The prognostic value of creatine kinase elevations extends across the whole spectrum of acute coronary syndromes

Association of Blood Metals and Metal Mixtures with the Myocardial Enzyme Profile: An Occupational Population-Based Study in China

To investigate a cross-sectional association between blood metal mixture and myocardial enzyme profile, we quantified creatine kinase (CK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LD), α-hydroxybutyrate dehydrogenase (α-HBD), and aspartate transaminase (AST) levels among participants from the manganese-exposed workers healthy cohort (MEWHC) (n = 544). The levels of 22 metals in blood cells were determined using inductively coupled plasma mass spectrometry. The least absolute shrinkage and selection operator (LASSO) penalized regression model was utilized for screening metals. The exposure-response relationship between specific metal and myocardial enzyme profile was identified by general linear regression and restricted cubic spline analyses. The overall effect and interactions were evaluated using Bayesian kernel machine regression (BKMR). Manganese was linearly and positively associated with CK (Poverall = 0.019, Pnon-linearity = 0.307), dominating the positive overall effect of mixture exposure (manganese, arsenic, and rubidium) on CK level. Calcium and zinc were linearly and negatively associated with LD levels (Poverall < 0.05, Pnon-linearity > 0.05), and asserted dominance in the negative overall effect of metal mixtures (rubidium, molybdenum, zinc, nickel, cobalt, calcium, and magnesium) on LD level. Interestingly, we observed a U-shaped dose-response relationship of molybdenum with LD level (Poverall < 0.001, Pnon-linearity = 0.015), an interaction between age and calcium on LD level (Pinteration = 0.041), and an interaction between smoking and molybdenum on LD level (Pinteration = 0.035). Our study provides evidence that metal mixture exposure affects the myocardial enzyme profile. Additional investigation is required to confirm these associations, and to reveal the fundamental mechanisms involved.

Role of Cardiac Biomarkers in Hepatic Disorders: A Literature Review

Various studies have reported the association between cardiac markers and hepatic disorders. The main objective of this review article was to elucidate the significance of important cardiac indicators such as ischemia-modified albumin, cardiac troponin, cardiac natriuretic peptides, creatine kinase, creatine kinase-MB, lactate dehydrogenase, heart-type fatty acid-binding protein, osteopontin, soluble suppression of tumorigenicity 2, C-reactive protein, and lipoprotein(a) in the development of hepatic disorders. In addition, it highlighted recent notable discoveries and accomplishments in this field and identified areas requiring further investigation, ongoing discussions, and potential avenues for future research. Early identification and control of these cardiac markers might be helpful to control the prevalence of hepatic disorders associated with cardiovascular diseases.

Post-Myocardial Infarction Ventricular Remodeling Biomarkers-The Key Link between Pathophysiology and Clinic

Studies in recent years have shown increased interest in developing new methods of evaluation, but also in limiting post infarction ventricular remodeling, hoping to improve ventricular function and the further evolution of the patient. This is the point where biomarkers have proven effective in early detection of remodeling phenomena. There are six main processes that promote the remodeling and each of them has specific biomarkers that can be used in predicting the evolution (myocardial necrosis, neurohormonal activation, inflammatory reaction, hypertrophy and fibrosis, apoptosis, mixed processes). Some of the biomarkers such as creatine kinase-myocardial band (CK-MB), troponin, and N-terminal-pro type B natriuretic peptide (NT-proBNP) were so convincing that they immediately found their place in the post infarction patient evaluation protocol. Others that are related to more complex processes such as inflammatory biomarkers, atheroma plaque destabilization biomarkers, and microRNA are still being studied, but the results so far are promising. This article aims to review the markers used so far, but also the existing data on new markers that could be considered, taking into consideration the most important studies that have been conducted so far.

Safety outcomes with high-dose daptomycin in patients with acute kidney injury and/or end-stage renal disease

WHAT IS KNOWN

Daptomycin is associated with a number of adverse effects including eosinophilic pneumonia, hypersensitivity reaction, myopathy, rhabdomyolysis, headache and transaminitis. The adverse effects of high-dose daptomycin have not been fully evaluated in patients with end-stage renal disease (ESRD).

OBJECTIVE

To determine the incidence and characteristics of significant adverse effects in patients receiving high-dose daptomycin with severe renal dysfunction.

METHODS

A single-centre, retrospective study was conducted to assess safety outcomes of high-dose daptomycin in patients with an estimated creatinine clearance less than 30 mL/min. Adult patients aged 18 to 89 years admitted between 1 July 2015 and 1 July 2019 were eligible for inclusion. Patients must have received definitive daptomycin therapy with doses greater than or equal to 7.5 mg/kg based on actual body weight. The primary outcome was overall incidence of creatine phosphokinase (CK) elevation, myopathy and rhabdomyolysis.

RESULTS AND DISCUSSION

A total of 74 patients who received daptomycin therapy were screened with 50 included in the study. The population was well distributed in terms of gender (48% male, n = 24) with a median age of 61 (IQR, 48-67) years. The primary indication for daptomycin use was Gram-positive bacteremia. The median daptomycin dose was 750 (IQR, 600-875) mg, or 8.46 (IQR, 7.92-9.96) mg/kg based on actual body weight, with a median patient weight of 81 (IQR, 65-113) kg. The median duration of therapy was 27 (IQR, 14-42) days. One patient experienced significant CK elevation while on daptomycin therapy with rhabdomyolysis; however, daptomycin was continued as there was an alternative explanation for an elevated CK. One patient experienced daptomycin discontinuation due to CK elevation without meeting the definition for significant CK elevation.

