Zurkurnai Yusof

Shortened activated partial thromboplastin time, a hemostatic marker for hypercoagulable state during acute coronary event

Various factors may contribute to a hypercoagulable state and acute vascular thrombosis. A prospective study was conducted involving 165 coronary heart disease (CHD) patients from the Cardiology Unit, Hospital Universiti Sains Malaysia. The purpose of this study was to investigate the relationship among factor VIII (FVIII), prothrombin time (PT), activated partial thromboplastin time (APTT), and activated protein C resistance (APC-R) state among CHD patients and to look for potential clinical applications from these laboratory findings. There were 110 cases diagnosed as acute coronary syndrome (ACS), whereas another 55 were stable coronary artery disease (SCAD) patients. PT, APTT, FVIII, and APC-R assays were performed on all subjects. There was a significant difference between the FVIII level and the APTT results (P value < 0.0001). A negative relationship was found between the FVIII level and the APTT from linear regression analysis (R(2) = 10%, P value < 0.0001). For each 1% increase in the FVIII level, the APTT was reduced by 0.013 s (95% confidence interval (CI) between -0.019 and -0.007). Interestingly, none of the SCAD patients had abnormally short APTT. Approximately 68.4% of cases with a positive APC-R assay were found to have a high FVIII level. In conclusion, the APTT test is a potential hemostatic marker for hypercoagulable state including in arterial thrombosis.

Analysis of sequence variations in low-density lipoprotein receptor gene among Malaysian patients with familial hypercholesterolemia.

BackgroundFamilial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown.We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements.ResultsA total of 29 gene sequence variants were reported in 117(76.0%) of the studied subjects. Eight different mutations (1 large rearrangement, 1 short deletion, 5 missense mutations, and 1 splice site mutation), and 21 variants. Eight gene sequence variants were reported for the first time and they were noticed in familial hypercholesterolemic patients, but not in controls (p.Asp100Asp, p.Asp139His, p.Arg471Gly, c.1705+117 T>G, c.1186+41T>A, 1705+112C>G, Dup exon 12 and p.Trp666ProfsX45). The incidence of the p.Arg471Gly variant was 11%. Patients with pathogenic mutations were younger, had significantly higher incidences of cardiovascular disease, xanthomas, and family history of hyperlipidemia, together with significantly higher total cholesterol and low density lipoprotein levels than patients with non-pathogenic variants.ConclusionsTwenty-nine gene sequence variants occurred among FH patients; those with predicted pathogenicity were associated with higher incidences of cardiovascular diseases, tendon xanthomas, and higher total and low density lipoprotein levels compared to the rest. These results provide preliminary information on the mutation spectrum of this gene among patients with FH in Malaysia.

Pulse Wave Velocity as a Marker of Severity of Coronary Artery Disease

To determine whether pulse wave velocity (PWV) as a measure of arterial stiffness is a marker of coronary artery diseases (CAD), the authors did a cross‐sectional study in 92 patients undergoing coronary angiography for suspected CAD. Arterial stiffness was assessed through recording PWV from the left carotid–right femoral arteries using an automated machine. The mean PWV was higher in patients with CAD than in those without CAD (11.13±0.91 vs 8.14±1.25 m/sec; P<.001). When the severity of CAD was expressed as 1‐, 2‐, and multiple‐vessel disease, there was a significant association between the severity of CAD and PWV. PWV differed significantly with different categorical severity of CAD even when age and total cholesterol were controlled for. In a univariable analysis, PWV was higher with higher systolic blood pressure (P<.004). The authors conclude that arterial stiffness measured through PWV is an independent and complementary cardiovascular risk marker.

