Short- and Long-Term Risk Stratification in Acute Coronary Syndromes

Machine learning-based models to predict one-year mortality among Chinese older patients with coronary artery disease combined with impaired glucose tolerance or diabetes mellitus

PURPOSE

An accurate prediction of survival prognosis is beneficial to guide clinical decision-making. This prospective study aimed to develop a model to predict one-year mortality among older patients with coronary artery disease (CAD) combined with impaired glucose tolerance (IGT) or diabetes mellitus (DM) using machine learning techniques.

METHODS

A total of 451 patients with CAD combined with IGT and DM were finally enrolled, and those patients randomly split 70:30 into training cohort (n = 308) and validation cohort (n = 143).

RESULTS

The one-year mortality was 26.83%. The least absolute shrinkage and selection operator (LASSO) method and ten-fold cross-validation identified that seven characteristics were significantly associated with one-year mortality with creatine, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and chronic heart failure being risk factors and hemoglobin, high density lipoprotein cholesterol, albumin, and statins being protective factors. The gradient boosting machine model outperformed other models in terms of Brier score (0.114) and area under the curve (0.836). The gradient boosting machine model also showed favorable calibration and clinical usefulness based on calibration curve and clinical decision curve. The Shapley Additive exPlanations (SHAP) found that the top three features associated with one-year mortality were NT-proBNP, albumin, and statins. The web-based application could be available at https://starxueshu-online-application1-year-mortality-main-49cye8.streamlitapp.com/ .

CONCLUSIONS

This study proposes an accurate model to stratify patients with a high risk of one-year mortality. The gradient boosting machine model demonstrates promising prediction performance. Some interventions to affect NT-proBNP and albumin levels, and statins, are beneficial to improve survival outcome among patients with CAD combined with IGT or DM.

ECG analysis in patients with acute coronary syndrome undergoing invasive management: rationale and design of the electrocardiography sub-study of the MATRIX trial

BACKGROUND

The twelve‑lead electrocardiogram (ECG) has become an essential tool for the diagnosis, risk stratification, and management of patients with acute coronary syndromes (ACS). However, several areas of residual controversies or gaps in evidence exist. Among them, P-wave abnormalities identifying atrial ischemia/infarction are largely neglected in clinical practice, and their diagnostic and prognostic implications remain elusive; the value of ECG to identify the culprit lesion has been investigated, but validated criteria indicating the presence of coronary occlusion in patients without ST-elevation are lacking; finally, which criteria among the multiple proposed, better define pathological Q-waves or success of revascularisation deserve further investigations.

METHODS

The Minimizing Adverse hemorrhagic events via TRansradial access site and systemic Implementation of AngioX (MATRIX) trial was designed to test the impact of bleeding avoidance strategies on ischemic and bleeding outcomes across the whole spectrum of patients with ACS receiving invasive management. The ECG-MATRIX is a pre-specified sub-study of the MATRIX programme which aims at analyzing the clinical value of ECG metrics in 4516 ACS patients (with and without ST-segment elevation in 2212 and 2304 cases, respectively) with matched pre and post-treatment ECGs.

CONCLUSIONS

This study represents a unique opportunity to further investigate the role of ECGs in the diagnosis and risk stratification of ACS patients with or without ST-segment deviation, as well as to assess whether the radial approach and bivalirudin may affect post-treatment ECG metrics and patterns in a large contemporary ACS population.

Temporal Biomarker Profiling Reveals Longitudinal Changes in Risk of Death or Myocardial Infarction in Non–ST-Segment Elevation Acute Coronary Syndrome

BACKGROUND

There are conflicting data on whether changes in N-terminal pro–B-type natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) concentrations between time points (delta NT-proBNP and hs-CRP) are associated with a change in prognosis.

METHODS

We measured NT-proBNP and hs-CRP at 3 time points in 1665 patients with non–ST-segment elevation acute coronary syndrome (NSTEACS). Cox proportional hazards was applied to the delta between temporal measurements to determine the continuous association with cardiovascular events. Effect estimates for delta NT-proBNP and hs-CRP are presented per 40% increase as the basic unit of temporal change.

RESULTS

Median NT-proBNP was 370.0 (25th, 75th percentiles, 130.0, 996.0), 340.0 (135.0, 875.0), and 267.0 (111.0, 684.0) ng/L; and median hs-CRP was 4.6 (1.7, 13.1), 1.9 (0.8, 4.5), and 1.8 (0.8, 4.4) mg/L at baseline, 30 days, and 6 months, respectively. The deltas between baseline and 6 months were the most prognostically informative. Every +40% increase of delta NT-proBNP (baseline to 6 months) was associated with a 14% greater risk of cardiovascular death (adjusted hazard ratio (HR) 1.14, 95% CI, 1.03–1.27) and with a 14% greater risk of all-cause death (adjusted HR 1.14, 95% CI, 1.04–1.26), while every +40% increase of delta hs-CRP (baseline to 6 months) was associated with a 9% greater risk of the composite end point (adjusted HR 1.09, 95% CI, 1.02–1.17) and a 10% greater risk of myocardial infarction (adjusted HR 1.10, 95%, CI 1.00–1.20).

CONCLUSIONS

Temporal changes in NT-proBNP and hs-CRP are quantitatively associated with future cardiovascular events, supporting their role in dynamic risk stratification of NSTEACS.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00699998

The contemporary value of peak creatine kinase-MB after ST-segment elevation myocardial infarction above other clinical and angiographic characteristics in predicting infarct size, left ventricular ejection fraction, and mortality

BACKGROUND

Complex multimarker approaches to predict outcome after ST-elevation myocardial infarction (STEMI) have only considered a single baseline sample, while neglecting easily obtainable peak creatine kinase and creatine kinase-MB (CK-MB) values during hospitalization.

METHODS

We studied 476 patients undergoing primary percutaneous coronary intervention for STEMI and cardiac magnetic resonance imaging (CMRI) at 4-6 months after STEMI. We determined the association with cardiac biomarkers (peak CK-MB, peak troponin T, N-terminal pro-brain natriuretic peptide), clinical and angiographic characteristics with infarct size, and LVEF, followed by association with mortality in 1120 STEMI patients.

RESULTS

Peak CK-MB was the strongest predictor for infarct size (P<0.001, R ² =0.60) and LVEF (P<0.001, R ² =0.40). The additional value of clinical and angiographic characteristics was limited. The optimal peak CK-MB cutpoints, for differentiation among small (<10% of the left ventricle), moderate (≥10%-<30%), and large infarct size (≥30%), were 210 U/L and 380 U/L, respectively. These cutpoints were associated with 90-day mortality; the hazard ratio for moderate infarct was 2.99 (95% confidence interval [CI]: 1.51-5.93, P=0.002) and for large infarct 6.53 (95% CI: 3.63-11.76, P<0.001).

CONCLUSIONS

Classical peak CK-MB measured during hospitalization for STEMI was superior to other clinical and angiographic characteristics in predicting CMRI-defined infarct size and LVEF, and should be included and validated in future multimarker studies. Peak CK-MB cutpoints differentiated among infarct size categories and were associated with increased 90-day mortality risk.

Simultaneous consideration of multiple candidate protein biomarkers for long-term risk for cardiovascular events

BACKGROUND

Although individual protein biomarkers are associated with cardiovascular risk, rarely have multiple proteins been considered simultaneously to identify which set of proteins best predicts risk.