WHAT IS NEW AND CONCLUSION

In a cohort of patients with severe renal dysfunction treated with daptomycin 7.5 mg/kg or greater, significant CK elevation on daptomycin therapy was infrequently observed. Future research should confirm these findings, with special consideration for higher mg/kg dosages and/or obese populations.

Occupational exposure to manganese and risk of creatine kinase and creatine kinase-MB elevation among ferromanganese refinery workers

BACKGROUND

Elevated exposure to manganese (Mn) could induce cardiovascular dysfunction. However, limited research is available on the effects of occupational Mn exposure on myocardial enzymes. We aimed to evaluate the relationships between Mn exposure and myocardial enzyme elevation among Mn-exposed workers.

METHODS

Data were from a follow-up investigation of a Mn-exposed workers healthy cohort in 2017. A total of 744 workers were divided into low-exposure and high-exposure groups according to Mn time-weighted average (Mn-TWA) of less than or equal to 0.15 mg/m³ or greater than 0.15 mg/m³ , respectively. Serum levels of myocardial enzymes, including creatine kinase (CK) and creatine kinase-MB (CK-MB), lactic dehydrogenase, α-hydroxybutyrate dehydrogenase, and aspartate transaminase, were assessed, as well as airborne Mn exposure levels.

RESULTS

After adjustment for sex, body mass index, seniority, education, current smoking status, current drinking status, and hypertension, Mn-TWA levels were positively associated with the risk of CK elevation (odds ratio [OR] = 1.47 (95% confidence interval [CI]: 1.18-1.83) per interquartile range [IQR] increase), and risk of CK-MB elevation [OR = 1.57 (95% CI: 1.03-2.38) per IQR increase]. In a stratified analysis, Mn-TWA levels were positively correlated with CK elevation in workers of seniority greater than 19 years, male workers, current smokers, and drinkers.

CONCLUSION

Our results suggest that occupational exposure to Mn is associated with increased risk of CK and CK-MB elevation. The potential mechanisms of the associations between airborne exposure to Mn and increased risk of these myocardial enzyme elevations warrant further investigation.

Convalescent troponin and cardiovascular death following acute coronary syndrome

OBJECTIVES

High-sensitivity cardiac troponin testing is used in the diagnosis of acute coronary syndromes but its role during convalescence is unknown. We investigated the long-term prognostic significance of serial convalescent high-sensitivity cardiac troponin concentrations following acute coronary syndrome.

METHODS

In a prospective multicentre observational cohort study of 2140 patients with acute coronary syndrome, cardiac troponin I concentrations were measured in 1776 patients at 4 and 12 months following the index event. Patients were stratified into three groups according to the troponin concentration at 4 months using the 99th centile (women>16 ng/L, men>34 ng/L) and median concentration of those within the reference range. The primary outcome was cardiovascular death.

RESULTS

Troponin concentrations at 4 months were measurable in 99.0% (1759/1776) of patients (67±12 years, 72% male), and were ≤5 ng/L (median) and >99th centile in 44.8% (795) and 9.3% (166), respectively. There were 202 (11.4%) cardiovascular deaths after a median of 4.8 years. After adjusting for the Global Registry of Acute Coronary Events score, troponin remained an independent predictor of cardiovascular death (HR 1.4, 95% CI 1.3 to 1.5 per doubling) with the highest risk observed in those with increasing concentrations at 12 months. Patients with 4-month troponin concentrations >99th centile were at increased risk of cardiovascular death compared with those ≤5 ng/L (29.5% (49/166) vs 4.3% (34/795); adjusted HR 4.9, 95% CI 3.8 to 23.7).

CONCLUSIONS

Convalescent cardiac troponin concentrations predict long-term cardiovascular death following acute coronary syndrome. Recognising this risk by monitoring troponin may improve targeting of therapeutic interventions.

TRIAL REGISTRATION NUMBER

ACTRN12605000431628;Results.

Cardiac Biomarkers: What Is and What Can Be

Cardiac biomarkers are of great importance in the timely, accurate diagnosis and management of acute coronary syndrome as well as the prognosis. Diagnosis in the golden period is of utmost importance to institute therapy at the earliest and possibly reverse the myocardial damage. Cardiac biomarkers are also a powerful tool for triaging. Among the many biomarkers, the earliest examined were the myocardial enzymes, several myocardial proteins, peptides, and many other molecules. The latest addition to the repertoire is the microRNAs, which are stable molecules detectable in circulation. About four groups are found to be involved in regulation of circulatory system, and some show promise as specific and early markers of acute coronary syndrome and cardiac dysfunction. As in other fields of medicine, personalized precise treatment may be possible with the use of microRNAs. However, as of now, a multipronged approach, involving different markers of which troponins are necessary, seems to be the best way forward.

Outcomes of Elderly Patients with ST-Elevation or Non-ST-Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

INTRODUCTION

Acute coronary syndromes (ACS) have been classified according to the finding of ST-segment elevation on the presenting electrocardiogram, with different treatment strategies and practice guidelines. However, a comparative description of the clinical characteristics and outcomes of acute coronary syndrome elderly patients undergoing percutaneous coronary intervention during index admission has not been published so far.

