High-sensitivity cardiac troponin for risk prediction in patients with and without coronary heart disease

Blood-Based and Imaging Biomarkers of Atherosclerosis

Atherosclerosis is the main cause of arterial thrombosis, causing acute occlusive cardiovascular syndromes. Numerous risk prediction models have been developed, which mathematically combine multiple predictors, to estimate the risk of developing cardiovascular events. Current risk models typically do not include information from biomarkers that can potentially improve these existing prediction models especially if they are pathophysiologically relevant. Numerous cardiovascular disease biomarkers have been investigated that have focused on known pathophysiological pathways including those related to cardiac stress, inflammation, matrix remodelling, and endothelial dysfunction. Imaging biomarkers have also been studied that have yielded promising results with a potential higher degree of clinical applicability in detection of atherosclerosis and cardiovascular event prediction. To further improve therapy decision-making and guidance, there is continuing intense research on emerging biologically relevant biomarkers. As the pathogenesis of cardiovascular disease is multifactorial, improvements in discrimination and reclassification in risk prediction models will likely involve multiple biomarkers. This article will provide an overview of the literature on potential blood-based and imaging biomarkers of atherosclerosis studied so far, as well as potential future directions.

Premorbid levels of high-sensitivity cardiac troponin T and natriuretic peptide and prognosis after incident myocardial infarction

High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at the time of myocardial infarction (MI) are strong predictors of prognosis. However, whether their premorbid (before MI occurrence) levels are associated with prognosis after incident MI is unknown.

METHODS

In 1,054 participants from the Atherosclerosis Risk in Communities Study with incident MI, we evaluated premorbid levels of hs-cTnT and NT-proBNP measured on median 5.8 (interquartile interval 3.0-11.5 [mean 5.5]) years prior to incident MI and their associations with subsequent composite and individual outcomes of all-cause mortality, cardiovascular mortality, recurrent MI, heart failure, and stroke.

RESULTS

During a median follow-up of 3.0 years after MI, 801 participants developed the composite outcome. Both hs-cTnT and NT-proBNP were independently associated with the composite outcome after incident MI. Among individual outcomes, all-cause mortality, cardiovascular mortality, and heart failure showed significant associations with both cardiac markers. Overall, NT-proBNP demonstrated a more evident relationship than hs-cTnT. Indeed, the addition of premorbid NT-proBNP alone, but not hs-cTnT alone, to conventional predictors at incident MI significantly improved risk prediction of the composite outcome after incident MI (Δc-statistic 0.013 [95% CI 0.005-0.022] from 0.691 with conventional predictors).

CONCLUSIONS

Premorbid levels of hs-cTnT and NT-proBNP assessed on average 6 years prior to incident MI were associated with adverse outcomes after incident MI. These results further highlight the importance of cardiac health at an earlier stage of life.

Associations between Skeletal Muscle and Myocardium in Aging: A Syndrome of "Cardio-Sarcopenia"?

OBJECTIVES

The link between skeletal muscle and heart disease remains intriguing. It is unknown how skeletal muscle may be associated with aspects of myocardial structure and function, particularly in the presence of aging-related sarcopenia. We hypothesize that among aging adults with sarcopenia, alterations in myocardial structure and/or function may exist, resulting in a syndrome of "cardio-sarcopenia."

METHODS

Participants derived from a community cohort study underwent same-day bioimpedance body composition analysis that measured skeletal muscle in sites such as the trunk, upper limb, and lower limb, and echocardiography for assessment of myocardial structure and function. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

We studied a total of 378 participants, of whom 88 (23.3%) had sarcopenia. Participants with sarcopenia had smaller left ventricular (LV) sizes (lower LV internal diameter end diastole (4.1 ± .7 vs 4.5 ± .6 cm; P < .0001), lower LV internal diameter end systole (2.3 ± .5 vs 2.5 ± .4 cm; P = .010), lower LV posterior wall end diastole (.7 ± .1 vs .8 ± .1 cm; P = .0036), and lower LV posterior wall end systole (1.4 ± .3 vs 1.5 ± .2 cm; P = .0031). Sarcopenic participants also had lower LV mass (106 ± 35 vs 126 ± 53; P = .0014) and lower left atrial (LA) volume (33 ± 13 vs 36 ± 13; P = .033). Adjusting for age and diabetes mellitus, skeletal muscle mass was associated with LV diameter (β = .06; 95% confidence interval [CI] = .03-.09; P < .0001), LV mass (β = 4.04; 95% CI = 1.78-6.29; P = .001), LA diameter (β = .05; 95% CI = .01-.09; P = .007), and LA volume (β = 1.26; 95% CI = .38-2.13; P = .005). A positive linear correlation was observed between LV mass and handgrip strength (r = .25; P < .0001).

