Mode and timing of treatment failure (recurrent ischemic events) after hospital admission for non-ST segment elevation acute coronary syndromes

Relation between the GRACE score and severity of atherosclerosis in acute coronary syndrome

BACKGROUND

Patients with non-ST-elevation acute coronary syndrome are heterogeneous in terms of clinical presentation and immediate- and long-term risk of death or non-fatal ischemic events. The aim of the present study was to evaluate the relationship between the Global Registry of Acute Coronary Events (GRACE) score and severity of coronary artery disease angiographically evaluated by Gensini score in patients with non-ST-elevation acute coronary syndrome.

METHODS

A total of 245 patients with non-ST-elevation acute coronary syndrome were enrolled to the study. Based on the GRACE risk score classification system, the patients were divided into low- (n=97, 39.6%), intermediate- (n=84, 34.3%), and high- (n=64, 26.1%) risk groups. All patients underwent coronary angiography within five days after admission.

RESULTS

The Gensini scores were 26±29 in the low-risk group, 29±19 in the intermediate-risk group, and 38±23 in the high-risk group (p=0.016). The low-risk group was significantly different from the high-risk group (p=0.013), and the difference from the intermediate-risk group almost reached significance. Normal, noncritical, one and two, or multivessel disease were identified in 15 (6.1%), 31 (12.7%), 75 (30.6%), and 124 (50.6%) patients, respectively. The prevalence of multivessel disease was 28% in the low-risk group, 30% in the intermediate-risk group, and 42% in the high-risk group. The high-risk group was significantly different from the low-risk group (p<0.01).

CONCLUSION

Our study demonstrates that the GRACE score has significant value for assessing the severity and extent of coronary artery stenosis in patients with non-ST-elevation acute coronary syndrome.

Integrated SPECT/CT for assessment of haemodynamically significant coronary artery lesions in patients with acute coronary syndrome

PURPOSE

Early risk stratification in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) is important since the benefit from more aggressive and costly treatment strategies is proportional to the risk of adverse clinical events. In the present study we assessed whether hybrid single photon emission computed tomography (SPECT)/coronary computed tomography angiography (CCTA) technology could be an appropriate tool in stratifying patients with NSTE-ACS.

METHODS

SPECT/CCTA was performed in 90 consecutive patients with NSTE-ACS. The Thrombolysis in Myocardial Infarction risk score (TIMI-RS) was used to classify patients as low- or high-risk. Imaging was performed using SPECT/CCTA to identify haemodynamically significant lesions defined as >50% stenosis on CCTA with a reversible perfusion defect on SPECT in the corresponding territory.

RESULTS

CCTA demonstrated at least one lesion with >50% stenosis in 35 of 40 high-risk patients (87%) as compared to 14 of 50 low-risk patients (35%; TIMI-RS<3; p<.0001). Of the 40 high-risk and 50 (16%) low-risk TIMI-RS patients, 16 (40%) and 8 (16%), respectively, had haemodynamically significant lesions (p=0.01). Patients defined as high-risk by a high TIMI-RS, a positive CCTA scan or both (n=45) resulted in a sensitivity of 95%, specificity of 49%, PPV of 35% and NPV of 97% for having haemodynamically significant coronary lesions. Those with normal perfusion were spared revascularization procedures, regardless of their TIMI-RS.

CONCLUSION

Noninvasive assessment of coronary artery disease by SPECT/CCTA may play an important role in risk stratification of patients with NSTE-ACS by better identifying the subgroup requiring intervention.

Preprocedural statin therapy to prevent myocardial damage in percutaneous coronary intervention: a review of randomized trials

Multiple landmark clinical trials have demonstrated the beneficial effects of statin therapy for primary and secondary prevention of cardiovascular disease, but the exact timing of how early to treat relative to acute presentation has been less clear. The benefits of statin in cardiovascular disease can be explained not only by their lipid-lowering potential but also by non-lipid-related mechanisms, called pleiotropic effects. Percutaneous coronary intervention (PCI) can result in myocardial injury that is reflected by an increase in creatine kinase-MB and troponin I isoenzymes with worsened long-term prognosis following PCI. Observational studies suggested that pretreatment with statins might reduce the incidence of myocardial infarction after coronary intervention and prevent myocardial injury. Thus, several randomized controlled trials were conducted. They showed that pretreatment with statin before elective PCI reduces periprocedural myocardial injury in patients with stable angina. Moreover, short-term high-dose statin administration before coronary procedures also improves clinical outcome in patients with acute coronary syndromes and/or high preprocedural C-reactive protein levels. Thus, this evidence strongly supports routine utilization of high-dose statins as adjuvant pharmacological therapy before percutaneous coronary revascularization.

The impact of platelet function or C-reactive protein, on cardiovascular events after an acute myocardial infarction

Background

Recurrent cardiovascular events following acute myocardial infarction (AMI) are common. The purpose of this study was to evaluate the impact of platelet aggregation, PFA-100 closure times and peak C-reactive protein (CRP), respectively, on the occurrence of death, myocardial infarction and ischemic cerebral events after an AMI. Furthermore, to examine the relationship between the platelet function tests and peak CRP.