METHODS

Retrospective cohort study of patients enrolled in the Elderly ACS-2 multicenter randomized trial. Main outcome measures were crude cumulative incidence and cause-specific hazard ratio (cHR) of cardiovascular death, noncardiovascular death, reinfarction, and stroke.

RESULTS

Of 1443 ACS patients aged >75 years (median age 80 years, interquartile range 77-84), 41% were classified as ST-elevation myocardial infarction (STEMI), and 59% had non-ST-elevation ACS (NSTEACS) (48% NSTEMI and 11% unstable angina). As compared with those with NSTEACS, STEMI patients had more favorable baseline risk factors, fewer prior cardiovascular events, and less severe coronary disease, but lower ejection fraction (45% vs 50%, P < .001). At a median follow-up of 12 months, 51 (8.6%) STEMI patients had died, vs 39 (4.6%) NSTEACS patients. After adjusting for sex, age, and previous myocardial infarction, the hazard among the STEMI group was significantly higher for cardiovascular death (cHR 1.85; 95% confidence interval [CI], 1.02-3.36), noncardiovascular death (cHR 2.10; 95% CI, 1.01-4.38), and stroke (cHR 4.8; 95% CI, 1.7-13.7).

CONCLUSIONS

Despite more favorable baseline characteristics, elderly STEMI patients have worse survival and a higher risk of stroke compared with NSTEACS patients after percutaneous coronary intervention.

Exercise-related resuscitated out-of-hospital cardiac arrest due to presumed myocardial ischemia: Result from coronary angiography and intravascular ultrasound

AIM

Possible causes of exercise-related out-of-hospital cardiac arrest (OHCA) in people with coronary artery disease (CAD) include atherosclerotic plaque rupture (PR) and intra-coronary thrombosis, exercise-induced myocardial ischaemia and other triggers. We investigated whether there are differences in the incidence of PR and/or intra-coronary thrombus and in clinical outcome between 'exercise-related' and 'non-exercise-related' OHCA.

METHODS

219 consecutive resuscitated patients with CAD diagnosed by emergency coronary angiography (CAG) were enrolled. They were divided into the exercise group (≥6 METs; n = 35) and non-exercise group (<6 METs; n = 184), according to estimated METs immediately before OHCA using 2011 Compendium of Physical Activities. We investigated whether culprit lesions had PR and/or thrombus using CAG and intravascular ultrasound. The clinical outcome was 30-day survival with minimal neurologic impairment.

RESULTS

Acute PR and/or thrombus occurred in fewer of the exercise group than the non-exercise group (11% vs. 90%; P < 0.001). The exercise group had a higher incidence of favorable neurological outcome (94% vs. 47%; P < 0.001) than the non-exercise group. Multivariable Cox proportional hazards models revealed that exercise immediately before OHCA was one of the predictors of a good neurological outcome (HR, 0.19; P = 0.025).

CONCLUSION

The incidence of PR and/or thrombosis was lower in the group taking higher levels of exercise, than in the group taking less or no exercise. "Exercise-related" OHCA with CAD has better clinical outcomes than "non-exercise-related" with a greater proportion of witnessed arrests and early return of spontaneous circulation.

Chip-based digital PCR as a novel detection method for quantifying microRNAs in acute myocardial infarction patients

miRNAs have shown promise as potential biomarkers for acute myocardial infarction (AMI). However, the current used quantitative real-time PCR (qRT-PCR) allows solely for relative expression of nucleic acids and it is susceptible to day-to-day variability, which has limited the validity of using the miRNAs as biomarkers. In this study we explored the technical qualities and diagnostic potential of a new technique, chip-based digital PCR, in quantifying the miRNAs in patients with AMI and ischaemia-reperfusion injury (I/R). In a dilution series of synthetic C.elegans-miR-39, chip-based digital PCR displayed a lower coefficient of variation (8.9% vs 46.3%) and a lower limit of detection (0.2 copies/μL vs 1.1 copies/μL) compared with qRT-PCR. In the serum collected from 24 patients with ST-elevation myocardial infarction (STEMI) and 20 patients with stable coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI), we used qRT-PCR and multiplexed chip-based digital PCR to quantify the serum levels of miRNA-21 and miRNA-499 as they have been validated in AMI in prior studies. In STEMI, I/R injury was assessed via measurement of ST-segment resolution (ST-R). Chip-based digital PCR revealed a statistical significance in the difference of miR-21 levels between stable CAD and STEMI groups (118.8 copies/μL vs 59 copies/μL; P=0.0300), whereas qRT-PCR was unable to reach significance (136.4 copies/μL vs 122.8 copies/μL; P=0.2273). For miR-499 levels, both chip-based digital PCR and qRT-PCR revealed statistically significant differences between stable CAD and STEMI groups (2 copies/μL vs 8.5 copies/μL, P=0.0011; 0 copies/μL vs 19.4 copies/μL; P<0.0001). There was no association between miR-21/499 levels and ST-R post-PCI. Our results show that the chip-based digital PCR exhibits superior technical qualities and promises to be a superior method for quantifying miRNA levels in the circulation, which may become a more accurate and reproducible method for directly quantifying miRNAs, particularly for use in large multi-centre clinical trials.

