How should patients with unstable angina and non-ST-segment elevation myocardial infarction be managed? A meta-analysis of randomized trials

Do patients with non-ST-elevation myocardial infarction without chest pain suffer a poor prognosis?

OBJECTIVE

Previous studies have discussed acute myocardial infarction (AMI) patients without chest pain, but have not focused on non-ST-elevation myocardial infarction (NSTEMI).

MATERIALS AND METHODS

This 1-year study investigated whether chest pain presence relates to demographics, risk factors, and outcomes in NSTEMI patients. We retrospectively reviewed 194 patients, 73 without chest pain vs. 121 with chest pain, and compared the differences between clinical presentations, risk factors, medical management, and outcomes of these two groups.

RESULTS

Compared to patients with chest pain, patients without chest pain were significantly older, had lower SBP, higher HR, more cerebrovascular disease, less ischemic heart disease, higher delay to ED (emergency department) visit, lower ED medication prescriptions, lower percutaneous cardiac intervention, and higher in-hospital and one-year mortality rate. In a multivariate logistic regression, the adjusted odds ratios (OR) of patients without chest pain were 4.38 for the elderly, 0.99 for every 1 mmHg increase in SBP, 1.02 for every beat/min HR increase, 0.37 for those with ischemic heart disease, and 5.09 for those with cerebrovascular disease. The adjusted OR of in-hospital mortality were 3.09 for patients without chest pain, 0.32 for those with hypertension, 0.32 for smokers, 3.98 for those with shock, and 0.16 for those with percutaneous cardiac intervention. Finally, the only significantly adjusted OR of one-year mortality was 5.37 for patients without chest pain.

CONCLUSION

NSTEMI patients without chest pain were significantly older, had lower SBP, more tachycardia, more cerebrovascular disease, but less ischemic heart disease. They also experienced higher in-hospital and one-year mortality rates.

Revascularization Strategies in Patients with Chronic Kidney Disease and Acute Coronary Syndromes

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is a highly prevalent condition that increases the incidence and complexity of acute coronary syndrome (ACS). The purpose of this review is to summarize current evidence, uncertainties, and opportunities in the management of patients with CKD and ACS, with a focus on revascularization.

RECENT FINDINGS

Patients with CKD have been systematically under-represented or excluded from clinical trials in ACS. Available data, however, demonstrates that although patients with CKD and ACS benefit from revascularization, they are also less likely to receive recommended medical and revascularization therapies when compared to patients with normal kidney function. Despite the increased short-term risk of major morbidity and mortality, patients with CKD and ACS should be considered for an early invasive strategy while also trying to mitigate the risks of procedural related complications. Until evidence emerges from randomized clinical trials, the decision about revascularization strategy should involve multi-disciplinary collaboration, heart team consensus, and patient shared decision-making.

Do elderly females have a higher risk of acute myocardial infarction? A retrospective analysis of 329 cases at an emergency department

OBJECTIVE

Acute myocardial infarction (AMI) is a medical emergency; a missed or delayed diagnosis of this disease may contribute to a poor outcome and even death. Several studies have found elderly patients with AMI have atypical presentations for diagnosis, therefore we undertook this study to determine the risks among the elderly population, especially in female patients.

MATERIALS AND METHODS

In this one-year retrospective study, we reviewed the cases of AMI patients who had visited the emergency department at Mackay Memorial Hospital, Taiwan, and who had either been discharged or had died following a diagnosis of AMI (ICD code 410). We compared the differences between the clinical presentations of these two groups as well as the risk factors, medical management, and outcomes.

RESULTS

In our study, only 329 patients (164 elderly; 165 adults) met the defined criteria. The most common symptom of AMI was chest pain, and this was more common in adult patients than in elderly patients (81.8% vs. 60.4%, p < 0.001). In comparison with patients in the adult group, the patients in the elderly group had a significantly higher proportion of females (46.3% vs. 12.7%), non-ST-elevation myocardial infarction (NSTEMI) (71.3% vs. 46.7%), presenting with no chest pain (39.6% vs. 18.2%), shortness of breath (17.7% vs. 8.8%), nausea/vomiting/dizziness (7.9% vs. 2.4%), abdominal pain (4.3% vs. 0.6%), diabetes mellitus (45.1% vs. 26.1%), cerebrovascular disease (22.6% vs. 6.1%), longer hospital stays (18.2 ± 31.0 days vs. 9.8 ± 8.2 days), and increased in-hospital mortality rates (15.9% vs. 6.7%).