METHODS AND RESULTS

In a nested case-control study of 273 death/myocardial infarction (MI) cases and 273 age- (within 10 years), sex-, and race-matched and event-free controls from among 2023 consecutive patients (median follow-up 2.5 years) with suspected coronary disease, plasma levels of 53 previously reported biomarkers of cardiovascular risk were determined in a core laboratory. Three penalized logistic regression models were fit using the elastic net to identify panels of proteins independently associated with death/MI: proteins alone (Model 1); proteins in a model constrained to retain clinical variables (Model 2); and proteins and clinical variables available for selection (Model 3). Model 1 identified 6 biomarkers strongly associated with death/MI: intercellular adhesion molecule-1, matrix metalloproteinase-3, N-terminal pro-B-type natriuretic peptide, interleukin-6, soluble CD40 ligand, and insulin-like growth factor binding protein-2. In Model 2, only soluble CD40 ligand remained strongly associated with death/MI when all clinical risk predictors were retained. Model 3 identified a set of 6 biomarkers (intercellular adhesion molecule-1, matrix metalloproteinase-3, N-terminal pro-B-type natriuretic peptide, interleukin-6, soluble CD40 ligand, and insulin-like growth factor binding protein-2) and 5 clinical variables (age, red-cell distribution width, diabetes mellitus, hemoglobin, and New York Heart Association class) strongly associated with death/MI.

CONCLUSIONS

Simultaneously assessing the association between multiple putative protein biomarkers of cardiovascular risk and clinical outcomes is useful in identifying relevant biomarker panels for further assessment.

Impact of nonculprit vessel myocardial perfusion on outcomes of patients undergoing percutaneous coronary intervention for acute coronary syndromes: analysis from the ACUITY trial (Acute Catheterization and Urgent Intervention Triage Strategy)

OBJECTIVES

This study evaluated the impact of nonculprit vessel myocardial perfusion on outcomes of non-ST-segment elevation acute coronary syndromes (NSTE-ACS) patients.

BACKGROUND

ST-segment elevation myocardial infarction patients have decreased perfusion in areas remote from the infarct-related vessel. The impact of myocardial hypoperfusion of regions supplied by nonculprit vessels in NSTE-ACS patients treated with percutaneous coronary intervention (PCI) is unknown.

METHODS

The angiographic substudy of the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial included 6,921 NSTE-ACS patients. Complete 3-vessel assessments of baseline coronary TIMI (Thrombolysis In Myocardial Infarction) flow grade and myocardial blush grade (MBG) were performed. We examined the outcomes of PCI-treated patients according to the worst nonculprit vessel MBG identified per patient.

RESULTS

Among the 3,826 patients treated with PCI, the worst nonculprit MBG was determined in 3,426 (89.5%) patients, including 375 (10.9%) MBG 0/1 patients, 475 (13.9%) MBG 2 patients, and 2,576 (75.2%) MBG 3 patients. Nonculprit MBG 0/1 was associated with worse baseline clinical characteristics. Patients with nonculprit MBG 0/1 versus MBG 3 had increased rates of 30-day (3.0% vs. 0.7%, p < 0.0001) and 1-year (4.4% vs. 1.0%, p < 0.0001) death. Similar results were found among patients with pre-procedural TIMI flow grade 3 in the culprit vessel, where nonculprit vessel MBG 0/1 (hazard ratio: 2.81 [95% confidence interval: 1.63 to 4.84], p = 0.0002) was the strongest predictor of 1-year mortality.

CONCLUSIONS

Reduced myocardial perfusion in an area supplied by a nonculprit vessel is associated with increased short- and long-term mortality rates in NSTE-ACS patients undergoing PCI. Furthermore, worst nonculprit MBG is able to risk-stratify patients with normal baseline flow of the culprit vessel.

Quantitative ST-depression in acute coronary syndromes: the PLATO electrocardiographic substudy

BACKGROUND

We evaluated whether electrocardiogram (ECG) characteristics were aligned with clinical outcomes and the effect of ticagrelor within the diverse spectrum of non-ST-elevation acute coronary syndrome patients enrolled in the PLATelet inhibition and patient Outcomes (PLATO) trial.

METHODS

There were 8884 PLATO patients who had baseline ECGs assessed by a core laboratory; of these, 4935 had an ECG at hospital discharge that also was assessed. Associations with study treatment on vascular death or myocardial infarction within 1 year were examined.

RESULTS

At baseline, most patients had either no or ≤0.5 mm of ST-segment depression (57%); 26% had 1.0 mm, and 17% had more extensive depression (>1.0 mm). Across the baseline ST-segment depression strata, there was a consistent treatment benefit with ticagrelor versus clopidogrel on vascular death/myocardial infarction. The extent of residual ST-segment depression at discharge was similar in the treatment groups, and the treatment effect did not differ by the extent of discharge ST-segment depression. There was a progressive increase in vascular death/myocardial infarction with increasing extent of baseline ST-segment depression (1.0 mm [vs no/0.5 mm]: hazard ratio [HR] 1.22; 95% confidence interval [CI], 1.03-1.45; >1.0 mm: HR 1.49; 95% CI, 1.24-1.78; P <.001) and at discharge (HR 1.28; 95% CI, 1.02-1.61; HR 2.13; 95% CI, 1.54-2.95; P <.001).

CONCLUSION

The treatment effect of ticagrelor among non-ST-segment-elevation acute coronary syndrome patients was consistently expressed across all baseline ST-segment depression strata. There was no indication of an anti-ischemic benefit of ticagrelor as reflected on the discharge ECG. Our data affirm the independent prognostic relationship of both baseline and hospital discharge ST-segment depression on outcomes within 1 year in non-ST-segment-elevation acute coronary syndrome patients.

Comparative prognostic value of T-wave inversion and ST-segment depression on the admission electrocardiogram in non-ST-segment elevation acute coronary syndromes

BACKGROUND

ST-segment depression (STD) is predictive of adverse outcomes in non-ST-segment elevation acute coronary syndromes (NSTE-ACS), but there are conflicting data on the incremental prognostic value of T-wave inversions (TWIs) on the admission electrocardiogram.

METHODS

Admission electrocardiograms of 7,343 patients with NSTE-ACS from the Global Registry of Acute Coronary Events (GRACE) and ACS I registry were independently analyzed at a core laboratory and stratified by TWI and STD status. We performed multivariable analyses to determine the independent prognostic significance of TWI and tested for interaction between TWI and STD for adverse outcomes.

RESULTS

Patients with TWI and/or STD had a higher prevalence of cardiovascular risk factors, higher Killip class, and higher GRACE risk scores. Among the 2,708 patients with available angiographic data, rates of 3-vessel or left main disease were similar between patients with TWI and those without TWI/STD. After adjusting for other established prognosticators, TWI did not independently predict in-hospital (adjusted odds ratio 1.03, 95% CI 0.75-1.42, P = .85) or 6-month mortality (adjusted odds ratio 1.02, 95% CI 0.80-1.30, P = .88); STD remained a strong independent predictor. There was no interaction between TWI and STD for these outcomes. No contiguous lead groups or cumulative number of leads with TWI provided independent prognostic information.

CONCLUSIONS

TWI is associated with other high-risk clinical features but is not an independent predictor of adverse short- and long-term mortality in NSTE-ACS. T-wave inversion does not provide additional prognostication beyond the GRACE risk model, and its concomitant presence does not alter the prognostic value of STD.