CKM Glu83Gly Is Associated With Blunted Creatine Kinase Variation, but Not With Myalgia

BACKGROUND

To test the association of a recently reported variant in the creatine kinase (CK) muscle gene, CKM Glu83Gly (rs11559024) with constitutive creatine phosphokinase (CK) levels, CK variation, and inducibility. Given the diagnostic importance of CK in determining muscle damage, we tested the association of the variant with myalgia.

METHODS AND RESULTS

Meta-analysis between longitudinal cohort GoDARTS (Genetics of Diabetes Audit and Research, Tayside Scotland), minor allele frequency (=0.02), and randomized clinical trial (JUPITER [Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin], minor allele frequency=0.018) was used to replicate the association with baseline CK measures. GoDARTS was used to study the relationship with CK variability. Myalgia was studied in JUPITER trial participants. Baseline and SDs of CK were on average 18% (P value=6×10^-63) and 24% (P value=2×10^-5) lower for carriers of the variant, respectively. The variant was not associated with myalgia (odds ratio, 0.84; 95% confidence interval, 0.52-1.38).

CONCLUSIONS

This study highlights that a genetic factor known to be associated with constitutive CK levels is also associated with CK variability and inducibility. This is discussed in the context of evidence to suggest that the variant has an impact on inducibility of CK by trauma through a previously reported case of a homozygous carrier. However, the lack of association between the variant and myalgia suggests that it cannot reliably be used as a biomarker for muscle symptoms.

Radial artery intima-media thickness regresses after secondary prevention interventions in patients' post-acute coronary syndrome and is associated with cardiac and kidney biomarkers

BACKGROUND

Radial artery intima-media thickness (rIMT) measured by ultra-high-resolution ultrasound is associated with increased cardiovascular risk and predicts outcomes. We performed non-invasive high-resolution ultrasound of the radial artery to investigate vascular changes in subjects presenting with acute coronary syndrome (ACS) and who had undergone percutaneous coronary intervention (PCI).

PURPOSE

In the present work, we aimed to follow rIMT change over time post-acute coronary syndrome as a tool to monitor potential response to intensified medical therapy.

METHODS

We examined 256 subjects who underwent PCI due to ACS and healthy controls (n= 39) and we measured a number of biomarkers, which are known to be associated with cardiovascular disease. Images of radial artery were acquired bilaterally in the longitudinal view using a 50 MHz transducer (Vevo 2100 VisualSonics, Inc, Toronto, Ontario, Canada). Carotid IMT (cIMT) and rIMT were measured at <1 month after index PCI followed by a repeated measurement of rIMT at 4 months from the ACS in a sub-set (n=117).

RESULTS

rIMT measured within 1 month post ACS was significantly higher than rIMT after 4 months from ACS, (p < 0.0001), mean ± SD (rIMT right 0.35 ± 0.08; rIMT left 0.37 ± 0.08) vs. (rIMT right 0.29 ± 0.08; rIMT left 0.31 ± 0.09) respectively. There was no statistically significant change in cIMT. In healthy controls there were no changes in rIMT or cIMT overtime. High levels of CX3CL1 and myeloperoxidase measured within one month post ACS are associated with increase of rIMT, r=0.38 (p< 0.0001) and r=0.41 (p< 0.0001) respectively.

CONCLUSIONS

rIMT seem to decrease systemically after ACS and is accompanied with corresponding biomarker change. The cause and clinical implications of the observed decrement in rIMT after ACS need further studies.

Biomarkers of Cardiac Injury: An Update

Conventional and promising new markers of myocardial injury have become an important diagnostic tool and their prognostic significance is also recognized. In addition, they help identify patients who will derive the most benefit from therapeutic interventions. The literature was searched from the websites of the National Library of Medicine (http://www.ncbi.nlm.nih.gov/) and PubMed Central, the U.S. National Library of Medicine’s digital archive of life sciences journal literature (http://www.pubmedcentral.nih.gov/). The data were accessed from books and journals that published relevant articles in this field. The diagnosis of acute myocardial infarction (AMI) has traditionally relied on the combination of chest pain, ECG features, and elevation in serum markers. However, chest symptoms are frequently atypical or absent and ECG changes may be nonspecific or absent. Hence, the diagnosis of acute coronary syndromes has become increasingly dependent on serum markers of cardiac injury. Among them, creatine kinase (CK) is an effective and widely used test, with the recent CKMB assay offering greater specificity and sensitivity. Cardiac troponins facilitate early and rapid diagnosis, enable effective risk stratification in patients with AMI (with or without traditional criteria for MI), and identify those who will benefit from aggressive medical or surgical intervention. Recent data suggest the potential of myoglobin and CKMB isoforms as sensitive markers in the early hours after symptom onset. Cardiac-specific troponins help in rapid diagnosis, prognostication, and treatment of AMI. Troponins also facilitate early detection of recent infarction owing to their prolonged diagnostic window and also aid in the detection of “microinfarction.” CKMB is used to detect reinfarction or infarct extension, if levels rise again after declining. Finally, novel biochemical markers are receiving attention in ongoing trials. They may prove to be more effective in diagnosis and prognosis than their existing counterparts.