CONCLUSION

Compared with the adult AMI group, the elderly AMI group had a higher proportion of females, electrocardiography with NSTEMI and no chest-pain complaints, and a larger proportion of elderly patients with diabetes, ischemic heart disease, heart attacks at home and cardiac shock, which had longer hospital stays, and higher mortality rates.

Early Invasive Strategy for Unstable Angina: a New Meta-Analysis of Old Clinical Trials

Randomized controlled trials (RCTs) were conflicting to support whether unstable angina versus non-ST-elevation myocardial infarction (UA/NSTEMI) patients best undergo early invasive or a conservative revascularization strategy. RCTs with cardiac biomarkers, in MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials from 1975-2013 were reviewed considering all cause mortality, recurrent non-fatal myocardial infarction (MI) and their combination. Follow-up lasted from 6-24 months and the use of routine invasive strategy up to its end was associated with a significantly lower composite of all-cause mortality and recurrent non-fatal MI (Relative Risk [RR] 0.79; 95% confidence interval [CI], 0.70-0.90) in UA/NSTEMI. In NSTEMI, by the invasive strategy, there was no benefit (RR 1.19; 95% CI, 1.03-1.38). In the shorter time period, from randomization to discharge, a routine invasive strategy was associated with significantly higher odds of the combined end-point among UA/NSTEMI (RR 1.29; 95% CI, 1.05-1.58) and NSTEMI (RR 1.82; 95% CI, 1.34-2.48) patients. Therefore, in trials recruiting a large number of UA patients, by routine invasive strategy the largest benefit was seen, whereas in NSTEMI patients death and non-fatal MI were not lowered. Routine invasive treatment in UA patients is accordingly supported by the present study.

Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

People with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) are managed with a combination of medical therapy, invasive angiography and revascularisation. Specifically, two approaches have evolved: either a 'routine invasive' strategy whereby all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularisation; or a 'selective invasive' (also referred to as 'conservative') strategy in which medical therapy alone is used initially, with a selection of patients for angiography based upon evidence of persistent myocardial ischaemia. Uncertainty exists as to which strategy provides the best outcomes for these patients. This Cochrane review is an update of a Cochrane review originally published in 2006, to provide a robust comparison of these two strategies in the early management of patients with UA/NSTEMI.

OBJECTIVES

To determine the benefits and harms associated with the following.1. A routine invasive versus a conservative or 'selective invasive' strategy for the management of UA/NSTEMI in the stent era.2. A routine invasive strategy with and without glycoprotein IIb/IIIa receptor antagonists versus a conservative strategy for the management of UA/NSTEMI in the stent era.

SEARCH METHODS

We searched the following databases and additional resources up to 25 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE and EMBASE, with no language restrictions.

SELECTION CRITERIA

We included prospective randomised controlled trials (RCTs) that compared invasive with conservative or 'selective invasive' strategies in participants with acute UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

Two review authors screened the records and extracted data in duplicate. Using intention-to-treat analysis with random-effects models, we calculated summary estimates of the risk ratio (RR) with 95% confidence intervals (CIs) for the primary endpoints of all-cause death, fatal and non-fatal myocardial infarction (MI), combined all-cause death or non-fatal MI, refractory angina and re-hospitalisation. We performed further analysis of included studies based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. We assessed the heterogeneity of included trials using Pearson χ² (Chi² test) and variance (I² statistic) analysis. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 (Review Manager) to create Summary of findings (SoF) tables.

MAIN RESULTS

Eight RCTs with a total of 8915 participants (4545 invasive strategies, 4370 conservative strategies) were eligible for inclusion. We included three new studies and 1099 additional participants in this review update. In the all-study analysis, evidence did not show appreciable risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; eight studies, 8915 participants; low quality evidence) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; seven studies, 7715 participants; low quality evidence) with invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. There was appreciable risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; eight studies, 8915 participants; moderate quality evidence), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; five studies, 8287 participants; moderate quality evidence) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; six studies, 6921 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies also at six to 12 months follow-up.Evidence also showed increased risks in bleeding (RR 1.73, 95% CI 1.30 to 2.31; six studies, 7584 participants; moderate quality evidence) and procedure-related MI (RR 1.87, 95% CI 1.47 to 2.37; five studies, 6380 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies.The low quality evidence were as a result of serious risk of bias and imprecision in the estimate of effect while moderate quality evidence was only due to serious risk of bias.