CONCLUSION

Among a community sample of older adults with preserved heart function, sarcopenia is associated with reductions in LV and LA sizes. Skeletal muscle mass was independently associated with specific indices of myocardial structure. J Am Geriatr Soc 67:2568-2573, 2019.

Galectin-3 as a candidate upstream biomarker for quantifying risks of myocardial ageing

AIMS

Galectin-3 (Gal-3) is implicated in the pathogenesis of heart failure and is also influenced by ageing. This study aims to determine the extent to which Gal-3 levels estimate odds of myocardial dysfunction in ageing cohorts, 'upstream' prior to clinical disease.

METHODS AND RESULTS

Four hundred seventy-five asymptomatic subjects underwent simultaneous assessments of cardiovascular structure and function, with measurements of circulating Gal-3. Myocardial dysfunction was defined as impaired myocardial relaxation (ratio of peak velocity flow in early diastole E (m/s) to peak velocity flow in late diastole by atrial contraction A (m/s) <0.84) (mean E/A ratio 0.84 in the cohort). Of 475 subjects (mean age 68 ± 12 years, 231 women), 222 (47%) had myocardial dysfunction. Subjects with myocardial dysfunction were older (mean age 73 ± 5 vs. 64 ± 14 years, P < 0.0001), and more had hypertension (59 vs. 40%, P < 0.0001), dyslipidaemia (54 vs. 39%, P = 0.001), diabetes mellitus (25 vs. 14%, P = 0.002), higher body mass index (BMI) (24 vs. 23 kg/m² , P = 0.002), and higher heart rate (76 vs. 71 b.p.m., P = 0.0001). Participants with impaired myocardial relaxation had lower peak velocity flow in early diastole E (0.6 ± 0.1 vs. 0.8 ± 0.2 m/s, P < 0.0001), higher peak velocity flow in late diastole by atrial contraction A (0.9 ± 0.1 vs. 0.7 ± 0.2 m/s, P < 0.0001), and higher mitral valve flow deceleration time (224.7 ± 43.2 vs. 204.8 ± 33.1 m/s, P < 0.0001). Participants with impaired myocardial relaxation had higher Gal-3 levels (17.2 ± 6.2 vs. 15.5 ± 4.1, P = 0.0004) but similar B-type natriuretic peptide (37 ± 4 vs. 34 ± 29, P = 0.37) and high-sensitivity troponin I (21 ± 72 vs. 11 ± 41, P = 0.061) levels and urine microalbumin-to-creatinine ratio (4.6 ± 8.1 vs. 4.2 ± 10.8, P = 0.75) compared with those without impaired myocardial relaxation. After multivariable adjustments, Gal-3 [odds ratio (OR) 1.05, 95% confidence interval (CI) 1.00-1.10, P = 0.039], age (OR 2.60, 95% CI 1.64-4.11, P < 0.0001), BMI (OR 2.16, 95% CI 1.44-3.23, P < 0.0001), and heart rate (OR 1.04, 95% CI 1.02-1.06, P < 0.0001) were associated with impaired myocardial relaxation. Adjusted ORs (95% CI) for myocardial dysfunction were 1.0 (ref), 1.62 (0.92-2.85), 1.92 (1.08-3.41), and 2.01 (1.11-3.66) across consecutive quartiles of Gal-3 after adjustment for age, BMI, risk factors, and heart rate.

CONCLUSIONS

Among asymptomatic community-dwelling elderly adults, the highest quartile of Gal-3 was associated with two-fold increased odds of myocardial dysfunction compared with the lowest quartile of Gal-3. Gal-3 may have a role as an 'upstream' biomarker in estimating odds of myocardial ageing prior to clinical disease.

Risk prediction in stable cardiovascular disease using a high-sensitivity cardiac troponin T single biomarker strategy compared to the ESC-SCORE

Objective

To evaluate the prognostic performance of high-sensitivity cardiac troponin T (hs-cTnT) compared with the ESC-SCORE.