Assessment of short-term prognosis by sinus heart rate turbulence in patients with unstable angina

The aim of this study was to explore the correlation between sinus heart rate turbulence (HRT) and short-term prognosis in patients with unstable angina (UA). Seventy-five patients with UA received Holter monitoring for 24 h, within 48 h of hospitalization to obtain parameters of HRT, including turbulence onset (TO) and turbulence slope (TS), as well as parameters of heart rate variability (HRV), including standard deviation of all NN intervals (SDNN) and average R-R interval. The left ventricular ejection fraction (LVEF) was measured with an ultrasound cardiogram. Patients were divided into a stable group and a refractory group based on the prognosis during a 7- to 21-day hospital stay. The correlation between the prognosis and each risk factor was analyzed. Of the 75 patients with UA, the pathogenetic condition was stable in 50 patients (stable group) and cardiac events occurred in 25 patients (refractory group). Univariate analysis indicated that the risk factors of short-term poor prognosis of UA include TS ≤2.5 msec/R-R, age ≥70 years, LVEF <40% and SDNN <70 msec. Logistic multivariate regression analysis revealed that only TS ≤2.5 msec/R-R and LVEF <40% were independent risk factors of short-term poor prognosis. Our study revealed that weakening or disappearance of HRT is an independent predictor of short-term poor prognosis in patients with UA.

Review on natriuretic peptides: where we are, where we are going

BACKGROUND

Tremendous advances have been made in our understanding of the pathophysiology and treatment of congestive heart failure. However, diagnosis of the disease still remains difficult, even with a comprehensive physical examination. Symptoms such as dyspnea are nonspecific and insensitive indicators for heart failure, which can go largely undetected. Several studies have suggested the need for new diagnostic capabilities, especially with the increasing prevalence of heart failure in the US. The discovery of natriuretic peptides as diagnostic biomarkers has been one of the most critical advances for the management of heart failure. Both B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide have the potential to diagnose heart failure, assess prognostic risk of rehospitalization and mortality, and even help guide treatment. Their relative cost-effectiveness and availability have also facilitated their acceptance into many emergency departments, clinics and in-patient units as standard care when evaluating patients with suspected heart failure. Our understanding of the natriuretic peptide system is still in its infancy, but natriuretic peptides have emerged as important diagnostic and prognostic tools that have generated interest in finding broader applications for their use.

OBJECTIVE

The purpose of this review is to discuss the clinical approaches and future applications of natriuretic peptides in diagnosing and managing treatment of congestive heart failure.

METHOD

A comprehensive review of studies to assess the utility of natriuretic peptides for diagnosis and prognosis of heart failure and other conditions.

CONCLUSION

Natriuretic peptides are powerful tools to aid the physician in the diagnosis, prognosis and management of heart failure in both in-patient and out-patient settings. However, natriuretic peptides should be used as an adjunct test as many circumstances can also influence changes in natriuretic peptide levels.

Risk stratification and timing of revascularization: which patients benefit from early versus later revascularization?

In acute coronary syndromes, risk stratification is essential, particularly in patients without ST elevation, and is based upon clinical, electrocardiogram (ECG), and biological markers. Among them, recent and repeated attacks of angina, ST-segment deviation from baseline on the admission ECG as well as elevated markers of myonecrosis (particularly increased troponin levels), myocardial dysfunction (B-type natriuretic peptide [BNP]; N-terminal prohormone of BNP[NT-proBNP]), and inflammation (high-sensitivity C-reactive protein) are predictors of an adverse outcome. These variables can be incorporated into broader risk predictive scores, among which the TIMI (Thrombolysis in Myocardial Infarction) and GRACE (Global Registry of Acute Coronary Events) scores are the most widely used. Two general therapeutic strategies (routine invasive vs conservative or selective invasive) are employed in the treatment of non-ST-segment elevation acute coronary syndrome (NSTEACS). Evidence-based analysis and the current American College of Cardiology/American Heart Association/Society for Cardiac Angiography and Interventions clinical practice guidelines recommend an early invasive treatment strategy (8-24 h) for intermediate or high clinical risk patients with NSTEACS.

Association of frontal QRS-T angle--age risk score on admission electrocardiogram with mortality in patients admitted with an acute coronary syndrome

Risk assessment is central to the management of acute coronary syndromes. Often, however, assessment is not complete until the troponin concentration is available. Using 2 multicenter prospective observational studies (Evaluation of Methods and Management of Acute Coronary Events [EMMACE] 2, test cohort, 1,843 patients; and EMMACE-1, validation cohort, 550 patients) of unselected patients with acute coronary syndromes, a point-of-admission risk stratification tool using frontal QRS-T angle derived from automated measurements and age for the prediction of 30-day and 2-year mortality was evaluated. Two-year mortality was lowest in patients with frontal QRS-T angles <38° and highest in patients with frontal QRS-T angles >104° (44.7% vs 14.8%, p <0.001). Increasing frontal QRS-T angle-age risk (FAAR) scores were associated with increasing 30-day and 2-year mortality (for 2-year mortality, score 0 = 3.7%, score 4 = 57%; p <0.001). The FAAR score was a good discriminator of mortality (C statistics 0.74 [95% confidence interval 0.71 to 0.78] at 30 days and 0.77 [95% confidence interval 0.75 to 0.79] at 2 years), maintained its performance in the EMMACE-1 cohort at 30 days (C statistics 0.76 (95% confidence interval 0.71 to 0.8] at 30 days and 0.79 (95% confidence interval 0.75 to 0.83] at 2 years), in men and women, in ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction, and compared favorably with the Global Registry of Acute Coronary Events (GRACE) score. The integrated discrimination improvement (age to FAAR score at 30 days and at 2 years in EMMACE-1 and EMMACE-2) was p <0.001. In conclusion, the FAAR score is a point-of-admission risk tool that predicts 30-day and 2-year mortality from 2 variables across a spectrum of patients with acute coronary syndromes. It does not require the results of biomarker assays or rely on the subjective interpretation of electrocardiograms.

N-terminal pro-B-type natriuretic peptide is associated with severity of the coronary lesions in unstable angina patients with preserved left ventricular function

OBJECTIVES

To evaluate the association between N-terminal pro-B-type natriuretic peptide (NT-proBNP) values and the severity of coronary lesions at angiography in unstable angina patients with preserved left ventricular function.

METHODS

A total of 133 patients with primary diagnosis of unstable angina were enrolled into this study. NT-proBNP level was determined before the angiography and Gensini score, a measurement of extent of myocardial ischemia, was calculated after the angiography by experienced cardiologists. Patients with >50% stenosis of the left main or 75% stenosis of one or more coronary branches with diameter >2 mm were defined as "angiography positive" and turned to percutaneous coronary intervention.

RESULTS

There was a significant difference of circulating NT-proBNP level between the angiography positive and negative groups and the median NT-proBNP values were 367.5 pg/mL and 112 pg/mL, respectively (P < 0.001). A significant correlation was observed between log NT-proBNP and log Gensini score (P < 0.001). NT-proBNP level was a predictor of angiography positive result and the area under the receiver operating characteristic curve was 0.776 (95% CI 0.693-0.858).

CONCLUSIONS

NT-proBNP level was found to be higher with the severity of myocardial ischemia. However, the ability of NT-proBNP to identify clinically significant angiographic lesions was moderate.

GRACE and TIMI risk scores but not stress imaging predict long-term cardiovascular follow-up in patients with chest pain after a rule-out protocol

Objective

To determine the long-term prognostic value of stress imaging and clinical risk scoring for cardiovascular mortality in chest pain patients after ruling out acute coronary syndrome (ACS).

Methods

A standard rule-out protocol was performed in emergency room patients with a normal or non-diagnostic admission electrocardiogram (ECG) within 6 h of chest pain onset. ACS patients were identified by troponin T, recurrent angina and serial ECG. Dobutamine stress echocardiography (DSE) was performed after ACS was ruled out. Myocardial perfusion scintigraphy (MPS) was performed within 6 months in an outpatient setting according to the physician’s discretion.