Systemic and coronary levels of CRP, MPO, sCD40L and PlGF in patients with coronary artery disease

BackgroundBiomarkers play a pivotal role in the diagnosis and management of patients with acute coronary syndrome. This study aimed to investigate the differences in level of several biomarkers, i.e. C-reactive protein, myeloperoxidase, soluble CD40 ligand and placental growth factor, between acute coronary syndrome and chronic stable angina patients. The relationship between these biomarkers in the coronary circulation and systemic circulation was also investigated.MethodsA total of 79 patients were recruited in this study. The coronary blood was sampled from occluded coronary artery, while the peripheral venous blood was withdrawn from antecubital fossa. The serum concentrations of C-reactive protein, soluble CD40 ligand and placental growth factor and plasma concentration of myeloperoxidase were measured using ELISA method.ResultsThe systemic level of the markers measured in the peripheral venous blood was significantly increased in acute coronary syndrome compared to chronic stable angina patients. The concentrations of the C-reactive protein, myeloperoxidase and soluble CD40 ligand taken from peripheral vein were closely similar to the concentration found in coronary blood of ACS patients. The level of placental growth factor was significantly higher in coronary circulation than its systemic level.ConclusionThe concentration of these C-reactive protein, myeloperoxidase, soluble CD40 ligand and placental growth factor were significantly increased in acute coronary syndrome patients. The concentration of the markers measured in the systemic circulation directly reflected those in the local coronary circulation. Thus, these markers have potential to become a useful tool in predicting plaque vulnerability in the future.

Identification of endogenous control genes for gene expression studies in peripheral blood of patients with coronary artery disease

AbstarctThe selection of stable endogenous control genes is critical for normalization of quantitative realtime PCR (qPCR) data. In this study, we aimed to identify a suitable set of control genes to be used as endogenous references for gene expression evaluation in human peripheral blood samples among coronary artery disease patients. The expression levels of 12 endogenous control genes procured from TATAA Biocenter (Goteborg, Sweden) were measured in five acute coronary syndrome patients and five chronic stable angina patients. Gene expression stability was analyzed using two different software applications i.e geNorm and NormFinder. Results suggested that beta-glucuronidase is the most stable endogenous control, followed by hypoxanthine-guanine phosphoribosyltransferase. The NormFinder analysis further confirmed that betaglucuronidase and hypoxanthine-guanine phosphoribosyltransferase were on the first rank order with the most stable expression among endogenous control genes analyzed and 60S acidic ribosomal protein P0. Besides, the expression levels of 18S rRNA were revealed to be highly variable between coronary heart disease patients. We thus recommend the use of beta-glucuronidase and hypoxanthine-guanine phosphoribosyltransferase as reference genes for accurate normalization of relative quantities of gene expression levels in coronary artery disease patients using qPCR. Also the use of 18S rRNA as a control gene should be avoided.

Aspirin Effects on Platelets Using Whole Blood Tested by Platelet Aggregometry: A Comparative Study for Test Validation in a Clinical Hemostasis Laboratory

Objective: Assessment on platelet responsiveness to aspirin may be required in selected clinical conditions. So far, no standardization in laboratory practices for aspirin assessment using whole blood (WB) platelet aggregation based test. A study for method validation was performed to investigate the aspirin effects on platelets by comparing with a reference method. Methods: Forty patients taking aspirin were analyzed using WB by conventional platelet aggregometer (Chrono-Log Model 500CA/560CA). Among these patients, nine of them had their platelet rich plasma (PRP) tested by the same analyzer (reference method). Another WB specimens from 25 patients were tested on both ChronoLog and Multiplate® (Dynabyte GmbH), which is a newer generation platelet function analyzer. Results: There were good and moderate agreements between WB on the Chronolog analyzer vs the reference method and WB on Chronolog vs WB on Multiplate® analyzers respectively. Conclusions: There are agreements between PRP and WB aggregation (WBA) methods in detecting aspirin effects on platelets. It is recommended that the test validation for the assessment of platelet responsiveness to aspirin is interpreted and correlated with the reference method preferably PRP.

