Prognostic value of clinical variables at presentation in patients with non-ST-segment elevation acute coronary syndromes: results of the Proyecto de Estudio del Pronóstico de la Angina (PEPA)

Quality Markers in Cardiology. Main Markers to Measure Quality of Results (Outcomes) and Quality Measures Related to Better Results in Clinical Practice (Performance Metrics). INCARDIO (Indicadores de Calidad en Unidades Asistenciales del Área del Corazón): A SEC/SECTCV Consensus Position Paper

Cardiology practice requires complex organization that impacts overall outcomes and may differ substantially among hospitals and communities. The aim of this consensus document is to define quality markers in cardiology, including markers to measure the quality of results (outcomes metrics) and quality measures related to better results in clinical practice (performance metrics). The document is mainly intended for the Spanish health care system and may serve as a basis for similar documents in other countries.

Likelihood of acute coronary syndrome in emergency department chest pain patients varies with time of presentation

BACKGROUND

There is a circadian and circaseptal (weekly) variation in the onset of acute coronary syndrome (ACS). The aim of this study was to elucidate whether the likelihood of ACS among emergency department (ED) chest pain patients varies with the time of presentation.

METHODS

All patients presenting to the Lund ED at Skåne University Hospital with chest pain or discomfort during 2006 and 2007 were retrospectively included. Age, sex, arrival time at the ED and discharge diagnose (ACS or not) were obtained from the electronic medical records.

RESULTS

There was a clear but moderate circadian variation in the likelihood of ACS among presenting chest pain patients, the likelihood between 8 and 10 am being almost twice as high as between 6 and 8 pm. This was mainly explained by a variation in the ACS likelihood in females and patients under 65 years, with no significant variation in males and patients over 65 years. There was no significant circaseptal variation in the ACS likelihood.

CONCLUSIONS

Our results indicate that there is a circadian variation in the likelihood of ACS among ED chest pain patients, and suggest that physicians should consider the time of presentation to the ED when determining the likelihood of ACS.

Prognosis and management of patients with acute coronary syndrome and polyvascular disease

INTRODUCTION AND OBJECTIVES

To assess prognosis and patterns of care in patients with acute coronary syndrome and peripheral arterial disease (PAD), cerebrovascular disease or both (i.e., polyvascular disease) in everyday clinical practice.

METHODS

We used data from the MASCARA acute coronary syndrome registry for 2004 and 2005. Patients were stratified according to the presence of PAD, cerebrovascular disease, neither, or both. In-hospital management, treatment at discharge and outcomes at 6 months were recorded.

RESULTS

Of 6745 patients, 597 (8.85%) had PAD, 392 (5.8%) had cerebrovascular disease, 131 (1.94%) had both and 5625 (83.4%) had neither. Patients with polyvascular disease had more extensive coronary disease, but less often received regularly recommended treatment (e.g., 75% with PAD received aspirin at discharge versus 84% of those without). In-hospital and 6-month mortality were significantly higher (P< .001) in patients with PAD (9.1% and 24.5%, respectively) or cerebrovascular disease (9.2% and 22.4%, respectively) or, especially, both (16.0% and 29.8%, respectively) than in those free from these conditions (4.8% and 10.8%, respectively). Cerebrovascular disease, PAD and their combination were all independently associated with in-hospital and 6-month mortality: for cerebrovascular disease, the odds ratio (OR) for mortality at 6 months was 1.45 (95% confidence interval [CI], 1.10-2.02); for PAD, it was 1.88 (95% CI, 1.45-2.40); and for both combined, 1.88 (95% CI, 1.17-3.00).

CONCLUSIONS

Patients with acute coronary syndrome and concomitant arterial disease had more extensive coronary artery disease and poorer outcomes, both inhospital and at 6 months, but frequently did not receive regularly recommended treatment.