Incidence and impact on prognosis of peri-procedural myocardial infarction in 2760 elective patients with stable angina pectoris in a historical prospective follow-up study

BACKGROUND

The clinical significance of myocardial infarction related to treatment with percutaneous coronary intervention (PCI) has been subject of great discussion. This subject has been studied for many years using different definitions of peri-procedural myocardial infarction and different biomarkers, the results have varied greatly depending on methods and time of the study. This study was to determine the incidence and prognostic significance of elevated cardiac biomarkers after elective PCI in patients with stable angina pectoris using the current cut-off set by the Third Universal Definition of Myocardial Infarction and current biomarkers.

METHODS

We performed a historical prospective follow-up study of all patients with stable angina pectoris who underwent elective PCI at Aalborg University Hospital, Denmark from January 1(st) 2000 to December 31(st) 2012. We stratified patients according to peak post-PCI troponin T (cTnT) and Creatine Kinase MB mass (CK-MBmass).

RESULTS

Follow-up for time to all-cause mortality was mean 5.8 years and total 15,891 years and mean 3.7 years and total 10,160 years for the combined endpoint of all-cause mortality and new onset heart failure. During the follow up period 399 of 2760 patients died (14.5 %) and 1095 (39.7 %) suffered the combined endpoint. Post-PCI concentration of cTnT and CK-MBmass was elevated above the defined cut-off in 419 patients (15.2 %) and 113 patients (4.1 %) respectively. There was no statistically significant difference between the groups in stratified analysis of the hazard rates by time regarding all-cause mortality for cTnT nor CK-MBmass. Regarding the combined endpoint the results were ambiguous. The results were unchanged in multivariable analyses that included age and gender.

CONCLUSION

The incidence of elevated biomarkers after elective PCI in patients with stable angina pectoris using the defined cut-off (>5 x URL) was 15.2 % using cTnT and 4.1 % using CK-MBmass. The independent prognostic value for both cardiac biomarkers of any cut-off showed no statistical significance for all-cause mortality, whereas the combined endpoint (all-cause mortality or new-onset heart failure) were ambiguous in both short- and long-term follow-up.

[Impact of plasma pro-B-type natriuretic peptide amino-terminal and galectin-3 levels on the predictive capacity of the LIPID Clinical Risk Scale in stable coronary disease]

INTRODUCTION

At present, there is no tool validated by scientific societies for risk stratification of patients with stable coronary artery disease (SCAD). It has been shown that plasma levels of monocyte chemoattractant protein-1 (MCP-1), galectin-3 and pro-B-type natriuretic peptide amino-terminal (NT-proBNP) have prognostic value in this population.

OBJECTIVE

To analyze the prognostic value of a clinical risk scale published in Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) study and determining its predictive capacity when combined with plasma levels of MCP-1, galectin-3 and NT-proBNP in patients with SCAD.

METHODS AND RESULTS

A total of 706 patients with SCAD and a history of acute coronary syndrome (ACS) were analyzed over a follow up period of 2.2 ± 0.99 years. The primary endpoint was the occurrence of an ischemic event (any SCA, stroke or transient ischemic attack), heart failure, or death. A clinical risk scale derived from the LIPID study significantly predicted the development of the primary endpoint, with an area under the ROC curve (Receiver Operating Characteristic) of 0.642 (0.579 to 0.705); P<0.001. A composite score was developed by adding the scores of the LIPID and scale decile levels of MCP -1, galectin -3 and NT-proBNP. The predictive value improved with an area under the curve of 0.744 (0.684 to 0.805); P<0.001 (P=0.022 for comparison). A score greater than 21.5 had a sensitivity of 74% and a specificity of 61% for the development of the primary endpoint (P<0.001, log -rank test).

CONCLUSION

Plasma levels of MCP-1, galectin -3 and NT-proBNP improve the ability of the LIPID clinical scale to predict the prognosis of patients with SCAD.

Myocardial washout rate of technetium-99m-sestamibi in the chronic phase predicts myocardial damage in patients with previous myocardial infarction

OBJECTIVE

This study aimed to clarify the correlation between the myocardial washout rate (WR) of technetium-99m hexakis 2-methoxy-isobutyl-isonitrile ((99m)Tc-sestamibi) and cardiac enzyme levels in patients with acute myocardial infarction (AMI) 6 months after the onset.

METHODS

Sixty-one consecutive AMI patients (mean age, 66.2 ± 9.7 years) who underwent percutaneous coronary intervention (PCI) on admission were enrolled. Creatinine kinase MB isoenzyme (CK-MB) levels were measured every 3 h. (99m)Tc-sestamibi myocardial scintigraphic images were obtained at the early (30 min) and delayed (4 h) phases after tracer injection for calculating heart-to-mediastinum (H/M) ratios and global WRs at 2 weeks (0 M) and 6 months (6 M) after the onset of AMI. Regional WRs in the culprit lesions (culprit WR) and the extent score (ES) and severity score (SS) of myocardial damage were also calculated.

RESULTS

PCI was performed 8.3 ± 7.7 h after AMI onset. At 6 M, the early H/M ratio (p = 0.04), delayed H/M ratio (p = 0.02), global WR (p = 0.01), culprit WR (p = 0.002), and delayed ES (p = 0.008) were alleviated. At 0 M, the peak CK-MB level correlated with the delayed H/M ratio (p = 0.003), global WR (p = 0.003), culprit WR (p < 0.001), early ES (p = 0.03), delayed ES (p = 0.01), early SS (p = 0.001), and delayed SS (p < 0.001). At 6 M, the peak CK-MB level correlated with the delayed H/M ratio (p < 0.001), global WR (p = 0.005), culprit WR (p = 0.001), early ES (p = 0.001), delayed ES (p < 0.001), early SS (p < 0.001), and delayed SS (p < 0.001).

