Ticagrelor versus clopidogrel in patients with ST-elevation acute coronary syndromes intended for reperfusion with primary percutaneous coronary intervention: A Platelet Inhibition and Patient Outcomes (PLATO) trial subgroup analysis.

BACKGROUND: Aspirin and clopidogrel are recommended for patients with acute coronary syndromes (ACS) or undergoing coronary stenting. Ticagrelor, a reversible oral P2Y12-receptor antagonist, provides faster, greater, and more consistent platelet inhibition than clopidogrel and may be useful for patients with acute ST-segment elevation (STE) ACS and planned primary percutaneous coronary intervention. METHODS AND RESULT: Platelet Inhibition and Patient Outcomes (PLATO), a randomized, double-blind trial, compared ticagrelor with clopidogrel for the prevention of vascular events in 18 624 ACS patients. This report concerns the 7544 ACS patients with STE or left bundle-branch block allocated to either ticagrelor 180-mg loading dose followed by 90 mg twice daily or clopidogrel 300-mg loading dose (with provision for 300 mg clopidogrel at percutaneous coronary intervention) followed by 75 mg daily for 6 to 12 months. The reduction of the primary end point (myocardial infarction, stroke, or cardiovascular death) with ticagrelor versus clopidogrel (10.8% versus 9.4%; hazard ratio [HR], 0.87; 95% confidence interval, 0.75 to 1.01; P=0.07) was consistent with the overall PLATO results. There was no interaction between presentation with STE/left bundle-branch block and randomized treatment (interaction P=0.29). Ticagrelor reduced several secondary end points, including myocardial infarction alone (HR, 0.80; P=0.03), total mortality (HR, 0.82; P=0.05), and definite stent thrombosis (HR, 0.66; P=0.03). The risk of stroke, low in both groups, was higher with ticagrelor (1.7% versus 1.0%; HR,1.63; 95% confidence interval, 1.07 to 2.48; P=0.02). Ticagrelor did not affect major bleeding (HR, 0.98; P=0.76). CONCLUSION: In patients with STE-ACS and planned primary percutaneous coronary intervention, the effects of ticagrelor were consistent with those observed in the overall PLATO trial. CLINICAL TRIAL REGISTRATION: URL: http://www.ClinicalTrials.gov. Unique identifier: NCT00391872.

Growth-differentiation factor-15 for long-term risk prediction in patients stabilized after an episode of non-ST-segment-elevation acute coronary syndrome.

BACKGROUND: Growth-differentiation factor-15 (GDF-15) has emerged as a prognostic biomarker in patients with non-ST-segment-elevation acute coronary syndrome. This study assessed the time course and the long-term prognostic relevance of GDF-15 levels measured repetitively in patients with non-ST-segment-elevation acute coronary syndrome during 6 months after the acute event. METHODS AND RESULTS: GDF-15 and other biomarkers were measured at randomization, after 6 weeks, and after 3 and 6 months in 950 patients with non-ST-segment-elevation acute coronary syndrome included in the FRagmin and Fast Revascularization during InStability in Coronary artery disease II study. Study end points were death, recurrent myocardial infarction, and their composite during 5-year follow-up. Median GDF-15 levels decreased slightly from 1357 ng/L at randomization to 1302 ng/L at 6 months (P<0.001). GDF-15 was consistently related to cardiovascular risk factors and biochemical markers of hemodynamic stress, renal dysfunction, and inflammation. Moreover, GDF-15 was independently related to the 5-year risk of the composite end point when measured at both 3 months (adjusted hazard ratio, 1.8 [1.0 to 3.0]) and 6 months (adjusted hazard ratio, 2.3 [1.3 to 4.1]). Serial measurements of GDF-15 at randomization and 6 months helped to identify patient cohorts at different levels of risk, with patients with persistently elevated GDF-15 levels >1800 ng/L having the highest rate of the composite end point. CONCLUSIONS: GDF-15 is independently related to adverse events in non-ST-segment-elevation acute coronary syndrome both in the acute setting and for at least 6 months after clinical stabilization. Therefore, continued research on GDF-15 should be focused on the usefulness of GDF-15 for support of clinical management in acute and chronic ischemic heart disease.

Seasonal genetic influence on serum 25-hydroxyvitamin D levels: a twin study.