Results

524 patients were included. GRACE and TIMI risk scores were 75 (57–96) and 1 (0–2) in the rule-out ACS group, and 89 (74–107) and 2 (1–3) in the ACS group, respectively (median, interquartile range). Follow-up (median 9.4 (8.9–10.0) years) was complete in 96%. 350 of 379 rule-out ACS patients had an interpretable DSE and 52 patients underwent an MPS. 21 of the rule-out ACS patients (6%) died of a cardiovascular cause compared with 24 (17%) ACS patients (p < 0.001). For rule-out ACS patients, C-statistics were 0.829 and 0.803 for the GRACE and TIMI scores. In these patients, DSE and MPS outcome did not predict long-term cardiovascular mortality. In multivariate analysis, known chronic heart failure, ACE inhibitor use, and GRACE score were independent predictors of cardiovascular mortality.

Conclusions

TIMI and GRACE score but not DSE and MPS are accurate predictors of long-term cardiovascular mortality, even in chest pain patients with a normal or non-diagnostic electrocardiogram undergoing a rule-out protocol.

Short- and long-term prognostic significance of ST-segment elevation in lead aVR in patients with non-ST-segment elevation acute coronary syndrome

We sought to evaluate the prognostic significance of ST-segment elevation (STE) in lead aVR in unselected patients with non-STE acute coronary syndrome (NSTE-ACS). We enrolled 1,042 consecutive patients with NSTE-ACS. Patients were divided into 5 groups according to the following electrocardiographic (ECG) patterns on admission: (1) normal electrocardiogram or no significant ST-T changes, (2) inverted T waves, (3) isolated ST deviation (ST depression [STD] without STE in lead aVR or transient STE), (4) STD plus STE in lead aVR, and (5) ECG confounders (pacing, right or left bundle branch block). The main angiographic end point was left main coronary artery (LM) disease as the culprit artery. Clinical end points were in-hospital and 1-year cardiovascular death defined as the composite of cardiac death, fatal stroke, and fatal bleeding. Prevalence of STD plus STE in lead aVR was 13.4%. Rates of culprit LM disease and in-hospital cardiovascular death were 8.1% and 3.8%, respectively. On multivariable analysis, patients with STD plus STE in lead aVR (group 4) showed an increased risk of culprit LM disease (odds ratio 4.72, 95% confidence interval [CI] 2.31 to 9.64, p <0.001) and in-hospital cardiovascular mortality (odds ratio 5.58, 95% CI 2.35 to 13.24, p <0.001) compared to patients without any ST deviation (pooled groups 1, 2, and 5), whereas patients with isolated ST deviation (group 3) did not. At 1-year follow-up 127 patients (12.2%) died from cardiovascular causes. On multivariable analysis, STD plus STE in lead aVR was a stronger independent predictor of cardiovascular death (hazard ratio 2.29, 95% CI 1.44 to 3.64, p <0.001) than isolated ST deviation (hazard ratio 1.52, 95% CI 0.98 to 2.36, p = 0.06). In conclusion, STD plus STE in lead aVR is associated with high-risk coronary lesions and predicts in-hospital and 1-year cardiovascular deaths in patients with NSTE-ACS. Therefore, this promptly available ECG pattern could be useful to improve risk stratification and management of patients with NSTE-ACS.

Multi-marker strategies in heart failure: clinical and statistical approaches

Advances in genomics and proteomics promise to transform biomarker research, in which the major challenges will not be the discovery of new markers but rather the optimal selection and validation of a subgroup of clinically useful markers from the large pool of candidates. Critically, the value of new biomarkers panels will need to be assessed in the context of readily available clinical information in order to create more actionable knowledge rather than just greater complexity. Appropriate methodologies for the clinical and statistical evaluation of so called "multi-marker strategies" have not been systematically defined. Although specific criteria for the appropriate clinical and statistical evaluation of multi-marker strategies will vary based on the intended use (e.g., diagnosis vs. screening), the ultimate measure of success is the ability for a biomarker panel to both correct a meaningful portion of misclassification by standard methods (discrimination) and to improve quantification of absolute risk (calibration) in comparison to existing clinical information. Findings should be validated in an independent dataset of the representative patient population before a given multi-marker strategy can be considered for clinical use. Here, we define multi-marker strategies, summarize recent examples of biomarker combinations in heart failure, address key statistical and clinical issues, and discuss future directions for this rapidly evolving field.

Use of multiple biomarkers in heart failure

Biomarkers are becoming increasingly available for clinical use, particularly in the care of patients with heart failure. For health care providers, a major difficulty is how to interpret and apply these increasing amounts of diagnostic and prognostic information. Consequently, the scientific challenge is evolving from the discovery of biomarkers to the selection and validation of select panels of clinically useful markers that balance performance and practicality. Optimal combinations of biomarkers will vary based on the intended use (eg, diagnosis vs prognosis). The final goal must be to generate more actionable knowledge that improves patient management and outcomes, rather than merely creating greater complexity. Here we conceptually define multiple biomarker strategies, provide examples of emerging biomarker panels used in the care of patients with heart failure, and address key statistical and clinical issues for this rapidly evolving field.

Prognostic value of standard electrocardiographic parameters for predicting major adverse cardiac events after acute myocardial infarction

BACKGROUND

The prognostic value of electrocardiographic (ECG) variables in predicting major adverse cardiac events (MACEs) after acute myocardial infarction (AMI) in the era of modern therapy is unclear. This study was conducted to evaluate the prognostic significance of ECG parameters in predicting 1-year MACEs for AMI patients.

METHODS

Between January 2006 and January 2008, 529 AMI patients were included. ECG variables were analyzed from the ECG taken on discharge day. The 1-year MACEs were defined as death, nonfatal MI, and revascularization including repeat percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Mean follow-up duration was 360 ± 119 days.

RESULTS

Of these patients, 497 (94%) patients provided complete follow-up data (355 males; 67 ± 12 years old). The rate of 1-year MACEs was 16%. In univariate analysis, heart rate, corrected QT interval, left ventricular (LV) hypertrophy, voltage (SV(1) + RV(5) ), lateral ST-depression (V(5-6) or I, aVL), pathologic Q wave (V(1-4) , V(5-6) ), ST-elevation (V(1-4) , V(5-6) or I, aVL), and T-wave inversion (V(1-4) , V(5-6) , or I, aVL) had a significant association with 1-year MACEs. In the Cox regression hazard model, lateral ST-depression (hazard ratio [HR] 2.260, 95% confidence interval [CI] 1.204 to 4.241, P = 0.011) and corrected QT interval (HR 1.007, 95% CI 1.002 to 1.011, P = 0.004) were independent predictors of 1-year MACEs. After adjustment for all risk variables, lateral ST-depression (HR 3.781, 95% CI 1.047 to 13.656, P = 0.042) was the only ECG variable that independently predicted 1-year MACEs.

CONCLUSION

Lateral ST-depression on discharge day ECG is an independent predictor of 1-year MACEs after AMI.

Prognostic significance of electrocardiographic-determined left ventricular hypertrophy and associated ST-segment depression in patients with non-ST-elevation acute coronary syndromes

BACKGROUND

Left ventricular hypertrophy (LVH) is frequently associated with ST depression (STD) on the electrocardiogram (ECG), a so-called strain pattern. Although STD is a well-established adverse prognosticator in non-ST-elevation acute coronary syndrome (NSTE-ACS), the relative prognostic importance of LVH and associated STD has not been elucidated.

METHODS

A total of 7,761 patients with NSTE-ACS in the Global Registry of Acute Coronary Events (GRACE) and ACS-I registries had admission ECGs analyzed at a core laboratory. Left ventricular hypertrophy (determined by Sokolow-Lyon and/or Casale criteria) was observed in 296 (3.8%) patients. We examined the independent association between LVH (determined by the admission ECG) and outcomes in relation to STD.