Methods

We included low-risk outpatients with stable cardiovascular (CV) disease categorised into need for non-secondary and secondary prevention. The prognostication of hs-cTnT at index visit was compared with the European Society of Cardiology-Systematic COronary Risk Evaluation (ESC-SCORE) with respect to all-cause mortality (ACM) and two composite endpoints (ACM, acute myocardial infarction (AMI) and stroke and ACM, AMI, stroke and rehospitalisation for acute coronary syndrome (ACS) and decompensated heart failure (DHF)).

Results

Within a median follow-up of 796 days, a total of 16 deaths, 32 composite endpoints of ACM, AMI and stroke and 83 composite endpoints of ACM, AMI, stroke, rehospitalisation for ACS and DHF were observed among 693 stable low-risk outpatients. Using C-statistics, measurement of hs-cTnT alone outperformed the ESC-SCORE for the prediction of ACM in the entire study population (Δarea under the curve (AUC) 0.221, p=0.0039) and both prevention groups (non-secondary: ΔAUC 0.164, p=0.0208; secondary: ΔAUC 0.264, p=0.0134). For the prediction of all other secondary endpoints, hs-cTnT was at least as effective as the ESC-SCORE, both in secondary and non-secondary prevention. Using continuous and categorical net reclassification improvement and integrated discrimination improvement, hs-cTnT significantly improved reclassification regarding all endpoints in the entire population and in the secondary prevention cohort. In non-secondary prevention, hs-cTnT improved reclassification only for ACM. The results were confirmed in an independent external cohort on 2046 patients.

Conclusions

Hs-cTnT is superior to the multivariable ESC-SCORE for the prediction of ACM and a composite endpoint in stable outpatients with and without relevant CV disease.

Trial registration number

NCT01954303; Pre-results.

Hematological Parameters Outperform Plasma Markers in Predicting Long-Term Mortality After Coronary Angiography

High-sensitivity troponin I (hsTnI) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) are predictors of coronary artery disease. Recently, routine hematological parameters emerged as mortality predictors. We examined the predictive value of hematological parameters (from the Utrecht Patient Oriented Database) and hsTnI and NT-pro-BNP for mortality in a coronary angiography population (Utrecht Coronary Biobank n = 1913). Using Cox regression, receiver operating characteristics, integrated discrimination improvement (IDI), and continuous net reclassification improvement (cNRI) analysis, we compared the predictive properties of hematological parameters with hsTnI and NT-pro-BNP for mortality. During a median follow-up duration of 1.8 years, 77 deaths occurred. A panel of 7 hematological parameters (leukocyte count, reticulocyte mean corpuscular hemoglobin concentration, red blood cell [RBC] green (FL1) fluorescence, %neutrophils, %large [>120 fL] RBCs, %monocytes, and coefficient of variation of neutrophil complexity) was highly predictive. Added to clinical characteristics, hematological parameters (area under the curve [AUC]: 0.855, P < .001; IDI: 0.04, P = .02; cNRI: 0.41, P < .001) were better predictors than hsTnI (AUC: 0.818) or NT-pro-BNP (AUC: 0.834) alone or combined (AUC: 0.834). Hematological parameters may provide mortality risk information following coronary angiography and may be superior to hsTnI and/or NT-pro-BNP.

Novel Risk Stratification Assays for Acute Coronary Syndrome

PURPOSE OF REVIEW

Since identification of aspartate aminotransferase as the first cardiac biomarker in the 1950s, there have been a number of new markers used for myocardial damage detection over the decades. There have also been several generations of troponin assays, each with progressively increasing sensitivity for troponin detection. Accordingly, the "standard of care" for myocardial damage detection continues to change. The purpose of this paper is to review the clinical utility, biological mechanisms, and predictive value of these various biomarkers in contemporary clinical studies.

RECENT FINDINGS

As of this writing, a fifth "next" generation troponin assay has now been cleared by the US Food and Drug Administration for clinical use in the USA for subjects presenting with suspected acute coronary syndromes. Use of these high-sensitivity assays has allowed for earlier detection of myocardial damage as well as greater negative predictive value for infarction after only one or two serial measurements. Recent algorithms utilizing these assays have allowed for more rapid rule-out of myocardial infarction in emergency department settings. In this review, we discuss novel assays available for the risk assessment of subjects presenting with chest pain, including both the "next generation" cardiac troponin assays as well as other novel biomarkers. We review the biological mechanisms for these markers, and explore the positive and negative predictive value of the assays in clinical studies, where reported. We also discuss the potential use of these new markers within the context of future clinical care in the modern era of higher sensitivity troponin testing. Finally, we discuss advances in new platforms (e.g., mass spectrometry) that historically have not been considered for rapid in vitro diagnostic capabilities, but that are taking a larger role in clinical diagnostics, and whose prognostic value and power promise to usher in new markers with potential for future clinical utility in acute coronary syndrome.