Impact of metabolic syndrome on future cardiovascular events in patients with first acute myocardial infarction

The prevalence of metabolic syndrome (MetS) is increasing worldwide and patients with MetS have increased risk of cardiovascular events. Recent studies in different populations showed higher prevalences of MetS in patients with acute myocardial infarction (MI) and identified MetS as an independent predictor of future cardiac events. This study sought to determine the prevalence of MetS in patients with acute MI and investigate the impact of MetS on adverse cardiovascular events after acute MI. One hundred and eighty-eight patients (155 men, 33 women) admitted with first acute MI were enrolled into the study. Of the total patients, 80 (42.6%) patients were diagnosed with MetS according to the National Cholesterol Education Program Adult Treatment Panel III criteria with modifications for high blood pressure and high fasting plasma glucose. Kaplan-Meier curves showed that the cumulative event-free survival rates did not differ between the patients with and without MetS during a median follow-up period of 27.7 (min:14, max:42) months (P>0.05). On multivariate Cox regression analysis controlling for hypertension, diabetes mellitus, glucose, MetS, and waist-to-hip ratio, there was no association between the major adverse coronary events and the presence of MetS (P>0.05), whereas Killip class (relative risk: 2.853, 95% confidence interval: 1.606-5.070; P<0.001) was identified as the only independent predictor of long-term cardiovascular outcomes. This study shows that MetS has no effect on long-term prognosis after MI. However, Killip class was identified as an independent predictor of major cardiac events.

Limitations of clinical history for evaluation of patients with acute chest pain, non-diagnostic electrocardiogram, and normal troponin

Decision making and risk stratification for patients with acute chest pain, nondiagnostic electrocardiogram results, and normal troponin levels are challenging. The aim of this study was to optimize the clinical history for the evaluation of these patients. A total of 1,011 patients presenting to an emergency department were included. The following data were collected: clinical presentation (pain characteristics and number of pain episodes), coronary risk factors, previous ischemic heart disease, and extracardiac vascular disease (peripheral artery disease, stroke, or creatinine >1.4 mg/dl). Two different predictive models were calculated according to the end points: model 1 for 1-year major events (death or myocardial infarction) and model 2 for 30-day cardiac events (major events or revascularization). For 1-year major events, model 1 showed optimal discrimination capacity (C statistic = 0.80), which was significantly better than that of model 2 (C statistic = 0.77, p = 0.04). With respect to 30-day cardiac events, however, discrimination was lower in the 2 models, without differences between them (C statistic = 0.74 vs 0.75, p = NS). Using model 1, a large low-risk subgroup with <3 predictive variables could be defined, including 442 patients (44% of the total population) with a 1.4% rate of 1-year major events; however, the incidence of 30-day cardiac events (8%) was not negligible, mainly because of revascularizations. In conclusion, in patients with acute chest pain of uncertain coronary origin, clinical predictive models afford good risk stratification for long-term major events. Short-term outcomes, including revascularization, however, are not predicted as well. Therefore, ancillary tools, such as noninvasive stress tests, should be implemented for decision making at initial hospitalization or discharge.

A practical approach with outcome for the prognostic assessment of non-ST-segment elevation chest pain and normal troponin

Patients with non-ST-elevation chest pain constitute a heterogeneous population. Our aim is to compare the outcome of patients with chest pain, non-ST-segment deviation, and normal troponin, categorized using a risk score, with that of patients with ST depression or troponin increase. A total of 1,449 patients with non-ST-elevation chest pain were evaluated. A validated risk score (using pain characteristics and risk factors) was applied to patients without ST depression or troponin increase. Accordingly, 4 risk categories were defined: group 1, no troponin increase, no ST depression, and risk score <3 points (n = 633); group 2, no troponin increase, no ST depression, but risk score > or = 3 points (n = 158); group 3, no troponin increase, ST depression (n = 106); and group 4, troponin increase (n = 552). Median follow-up was 26 months, and the end point was death or myocardial infarction. Group 1 experienced fewer events at 30 days (1.7%, p = 0.0001) and long-term follow-up (9.4%, p = 0.0001) than groups 2 (10.8% and 26%), 3 (6.6% and 30%), and 4 (9.5% and 25%). Kaplan-Meier curves overlapped among groups 2, 3, and 4, whereas group 1 showed a flatter curve (p = 0.0001). Using multivariate analysis, risk group (group 1 vs remaining groups) predicted 30-day (p = 0.0003) and long-term (p = 0.0001) outcome. There were no differences among groups 2, 3, and 4. In conclusion, application of a risk score to patients without troponin increase or ST deviation identified a high-risk group with prognosis similar to that of patients with troponin increase or ST depression and affords a practical classification for the full spectrum of non-ST-elevation chest pain.

Non-ST Segment Elevation Acute Coronary Syndromes: A Comprehensive Review

As the non-ST segment elevation acute coronary syndromes (NSTEACS) include unstable angina pectoris (UAP) and the non-ST segment elevation myocardial infarction (NSTEMI), acute diagnosis and risk stratification can often prove challenging. This review will cover guidelines and strategies for risk assessment, contemporary approaches to acute patient management as well as recommendations for timing of specialist referral.