AUTHORS' CONCLUSIONS

In the all-study analysis, the evidence failed to show appreciable benefit with routine invasive strategies for unstable angina and non-ST elevation MI compared to conservative strategies in all-cause mortality and death or non-fatal MI at six to 12 months. There was evidence of risk reduction in MI, refractory angina and re-hospitalisation with routine invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. However, routine invasive strategies were associated with a relatively high risk (almost double the risk) of procedure-related MI, and increased risk of bleeding complications. This systematic analysis of published RCTs supports the conclusion that, in patients with UA/NSTEMI, a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons

BACKGROUND

It is often assumed that differences in the efficacy of treatments between countries (or regions) will be neither negligible nor minor and therefore cannot be overlooked when assessing the potential benefit of treatments in one country (or region) on the basis of trials conducted in another country (or region).

AIM

To assess differences in the results of cardiovascular trials between Europe and North America on the basis of data from an extensive collection of trials.

METHODS

A systematic search was conducted of Medline (from the year 2005 to 2008) and the Cochrane Library (from 2000 to 2008) for all meta-analyses of randomized controlled trials aimed at treating and preventing cardiovascular disease. Within each meta-analysis that satisfied given criteria, trial results were compared between Europe and North America with respect to a fatal and/or non-fatal endpoint by forming separate estimates of treatment efficacy for each of these continents.

RESULTS

The literature search found 59 meta-analyses that satisfied all the inclusion criteria. For most meta-analyses, it was the case that relative to the control, the intervention was more favoured in trials conducted in Europe than in North America with regard to both fatal endpoints (28 out of 43 meta-analyses) and non-fatal endpoints (28 out of 40 meta-analyses). However, it was only with regard to non-fatal endpoints that this imbalance turned out to be statistically significant at the 5% level (P=0.017). Also, the lack of statistically significant differences in trial results between Europe and North America within individual meta-analyses meant that it was not possible to determine for which types of intervention these intercontinental differences are likely to be more pronounced than others.

CONCLUSION

There is some evidence to support the theory that, relative to controls, interventions are more favoured in cardiovascular trials conducted in Europe than in North America, when treatment efficacy is measured in terms of a non-fatal endpoint. However, the overall support for systematic differences in cardiovascular trial results between Europe and North America is weak, which may be surprising given the amount of data collected.

Outcomes in patients with non-ST-elevation acute coronary syndrome randomly assigned to invasive versus conservative treatment strategies: a meta-analysis

OBJECTIVE

The goal of the present study was to compare the prognoses of patients with non-ST-elevation acute coronary syndromes who were treated with invasive or conservative treatment strategies.

METHODS

We performed a meta-analysis of studies of patients with non-ST-elevation acute coronary syndromes to assess the benefits of an invasive strategy vs. a conservative strategy for short- and long-term survival. We searched PubMed for studies published from 1990 to November 2012 that investigated the effects of an invasive vs. conservative strategy in patients with non-ST-elevation acute coronary syndromes. The following search terms were used: "non-ST-elevation myocardial infarction", "unstable angina", "acute coronary syndromes", "invasive strategy", and "conservative strategy". The primary endpoints were all-cause mortality at 30 days and 1 year.

RESULTS

Seven published studies were included in the present meta-analysis. The pooled analyses show that an invasive strategy decreased the risk of death (risk ratio [0.839] [95% confidence interval {0.648-1.086}; I 2, 86.46%] compared to a conservative strategy over a 30-day-period. Furthermore, invasive treatment also decreased patient mortality (risk ratio [0.276] [95% confidence interval {0.259-0.294}; I 2, 94.58%]) compared to a conservative strategy for one year.

CONCLUSION

In non-ST-elevation acute coronary syndromes, an invasive strategy is comparable to a conservative strategy for decreasing short- and long-term mortality rates.

Comparison of outcomes in ST-segment depression and ST-segment elevation myocardial infarction patients treated with emergency PCI: data from a multicentre registry

Background

Traditionally, acute myocardial infarction (AMI) has been described as either STEMI (ST-elevation myocardial infarction) or non-STEMI myocardial infarction. This classification is historically related to the use of thrombolytic therapy, which is effective in STEMI. The current era of widespread use of coronary angiography (CAG), usually followed by primary percutaneous coronary intervention (PCI) puts this classification system into question.

Objectives

To compare the outcomes of patients with STEMI and ST-depression myocardial infarction (STDMI) who were treated with emergency PCI.