T-009 IMPROVED INSULIN SENSITIVITY, CENTRAL SYSTOLIC PRESSURE AND INFLAMMATORY MARKER WITH MINOR WEIGHT REDUCTION IN OVERWEIGHT AND OBESE SUBJECTS ON MODOFIED LIIFESTYLE INTERVENTION

Background Obesity is a global epidemic disease that associated with an increased risk of multiple health problems. Obesity occurs as a result of prolonged positive energy balance, where energy intake exceeds energy expenditure. Lifestyle modification through exercise and dietary intervention had been proven to reduce body weight and cardiovascular risk factors associated with obesity. The aim of this study is to determine the effect of a 9 months’ lifestyle intervention to reduce weight on selected cardiovascular, inflammatory and metabolic risk markers among overweight and obese subjects. Methods 25 overweight and obese subjects (body mass index >25.0 kg/m2, age: 36.8 ± 9.8 years) completed the nine months’ lifestyle modification intervention program. All subjects were requested to attend dietary consultations with dieticians and physical activity and exercise consultation regularly during the 9 months. Assessment of anthropometric measurements, arterial stiffness parameters, body fat percentage, visceral fat, peripheral and aortic blood pressure were performed at baseline and every three months thereafter. Arterial stiffness parameters (augmentation index and pulse wave velocity) were assessed non-invasively using the SphygmoCor device. Lipid profile, hs-CRP and insulin sensitivity were performed during baseline, six and nine months. Results Body weight reduced significantly by 2.9% (p = 0.019) by the end of intervention compared to baseline. Waist and hip circumference were significantly decreased (89.5 ± 8.1 cm vs 86.4 ± 9.4 cm, p = 0.034 and 107.2 ± 10.0 vs 104.0 ± 11.8 cm, p = 0.004). Significant improvement was seen in aortic systolic blood pressure (110 ± 14 vs 105 ± 13 mmHg, p = 0.02) after 9 months intervention. All insulin sensitivity parameters measured were significantly improved with treatment (serum fasting insulin level; p = 0.001, HOMA%S; p = 0.008, HOMA%B; p = 0.004, HOMA-IR; p = 0.007). The inflammatory marker, hs-CRP was significantly reduced after 9 months (9.12 ± 12.1 vs 7.37 ± 9.9 mg/l, p = 0.01). However, no significant differences were seen in arterial stiffness parameters, peripheral blood pressure, lipid profile and body composition after intervention Conclusion Even Small reduction in weight through modified lifestyle intervention improved aortic blood pressure, insulin sensitivty and hsCRP in overweight and obese subjects.

Add-on rosiglitazone therapy improves plasminogen activity and high-density lipoprotein cholesterol in type 2 diabetes mellitus.

Rosiglitazone is an oral hypoglycaemic agent of the thiazolidinedione group. This study aimed to assess changes in the diabetic prothrombotic state via plasminogen activity and changes in surrogate markers of atherosclerotic burden via ankle-brachial pressure index (ABPI) measurements after rosiglitazone was added to a pre-existing type 2 diabetes mellitus treatment regime. A nonblinded interventional study was designed. Fifty-nine patients were enrolled. Rosiglitazone-naïve patients were prescribed oral rosiglitazone 4 mg daily for 10 weeks. ABPI, plasminogen activity, glycosylated haemoglobin (HbA1c) and fasting lipid profile were measured pretreatment and post-treatment. Forty-eight patients completed the study. At the end of this study, mean plasminogen activity improvement was nearly 16% (P < 0.05), mean ABPI improvement was 0.01 (P = 0.439), mean HbA1c reduction was 0.51% (P < 0.05), mean total cholesterol (TC) increase was 0.36 mmol/l (P < 0.05), mean high-density lipoprotein cholesterol (HDL-C) increase was 0.15 mmol/l (P < 0.05) and mean low-density lipoprotein cholesterol increased by 0.19 mmol/l (P = 0.098). Rosiglitazone significantly improved plasminogen activity. There was also significant HbA1c reduction, and rise in both TC and HDL-C. Thus, rosiglitazone potentially improves the atherosclerotic burden and prothrombotic state. In future, more studies are needed to confirm the relationship between rosiglitazone, fibrinolytic system and atheromatous reduction in type 2 diabetes mellitus.