A simple statistical model for prediction of acute coronary syndrome in chest pain patients in the emergency department

BACKGROUND

Several models for prediction of acute coronary syndrome (ACS) among chest pain patients in the emergency department (ED) have been presented, but many models predict only the likelihood of acute myocardial infarction, or include a large number of variables, which make them less than optimal for implementation at a busy ED. We report here a simple statistical model for ACS prediction that could be used in routine care at a busy ED.

METHODS

Multivariable analysis and logistic regression were used on data from 634 ED visits for chest pain. Only data immediately available at patient presentation were used. To make ACS prediction stable and the model useful for personnel inexperienced in electrocardiogram (ECG) reading, simple ECG data suitable for computerized reading were included.

RESULTS

Besides ECG, eight variables were found to be important for ACS prediction, and included in the model: age, chest discomfort at presentation, symptom duration and previous hypertension, angina pectoris, AMI, congestive heart failure or PCI/CABG. At an ACS prevalence of 21% and a set sensitivity of 95%, the negative predictive value of the model was 96%.

CONCLUSION

The present prediction model, combined with the clinical judgment of ED personnel, could be useful for the early discharge of chest pain patients in populations with a low prevalence of ACS.

Association of peripheral artery disease with treatment and outcomes in acute coronary syndromes. The Global Registry of Acute Coronary Events (GRACE)

BACKGROUND

National guidelines recommend the use of secondary prevention modalities for patients with peripheral artery disease (PAD) and coronary artery disease. The effect of prior PAD on the treatment and outcomes of patients with acute coronary syndromes (ACS), however, is not well characterized. The objectives of this study were to assess treatment practices and hospital outcomes in patients with ACS and prior PAD.

METHODS

Data were analyzed from 41,108 patients aged > or =18 years with ACS and enrolled in the large multinational GRACE between 1999 and 2004.

RESULTS

Of the 41,108 patients, 4003 (9.7%) had prior PAD. Patients with PAD were older, more likely to be men, to have a variety of prior comorbidities, and to present with non-ST-segment elevation myocardial infarction and a higher Killip class than patients without PAD. Patients with PAD were less likely to be treated with effective cardiac medications than patients without PAD. At the time of hospital presentation, patients with prior PAD had low rates of use of beneficial cardiac medications, including angiotensin-converting enzyme inhibitors, aspirin, beta-blockers, and lipid-lowering agents. Patients with PAD were significantly more likely to experience the composite hospital end point (death, shock, recurrent angina, stroke) than patients without prior PAD (adjusted OR 1.17; 95% CI 1.08-1.26).

CONCLUSIONS

Patients with prior PAD received less aggressive treatment with proven cardiac medications during hospitalization for an ACS than patients without PAD. Utilization of beneficial medical therapies in patients with PAD before hospitalization with ACS was also less than optimal. Given the poorer hospital outcomes in patients with PAD, our findings suggest considerable opportunity to improve care for these high-risk patients.

Magnitude and consequences of undertreatment of high-risk patients with non-ST segment elevation acute coronary syndromes: insights from the DESCARTES Registry

OBJECTIVE

To analyse intensity of treatment of high-risk patients with non-ST elevation acute coronary syndromes (NSTEACS) included in the DESCARTES (Descripción del Estado de los Sindromes Coronarios Agudos en un Registro Temporal Español) registry.

PATIENTS AND SETTING

Patients with NSTEACS (n = 1877) admitted to 45 randomly selected Spanish hospitals in April and May 2002 were studied.

DESIGN

Patients with ST segment depression and troponin rise were considered high risk (n = 478) and were compared with non-high risk patients (n = 1399).

RESULTS

46.9% of high-risk patients versus 39.5% of non-high-risk patients underwent angiography (p = 0.005), 23.2% versus 18.8% (p = 0.038) underwent percutaneous revascularisation, and 24.9% versus 7.4% (p < 0.001) were given glycoprotein IIb/IIIa inhibitor. In-hospital and six-month mortality were 7.5% versus 1.1% and 17% versus 4.6% (p < 0.001), respectively. A treatment score (> or = 4, 2-3 and < 2) was defined according to the number of class I interventions recommended in clinical guidelines: aspirin, clopidogrel, beta blockers, angiotensin-converting enzyme inhibitors, statins and revascularisation. Independent predictors of six-month mortality were age (odds ratio (OR) 1.07, 95% confidence interval (CI) 1.04 to 1.10, p < 0.001), diabetes (OR 1.92, 95% CI 1.14 to 3.22, p = 0.014), previous cardiovascular disease (OR 4.17, 95% CI 1.63 to 10.68, p = 0.003), high risk (OR 2.20, 95% CI 1.30 to 3.71, p = 0.003) and treatment score < 2 versus > or = 4 (OR 2.87, 95% CI 1.27 to 6.52, p = 0.012).

