolumic acceleration. Conclusion: The present study demonstrates that non-dipper hypertensives have increased left and right ventricular subclinical systolic dysfunction compared with dippers. Isovolumic acceleration is the only echocardiographic parameter in predicting this subtle impairment.

Higher copeptin levels are associated with worse outcome in patients with hypertrophic cardiomyopathy

Correlation of increased copeptin levels with various cardiovascular diseases has been described. The clinical use of copeptin levels in patients with hypertrophic cardiomyopathy (HCM) has not been investigated before.

Assessment of mean platelet volume and soluble CD40 ligand levels in patients with non-dipper hypertension, dippers and normotensives

Abstract Objective: Patients with a lack of nocturnal decline in blood pressure (BP) are at an increased risk for cardiovascular events. Mean platelet volume (MPV) and soluble CD40 ligand (sCD40L) are accepted biomarkers of platelet activation and considered as a risk factor for cardiovascular disease. The aim of this study was to determine whether MPV and sCD40L levels are higher in non-dipper hypertensive (NDHT) patients than in dipper hypertensive (DHT) patients and healthy controls. Methods: 124 consecutive patients were included to this study. Patients were divided into three groups: NDHT patient group [n = 43; mean age 51.8 ± 6.6; 31 males (72.1%)]; DHT patient group [n = 41; mean age 50.2 ± 7.3; 22 males (53.7%)]; and normotensive group [n = 40; mean age 49.9 ± 6.7; 22 males (55%)]. Physical examination, laboratory work-up and 24-h ABPM were performed for all participants. Results: The sCD40L and MPV levels were significantly higher in the NDHT group than in the DHT and normotensive groups (p < 0.05). In correlation analysis, MPV, 24-h systolic blood pressure (SBP), 24-h diastolic blood pressure (DBP), night-time SBP and night-time DBP were positively correlated with sCD40L. Conclusion: Our study demonstrated that MPV and sCD40L levels were significantly higher in NDHT patients compared to DHT and normotensive patients. sCD40L levels were positively correlated with MPV, 24-h SBP, 24-h DBP, night-time SBP and night-time DBP.

Effects of percutaneous closure of atrial septal defect on left atrial mechanical and conduction functions

AIMS Atrial septal defect (ASD) is one of the most common congenital heart diseases in adults. We prospectively evaluated early and mid-term effects of the percutaneous closure of secundum ASD on atrial electromechanical delay (AEMD) and left atrial (LA) mechanical functions at the first day and sixth month in patients undergoing percutaneous closure. METHODS AND RESULTS Forty-one patients were included in this study. Twenty-six (63.4%) of the 41 patients were female and the mean age was 41 ± 13 years. All the patients had echocardiographic examination before the procedure and at the first day and sixth month after the procedure. LA volumes (maximal, minimal, and presystolic) and EMD (lateral, septal, and tricuspid) were measured. Left and right intra- and inter-AEMD were not changed at the first day but both were significantly shorter at the sixth month. There was no change in the total emptying volume and fraction before and after the procedure. LA maximal, minimal, and pre-systolic volumes, active emptying volume, and fractions were decreased at the first day and at the sixth month compared with pre-procedural volumes. LA passive emptying volume, passive emptying fraction, and conduit volume were increased at the first day and at the sixth month compared with pre-procedural volumes. CONCLUSION Our results revealed that there was no change in the LA mechanical reservoir functions, but improved conduit function and impaired contractility functions early and in the mid-term after percutaneous closure of ASD and decreased AEMD only in the mid-term.

Does intravenous or oral high-dose N-acetylcysteine in addition to saline prevent contrast-induced nephropathy assessed by cystatin C?

AimsThe objective of this study is to determine the effect of intravenous (i.v.) or oral N-acetylcysteine (NAC) in preventing contrast-induced nephropathy (CIN) in patients with moderate-to-severe renal insufficiency undergoing intra-arterial interventions. Materials and methodsWe studied 307 patients with estimated glomerular filtration rate of less than 60 ml/min/1.73 m2 undergoing an elective intra-arterial procedure. Patients were assigned randomly to three groups according to the prophylactic regimen used. In group 1, patients were administered an i.v. infusion of 0.9% saline (n=103); in group 2, patients were administered oral NAC in addition to an i.v. saline infusion (n=102); and in group 3, patients were administered i.v. NAC in addition to an i.v. saline infusion (n=102). Serum creatinine (SCr) and cystatin C levels were measured at baseline and 4, 24, and 48 h after the application of contrast media. The primary endpoint was defined as an increase in the SCr or cystatin C concentration of at least 0.5 mg/dl and/or of at least 25% from the baseline value at 48 h after administration of the contrast dye. ResultsThe overall incidence of SCr-based CIN was 11.1%: 6.8% in the saline group, 13.7% in the oral NAC group, and 12.7% in the i.v. NAC group (P=0.231). That of cystatin C-based CIN was 8.1%: 6.8% in the saline group, 6.9% in the oral NAC group, and 10.8% in the i.v. NAC group (P=0.491). ConclusionIn this study, there was no detectable benefit of either high-dose oral or i.v. NAC over an aggressive hydration protocol in patients with moderate-to-severe renal insufficiency.

Long-term prognostic value of admission haemoglobin A1c (HbA1c) levels in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Introduction Many studies have reported the diagnostic and prognostic value of haemoglobin A1c (HbA1c) levels in patients with acute coronary syndrome. However, the short- and long-term prognostic value of HbA1c level in patients with ST elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) is controversial. Aim To investigate whether admission HbA1c level has a prognostic value for in-hospital, short-, and long-term cardiovascular (CV) mortality and major adverse cardiovascular events in patients with STEMI undergoing primary PCI. Material and methods This prospective study included 443 consecutive patients with STEMI who underwent primary PCI between September 2010 and July 2012. The patients were divided into three groups based on admission HbA1c levels: group I (HbA1c ≤ 5.6%), group II (HbA1c 5.7–6.4%), and group III (HbA1c ≥ 6.5%). The in-hospital, 1-month, and 1-year CV events of all 3 patient groups were followed up. Results A significant association was found between HbA1c level and 1-year primary clinical outcomes, including CV mortality, non-fatal reinfarction, and stroke (p = 0.037). In addition, age, Killip class > 1, and left ventricular ejection fraction were found to be independent predictors of long-term CV mortality in multivariate analysis (hazard ratios (95% confidence interval) 1.081 (1.020–1.146), 4.182 (1.171–14.935), and 0.832 (0.752–0.920); p = 0.009, p = 0.028, and p < 0.001, respectively). Conclusions In this study, we demonstrated that increased admission HbA1c levels were associated with higher rates of major adverse CV events, including mortality, non-fatal reinfarction, and stroke, in patients with STEMI who underwent primary PCI.