CONCLUSIONS

These results demonstrated that (99m)Tc-sestamibi WR in the chronic phase as well as that in the acute phase reflects the extent of initial myocardial damage in AMI patients after PCI. Moreover, it might indicate the myocardial condition in the clinical course.

Explicit risk in acute coronary syndrome management

At least implicitly, most clinical decisions represent an integration of disease and treatment-based risk assessments. Often, as is the case with acute coronary syndrome (ACS), these decisions need to be made quickly at a time when data elements are limited, and published risk models are very useful in clarifying time-dependent determinants of risk. The present review emphasizes the value of explicit risk assessment and reinforces the fact that patients at highest risk are often those most likely to benefit from newer and more invasive therapies. Suggested ways to incorporate published ACS risk models into clinical practice are included. In addition, the need to adopt a longer-term view of risk in ACS patients is stressed, with particular regard to the important role of heart failure prediction and treatment.

Target populations and relevant therapeutic end points to further improve outcomes in NSTEACS patients

An aggressive pharmaco-interventional approach has been shown to improve long-term outcome among high-risk patients with acute coronary syndromes without ST-segment elevation (NSTEACS). However, these patients continue to represent a minority among those enrolled in clinical trials, thus precluding the possibility to further improve therapeutic efficacy. Target populations that are not adequately addressed by the majority of therapeutic trials are mainly the elderly and those with reduced renal function, who all show unfavorable outcome after an episode of NSTEACS. In order to allow comparison among different studies, a prerequisite for the planning of meaningful trials should be a uniform definition of the study end points besides mortality, particularly with reference to recurrent myocardial infarction, and rehospitalization owing to cardiovascular instability or severe bleeding. In addition to trial design issues, improvements in the regulatory rules for drug development and in hospital networking conceal significant opportunities to improve treatment of NSTEACS.

Prevalence and Impact of Diabetes Mellitus in Patients With Acute Myocardial Infarction: A 10-year Experience

Background: Diabetes mellitus is associated with a higher incidence of acute myocardial infarction. Objective: To study the prevalence and outcome of patients with diabetes among patients with acute myocardial infarction. Methods: Retrospectively, patients who presented with acute myocardial infarction in a 10-year period were identified from the coronary care unit database. Results: A total of 1598 Qatari patients were admitted with acute myocardial infarction, 863 (54%) of them had diabetes mellitus (females 68.5% vs males 48.3%; P < .001). In-hospital mortality rate was non-significantly higher in diabetic patients (18% vs 15% P = .15). Aspirin (odds ratio 2.39, 95% confidence interval 1.96-2.90, P = .003] and β-blocker use (odds ratio 1.75, 95% CI 1.21-2.52, P = .0001) were independently associated with reduced mortality risk. Conclusions: The prevalence of diabetes mellitus among patients with acute myocardial infarction in a geographically defined population in the developing world is high with a trend for poor outcomes. However, mortality was not significantly higher in diabetes mellitus than non-diabetes mellitus patients.

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.

Prognostic importance of creatine kinase and creatine kinase-MB after primary percutaneous coronary intervention for ST-elevation myocardial infarction

BACKGROUND

Although the prognostic significance of creatine kinase (CK) and creatine kinase-MB (CK-MB) after myocardial infarction has been established after thrombolysis or no reperfusion therapy, there is limited evidence of the prognostic importance after primary percutaneous coronary intervention (PCI).

METHODS

In this prospective, observational study, individual data from all patients who survived at least 2 days after primary PCI between 1991 and 2004 in our hospital were recorded. The association between enzymatic infarct size (examined by peak CK and peak CK-MB levels, each divided into tertiles) and both left ventricular ejection fraction (LVEF) and 1-year mortality was evaluated.

RESULTS

In the study group of 4670 patients, mean peak CK was 2327 U/L (SD 2008) and mean peak CK-MB was 244 U/L (SD 208). Both increased CK and CK-MB were associated with a lower LVEF. A total of 252 patients (5.4%) died between 2 days and 1 year after admission. Both peak CK and peak CK-MB were higher in those who died. Particularly, patients in the highest tertile of either peak CK or peak CK-MB had increased mortality, whereas the differences between the lower tertiles were not significant. In 2738 patients, after multivariable analysis including LVEF, the hazard ratio for 1-year mortality in patients in the highest CK tertile was 2.28 (95% CI 1.32-3.91) and for CK-MB, 1.91 (95% CI 1.11-3.26), compared to those in the other tertiles.

CONCLUSIONS

According to this large-scale study, peak CK and peak CK-MB are comparable independent predictors of LV function and 1-year mortality in patients after primary PCI.

Prognostic Implications of Creatine Kinase Elevation After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

OBJECTIVES

We examined the prognostic implications of the absolute level and rate of increase of creatine kinase (CK) elevation after primary percutaneous coronary intervention (PCI).