RESULTS

Patients with LVH were older, had more comorbidities and STD, and presented with a higher Killip class. They were less likely to undergo cardiac catheterization (43.1% vs 51.2%, P = .006) and percutaneous coronary intervention (18.3% vs 24.6%, P = .014). Patients with LVH had higher unadjusted mortality at 6 months (10.5% vs 7.1%, P = .038), but similar rates of in-hospital mortality (4.1% vs 3.4%, P = .54) and reinfarction (7.1% vs 7.6%, P = .75). Patients with LVH were more likely to have heart failure in-hospital (21.8% vs 11.8%, P < .001). Among LVH patients, degree of quantitative STD did not predict higher short- or long-term mortality, but was associated with in-hospital heart failure. Multivariable analysis adjusting for other clinical prognosticators of the GRACE risk models revealed that LVH was not a significant independent predictor of in-hospital mortality (adjusted odds ratio = 0.75, 95% CI 0.40-1.41, P = .37) or 6-month mortality (adjusted odds ratio = 0.83, 95% CI 0.52-1.35, P = .44). In contrast, STD remained a strong independent predictor of adverse outcomes. There was no significant interaction between STD and LVH.

CONCLUSIONS

Across the broad spectrum of NSTE-ACS, LVH is associated with adverse prognostic factors including STD. Electrocardiographic-determined LVH provides no significant additional prognostic utility beyond comprehensive risk assessment using the GRACE risk score. The adverse prognosis associated with LVH in NSTE-ACS may be attributable to other prognosticators such as STD.

Estimated Glomerular Filtration Rate in Short-Risk Stratification in Acute Myocardial Infarction

BACKGROUND/AIMS

Renal dysfunction is associated with a higher risk of cardiovascular disease in patients with acute myocardial infarction (AMI). The aim of this study was to investigate the independent prognostic value of renal dysfunction and its incremental predictability risk after adjusting for well-known clinical factors in patients with AMI.

METHODS

751 consecutive patients with AMI admitted to the Coronary Care Unit (CCU) were included. Patients were grouped into 2 categories according to the baseline estimated glomerular filtration rate (eGFR) on admission (eGFR <60 vs. eGFR ≧60 ml/min/1.73 m2). C-reactive protein and white blood cell count (WBC) as well as clinical prognostic variables were assessed. The endpoint was mortality during CCU stay. The discriminatory power was estimated by the C-index.

RESULTS

The patient group with an eGFR <60 ml/min/1.73 m2 was older, had more cardiovascular risk factors, a lower left ventricular ejection fraction and higher cardiovascular mortality during CCU stay (13 vs. 3%). Logistic regression analysis revealed the following predictors of mortality: degree of renal impairment (eGFR <60 ml/min/1.73 m2), hazard ratio (HR) = 2.2 (95% CI 1.1-4.3; p = 0.028); WBC >11,000 × 106/l, HR = 2.3 (95% CI 1.2-4.5; p = 0.017); Killip class on admission, HR = 3.8 (95% CI 1.7-8.5; p = 0.001), and New York Heart Association Functional Classification, HR = 3.6 (95% CI 1.7-7.4; p = 0.001). The adjusted C-index was 0.78 for baseline clinical variables and 0.84 for eGFR.

CONCLUSIONS

In patients with AMI, decreased eGFR is an important prognostic factor for impaired cardiac function and mortality in the short-term follow-up. The eGFR may be reliably used in the risk stratification of patients with AMI.

Biochemical markers in acute coronary syndrome

Owing to their higher risk for cardiac death or ischemic complications, patients with acute coronary syndrome (ACS) must be identified from other causes of chest pain. Patients with acute coronary syndrome are divided into categories based on their electrocardiogram; those with new ST-segment elevation and those who present with ST-segment depression. The subgroups of patients with ST-segment elevation are candidates for immediate reperfusion, while fibrinolysis appears harmful for those with non-ST elevation myocardial infarction. There is increasing evidence to encourage appropriate risk stratification before deciding on a management strategy (invasive or conservative) for each patient. The TIMI, GRACE or PURSUIT risk models are recommended as useful for decisions regarding therapeutic options. Cardiac biomarkers are useful additions to these clinical tools to correctly risk stratify ACS patients. Cardiac troponin is the biomarker of choice to detect myocardial necrosis and is central to the universal definition of myocardial infarction. The introduction of troponin assays with a lower limit of detection will allow for earlier diagnosis of patients who present with chest pain. Analytical and clinical validations of these new assays are currently in progress. The question is whether the lower detection limit of the troponin assays will be able to indicate myocardial ischemia in the absence of myocardial necrosis. Previous to the development of ultrasensitive cardiac troponin assays free fatty acids unbound to albumin and ischemia modified albumin were proposed as biochemical markers of ischemia. Advances in our knowledge of the pathogenesis of acute coronary thrombosis have stimulated the development of new biomarkers. Markers of left ventricular performance (N-terminal pro-brain natriuretic peptide) and inflammation (e.g. C-reactive protein) are generally recognized as risk indicators. Studies suggest that using a number of biomarkers clinicians can risk stratify patients over a broad range of short and long term cardiac events. Nevertheless, it is still under debate as to which biomarker combination is best preferred for risk prediction. This review will focus on recent practice guidelines for the management of patients with ACS as well as current advances in cardiac biomarkers, their integration into clinical care and their diagnostic, prognostic and therapeutic utility.

Effectiveness of serial increases in amino-terminal pro-B-type natriuretic peptide levels to indicate the need for mechanical circulatory support in children with acute decompensated heart failure

We sought to determine prospectively whether serial assessment of the natriuretic peptide prohormone, amino-terminal pro-B-type natriuretic peptide (NT-pro-BNP), correlated with clinical severity and outcomes in children hospitalized for acute decompensated heart failure (ADHF). Patients (>1 month of age) admitted from 2005 to 2007 with ADHF requiring intravenous vasoactive/diuretic therapy for ADHF were eligible. Serum NT-pro-BNP levels were obtained within 24 hours of admission and at prespecified intervals, and clinical caregivers were blinded to these levels. End points included hospital discharge, death or cardiac transplantation, and care escalation including the need for mechanical circulatory support (MCS) was noted. Twenty-four patients were enrolled: 22 survived to hospital discharge and 2 died. Ten required MCS (of which 6 underwent cardiac transplantation). Two patients underwent transplantation without MCS. For the entire cohort, NT-pro-BNP levels peaked at days 2 to 3 after admission, with a subsequent gradual decrease until discharge. However, for those who did require MCS, NT-pro-BNP failed to decrease consistently until after MCS initiation. At discharge, NT-pro-BNP levels were significantly decreased from admission levels but remained well above normal for all patients. Single-point NT-pro-BNP levels on admission did not correlate with independently assessed clinical scores of heart failure severity or predict the need for MCS in this cohort. In conclusion, serial NT-pro-BNP levels demonstrated an incremental trend after 48 hours in patients who went on to require MCS but decreased in all other patients and may therefore assist the decision to initiate or avoid MCS after admission for pediatric ADHF.