BACKGROUND: Although environmental factors, mainly nutrition and UV-B radiation, have been considered major determinants of vitamin D status, they have only explained a modest proportion of the variation in serum 25-hydroxyvitamin D. We aimed to study the seasonal impact of genetic factors on serum 25-hydroxyvitamin D concentrations. METHODOLOGY/PRINCIPAL FINDINGS: 204 same-sex twins, aged 39-85 years and living at northern latitude 60 degrees, were recruited from the Swedish Twin Registry. Serum 25-hydroxyvitamin D was analysed by high-pressure liquid chromatography and mass spectrometry. Genetic modelling techniques estimated the relative contributions of genetic, shared and individual-specific environmental factors to the variation in serum vitamin D. The average serum 25-hydroxyvitamin D concentration was 84.8 nmol/l (95% CI 81.0-88.6) but the seasonal variation was substantial, with 24.2 nmol/l (95% CI 16.3-32.2) lower values during the winter as compared to the summer season. Half of the variability in 25-hydroxyvitamin D during the summer season was attributed to genetic factors. In contrast, the winter season variation was largely attributable to shared environmental influences (72%; 95% CI 48-86%), i.e., solar altitude. Individual-specific environmental influences were found to explain one fourth of the variation in serum 25-hydroxyvitamin D independent of season. CONCLUSIONS/SIGNIFICANCE: There exists a moderate genetic impact on serum vitamin D status during the summer season, probably through the skin synthesis of vitamin D. Further studies are warranted to identify the genes impacting on vitamin D status.

Growth-differentiation factor-15 is an independent marker of cardiovascular dysfunction and disease in the elderly: results from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) Study.

AIMS: Growth-differentiation factor-15 (GDF-15) is emerging as an independent prognostic biomarker in patients with cardiovascular (CV) disease. Little is known about the pathophysiological basis for the close association of GDF-15 to future CV events. We hypothesized that GDF-15 is related to underlying CV pathologies. METHODS AND RESULTS: To relate the levels of GDF-15 to indices of CV dysfunction and disease in elderly individuals, serum levels of GDF-15 were measured in 1004 subjects aged 70 years from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Carotid intima-media thickness and plaque burden, and left ventricular (LV) geometry and function were assessed by ultrasound. Endothelial function was evaluated in forearm resistance vessels and in the brachial artery by venous occlusion plethysmography and ultrasound imaging, respectively. Elevated levels of GDF-15 were related to several CV risk factors (male gender, current smoking, body mass index, waist circumference, diabetes, fasting glucose, triglycerides, and low HDL cholesterol). After adjustment for CV risk factors, increased levels of GDF-15 were associated with reduced endothelium-dependent vasodilation in resistance vessels, plaque burden, LV mass and concentric LV hypertrophy, reduced LV ejection fraction, and clinical manifestations of coronary artery disease and heart failure. CONCLUSION: GDF-15 carries information on CV dysfunction and disease that is not captured by traditional CV risk factors in elderly individuals.

Assessment of P2Y(12) inhibition with the point-of-care device VerifyNow P2Y12 in patients treated with prasugrel or clopidogrel coadministered with aspirin.

BACKGROUND: Variability in response to thienopyridines has led to the development of point-of-care devices to assess adenosine diphosphate (ADP)-induced platelet aggregation. These tests need to be evaluated in comparison to reference measurements of P2Y(12) function during different thienopyridine treatments. METHODS: After a run-in on 75 mg aspirin, 110 subjects were randomized to double-blind treatment with clopidogrel 600 mg loading dose (LD)/75 mg maintenance dose (MD) or prasugrel 60 mg LD/10 mg MD. Antiplatelet effects were evaluated by VerifyNow P2Y12 (VN-P2Y12) device (Accumetrics, San Diego, CA), vasodilator-stimulated phosphoprotein (VASP) phosphorylation assay, and light transmission aggregometry (LTA). Prasugrel's and clopidogrel's active metabolite concentration were also determined. RESULTS: Dose- and time-dependent inhibition of P2Y(12) was evident with VN-P2Y12. There was strong correlation with VN-P2Y12 and VASP or LTA for all treatments through a wide range of P2Y(12) function. At high levels of P2Y(12) inhibition, platelet function measured by VN-P2Y12 was maximally inhibited and could not reflect further changes seen with VASP or LTA methods. Correlation was also observed between exposure to clopidogrel's active metabolite and VN-P2Y12 during MD and LD, whereas it was observed only with prasugrel MD. CONCLUSION: The VN-P2Y12 correlated strongly with inhibition of P2Y(12) function, as measured with either VASP or LTA. VN-P2Y12 also correlated to exposure to the active metabolite of prasugrel and clopidogrel up to levels associated with assumed saturation of the P2Y(12) receptor.

Growth-differentiation factor-15 improves risk stratification in ST-segment elevation myocardial infarction.