BACKGROUND

Peak creatine kinase (CK(peak)) and the rate of CK increase are related to reperfusion success and clinical outcomes after thrombolytic therapy for acute myocardial infarction (AMI). The utility of routine serial CK monitoring after primary PCI, in which normal antegrade blood flow is restored in most patients, is unknown.

METHODS

In the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial, 1,529 patients with AMI randomized to either stenting or balloon angioplasty, each with or without abciximab, had CK levels determined at baseline and at 8 +/- 1 h, 16 +/- 1 h, and 24 +/- 1 h after PCI.

RESULTS

The CK(peak) occurred at baseline in 3.9% of patients, at 8 +/- 1 h in 69.6%, at 16 +/- 1 h in 20.0%, and at 24 +/- 1 h in 6.5%. The CK levels at all post-procedural time points were significantly higher in patients who died compared with the one-year survivors, as was CK(peak) (mean, 2,865 U/l vs. 1,885 U/l, respectively, p < or = 0.001). By multivariate analysis, CK(peak) was a significant predictor of one-year mortality (hazard ratio = 2.15, p = 0.0002), independent from post-PCI Thrombolysis In Myocardial Infarction (TIMI) flow. Both the improvement in left ventricular ejection fraction from baseline to seven months and its absolute level were inversely correlated with CK(peak) (p < 0.001 for both). In contrast, the time to CK(peak) was not an independent predictor of mortality or myocardial recovery.

CONCLUSIONS

The CK(peak) after primary PCI is a powerful predictor of one-year mortality independent of other clinical and angiographic measures.

Elevated creatine kinase-MB with normal creatine kinase predicts worse outcomes in patients with acute coronary syndromes: results from 4 large clinical trials

BACKGROUND

The degree to which elevated creatine kinase (CK)-MB in the presence of normal CK is predictive of outcome is not well understood despite having been studied for decades. This analysis examined whether normal CK with elevated CK-MB in patients with non-ST-segment elevation acute coronary syndrome (NSTE ACS) is an independent predictor of worse outcomes. A concomitant goal was to contribute insight to the debate over how patients with NSTE ACS should be managed.

METHODS

Data for 25,960 patients from the GUSTO IIb, PARAGON A and B, and PURSUIT trials were analyzed. Of these patients, 6402 were excluded from primary analysis because of missing (unmeasured) biomarkers. Patients with complete laboratory data (n = 19,558) were grouped by CK and CK-MB results. To confirm the primary analysis results, data from patients with missing biomarkers were used in an imputation model.

RESULTS

Patients were categorized in 1 of 4 groups: normal CK + normal CK-MB; normal CK + elevated CK-MB; elevated CK + normal CK-MB; or elevated CK + elevated CK-MB. For the primary outcome, 180-day death, or myocardial infarction, Kaplan-Meier estimates were 14.9%, 20.8%, 14.5%, and 18.2%, respectively. Regardless of total CK, elevated CK-MB was associated with a 25% to 49% increased relative risk of worse outcomes. Findings from the analyses were verified by the multivariable model.

CONCLUSIONS

CK-MB remains a reliable marker for myocardial necrosis and a strong predictor of worse prognosis. All patients with ACS should have CK-MB measurement to search for cardiac ischemia. Patients with elevated CK-MB should receive aggressive management commensurate with their increased risks.

Effects of tirofiban plus clopidogrel versus clopidogrel plus provisional abciximab on biomarkers of myocardial necrosis in patients with non-ST-elevation acute coronary syndromes treated with early aggressive approach. Results of the CLOpidogrel, upstream TIrofiban, in cath Lab Downstream Abciximab (CLOTILDA) study

BACKGROUND

In non-ST-elevation acute coronary syndromes (NSTE-ACS), a strong correlation between adverse clinical events and peak values of myocardial necrosis markers has been found. In this study, we evaluated whether the adjunctive treatment with upstream tirofiban reduces the peak levels of cardiac troponin I and creatine kinase-MB (CK-MB) fraction in patients with NSTE-ACS undergoing early invasive strategy and pretreated with aspirin, heparin, and clopidogrel.

METHODS

A total of 300 patients were randomized to receive tirofiban (group 1) or not (group 2). Serial marker samples were collected before and after coronary angiography in all cases and after percutaneous coronary intervention (PCI) when performed.

RESULTS

Between the 2 groups, no differences were observed in clinical and angiographic findings. Percutaneous coronary intervention was globally performed in 198 patients (66%). Of 99 group 2 patients, 26 (26%) received abciximab just before PCI. No significant differences between the 2 groups were observed with regard to cardiac troponin I and CK-MB values at admission and at 6, 12, and 24 hours thereafter; peak values before coronary angiography; and peak values of index event. In addition, the cumulative biomarkers release of the index event was similar between the 2 groups. Major bleeding rate was 2% in group 1 and 1% in group 2 (P = not significant). Composite incidence of death, myocardial infarction, or rehospitalization for ACS at 30 days was 9% in group 1 and 10% in group 2.

CONCLUSIONS

In patients with NSTE-ACS undergoing early invasive strategy, the adjunctive administration of upstream tirofiban did not reduce the peak values and the cumulative release of myocardial necrosis markers, compared with aspirin, heparin, and clopidogrel given on admission and associated with selective use of abciximab just before PCI.