Methods

This multicentre registry enrolled a total of 6 602 consecutive patients with AMI. Patients were divided into the following subgroups: STEMI (n = 3446), STDMI (n = 907), left bundle branch block (LBBB) AMI (n = 241), right bundle branch block (RBBB) AMI (n = 338) and other electrocardiographic (ECG) AMI (n = 1670). Baseline and angiographic characteristics were studied, and revascularisation therapies and in-hospital mortality were analysed.

Results

Acute heart failure was present in 29.5% of the STDMI vs 27.4% of the STEMI patients (p < 0.001). STDMI patients had more extensive coronary atherosclerosis than patients with STEMI (three-vessel disease: 53.1 vs 30%, p < 0.001). The left main coronary artery was an infract-related artery (IRA) in 6.0% of STDMI vs 1.1% of STEMI patients (p < 0.001). TIMI flow 0–1 was found in 35.0% of STDMI vs 66.0% of STEMI patients (p < 0.001). Primary PCI was performed in 88.1% of STEMI (with a success rate of 90.8%) vs 61.8% of STDMI patients (with a success rate of 94.5%) (p = 0.012 for PCI success rates). In-hospital mortality was not significantly different (STDMI 6.3 vs STEMI 5.4%, p = 0.330).

Conclusion

These data suggest that similar strategies (emergency CAG with PCI whenever feasible) should be applied to both these types of AMI.

Early invasive versus conservative strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) two strategies are possible, either a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially, with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE and EMBASE were searched (1996 to February 2008) with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified five studies (7818 participants). Using intention-to-treat analysis with random-effects models, summary estimates of relative risk (RR) with 95% confidence interval (CI) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction, all-cause death or non-fatal myocardial infarction, and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using Chi(2) and variance (I(2) statistic) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy (RR 1.59, 95% CI 0.96 to 2.64). The invasive strategy did not reduce death on longer-term follow up. Myocardial infarction rates assessed at 6 to 12 months (5 trials) and 3 to 5 years (3 trials) were significantly decreased by an invasive strategy (RR 0.73, 95% CI 0.62 to 0.86; and RR 0.78, 95% CI 0.67 to 0.92 respectively). The incidence of early (< 4 month) and intermediate (6 to 12 month) refractory angina were both significantly decreased by an invasive strategy (RR 0.47, 95% CI 0.32 to 0.68; and RR 0.67, 95% CI 0.55 to 0.83 respectively), as were early and intermediate rehospitalization rates (RR 0.60, 95% CI 0.41to 0.88; and RR 0.67, 95% CI 0.61 to 0.74 respectively). The invasive strategy was associated with a two-fold increase in the RR of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the RR of (minor) bleeding with no hazard of stroke.

AUTHORS' CONCLUSIONS

Compared to a conservative strategy for UA/NSTEMI, an invasive strategy is associated with reduced rates of refractory angina and rehospitalization in the shorter term and myocardial infarction in the longer term. However, the invasive strategy is associated with a doubled risk of procedure-related heart attack and increased risk of bleeding and procedural biomarker leaks. Available data suggest that an invasive strategy may be particularly useful in those at high risk for recurrent events.

Receiving hospital characteristics associated with survival after out-of-hospital cardiac arrest

AIM

Survival after out-of-hospital cardiac arrest (OOHCA) varies between regions, but the contribution of different factors to this variability is unknown. This study examined whether survival to hospital discharge was related to receiving hospital characteristics, including bed number, capability of performing cardiac catheterization and hospital volume of OOHCA cases.

MATERIAL AND METHODS

Prospective observational database of non-traumatic OOHCA assessed by emergency medical services was created in 8 US and 2 Canadian sites from December 1, 2005 to July 1, 2007. Subjects received hospital care after OOHCA, defined as either (1) arriving at hospital with pulses, or (2) arriving at hospital without pulses, but discharged or died > or =1 day later.

RESULTS

A total of 4087 OOHCA subjects were treated at 254 hospitals, and 32% survived to hospital discharge. A majority of subjects (68%) were treated at 116 (46%) hospitals capable of cardiac catheterization. Unadjusted survival to discharge was greater in hospitals performing cardiac catheterization (34% vs. 27%, p=0.001), and in hospitals that received > or =40 patients/year compared to those that received <40 (37% vs. 30%, p=0.01). Survival was not associated with hospital bed number, teaching status or trauma center designation. Length of stay (LOS) for surviving subjects was shorter at hospitals performing cardiac catheterization (p<0.01). After adjusting for all variables, there were no independent associations between survival or LOS and hospital characteristics.