AIMS: Growth-differentiation factor-15 (GDF-15) is a transforming growth factor-beta-related cytokine that is induced in the heart following ischaemia-reperfusion injury. We explored the prognostic utility of GDF-15 in patients with ST-segment elevation myocardial infarction (STEMI) receiving fibrinolytic therapy. METHODS AND RESULTS: Circulating levels of GDF-15 were determined by an immunoradiometric assay in 741 STEMI patients who were included in the Assessment of the Safety and Efficacy of a New Thrombolytic (ASSENT)-2 and ASSENT-plus trials. About 72.7% of the patients presented with GDF-15 levels > or =1200 ng/L, the upper limit of normal in apparently healthy elderly individuals. Increased levels of GDF-15 were associated with a higher risk of death during 1-year follow-up. Mortality rates at 1 year were 2.1, 5.0, and 14.0% in patients with GDF-15 levels <1200, 1200-1800, and >1800 ng/L, respectively (P < 0.001). GDF-15 remained an independent predictor of mortality after adjustment for clinical variables, troponin T, and N-terminal pro-B-type natriuretic peptide (NT-proBNP). GDF-15 provided prognostic information in clinically relevant patient subgroups, defined according to age, gender, cardiovascular risk factors, haemodynamic status, and the TIMI risk score. Moreover, GDF-15 added prognostic information to the established biomarkers of adverse prognosis in STEMI, troponin T, and NT-proBNP. CONCLUSION: GDF-15 is a new biomarker in STEMI that provides prognostic information beyond established clinical and biochemical markers.

Growth differentiation factor 15 for risk stratification and selection of an invasive treatment strategy in non ST-elevation acute coronary syndrome.

BACKGROUND: An invasive treatment strategy improves outcome in patients with non-ST-elevation acute coronary syndrome at moderate to high risk. We hypothesized that the circulating level of growth differentiation factor 15 (GDF-15) may improve risk stratification. METHODS AND RESULTS: The Fast Revascularization during InStability in Coronary artery disease II (FRISC-II) trial randomized patients with non-ST-elevation acute coronary syndrome to an invasive or conservative strategy with a follow-up for 2 years. GDF-15 and other biomarkers were determined on admission in 2079 patients. GDF-15 was moderately elevated (between 1200 and 1800 ng/L) in 770 patients (37.0%), and highly elevated (>1800 ng/L) in 493 patients (23.7%). Elevated levels of GDF-15 independently predicted the risk of the composite end point of death or recurrent myocardial infarction in the conservative group (P=0.016) but not in the invasive group. A significant interaction existed between the GDF-15 level on admission and the effect of treatment strategy on the composite end point. The occurrence of the composite end point was reduced by the invasive strategy at GDF-15 levels >1800 ng/L (hazard ratio, 0.49; 95% confidence interval, 0.33 to 0.73; P=0.001), between 1200 and 1800 ng/L (hazard ratio, 0.68; 95% confidence interval, 0.46 to 1.00; P=0.048), but not <1200 ng/L (hazard ratio, 1.06; 95% confidence interval, 0.68 to 1.65; P=0.81). Patients with ST-segment depression or a troponin T level >0.01 microg/L with a GDF-15 level <1200 ng/L did not benefit from the invasive strategy. CONCLUSIONS: GDF-15 is a potential tool for risk stratification and therapeutic decision making in patients with non-ST-elevation acute coronary syndrome as initially diagnosed by ECG and troponin levels. A prospective randomized trial is needed to validate these findings.

Prognostic value of growth-differentiation factor-15 in patients with non-ST-elevation acute coronary syndrome.

BACKGROUND: Growth-differentiation factor-15 (GDF-15) is a member of the transforming growth factor-beta cytokine superfamily that is induced in the heart after ischemia-and-reperfusion injury. Circulating levels of GDF-15 may provide prognostic information in patients with non-ST-elevation acute coronary syndrome. METHODS AND RESULTS: Blood samples were obtained on admission from 2081 patients with acute chest pain and either ST-segment depression or troponin elevation who were included in the Global Utilization of Strategies to Open Occluded Arteries (GUSTO)-IV Non-ST-Elevation Acute Coronary Syndrome trial and from a matching cohort of 429 apparently healthy individuals. GDF-15 levels were determined by immunoradiometric assay. Approximately two thirds of patients presented with GDF-15 levels above the upper limit of normal in healthy controls (1200 ng/L); one third presented with levels >1800 ng/L. Increasing tertiles of GDF-15 were associated with an enhanced risk of death at 1 year (1.5%, 5.0%, and 14.1%; P<0.001). By multiple Cox regression analysis, only the levels of GDF-15 and N-terminal pro-B-type natriuretic peptide, together with age and a history of previous myocardial infarction, contributed independently to 1-year mortality risk. Receiver operating characteristic curve analyses further illustrated that GDF-15 is a strong marker of 1-year mortality risk (area under the curve, 0.757; best cutoff, 1808 ng/L). At this cutoff value, GDF-15 added significant prognostic information in patient subgroups defined by age; gender; time from symptom onset to admission; cardiovascular risk factors; previous cardiovascular disease; and the risk markers ST-segment depression, troponin T, N-terminal pro-B-type natriuretic peptide, C-reactive protein, and creatinine clearance. CONCLUSIONS: GDF-15 is a new biomarker of the risk for death in patients with non-ST-elevation acute coronary syndrome that provides prognostic information beyond that provided by established clinical and biochemical markers.