An early and simple predictor of severe left main and/or three-vessel disease in patients with non-ST-segment elevation acute coronary syndrome

Clopidogrel should be initiated as soon as possible in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) except those who urgently require coronary artery bypass grafting (CABG). The present study assessed the ability to predict severe left main coronary artery and/or 3-vessel disease (LM/3VD) that would most likely require urgent CABG based on only clinical factors on admission in 572 patients with NSTE-ACS undergoing coronary angiography. Severe LM/3VD was defined as ≥75% stenosis of LM and/or 3VD with ≥90% stenosis in ≥2 proximal lesions of the left anterior descending coronary artery and other major epicardial arteries. Patients were divided into the 3 groups according to angiographic findings: no LM/3VD (n = 460), LM/3VD but not severe LM/3VD (n = 57), and severe LM/3VD (n = 55). Severe LM/3VD was associated with a higher rate of urgent CABG compared to no LM/3VD and LM/3VD but not severe LM/3VD (46%, 2%, and 2%, p <0.001). On multivariate analysis, degree of ST-segment elevation in lead aVR was the strongest predictor of severe LM/3VD (odds ratio 29.1, p <0.001), followed by positive troponin T level (odds ratio 1.27, p = 0.044). ST-segment elevation ≥1.0 mm in lead aVR best identified severe LM/3VD with 80% sensitivity, 93% specificity, 56% positive predictive value, and 98% negative predictive value. In conclusion, ST-segment elevation ≥1.0 mm in lead aVR on admission electrocardiogram is highly suggestive of severe LM/3VD in patients with NSTE-ACS. Selected patients with this finding might benefit from promptly undergoing angiography, withholding clopidogrel to allow early CABG.

Prevalence of stroke/transient ischemic attack among patients with acute coronary syndromes in a real-world setting

BACKGROUND

Atherothrombosis is a systemic disease that may manifest as acute ischemic events in multiple vascular beds. Patients who have experienced an atherothrombosis-related ischemic event in 1 vascular bed are at risk for developing ischemic events in other vascular beds. Antiplatelet therapy demands an understanding of the balance between arterial thrombosis benefit and adverse event risk. Clinical trials indicate that dual antiplatelet therapy with aspirin and the newer thienopyridines increases the risk of bleeding in patients with acute coronary syndromes (ACS) with prior cerebrovascular events. Informed clinical decision making requires a better understanding of the real-world prevalence of cerebrovascular events.

OBJECTIVE AND PURPOSE

To estimate the prevalence of stroke and/or transient ischemic attack (TIA) among patients with ACS within US health plan populations.

METHODS

A retrospective, observational cohort study was conducted of patients with ACS in 5 health care claims databases. The index event was defined as the first documented inpatient health care claim for myocardial infarction or unstable angina. Patients with ≥12 months of pre-index medical care encounter information were included. Stroke/TIA was identified by the first health care claim for these conditions any time prior to or within 90 days following the index ACS event.

RESULTS

Across all databases, between 3.8% and 15.7% of patients with ACS had prior stroke/TIA and between 3.4% and 11.7% of patients with ACS with no history of cerebrovascular events had documented stroke/TIA following the index ACS hospitalization.

CONCLUSION

Despite important differences between the various database populations, there is a high prevalence of documented stroke/TIA in patients with ACS both prior to and following the ACS event. These real-world findings, set within the context of the increased bleeding risk observed with the newer thienopyridines, are important considerations when selecting antiplatelet therapy for patients with ACS.

Clinical and Angiographic Predictors of Short- and Long-Term Ischemic Events in Acute Coronary Syndromes

Background—

Contemporary adjunctive pharmacology and revascularization strategies have improved the prognosis of patients with acute coronary syndromes (ACSs). We sought to identify the clinical and angiographic predictors of cardiac ischemic events in patients with ACSs treated with an early invasive strategy.

Methods and Results—

Multivariable logistic regression was used to analyze the relation between baseline characteristics and 30-day and 1-year composite ischemia (death, myocardial infarction, or unplanned revascularization) among the 6921 ACS patients included in the prespecified angiographic substudy of the Acute Catheterization and Urgent Intervention Triage strategY (ACUITY) trial. Of the 6921 patients, 3826 (55.3%) were treated with percutaneous coronary intervention, 755 (10.9%) with coronary artery bypass grafting, and 2340 (33.8%) with medical therapy. Composite ischemia occurred in 595 (8.6%) patients at 30 days and in 1153 (17.4%) at 1 year. Renal insufficiency, biomarker elevation, ST-segment deviation, nonuse of aspirin or thienopyridine, insulin-treated diabetes, older age, baseline lower hemoglobin value, history of percutaneous coronary intervention, and current smoking were independently associated with 30-day or 1-year ischemic events. Angiographic characteristics predicting ischemic events included number of diseased vessels, moderate/severe calcification, worst percent diameter stenosis, jeopardy score, lower left ventricular ejection fraction, lesion eccentricity, and thrombus. With use of receiver operating characteristic methodology, the c statistic improved for the predictive model by adding angiographic to clinical parameters for the 30-day composite ischemia (from 0.62 to 0.68) and myocardial infarction (from 0.64 to 0.71) and 1-year composite ischemia (from 0.61 to 0.65) and myocardial infarction (from 0.63 to 0.69) end points.

Conclusions—

Among ACS patients managed with an early invasive strategy, baseline angiographic markers of disease burden, calcification, lesion severity, lower left ventricular ejection fraction, and morphological characteristics provided important added independent predictive value for 30-day and 1-year ischemic outcomes, beyond the well-recognized clinical risk factors. These findings emphasize the prognostic importance of the diagnostic angiogram in the risk stratification of patients presenting with ACSs.

Clinical Trial Registration—

URL: http://clinicaltrials.gov . Unique identifier: NCT00093158.

Predictors of outcomes in medically treated patients with acute coronary syndromes after angiographic triage: an Acute Catheterization And Urgent Intervention Triage Strategy (ACUITY) substudy

BACKGROUND

Outcomes of patients presenting with acute coronary syndromes are improved with an early invasive approach; however, approximately one third of these patients are treated medically after angiographic screening. We sought to assess the predictors of adverse cardiac events in patients with acute coronary syndrome assigned to medical management.

METHODS AND RESULTS

This substudy of the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial included 4491 acute coronary syndrome patients treated medically after angiographic triage. Rates of bleeding and composite ischemia (death, myocardial infarction, revascularization) were compared among the 3 antithrombotic treatment arms. Composite ischemia occurred in 399 patients (9.5%) at 1 year. Treatment with bivalirudin glycoprotein IIb/IIIa inhibitors significantly reduced major bleeding at 30 days (2.5% bivalirudin monotherapy; P=0.005, 2.0% bivalirudin plus glycoprotein IIb/IIIa inhibitors; P=0.0002 versus 4.4% heparin with glycoprotein IIb/IIIa inhibitors). Composite ischemic events at 1 year were not significantly different in the 3 groups (bivalirudin monotherapy, 9.6%; bivalirudin plus glycoprotein IIb/IIIa inhibitors, 9.7%; heparin plus glycoprotein IIb/IIIa inhibitors, 9.1%). Independent predictors of composite ischemia were mostly angiographic factors at 30 days, including jeopardy score and coronary ectasia, and at 1 year, including previous percutaneous coronary intervention, jeopardy score, coronary ectasia, and increasing number of diseased vessels.

CONCLUSIONS

Among the ACUITY acute coronary syndrome patients treated medically after angiographic triage, bivalirudin therapy significantly reduced bleeding complications compared with heparin without any negative impact on ischemic outcomes at 1 year. The most powerful predictors of ischemic outcomes were angiographic rather than traditional clinical parameters, supporting the early use of angiographic screening in the moderate- and high-risk but medically treated acute coronary syndrome population. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00093158.

Growth-Differentiation Factor-15 for Long-Term Risk Prediction in Patients Stabilized After an Episode of Non–ST-Segment–Elevation Acute Coronary Syndrome

Background— Growth-differentiation factor-15 (GDF-15) has emerged as a prognostic biomarker in patients with non–ST-segment–elevation acute coronary syndrome. This study assessed the time course and the long-term prognostic relevance of GDF-15 levels measured repetitively in patients with non–ST-segment–elevation acute coronary syndrome during 6 months after the acute event.