CONCLUSIONS

Class I recommended treatments were underused in high-risk patients in the DESCARTES registry. This undertreatment was an independent predictor of death of patients with an acute coronary syndrome.

New Risk Score for Patients With Acute Chest Pain, Non-ST-Segment Deviation, and Normal Troponin Concentrations

OBJECTIVES

The purpose of this research was to develop a risk score for patients with chest pain, non-ST-segment deviation electrocardiogram (ECG), and normal troponin levels.

BACKGROUND

Prognosis assessment in this population remains a challenge.

METHODS

A total of 646 consecutive patients were evaluated by clinical history (risk factors and chest pain score according to pain characteristics), ECG, and early exercise testing. ST-segment deviation and troponin elevation were exclusion criteria. The primary end point was mortality or myocardial infarction at one year. The secondary end point was mortality, myocardial infarction, or urgent revascularization at 14 days (similar to the Thrombolysis In Myocardial Infarction [TIMI] risk score).

RESULTS

Primary and secondary end point rates were 6.7% and 5.4%. A risk score was constructed using the variables related to the primary end point: chest pain score > or =10 points (hazard ratio [HR] = 2.5; 1 point), > or =2 pain episodes in last 24 h (HR = 2.2; 1 point), age > or =67 years (HR = 2.3; 1 point), insulin-dependent diabetes mellitus (HR = 4.2; 2 points), and prior percutaneous transluminal coronary angioplasty (HR = 2.2; 1 point). Patients were classified into five categories of risk (p = 0.0001): 0 points, 0% event rate; 1 point, 3.1%; 2 points, 5.4%; 3 points, 17.6%; > or =4 points, 29.6%. The accuracy of the score was greater than that of the TIMI risk score for the primary (C index of 0.78 vs. 0.66, p = 0.0002) and secondary (C index of 0.70 vs. 0.66, p = 0.1) end points.

CONCLUSIONS

Patients presenting with chest pain despite no ST-segment deviation or troponin elevation show a non-negligible rate of events at one year. A risk score derived from this specific population allows more accurate stratification than when using the TIMI risk score.

Risk stratification of patients with acute chest pain and normal troponin concentrations

OBJECTIVE

To investigate the outcome of patients with acute chest pain and normal troponin concentrations.

DESIGN

Prospective cohort design.

SETTING

Single centre study in a teaching hospital in Spain.

PATIENTS

609 consecutive patients with chest pain evaluated in the emergency department by clinical history (risk factors and a chest pain score according to pain characteristics), ECG, and early (< 24 hours) exercise testing for low risk patients with physical capacity (n = 283, 46%). All had normal troponin concentrations after serial determination.

MAIN OUTCOME MEASURES

Myocardial infarction or cardiac death during six months of follow up.

RESULTS

29 events were detected (4.8%). No patient with a negative early exercise test (n = 161) had events versus the 6.9% event rate in the remaining patients (p = 0.0001). Four independent predictors were found: chest pain score > or = 11 points (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.1 to 5.5, p = 0.04), diabetes mellitus (OR 2.3, 95% CI 1.1 to 4.7, p = 0.03), previous coronary surgery (OR 3.1, 95% CI 1.3 to 7.6, p = 0.01), and ST segment depression (OR 2.8, 95% CI 1.3 to 6.3, p = 0.003). A risk score proved useful for patient stratification according to the presence of 0-1 (2.7% event rate), 2 (10.2%, p = 0.008), and 3-4 predictors (29.2%, p = 0.0001).

CONCLUSIONS

A negative troponin result does not assure a good prognosis for patients coming to the emergency room with chest pain. Early exercise testing and clinical data should be carefully evaluated for risk stratification.

[Emergency room risk stratification of patients with chest pain without ST segment elevation]

OBJECTIVES

To investigate the prognostic factors in patients who come to the emergency room with chest pain but without ST segment elevation.