CONCLUSIONS

Some subsets of hospitals displayed higher survival and shorter LOS for OOHCA subjects but there was no independent association between hospital characteristics and outcome.

[Invasive revascularization strategy in non-ST-segment acute coronary syndromes. The debate continues]

Revascularization strategy in the setting of non-ST-segment acute coronary syndromes remains a controversy. Evidence obtained from clinical trials, generally performed in selected patients, reveals heterogeneous and insufficient results when a routine invasive revascularization strategy and a conservative one are compared. The conflicting results among trials are due to differences in: a) baseline characteristics; b) methodology and protocols applied and; c) objectives and outcomes definitions. Although present guidelines recommend that a routine invasive strategy should be used in high risk non-ST-segment elevation acute coronary syndromes, there is no consistent evidence that supports this approach. In order to reach definitive conclusions, further randomized studies should: a) expand inclusion criteria to highest risk populations and; b) standardize the methodology, objectives and outcome definitions.

Early angiography in patients with chronic kidney disease: a collaborative systematic review

BACKGROUND AND OBJECTIVES

In the general population, an early invasive strategy of routine coronary angiography is superior to a conservative strategy of selective angiography in patients who are admitted with unstable angina or non-ST segment elevation myocardial infarction (MI), but the effectiveness of this strategy in individuals with chronic kidney disease (CKD) is uncertain.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a collaborative meta-analysis with data provided by the main authors of identified trials to estimate the effectiveness of early angiography in patients with CKD. The Cochrane, Medline, and EMBASE databases were searched to identify randomized trials that compared invasive and conservative strategies in patients with unstable angina or non-ST MI. Pooled risks ratios were estimated using data from enrolled patients with estimated GFR <60 ml/min per 1.73 m(2).

RESULTS

Five randomized trials that enrolled 1453 patients with CKD were included. An early invasive strategy was associated with nonsignificant reductions in all-cause mortality, nonfatal MI, and a composite of death or nonfatal MI. The invasive strategy significantly reduced rehospitalization.

CONCLUSIONS

This collaborative study suggests that the benefits of an early invasive strategy are preserved in patients with CKD and that an early invasive approach reduces the risk for rehospitalization and is associated with trends of reduction in the risk for death and nonfatal re-infarction in patients with CKD. Coronary angiography should be considered for patients who have CKD and are admitted with non-ST elevation acute coronary syndromes.

Using triple antiplatelet therapy in patients with non-ST elevation acute coronary syndrome managed invasively: a cost-effectiveness analysis

OBJECTIVES

To assess the incremental cost-effectiveness ratio (ICER) of glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) pretreated with aspirin and clopidogrel undergoing an early invasive treatment strategy.

METHODS

Cost-effectiveness analysis and cost-utility analysis were performed from a health-care system perspective, based on a Markov model with a time horizon of the patient life span. The risk of death and ischemic events was assessed using the Thrombolysis in Myocardial Infarction (TIMI) risk score. We compared three strategies: 1) routine upstream use of a GPIIb/IIIa inhibitor to all patients before angiography, 2) deferred selective use of abciximab in the catheterization laboratory just before angioplasty, and 3) double antiplatelet therapy without GPIIb/IIIa inhibitors. Both univariate sensitivity analysis and second-order probabilistic microsimulation were performed.

RESULTS

In the base case (65 years old, TIMI score 3), strategy A was the most effective, with an ICER of 15,150 euros per quality-adjusted life-year gained. Strategy B was dominated by a combination of strategies A and C. The ICER was very sensitive to the age and baseline risk of the patient. According to the widely accepted cost-effectiveness thresholds, strategy A would be cost-effective only in patients with an intermediate to high TIMI score, especially within the younger age groups. The probability that strategy A was cost-effective under the base case was 91.2%.

CONCLUSIONS

The use of GPIIb/IIIa inhibitors upstream in high-risk NSTE-ACS patients (TIMI score > or = 3) pretreated with aspirin and clopidogrel is cost-effective, particularly in the younger age groups.

Management of acute coronary syndrome

This is a review of acute coronary syndrome as a clinical entity. An appreciation of acute coronary syndrome as a disease spectrum is presented along with contemporary evidence for its diagnosis and approach to medical and surgical management.