Methods and Results— GDF-15 and other biomarkers were measured at randomization, after 6 weeks, and after 3 and 6 months in 950 patients with non–ST-segment–elevation acute coronary syndrome included in the FRagmin and Fast Revascularization during InStability in Coronary artery disease II study. Study end points were death, recurrent myocardial infarction, and their composite during 5-year follow-up. Median GDF-15 levels decreased slightly from 1357 ng/L at randomization to 1302 ng/L at 6 months ( P <0.001). GDF-15 was consistently related to cardiovascular risk factors and biochemical markers of hemodynamic stress, renal dysfunction, and inflammation. Moreover, GDF-15 was independently related to the 5-year risk of the composite end point when measured at both 3 months (adjusted hazard ratio, 1.8 [1.0 to 3.0]) and 6 months (adjusted hazard ratio, 2.3 [1.3 to 4.1]). Serial measurements of GDF-15 at randomization and 6 months helped to identify patient cohorts at different levels of risk, with patients with persistently elevated GDF-15 levels >1800 ng/L having the highest rate of the composite end point.

Conclusions— GDF-15 is independently related to adverse events in non–ST-segment–elevation acute coronary syndrome both in the acute setting and for at least 6 months after clinical stabilization. Therefore, continued research on GDF-15 should be focused on the usefulness of GDF-15 for support of clinical management in acute and chronic ischemic heart disease.

Long-Term clinical outcomes according to initial management and thrombolysis in myocardial infarction risk score in patients with acute non-ST-segment elevation myocardial infarction

PURPOSE

There is still debate about the timing of revascularization in patients with acute non-ST-segment elevation myocardial infarction (NSTEMI). We analyzed the long-term clinical outcomes of the timing of revascularization in patients with acute NSTEMI obtained from the Korea Acute Myocardial Infarction Registry (KAMIR).

MATERIALS AND METHODS

2,845 patients with acute NSTEMI (65.6 +/- 12.5 years, 1,836 males) who were enrolled in KAMIR were included in the present study. The therapeutic strategy of NSTEMI was categorized into early invasive (within 48 hours, 65.8 +/- 12.6 years, 856 males) and late invasive treatment (65.3 +/- 12.1 years, 979 males). The initial- and long-term clinical outcomes were compared between two groups according to the level of Thrombolysis In Myocardial Infarction (TIMI) risk score.

RESULTS

There were significant differences in-hospital mortality and the incidence of major adverse cardiac events during one-year clinical follow-up between two groups (2.1% vs. 4.8%, p < 0.001, 10.0% vs. 13.5%, p = 0.004, respectively). According to the TIMI risk score, there was no significant difference of long-term clinical outcomes in patients with low to moderate TIMI risk score, but significant difference in patients with high TIMI risk score (>or= 5 points).

CONCLUSIONS

The old age, high Killip class, low ejection fraction, high TIMI risk score, and late invasive treatment strategy are the independent predictors for the long-term clinical outcomes in patients with NSTEMI.

Significance of T-wave amplitude and dynamics at the time of reperfusion in patients with acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

Peri-interventional T-wave changes may reflect the microvascular reperfusion status and potentially carry early independent, prognostic information in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

The first available electrocardiogram (ECG) (index ECG) and the ECG recorded immediately post-PCI were analyzed for T-wave morphology in 207 patients with STEMI. Absolute T-wave amplitude was recorded and any change in T-wave amplitude from index ECG to post-PCI ECG was calculated. Continuous ST monitoring was performed from hospital arrival until 90 minutes after PCI. Maximum troponin level and left ventricular ejection fraction were evaluated before discharge. Final infarct size was assessed by myocardial perfusion imaging after 1 month.

RESULTS

Large, positive T-wave amplitude in the index ECG and the post-PCI ECG was associated with delayed ST resolution after PCI. In the post-PCI ECG, T-wave amplitude was positively associated with troponin-T value (P < .001) and final infarct size (P = .036), and inversely associated with left ventricular ejection fraction (P < .001). However, T-wave amplitude in the post-PCI ECG was also associated with procedural increase in ST elevation (P < .001) and inversely associated with spontaneous ST resolution (P < .017). A net decrease in T-wave amplitude during reperfusion therapy was associated with faster microvascular reperfusion as evaluated by time to ST resolution.

CONCLUSION

Large T-wave amplitudes in static pre- and post-PCI ECGs are associated with delayed microvascular reperfusion, whereas the dynamic development of more negative T waves during PCI is associated with earlier microvascular reperfusion. However, in the acute setting, T waves provide little incremental information when compared to ST parameters available in the per-interventional phase.

Comparison of the long-term prognostic value of cystatin C to other indicators of renal function, markers of inflammation and systolic dysfunction among patients with acute coronary syndrome

OBJECTIVE

Emerging evidence indicates the prognostic importance of cystatin C (Cys-C) in patients with coronary artery disease. However, whether Cys-C concentrations are associated with adverse clinical events among patients with acute coronary syndromes (ACS) have not been studied extensively. We compared the long-term prognostic efficacy of Cys-C with other markers of renal dysfunction, inflammation and systolic dysfunction in patients with ACS.

METHODS AND RESULTS

Serum levels of Cys-C, high sensitive C-reactive protein (hs-CRP), brain natriuretic peptide (BNP) and creatinine were measured in 160 patients with ACS (112 males, 48 females, mean age 60+/-10 years) on admission. Primary end point of the study was major adverse cardiac events (MACE) defined as the combination of cardiac death, non-fatal myocardial infarction and recurrent rest angina that required hospitalization within 12 months of follow-up. During the follow-up period, 42 (26%) patients met the MACE criteria. The occurrence of MACE was significantly higher among patients with higher Cys-C levels. In multivariate analysis, Cys-C was the most important parameter associated with the occurrence of MACE (OR=9.62, 95% CI=2.3-40.5, p<0.001). ROC curve analysis showed that the predictive cut-off value of Cys-C for MACE was 1051ng/ml. In the Cox regression analysis adjusted for multiple risk factors, Cys-C was found as the most powerful predictor for MACE (RR=9.43, 95% CI=4.0-21.8, p<0.001).

CONCLUSION

The results of the present study indicate that admission levels of Cys-C may be a good prognostic indicator of recurrent cardiovascular events in patients with ACS. Further studies are needed to confirm these results.

Value of serial C-reactive protein measurements in non ST-segment elevation acute coronary syndromes

BACKGROUND

Elevated C-reactive protein (CRP) levels at admission are associated with adverse outcomes in patients with non ST-segment elevation acute coronary syndromes (NSTE-ACS).

HYPOTHESIS

C-reactive protein measurement not only at admission, but also after admission, may be useful for predicting adverse outcomes in NSTE-ACS.

METHODS

We measured high-sensitivity CRP levels at admission and at 24 h in 215 patients with NSTE-ACS. An elevated CRP level at admission (admission elevation) was defined as a CRP level of >or=0.300 mg/dL. An increase in the CRP level after admission (increase at 24 h) was considered present when the CRP level at 24 h was higher than the level at admission. Patients were divided into 4 groups according to the presence or absence of admission elevation and increase at 24 h. Coronary angiography was performed at a mean of 3 d after admission.

RESULTS

There were no significant differences among the 4 groups in age, sex, coronary risk factors, or multivessel disease. Patients with both admission elevation and increase at 24 h had higher rates of ST-segment depression and positive troponin T at admission. Multivariate analysis showed that admission elevation (odds ratio [OR] 1.50, p<0.05) and increase at 24 h (OR 6.56, p=0.03) were independent predictors of 30-d events (e.g., death, myocardial infarction, or refractory angina). The highest risk of 30-d events was associated with both admission elevation and increase at 24 h.