Methods

Three hundred and thirty-four patients with AMI were included in the study. Platelet aggregation was analyzed by an aggregometer using laser light (PA-200). The state of high residual platelet reactivity was defined as normal closure times (PFA-100) during treatment with aspirin.

Results

The fourth quartile of peak CRP was associated with poorer outcome as compared to the first quartile in a multivariate Cox-regression analysis, with a hazard ratio of 2.0 (95% CI 1.1–3.7) for the occurrence of death, myocardial infarction and ischemic cerebral events. The fourth quartile of peak CRP (>64.6 mg/l) was associated with platelet aggregation (p < 0.001, adjusted R² = 0.13) and high residual platelet reactivity, in a multivariate model, with an odds ratio of 2.9 (CI 95% 1.3–6.8), as compared to the first quartile. Neither the highest quartile of platelet aggregation nor the state of high residual platelet reactivity predicted new cardiovascular events.

Conclusion

In patients with myocardial infarction, measured peak CRP is associated with new cardiovascular events. Despite an association with peak CRP neither more pronounced platelet aggregation nor PFA-100 closure times independently predict new cardiovascular events.

Balancing myocardial ischemic and bleeding risks in patients with non-ST-segment elevation myocardial infarction

Achieving an appropriate balance of anti-ischemic efficacy versus bleeding risk with antiplatelet and anticoagulant agents demands an accurate estimation of risks. Although traditional risk stratification is available to decrease complications, and various methods of stratifying these risks have been proposed and validated, the stratification of bleeding risk is in its infancy. However, no model currently available permits the simultaneous estimation of these risks. Ischemic risk may be determined using 1 of several validated models, followed by the estimation of bleeding risk according to known risk factors. After selecting appropriate pharmacotherapy on the basis of the stratification of these risks, attention must be paid to proper dosing according to individual risk factors and patient, clinical, and technical variables. The aim of this study was to examine risk stratification models for these parameters to determine clinical characteristics common to ischemia and bleeding that can be used to minimize risks. A "bleeding risk subscale" is proposed, with factors extrapolated from current ischemic risk models, to integrate ischemic mortality and bleeding risk in patients with non-ST-segment elevation acute coronary syndromes. In conclusion, a validated tool to simultaneously evaluate ischemic and bleeding risk will help determine the most well-balanced pharmacotherapy for patients with non-ST-segment elevation acute coronary syndromes.

Importance of intensive lipid lowering in acute coronary syndrome and percutaneous coronary intervention

Lipid-lowering therapy with statins reduces the risk of cardiovascular events in patients with established coronary heart disease (CHD). Traditionally, statins were perceived to lower the long-term cardiovascular risk by reducing elevated low-density lipoprotein cholesterol (LCL-C). Recently, this benefit has been established for patients early after acute coronary syndrome (ACS). The benefit appears linked to reductions in both LDL-C and C-reactive protein (CRP) that is a marker of systemic inflammation. This paper will review the current state of evidence from key recent statin trials in ACS and percutaneous coronary intervention (PCI) and discuss their significance for clinical practice.

Prediction of risk of death and myocardial infarction in the six months after presentation with acute coronary syndrome: prospective multinational observational study (GRACE)

OBJECTIVE

To develop a clinical risk prediction tool for estimating the cumulative six month risk of death and death or myocardial infarction to facilitate triage and management of patients with acute coronary syndrome.

DESIGN

Prospective multinational observational study in which we used multivariable regression to develop a final predictive model, with prospective and external validation.

SETTING

Ninety four hospitals in 14 countries in Europe, North and South America, Australia, and New Zealand.

POPULATION

43,810 patients (21,688 in derivation set; 22,122 in validation set) presenting with acute coronary syndrome with or without ST segment elevation enrolled in the global registry of acute coronary events (GRACE) study between April 1999 and September 2005.

MAIN OUTCOME MEASURES

Death and myocardial infarction.

RESULTS

1989 patients died in hospital, 1466 died between discharge and six month follow-up, and 2793 sustained a new non-fatal myocardial infarction. Nine factors independently predicted death and the combined end point of death or myocardial infarction in the period from admission to six months after discharge: age, development (or history) of heart failure, peripheral vascular disease, systolic blood pressure, Killip class, initial serum creatinine concentration, elevated initial cardiac markers, cardiac arrest on admission, and ST segment deviation. The simplified model was robust, with prospectively validated C-statistics of 0.81 for predicting death and 0.73 for death or myocardial infarction from admission to six months after discharge. The external applicability of the model was validated in the dataset from GUSTO IIb (global use of strategies to open occluded coronary arteries).

CONCLUSIONS

This risk prediction tool uses readily identifiable variables to provide robust prediction of the cumulative six month risk of death or myocardial infarction. It is a rapid and widely applicable method for assessing cardiovascular risk to complement clinical assessment and can guide patient triage and management across the spectrum of patients with acute coronary syndrome.