PATIENTS AND METHOD

743 consecutive patients were evaluated by recording clinical history, electrocardiogram and troponin I determination, and early (<24 h) exercise testing was done for the low-risk subgroup of patients (n=203). All patients were followed during 3 months for major events (acute myocardial infarction or death).

RESULTS

Major events occurred in 71 patients (9.6%). Multivariate analysis (C statistic=0.79; 95% CI 0.73-0.84; p=0.0001) identified the following predictors: age > or =72 years (OR=1.7; 95% CI, 1.0-2.9; p=0.05), insulin-dependent diabetes mellitus (OR=2.9; 95% CI, 1.5-5.4; p=0.001), previous ischemic heart disease (OR=1.9; 95% CI, 1.1-3.2; p=0.02), ST depression (OR=2.1; 95% CI, 1.2-3.8; p=0.01) and troponin I elevation (OR=2.9; 95% CI, 1.5-5.3; p=0.001). These five predictors were used to construct a risk score based on their odds ratios, which allowed event rate stratification by quartiles of the score: 0-2 points (1.6% events), 3-4 points (8.1% events), 5-7 points (11.9% events) and > or =8 points (26.2% events); p=0.0001. No patient with negative findings in the early exercise testing had major events.

CONCLUSIONS

In patients with chest pain, the combination of clinical, electrocardiographic and biochemical data available on admission to the emergency service allows rapid prognostic stratification. Early exercise testing is advisable for the final stratification of low risk patients.

A new scoring system to stratify risk in unstable angina

BACKGROUND

We performed this study to develop a new scoring system to stratify different levels of risk in patients admitted to hospital with a diagnosis of unstable angina (UA), which is a complex syndrome that encompasses different outcomes. Many prognostic variables have been described but few efforts have been made to group them in order to enhance their individual predictive power.

METHODS

In a first phase, 473 patients were prospectively analyzed to determine which factors were significantly associated with the in-hospital occurrence of refractory ischemia, acute myocardial infarction (AMI) or death. A risk score ranging from 0 to 10 points was developed using a multivariate analysis. In a second phase, such score was validated in a new sample of 242 patients and it was finally applied to the entire population (n = 715).

RESULTS

ST-segment deviation on the electrocardiogram, age > or = 70 years, previous bypass surgery and troponin T > or = 0.1 ng/mL were found as independent prognostic variables. A clear distinction was shown among categories of low, intermediate and high risk, defined according to the risk score. The incidence of the triple end-point was 6 %, 19.2 % and 44.7 % respectively, and the figures for AMI or death were 2 %, 11.4 % and 27.6 % respectively (p < 0.001).

CONCLUSIONS

This new scoring system is simple and easy to achieve. It allows a very good stratification of risk in patients having a clinical diagnosis of UA. They may be divided in three categories, which could be of help in the decision-making process.

[Clinical characteristics, prognosis, and variability in the management of non-ST-segment elevation acute coronary syndromes. Data from the PEPA registry]

OBJECTIVES

To assess the clinical characteristics and inter-hospital variability in the treatment and prognosis of patients with non-ST-segment elevation acute coronary syndromes.

PATIENTS AND METHOD

Data from the PEPA study, a prospective registry that enrolled 4,115 patients in 18 Spanish hospitals, were analyzed.

RESULTS

The mean age of the patients enrolled was 65 years, 33% were women, and 26% had diabetes. Large differences were observed in the clinical profile of patients admitted to different centers, especially relative the history of previous disease, prior coronary revascularization, and co-morbidity. Antiplatelet treatment was used in 93% of patients, heparin in 45%, beta-blockers in 42%, nitrates in 67%, and calcium antagonists in 46%. During hospitalization, exercise stress testing was performed in 37% of patients, coronary angiography in 32%, coronary angioplasty in 9%, and coronary surgery in 4%. Inter-hospital variability was minimal for the use of antiplatelet agents, wide for the use of heparin and beta-blockers, and huge for the use of revascularization procedures. Mortality and the incidence of death or myocardial infarction were 2.6% and 4.4% during hospitalization, and 4.6% and 8% at 3 months, with wide inter-hospital variability. These differences were not significant once adjusted for clinical characteristics and the treatment received at admission.

CONCLUSIONS

Patients with non-ST-segment elevation acute coronary syndromes represent an heterogeneous group with a high incidence of complications. Pharmacologic and, especially, invasive treatment varies widely in different hospitals. These results underline the importance of correct initial risk stratification and uniform treatment following the recommendations of clinical guidelines.