CONCLUSIONS

Serial CRP measurements are useful for predicting the risk of subsequent ischemic complications in patients with NSTE-ACS.

Growth-differentiation factor-15 for early risk stratification in patients with acute chest pain

AIMS

Growth-differentiation factor-15 (GDF-15) has emerged as a biomarker of increased mortality and recurrent myocardial infarction (MI) in patients diagnosed with non-ST-elevation acute coronary syndrome. We explored the usefulness of GDF-15 for early risk stratification in 479 unselected patients with acute chest pain.

METHODS AND RESULTS

Sixty-nine per cent of the patients presented with GDF-15 levels above the previously defined upper reference limit (1200 ng/L). The risks of the composite endpoint of death or (recurrent) MI after 6 months were 1.3, 5.1, and 12.6% in patients with normal (<1200 ng/L), moderately elevated (1200-1800 ng/L), or markedly elevated (>1800 ng/L) levels of GDF-15 on admission, respectively (P < 0.001). By multivariable analysis that included clinical characteristics, ECG findings, peak cardiac troponin I levels within 2 h (cTnI(0-2 h)), N-terminal pro-B-type natriuretic peptide, C-reactive protein, and cystatin C, GDF-15 remained an independent predictor of the composite endpoint. The ability of the ECG combined with peak cTnI(0-2 h) to predict the composite endpoint was markedly improved by addition of GDF-15 (c-statistic, 0.74 vs. 0.83; P < 0.001).

CONCLUSION

GDF-15 improves risk stratification in unselected patients with acute chest pain and provides prognostic information beyond clinical characteristics, the ECG, and cTnI.

Minimally elevated cardiac troponin T and elevated N-terminal pro-B-type natriuretic peptide predict mortality in older adults: results from the Rancho Bernardo Study

OBJECTIVES

This study investigated the prognostic value of detectable cardiac troponin T (TnT) and elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in a population of community-dwelling older adults.

BACKGROUND

Minimally elevated levels of TnT, a marker of cardiomyocyte injury, have been found in small subsets of the general population, with uncertain implications. A marker of ventricular stretch, NT-proBNP has clinical utility in many venues, but its long-term prognostic value in apparently healthy older adults and in conjunction with TnT is unknown.

METHODS

Participants were 957 older adults from the Rancho Bernardo Study with plasma NT-proBNP and TnT measured at baseline (1997 to 1999) and followed up for mortality through July 2006.

RESULTS

Participants with detectable TnT (>/=0.01 ng/ml, n = 39) had an increased risk of all-cause and cardiovascular death (adjusted hazard ratio [HR] by Cox proportional hazards analysis: 2.06; 95% confidence interval [CI]: 1.29 to 3.28, p = 0.003 for all-cause mortality; HR: 2.06, 95% CI: 1.03 to 4.12, p = 0.040 for cardiovascular mortality); elevated NT-proBNP also predicted an increased risk of all-cause and cardiovascular mortality (adjusted HR per unit-log increase in NT-proBNP: 1.85, 95% CI: 1.36 to 2.52, p < 0.001 for all-cause mortality; HR: 2.51, 95% CI: 1.55 to 4.08, p < 0.001 for cardiovascular mortality). Those with both elevated NT-proBNP and detectable TnT had poorer survival (HR for high NT-proBNP and detectable TnT vs. low NT-proBNP and any TnT: 3.20, 95% CI: 1.91 to 5.38, p < 0.001). Exclusion of the 152 participants with heart disease at baseline did not materially change the TnT mortality or NT-proBNP mortality associations.

CONCLUSIONS

Apparently healthy adults with detectable TnT or elevated NT-proBNP levels are at increased risk of death. Those with both TnT and NT-proBNP elevations are at even higher risk, and the increased risk persists for years.

Quantitative troponin elevation does not provide incremental prognostic value beyond comprehensive risk stratification in patients with non-ST-segment elevation acute coronary syndromes

BACKGROUND

The aim of this study was to evaluate whether quantitative cardiac troponin (cTn) assessment can improve risk stratification in a spectrum of patients with non-ST-segment elevation (NSTE) acute coronary syndrome (ACS) using the validated Global Registry of Acute Cardiac Events (GRACE) risk model.

METHODS

The Canadian ACS Registry II is a prospective, multicenter study that enrolled patients admitted to hospital with a suspected NSTE ACS within 24 hours of symptom onset. Of the total 2297 patients, those with elevated cTn (n = 1013) were further stratified into tertiles of cTn ranges. Our primary end point was death and our secondary end point was a composite of death or/and recurrent myocardial infarction at 1-year follow-up.

RESULTS

Multivariable analysis adjusting for validated predictors of death confirmed the independent prognostic value of any abnormal cTn (vs normal) for death (adjusted odds ratio 2.28, 95% CI 1.49-3.49, P < .001) and for the composite outcome (adjusted odds ratio 2.18, 95% CI 1.61-2.95, P < .001) at 1 year. With quantitative assessment, the gradient of mortality risk with increasing cTn level was not evident after adjusting for other prognosticators. Quantitative (compared to qualitative) assessment of cTn level did not improve either the GRACE risk model discrimination for 1-year death.

CONCLUSIONS

Any cTn elevation is associated with higher rate of death at 1 year, but its quantitative assessment did not prove as important as its mere presence as an independent long-term prognosticator in a nonclinical trial, "real-world" NSTE ACS population.

Usefulness of quantitative versus qualitative ST-segment depression for risk stratification of non-ST elevation acute coronary syndromes in contemporary clinical practice

This aim of this study was to assess the clinical utility of quantitative ST-segment depression (STD) for refining the risk stratification of non-ST elevation acute coronary syndromes in the prospective, multinational Global Registry of Acute Coronary Events (GRACE). Quantitative measurements of STD on admission electrocardiograms were evaluated independently by a core laboratory, and their predictive value for in-hospital and cumulative 6-month mortality was examined. Although more severe STD is a marker of increased short- and long-term mortality, it is also associated with higher risk clinical features and biomarkers. Thus, after adjustment for these clinically important predictors, quantitative STD does not provide incremental prognostic value beyond simple dichotomous evaluation for the presence of STD. Furthermore, adopting quantitative instead of the prognostically proven qualitative evaluation of STD does not improve risk discrimination afforded by the validated GRACE risk models. In conclusion, the findings do not support the quantification of STD in routine clinical practice beyond simple evaluation for the presence of STD as an integral part of comprehensive risk stratification using the GRACE risk score.

A systematic review of BNP as a predictor of prognosis in persons with coronary artery disease

OBJECTIVE

This systematic review was conducted to examine whether B-type natriuretic peptide (BNP) can predict mortality and other cardiac endpoints in persons diagnosed with coronary artery disease (CAD).

DESIGN AND METHODS

Databases were searched from 1989 to February 2005 for primary studies that measured BNP for the purpose of diagnosis, prognosis, and monitoring treatment.

RESULTS

In 18 studies, concentrations of BNP were found to have consistent positive associations with poorer prognoses for persons with CAD. The overall range of effect (95% confidence interval) was 2.31 to 5.02, measured via a random effects meta-analysis on studies reporting an odds ratio. Prognostic ability was similar for mortality and non-fatal outcomes. Ranges of estimated measures of effect (i.e., odds ratio, relative risk, hazard ratio) were concentrated between 1.33 to 2.94 for mortality and 1.01 to 3.03 for non-fatal outcomes.

CONCLUSIONS

Further research is needed to assess whether prognostic ability differs by comorbidity or concomitant treatment. As well, the importance and selection of cut points remains unresolved. Until greater clarity is given to these matters, it would be prudent for clinicians to employ caution when using concentrations of BNP to predict the prognosis of persons with CAD.