***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: A high platelet turnover rate produce a population of immature reticulated platelets ( RP ) that could confer , despite of antiplatelet drugs , a residual platelet reactivity ( RPR ) in coronary artery disease ( CAD ) patients . To assess the influence of RP on platelet reactivity in CAD patients on dual antiplatelet therapy  we measured RP in 372 patients by using the Sysmex XE-2100 haematology analyzer  and platelet function by optical platelet aggregometry ( PA ) on platelet-rich-plasma induced by 1 mmol arachidonic acid ( AA-PA ) and 10 microM ADP ( ADP-PA ) . RPR was defined as either AA-PA>20 % or ADP-PA>70 % . RP were expressed as a percentage of RP of the total optical platelet count ( immature platelet fraction ; IPF ) and as the percentage of RP highly fluorescent ( highly fluorescent immature platelet fraction ; H-IPF ) . Moderate but significant positive correlations between PA , IPF , H-IPF , and mean platelet volume ( MPV ) were found . According to tertiles of IPF , H-IPF and MPV , a significant trend for an increase of platelet aggregation by AA and ADP was evidence d. Furthermore , a significant difference for IPF , H-IPF and MPV between patients with and without RPR was observed . A linear regression analysis showed that IPF , H-IPF and MPV significantly affected PA measured by AA and ADP . At multivariate linear regression analysis these associations were confirmed . Moreover , a logistic regression analysis demonstrated that IPF , H-IPF and MPV significantly influenced the risk of RPR , and in the multivariate model these results remained significant . This study indicates that a high rate of platelet turnover is a new mechanism associated with platelet reactivity in high risk CAD patients on dual antiplatelet therapy BACKGROUND Mean platelet volume ( MPV ) is a strong predictor of impaired angiographic reperfusion and 6-month mortality in ST-elevation myocardial infa rct ion ( MI ) treated with  primary percutaneous coronary intervention ( PCI )  . No data is available for other platelet volume indices : platelet distribution width ( PDW ) and platelet large cell ratio ( P-LCR ) . The aim was to assess the impact of 3 platelet volume indices on long-term prognosis in patients treated with primary PCI in acute MI . METHODS This prospect i ve study enrolled 538 patients who underwent primary PCI in acute MI . Admission blood sample s were measured for MPV , PDW , and P-LCR . The patients were followed-up a mean period of 26 ± 11 months with regard to cardiac death , non-fatal reinfa rct ion , re-PCI or coronary artery bypass grafting . RESULTS Kaplan-Meier survival analysis showed a significantly higher 26-month mortalityrate in patients with high MPV ( ≥ 11.7 fL ) than in those with low MPV ( < 11.7 fL ) ( 14.6 % vs. 5.5 % , p = 0.0008 ) . Similar findings were related to high P-LCR ( ≥ 38.1 % ) vs. low P-LCR ( < 38.1 % ) - mortality 13.8 % vs. 5.8 % , p = 0.0025 . Higher PDW values ( ≥ 16 fL ) correlated with higher mortality rate as compared to PDW < 16 fL ( 17.4 % vs. 6.3 % , p = 0.0012 ) . PDW was found to be an independent prognostic factor for cardiac mortality and composite endpoint . CONCLUSIONS Mean platelet volume , platelet distribution width and platelet large cell ratio measured on admission are strong , independent prognostic factors in PCI-treated acute MI CONTEXT Patients with unstable angina/non-ST-segment elevation myocardial infa rct ion ( MI ) ( UA/NSTEMI ) present with a wide spectrum of risk for death and cardiac ischemic events . OBJECTIVE To develop a simple risk score that has broad applicability , is easily calculated at patient presentation , does not require a computer , and identifies patients with different responses to treatments for UA/NSTEMI . DESIGN , SETTING , AND PATIENTS Two phase 3 , international , r and omized , double-blind trials ( the Thrombolysis in Myocardial Infa rct ion [ TIMI ] 11B trial [ August 1996-March 1998 ] and the Efficacy and Safety of Subcutaneous Enoxaparin in Unstable Angina and Non-Q-Wave MI trial [ ESSENCE ; October 1994-May 1996 ] ) . A total of 1957 patients with UA/NSTEMI were assigned to