***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The objective was to assess the safety and efficacy of L-NMMA in the treatment of cardiogenic shock . METHODS We enrolled 11 consecutive patients with cardiogenic shock that persisted after > 24 hours from admission , despite coronary catheterization and primary percutaneous transluminal coronary revascularization , when feasible , and treatment with mechanical ventilation , intraaortic balloon pump ( IABP ) , and high doses of catecholamines . L-NMMA was administered as an IV bolus of 1 mg/kg and continuous drip of 1 mg . kg(-1 ) . h(-1 ) for 5 hours . Treatment with catecholamines , mechanical ventilation , and IABP was kept constant throughout the study . RESULTS Within 10 minutes of L-NMMA administration , mean arterial blood pressure ( MAP ) increased from 76+/-9 to 109+/-22 mm Hg ( + 43 % ) . Urine output increased within 5 hours from 63+/-25 to 156+/-63 cc/h ( + 148 % ) . Cardiac index decreased during the steep increase in MAP from 2 . 0+/-0.5 to 1.7+/-0.4 L/(min . m(2 ) ) ( -15 % ) ; however , it gradually increased to 1.85+/-0.4 L/(min . m(2 ) ) after 5 hours . The heart rate and the wedge pressure remained stable . Twenty-four hours after L-NMMA discontinuation , MAP ( + 36 % ) and urine output ( + 189 % ) remained increased ; however , cardiac index returned to pretreatment level . No adverse events were detected . Ten out of eleven patients could be weaned off mechanical ventilation and IABP . Eight patients were discharged from the coronary intensive care unit , and seven ( 64 % ) were alive at 1-month follow-up . CONCLUSIONS L-NMMA administration in patients with cardiogenic shock is safe and has favorable clinical and hemodynamic effects Background —Few data are available on the impact of heart failure ( HF ) across all types of acute coronary syndromes ( ACS ) . Methods and Results —The Global Registry of Acute Coronary Events ( GRACE ) is a prospect i ve study of patients hospitalized with ACS . Data from 16 166 patients were analyzed : 13 707 patients without prior HF or cardiogenic shock at presentation were identified . Of these , 1778 ( 13 % ) had an admission diagnosis of HF ( Killip class II or III ) . HF on admission was associated with a marked increase in mortality rates during hospitalization ( 12.0 % versus 2.9 % [ with versus without HF ] , P < 0.0001 ) and at 6 months after discharge ( 8.5 % versus 2.8 % , P < 0.0001 ) . Of note , HF increased mortality rates in patients with unstable angina ( defined as ACS with normal biochemical markers of necrosis ; mortality rates : 6.7 % with versus 1.6 % without HF at admission , P < 0.0001 ) . By logistic regression analysis , admission HF was an independent predictor of hospital death ( odds ratio , 2.2 ; P < 0.0001 ) . Admission HF was associated with longer hospital stay and higher readmission rates .  Patients with HF had lower rates of catheterization and percutaneous cardiac intervention , and fewer received & bgr;-blockers and statins . Hospital development of HF ( versus HF on presentation ) was associated with an even higher in-hospital mortality rate ( 17.8 % versus 12.0 % , P < 0.0001 ) . In patients with HF , in-hospital revascularization was associated with lower 6-month death rates ( 14.0 % versus 23.7 % , P < 0.0001 ; adjusted hazard ratio , 0.5 ; 95 % CI , 0.37 to 0.68 , P < 0.0001 ) . Conclusions —In this observational registry , heart failure was associated with reduced hospital and 6-month survival across all ACS subsets , including patients with normal markers of necrosis . More aggressive treatment of these patients may be warranted to improve prognosis BACKGROUND Traditional and largely qualitative review s of evidence are now giving way to much more structured systematic overviews that use a quantitative method to calculate the overall effect of treatment . The latter approach is dependent on the quality of primary studies , which may introduce bias if they are of poor method ologic quality . OBJECTIVE To test the hypothesis that the inclusion of poor- quality trials in meta-analyses would bias the conclusions and produce incorrect estimates of treatment effect . METHODS An overview of r and omized trials of antiestrogen therapy in subfertile men with oligospermia was performed to test the hypothesis . Data sources included online search ing of MEDLINE and Science Citation Index data bases between 1966 and 1994 , scanning the bibliography of known primary studies and review articles , and contacting experts in the field . After independent , blind assessment , nine of 149 originally identified studies met the inclusion criteria and were selected . We assessed study quality independently . Outcome data from each study were pooled and statistically summarized . RESULTS There was a marginal improvement in pregnancy rate with antiestrogen treatment ( odds ratio , 1.6 ; 95 % confidence interval , 0.9 to 2.6 ) . Sensitivity analyses on the basis of method ologic quality demonstrated that poor- quality studies produced a positive effect with treatment , whereas no benefit was observed with high- quality studies . CONCLUSION The results of a meta- analysis are influenced by the quality of the primary studies included . Method ologically , poor studies tend to exaggerate the overall estimate of treatment effect and may lead to incorrect inferences The results of this study showed an advantage of nesiritide compared with high-dose nitroglycerin in the treatment of patients with decompensated heart failure .  Nesiritide result ed in an early decrease in pulmonary capillary wedge pressure ( < or = 15 minutes ) , which was sustained throughout the study period ( 24 hours ) without the need for up-titration . In contrast , the onset of the nitroglycerin-mediated  hemodynamic effect was delayed , and despite aggressive up-titration , the decrease in pulmonary capillary wedge pressure was gradually attenuated because of the early development of tolerance BACKGROUND To compare the safety and efficacy of nesiritide versus intravenous nitroglycerin ( NTG ) in patients with acute coronary syndromes enrolled in the Vasodilation in the Management of Acute Congestive heart failure trial . Methods and results Retrospective review of Vasodilation in the Management of Acute Congestive heart failure trial data for heart failure associated with prospect ively diagnosed acute coronary syndromes . Sixty-one patients were included ; 34 received nesiritide and 27 received NTG .  Pulmonary capillary wedge pressure was measured in right heart-catheterized patients ( 11 nesiritide , 9 NTG ) . Death at 6 months occurred in 2 nesiritide and 5 NTG patients ( P>.2 ) . Hypotension occurred in 4 nesiritide and 3 NTG patients ( P>.6 ) . At 24 hours , pulmonary capillary wedge pressure improvements persisted ( P=.001 ) in the nesiritide group , whereas the NTG group had returned to baseline ( P>.1 ) . In non-right heart-catheterized patients , 24-hour dyspnea scores were at least moderately improved in all nesiritide and 71 % of NTG ( P=.031 ) . At least minimal dyspnea improvement was seen in 100 % of nesiritide versus 71 % of NTG patients ( P>.3 ) , and 6-hour global clinical scores were at least moderately better in 75 % of nesiritide versus 32 % of NTG ( P=.031 ) . In non-right heart-catheterized patients , there were no 30-day readmissions with nesiritide versus 17 % with NTG ( P>.2 ) . CONCLUSIONS Nesiritide is as safe as NTG in heart failure patients with acute coronary syndromes BACKGROUND The leading cause of death in patients hospitalized for acute myocardial infa rct ion is cardiogenic shock . We conducted a r and omized trial to evaluate early revascularization in patients with cardiogenic shock . METHODS Patients with shock due to left ventricular failure complicating myocardial infa rct ion were r and omly assigned to emergency revascularization ( 152 patients ) or initial medical stabilization ( 150 patients ) .  Revascularization was accomplished by either coronary-artery bypass grafting or angioplasty . Intraaortic balloon counterpulsation was performed in 86 percent of the patients in both groups . The primary end point was mortality from all causes at 30 days . Six-month survival was a secondary end point . RESULTS The mean age of the patients was 66+/-10 years , 32 percent were women and 55 percent were transferred from other hospitals . The median time to the onset of shock was 5.6 hours after infa rct ion , and most infa rcts were anterior in location . Ninety-seven percent of the patients assigned to revascularization underwent early coronary angiography  , and 87 percent underwent  revascularization ;  only 2.7 percent of the patients assigned to medical therapy crossed over to early revascularization without clinical indication . Overall mortality at 30 days did not differ significantly between