TIMI Risk Score predicts early readmission

AIM

To assess if the TIMI Risk Score could predict early readmission.

PARTICIPANTS

869 consecutive admissions to a Scottish district general hospital with suspected acute coronary syndrome.

METHODS

A computerised clinical information system was interrogated to verify readmission. Area under the receiver operator characteristic curve and chi-square test for trend between TIMI Risk Score and readmission rate were calculated.

RESULTS

Median follow up was 73 days. There was a strong association between TIMI Risk Score and readmission rate (chi-square test for trend, p<0.001), with an area under the receiver operator characteristic curve of 0.60 (95% C.I. 0.55-0.65).

CONCLUSION

The TIMI Risk Score can predict readmission. This study reinforces its utility as a tool for identifying patients more likely to benefit from aggressive intervention.

Early invasive versus conservative strategies for unstable angina & non-ST-elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST-elevation myocardial infarction (UA/NSTEMI) two strategies are possible: a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to a conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (Issue 3 2005), MEDLINE and EMBASE were searched from 1996 to September 2005 with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified 5 studies (7818 participants). Using intention-to-treat analysis with random effects models, summary estimates of relative risk (95% confidence interval [CI]) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction; all-cause death or non-fatal myocardial infarction; and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using chi-square and variance (I(2)) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy; relative risk 1.59 (95% CI 0.96 to 2.64). Mortality and myocardial infarction assessed at 2-5 years in two trials were significantly decreased by an invasive strategy with relative risk of 0.75 (95% CI 0.62 to 0.92) and 0.75 (95% CI 0.61 to 0.91) respectively. The composite end-point of death or non-fatal myocardial infarction was significantly decreased by an invasive strategy at several time points after initial hospitalization. The incidence of early (<4 months) and intermediate (6-12 months) refractory angina were both significantly decreased by an invasive strategy; relative risk 0.47 (95% CI 0.32 to 0.68) and 0.67 (95% CI 0.55 to 0.83) respectively, as were early and intermediate rehospitalization rates with relative risk 0.60 (95% CI 0.41 to 0.88) and 0.67 (95% CI 0.61 to 0.74) respectively. The invasive strategy was associated with a two-fold increase in the relative risk of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the relative risk of bleeding.

AUTHORS' CONCLUSIONS

An early invasive strategy is preferable to a conservative strategy in the treatment of UA/NSTEMI.

Non ST segment elevation acute coronary syndromes: A simplified risk-orientated algorithm

Non-ST segment elevation acute coronary syndromes (NSTE ACS) include a clinical spectrum that ranges from unstable angina to NSTE myocardial infarction. Management goals aim to prevent recurrent ACS and improve long-term outcomes by choosing a treatment strategy according to an estimate of the risk of an adverse outcome. Recent registry data suggest that patients with NSTE ACS frequently do not receive recommended treatment, and that risk stratification is not used to determine either the choice of treatment or the speed of access to coronary angiography. The present article evaluates the evidence for recommended treatment using information from recent trials and guidelines published by the major cardiac organizations in Europe and North America. Using this information, a multidisciplinary group developed a simplified algorithm that uses risk stratification to select an optimal early management strategy. Long-term outcomes are improved by a multi-faceted vascular protection strategy that is initiated at the time of hospitalization for NSTE ACS.

Treating non-ST-segment elevation ACS. Pros and cons of current strategies

NSTE-ACS is a complex clinical event characterized by a variable degree of myocardial ischemia and triggered, in most patients, by a rupture of a vulnerable plaque that leads to acute intraluminal nonocclusive thrombosis. Traditionally, acute management strategies for NSTE-ACS have been aimed at identification of vascular areas with discrete atheroma and revascularization of the affected myocardium. Studies that have evaluated invasive strategies in NSTE-ACS suggest that the rates of hard clinical events are similar for both intensive medical treatment and early invasive management strategies. As shown recently in the Cooperative Cardiovascular Project study, intensive therapy with beta-blockers appears to be a viable management option that has comparable outcomes in most patients with NSTE-ACS. Although several different treatment strategies have been advocated in the management of NSTE-ACS, the available evidence-based information does not fully support some of these traditional approaches. Future prospective, well-controlled trials are needed to fully ascertain the role of invasive and other medical management strategies in patients with NSTE-ACS. Long-term aggressive management of established risk factors for CAD is unquestionably the most prudent and cost-effective therapeutic approach in the long-term management in patients recovering from NSTE-ACS.