receive unfractionated heparin ( test cohort )  and 1953 to receive enoxaparin in TIMI 11B ; 1564 and 1607 were assigned respectively in ESSENCE . The 3 validation cohorts were the unfractionated heparin group from ESSENCE and both enoxaparin groups . MAIN OUTCOME MEASURES The TIMI risk score was derived in the test cohort by selection of independent prognostic variables using multivariate logistic regression , assignment of value of 1 when a factor was present and 0 when it was absent , and summing the number of factors present to categorize patients into risk strata . Relative differences in response to therapeutic interventions were determined by comparing the slopes of the rates of events with increasing score in treatment groups and by testing for an interaction between risk score and treatment . Outcomes were TIMI risk score for developing at least 1 component of the primary end point ( all-cause mortality , new or recurrent MI , or severe recurrent ischemia requiring urgent revascularization ) through 14 days after r and omization . RESULTS The 7 TIMI risk score predictor variables were age 65 years or older , at least 3 risk factors for coronary artery disease , prior coronary stenosis of 50 % or more ,  ST-segment deviation on electrocardiogram at presentation  , at least 2 anginal events in prior 24 hours , use of aspirin in prior 7 days , and elevated serum cardiac markers . Event rates increased significantly as the TIMI risk score increased in the test cohort in TIMI 11B : 4.7 % for a score of 0/1 ; 8.3 % for 2 ; 13 . 2 % for 3 ; 19.9 % for 4 ; 26.2 % for 5 ; and 40.9 % for 6/7 ( P<.001 by chi(2 ) for trend ) . The pattern of increasing event rates with increasing TIMI risk score was confirmed in all 3 validation groups ( P<.001 ) . The slope of the increase in event rates with increasing numbers of risk factors was significantly lower in the enoxaparin groups in both TIMI 11B ( P = .01 ) and ESSENCE ( P = .03 ) and there was a significant interaction between TIMI risk score and treatment ( P = . 02 ) . CONCLUSIONS In patients with UA/NSTEMI , the TIMI risk score is a simple prognostication scheme that categorizes a patient 's risk of death and ischemic events and provides a basis for therapeutic decision making . JAMA . 2000;284:835 - Data from the Diet and Reinfa rct ion Trial were examined to check the prognostic effects of plasma fibrinogen , plasma viscosity , white blood cell count , haemoglobin and mean platelet volume in 92 deaths among 1755 men who had recently recovered from acute myocardial infa rct ion . All these variables were significantly associated with all-cause mortality over the following 18 months ( haemoglobin negatively , the others positively ) . Those who gave up smoking following their infa rct had a lower mortality than those who continued to smoke ( 4.1 % and 7.9 % respectively ) , and this effect appeared to be mediated by fibrinogen levels . Smoking habit accounted for only part of the prognostic effect of fibrinogen and white blood cell count . Haematological variables have an important prognostic significance after myocardial infa rct ion . Cessation of smoking after myocardial infa rct ion is worthwhile and has a favourable effect on plasma fibrinogen Mean  platelet volume ( MPV ) has been proposed as a marker of platelet reactivity and cardiovascular risk . Its prognostic significance has not been thoroughly investigated in patients with non-ST elevation acute coronary syndrome ( NSTE-ACS ) . We included 1,041 consecutive patients with NSTE-ACS . Patients were divided in quartiles according to the MPV value on admission ( fl ) i.e. Q1<7.5 ; Q2=7.5 - 8.0 ; Q3=8.1 - 8.8 ; Q4≥8.9 . The primary study endpoint was the composite of cardiovascular death and re-myocardial infa rct ion ( MI ) at one year . Secondary study endpoints were individual cardiovascular death and re-MI . Patients in Q4 were older , had a higher prevalence of previous MI , peripheral artery disease and advanced Killip class compared to patients in Q1-Q3 . Elevated MPV levels ( Q4 ) was independently associated with gender , smoking status , platelet count and creatinine level . Overall , 210 patients ( 20.2 % ) reached