Statins and the acute coronary syndrome: 'the early bird catches the worm'

The early period following an acute coronary syndrome (ACS) is characterised by atherosclerotic plaque destabilisation and a pro-coagulant state, and is when patients are at highest risk for recurrent cardiovascular events and mortality. Statins decrease thrombus formation and increase fibrinolysis, inhibit platelet reactivity and aggregation, improve endothelial function in patients with coronary artery disease and have a major role in plaque stabilisation. Several studies showed that initiation of early statin therapy in these settings may have beneficial effects. This review summarises the current data on statins in the setting of ACSs. Known and other possible mechanisms of action are described. The pathophysiological mechanisms, histological features and biochemical characteristics of ACS are different than those with stable coronary disease, thereby suggesting that the mechanisms whereby statins exert their benefits in ACS may be distinct from those for stable CHD. Initiation of the therapy during hospitalisation rather than at the time of hospital discharge may provide protection against early recurrent cardiovascular events and also improve patients' compliance.

TIMI, PURSUIT, and GRACE risk scores: sustained prognostic value and interaction with revascularization in NSTE-ACS

AIMS

Regarding prognosis, patients with a non-ST elevation acute coronary syndrome (ACS) are a very heterogeneous population, with varying risks of early and long-term adverse events. Early risk stratification at admission seems to be essential for a tailored therapeutic strategy. We sought to compare the prognostic value of three ACS risk scores (RSs) and their ability to predict benefit from myocardial revascularization performed during initial hospitalization.

METHODS AND RESULTS

We studied 460 consecutive patients admitted to our coronary care unit with an ACS [age: 63+/-11 years, 21.5% female, 55% with myocardial infarction (MI)]. For each patient, the Thrombolysis In Myocardial Infarction (TIMI), Platelet glycoprotein IIb/IIIa in Unstable agina: Receptor Suppression Using Integrilin (PURSUIT), and Global Registry of Acute Coronary Events (GRACE) RSs were calculated using specific variables collected at admission. Their prognostic value was evaluated by the combined endpoint of death or MI at 1 year. The best cut-off value for each RS, calculated with receiver operating characteristic curves, was used to assess the impact of myocardial revascularization on the combined incidence of death or MI. Death or MI at 1 year was 15.4% (32 deaths/49 MIs). The best predictive accuracy for death or MI at 1 year was obtained by the GRACE RS (AUC) [area under the curve: 0.715; confidence interval (CI: 0.672-0.756)] but the performance of the PURSUIT RS (AUC: 0.630; CI: 0.584-0.674), and TIMI RS (AUC: 0.585; CI: 0.539-0.631) was also good. We found a statistically significant interaction between the risk stratified by the best cut-off value for the GRACE and PURSUIT RSs and myocardial revascularization, with a better prognosis for the high-risk patients. The high-risk patients represented 36.7, 28.7, and 57.8% of the population, for the GRACE, PURSUIT, and TIMI RSs, respectively.

CONCLUSION

The RSs studied demonstrated a good predictive accuracy for death or MI at 1 year and enabled the identification of high-risk subsets of patients who will benefit most from myocardial revascularization performed during initial hospital stay.

Identification of patients at high risk for death and cardiac ischemic events after hospital discharge

BACKGROUND

Patients with unstable angina (UA) and non-ST-elevation myocardial infarction (NSTEMI) remain at risk for death and cardiac ischemic events after being discharged from the hospital.

METHODS

We examined whether the Thrombolysis In Myocardial Infarction (TIMI) risk score for UA/NSTEMI, ascertained at presentation in patients enrolled in the TIMI 11B and Efficacy and Safety of Subcutaneous Enoxaparin in Unstable Angina and Non-Q-Wave MI (ESSENCE) trials, could be used to identify patients at high risk for major cardiac events after hospital discharge.

RESULTS

There were a total of 1218 major cardiac events, defined as death, nonfatal myocardial infarction, or urgent revascularization, by day 43. Of these events, 336 (28%) occurred in patients after they were discharged from the hospital. Use of the TIMI risk score for UA/NSTEMI revealed a progressive, statistically significant increase in the rate of events after leaving the hospital as the patients' baseline level of risk increased (P <.001 for chi(2) test for trend). For patients with a risk score of 5 to 7, treatment with enoxaparin during the acute phase was associated with an odds ratio of 0.51 (95% CI 0.29-0.91) for the occurrence of death and cardiac ischemic events after hospital discharge.

CONCLUSIONS

More than one fourth of the major cardiac events that will occur in the first 6 weeks occur after discharge from the hospital. Stratification at presentation on the basis of the TIMI risk score for UA/NSTEMI can be used to identify patients at high risk for these events. Among patients at high-risk, acute-phase treatment with enoxaparin significantly reduces the risk of major cardiac events after leaving the hospital.