the revascularization and medical-therapy groups ( 46.7 percent and 56.0 percent , respectively ; difference , -9.3 percent ; 95 percent confidence interval for the difference , -20.5 to 1.9 percent ; P=0.11 ) . Six-month mortality was lower in the revascularization group than in the medical-therapy group ( 50.3 percent vs. 63.1 percent , P=0.027 ) . CONCLUSIONS In patients with cardiogenic shock , emergency revascularization did not significantly reduce overall mortality at 30 days . However , after six months there was a significant survival benefit . Early revascularization should be strongly considered for patients with acute myocardial infa rct ion complicated by cardiogenic shock OBJECTIVE To determine the feasibility , safety and efficacy of bilevel positive airway ventilation ( BiPAP ) in the treatment of severe pulmonary edema compared to high dose nitrate therapy . BACKGROUND Although noninvasive ventilation is increasingly used in the treatment of pulmonary edema , its efficacy has not been compared prospect ively with newer treatment modalities . METHODS We enrolled 40 consecutive patients with severe pulmonary edema ( oxygen saturation < 90 % on room air prior to treatment ) . All patients received oxygen at a rate of 10 liter/min , intravenous ( IV ) furosemide 80 mg and IV morphine 3 mg . Thereafter patients were r and omly allocated to receive 1 ) repeated boluses of IV isosorbide-dinitrate ( ISDN ) 4 mg every 4 min ( n = 20 ) , and 2 ) BiPAP ventilation and st and ard dose nitrate therapy ( n = 20 ) . Treatment was administered until oxygen saturation increased above 96 % or systolic blood pressure decreased to below 110 mm Hg or by more than 30 % . Patients whose conditions deteriorated despite therapy were intubated and mechanically ventilated . All treatment was delivered by mobile intensive care units prior to hospital arrival . RESULTS Patients treated by BiPAP had significantly more adverse events . Two BiPAP treated patients died versus zero in the high dose ISDN group . Sixteen BiPAP treated patients ( 80 % ) required intubation and mechanical ventilation compared to four ( 20 % ) in the high dose ISDN group ( p = 0.0004 ) . Myocardial infa rct ion ( MI ) occurred in 11 ( 55 % ) and 2 ( 10 % ) patients , respectively ( p = 0.006 ) . The combined primary end point ( death , mechanical ventilation or MI ) was observed in 17 ( 85 % ) versus 5 ( 25 % ) patients , respectively ( p = 0.0003 ) . After 1 h of treatment , oxygen saturation increased to 96 + /- 4 % in the high dose ISDN group as compared to 89 + /- 7 % in the BiPAP group ( p = 0.017 ) . Due to the significant deterioration observed in patients enrolled in the BiPAP arm , the study was prematurely terminated by the safety committee . CONCLUSIONS High dose ISDN is safer and better than BiPAP ventilation combined with conventional therapy in patients with severe pulmonary edema The immediate haemodynamic effects of intravenous frusemide ( 1 mg/kg ) and intravenous isosorbide dinitrate ( 50 - 200 micrograms/kg/h ) were compared in a prospect i ve , r and omised , between-group study in 28 men with radiographic and haemodynamic evidence of left ventricular failure following acute myocardial infa rct ion . The diuresis induced by frusemide reduced the left heart filling pressure and cardiac output and transiently raised systemic blood-pressure . In contrast , isosorbide dinitrate was accompanied by a reduction in systemic blood-pressure and peripheral resistance with the result that the cardiac output was not decreased despite a large fall in the pulmonary vascular and left heart filling pressures . These results indicate that reduction of excessive preload by venodilatation may be haemodynamically superior to that induced by diuresis in terms of both 
    Output:
    
There was no consistent evidence to support a difference in AHFS patients receiving intravenous nitrate vasodilator therapy or alternative interventions  with regard to the following secondary outcome measures : SBP change after 30 and 60 minutes , heart rate change after 90 minutes , and PAOP change after 90 minutes .
There appears to be no significant difference between nitrate vasodilator therapy and alternative interventions in the treatment of AHFS , with regard to symptom relief and haemodynamic variables .
Nitrates may be associated with a lower incidence of adverse effects after three hours compared with placebo .