the primary endpoint , 124 ( 12.1 % ) died from cardiovascular causes and 125 ( 12.0 % ) suffered from re-MI . On multivariable analysis patients in Q4 were at higher risk of primary endpoint ( HR=1.41 ; 95%CI 1.06 - 1.89 ; p=0.02 ) whilst the association with cardiovascular death and re-MI was attenuated . MPV as continuous variable was independently associated with both primary endpoint ( HR=1.19 ; 95%CI 1.06 - 1.33 ; p=0.003 ) and cardiovascular death ( HR=1.23 ; 95%CI 1.06 - 1.42 , p=0.006 ) . The incorporation of MPV into a comprehensive model of risk significantly increased the likelihood ratio chi-square for prediction of both the composite endpoint ( p=0.004 ) and cardiovascular death ( p=0.009 ) . Therefore , MPV may be useful to improve risk stratification in NSTE-ACS patients and should be included in future prospect i ve studies evaluating the role of platelet function in promoting cardiovascular events BACKGROUND Appropriate treatment policies should include an accurate estimate of a patient 's baseline risk . Risk modeling to date has been underutilized in patients with acute coronary syndromes without persistent ST-segment elevation . METHODS AND RESULTS We analyzed the relation between baseline characteristics and the 30-day incidence of death and the composite of death or myocardial (re)infa rct ion in 9461 patients with acute coronary syndromes without persistent ST-segment elevation enrolled in the PURSUIT trial [ Platelet glycoprotein IIb/IIIa in Unstable angina : Receptor Suppression Using Integrilin ( eptifibatide ) Therapy ] . Variables examined included demographics , history , hemodynamic condition , and symptom duration . Risk models were created with multivariable logistic regression and vali date d by bootstrapping techniques . There was a 3.6 % mortality rate and 11.4 % infa rct ion rate by 30 days . More than 20 significant predictors for mortality and for the composite end point were identified . The most important baseline determinants of death were age ( adjusted chi(2)=95 ) , heart rate ( chi(2)=32 ) , systolic blood pressure ( chi(2)=20 ) , ST-segment depression ( chi(2)=20 ) , signs of heart failure ( chi(2)=18 ) , and cardiac enzymes ( chi(2)=15 ) . Determinants of mortality were generally also predictive of death or myocardial (re)infa rct ion . Differences were observed , however , in the relative prognostic importance of predictive variables for mortality alone or the composite end point ; for example , sex was a more important determinant of the composite end point ( chi(2)=21 ) than of death alone ( chi(2)=10 ) . The accuracy of the prediction of the composite end point was less than that of mortality ( C-index 0.67 versus 0.81 ) . CONCLUSIONS The occurrence of adverse events after presentation with acute coronary syndromes is affected by multiple factors . These factors should be considered in the clinical decision-making process A prospect i ve study was performed to investigate the role of the endogenous fibrinolytic system and platelet function for the occurrence of reocclusion after successful recanalization of chronic coronary occlusions . At control coronary angiography 8 + /- 2 weeks after recanalization , reocclusion was found in 10 ( 21 % ) of 47 patients . After correction for angiographic and clinical confounding factors , endogenous concentrations of tissue plasminogen activator ( TPA ) were lower in patients with reocclusion than in patients without . In contrast , plasma levels of plasminogen activator inhibitor-1 and alpha 2-antiplasmin were similar in the two groups . The mean platelet volume was significantly higher in patients with reocclusion than in patients without . In addition , agonist-induced platelet aggregation in platelet-rich plasma was enhanced in the patients with reocclusion . Decreased endogenous plasma TPA concentrations and enhanced platelet reactivity may contribute to the occurrence of reocclusion after primarily successful coronary artery recanalization Mean platelet volume ( MPV ) is a value that is available from st and ard blood count . Increased 
    Output:
    
These findings suggest that MPV may be a useful prognostic marker in patients with CAD