Extent of ST-segment depression and cardiac events in non-ST-segment elevation acute coronary syndromes

AIMS

We sought to determine whether the extent of myocardial ischaemia on the admission electrocardiogram (ECG) has independent predictive value for short-term risk stratification of patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS). Although the presence of ischaemic ECG changes on admission has been shown to predict outcome, the relationship between the extent of ECG changes and the risk of cardiac events is still ill defined.

METHODS AND RESULTS

We analysed the admission ECGs of 5192 ACS patients enrolled in the GUSTO-IIb trial, without an ECG indication for thrombolysis. ECG tracings showing one or more of the following were eligible: ST-segment depression >0.5 mm, T-wave inversion >1 mm, and ST-segment elevation >0.5 mm but <1 mm. ECG variables associated with unfavourable 30 day outcomes in a univariable analysis were further assessed in a multivariable logistic regression model including independent clinical predictors. In the multivariable clinical, enzymatic, and ECG model, the sum of ST-segment depression (in millimetres) in all leads was a powerful independent predictor of 30 day death (P<0.0001), with a continuous increase in risk with the extent of ST-segment depression. The sum of ST-segment depression (P<0.0001) and the presence of minimal inferior ST-segment elevation (P<0.0001) or anterior ST-segment elevation (P=0.0182) were also independent predictors of the composite of death and myocardial infarction or reinfarction. The extent of ST-segment depression showed a highly significant correlation with the prevalence of three-vessel (P<0.0001) or left main coronary disease (P<0.0001), and also with the peak levels of creatine kinase (P<0.0001) during the index episode of ACS.

CONCLUSION

In patients with NSTE ACS, the sum of ST-segment depression in all ECG leads is a powerful predictor of all-cause mortality at 30 days, independent of clinical variables and correlates with the extent and severity of coronary artery disease. The presence of even minimal (<1 mm) ST-segment elevation in anterior or inferior leads is independently associated with adverse outcomes.

Reduced creatine kinase release with statin use at the time of myocardial infarction

BACKGROUND

Statin pre-treatment has been shown to reduce myocardial infarct size in animal models. We evaluated peak creatine kinase levels in humans based on concomitant or very early statin initiation following myocardial infarction.

METHODS

We identified 66 consecutive patients who received a statin within 24 h of admission to our coronary care unit for myocardial infarction. Each statin patient was matched with three patients who had not received statin therapy (n=198). Statin patients were subgrouped into those receiving statin therapy at the time of infarction (n=44) and those initiated on statin therapy within 24 h of infarction (n=22). Peak total creatine kinase concentrations were compared between groups. A linear regression model was developed to test for differences in peak creatine kinase after adjusting for differences between groups.

RESULTS

Patients receiving statin therapy within 24 h of admission had significantly smaller median peak creatine kinase concentrations compared to those not receiving a statin (416 IU/l [258, 992] vs. 699 IU/l [339, 1728]; p=0.020). Subgroup analysis revealed that the lower peak creatine kinase concentrations within the statin group were a result of lower creatine kinase concentrations in those patients on a statin at the time of myocardial infarction (399 IU/l [255, 869] vs. 678 IU/l [276, 1870]; p<0.05). This difference retained statistical significance after adjustment for differences between groups.

CONCLUSION

Statin therapy at the time of myocardial infarction is associated with lower peak creatine kinase concentrations. This suggests that statins may exhibit protective effects in the setting of myocardial ischemia and/or infarction in humans.

A single serum glucose measurement predicts adverse outcomes across the whole range of acute coronary syndromes

OBJECTIVES

To analyse the relation between serum glucose concentration and hospital outcome across the whole spectrum of acute coronary syndromes.

METHODS

This was a prospective cohort study of 2127 patients presenting with acute coronary syndromes. The patients were stratified into quartile groups (Q1 to Q4) defined by serum glucose concentrations of 5.8, 7.2, and 10.0 mmol/l. The relation between quartile group and major in-hospital complications was analysed.

RESULTS

The proportion of patients with acute myocardial infarction increased incrementally across the quartile groups, from 21.4% in Q1 to 47.9% in Q4 (p < 0.0001). The trend for frequency of in-hospital major complications was similar, particularly left ventricular failure (LVF) (Q1 6.4%, Q4 25.2%, p < 0.0001) and cardiac death (Q1 0.7%, Q4 6.1%, p < 0.0001). The relations were linear, each glucose quartile increment being associated with an odds ratio of 1.46 (95% confidence interval (CI) 1.27 to 1.70) for LVF and 1.52 (95% CI 1.17 to 1.97) for cardiac death. Although complication rates were higher for a discharge diagnosis of acute myocardial infarction than for unstable angina, there was no evidence that the effects of serum glucose concentration were different for the two groups, there being no significant interaction with discharge diagnosis in the associations between glucose quartile and LVF (p = 0.69) or cardiac death (p = 0.17). Similarly there was no significant interaction with diabetic status in the associations between glucose quartile and LVF (p = 0.08) or cardiac death (p = 0.09).

CONCLUSION

Admission glycaemia stratified patients with acute coronary syndromes according to their risk of in-hospital LVF and cardiac mortality. There was no detectable glycaemic threshold for these adverse effects. The prognostic correlates of admission glycaemia were unaffected by diabetic status and did not differ significantly between patients with acute myocardial infarction and those with unstable angina.