Prognostic Value of High-Sensitivity Cardiac Troponin T Compared with Risk Scores in Stable Cardiovascular Disease

BACKGROUND

Risk stratification of patients with cardiovascular disease remains challenging despite consideration of risk scores.

METHODS

We aimed to evaluate the prognostic performance of high-sensitivity cardiac troponin T in a low-risk outpatient population presenting for nonsecondary and secondary prevention. All-cause mortality, a composite of all-cause mortality, acute myocardial infarction, and stroke (end point 2), and a composite of all-cause mortality, acute myocardial infarction, stroke and rehospitalization for acute coronary syndrome, and decompensated heart failure (end point 3) were defined. The prognostic performance of high-sensitivity cardiac troponin T on index visit was compared with the PROCAM score and 3 FRAMINGHAM subscores.

RESULTS

In 693 patients with a median follow-up of 796 days, we observed 16 deaths, 32 patients with end point 2, and 83 patients with end point 3. All risk scores performed better in the prediction of all-cause mortality in nonsecondary prevention (area under the curve [AUC]: PROCAM: 0.922 vs 0.523, P = .001, consistent for all other scores). In secondary prevention, high-sensitivity cardiac troponin T outperformed all risk scores in the prediction of all-cause mortality (ΔAUC: PROCAM: 0.319, P <.001, consistent for all other scores) and performed superiorly in the prediction of end point 2 compared with the PROCAM, FRAMINGHAM-Coronary Heart Disease, and FRAMINGHAM-Hard Coronary Heart Disease scores (ΔAUC: PROCAM: 0.176, P = .047, consistent for FRAMINGHAM-Coronary Heart Disease and FRAMINGHAM-Hard Coronary Heart Disease). In nonsecondary prevention, we observed a comparable prognostic performance of high-sensitivity cardiac troponin T and multivariable risk scores. Our findings on the prediction of all-cause mortality compared with the FRAMINGHAM-Hard Coronary Heart Disease score were confirmed in an independent validation cohort on 2046 patients.

CONCLUSIONS

High-sensitivity troponin T provides excellent risk stratification regarding all-cause mortality and all-cause mortality, acute myocardial infarction, and stroke in a secondary prevention cohort in whom risk scores perform poorly.

Anthracycline Chemotherapy and Cardiotoxicity

Anthracycline chemotherapy maintains a prominent role in treating many forms of cancer. Cardiotoxic side effects limit their dosing and improved cancer outcomes expose the cancer survivor to increased cardiovascular morbidity and mortality. The basic mechanisms of cardiotoxicity may involve direct pathways for reactive oxygen species generation and topoisomerase 2 as well as other indirect pathways. Cardioprotective treatments are few and those that have been examined include renin angiotensin system blockade, beta blockers, or the iron chelator dexrazoxane. New treatments exploiting the ErbB or other novel pro-survival pathways, such as conditioning, are on the cardioprotection horizon. Even in the forthcoming era of targeted cancer therapies, the substantial proportion of today's anthracycline-treated cancer patients may become tomorrow's cardiac patient.

Association of a Biomarker of Glucose Peaks, 1,5-Anhydroglucitol, With Subclinical Cardiovascular Disease

OBJECTIVE

1,5-Anhydroglucitol (1,5-AG) is a biomarker of glucose peaks and has been associated with clinical cardiovascular disease. However, the association between 1,5-AG and subclinical cardiovascular disease is unknown. We investigated the association of 1,5-AG with subclinical myocardial damage (assessed by high-sensitivity cardiac troponin T [hs-cTnT]) and atherosclerosis (assessed by carotid intima-media thickness [CIMT] and carotid plaque).

RESEARCH DESIGN AND METHODS

We measured 1,5-AG, hs-cTnT, CIMT, and carotid plaque among 10,072 people without diabetes and 681 with diabetes who attended the second examination of the Atherosclerosis Risk in Communities (ARIC) Study (baseline, 1990-1992). We used Poisson regression to characterize the associations between 1,5-AG and prevalent elevated hs-cTnT, thick CIMT, or carotid plaque. Among 9,145 people with a second hs-cTnT measurement 6 years later, we used multinomial logistic regression to assess associations with incident elevation in hs-cTnT.

RESULTS

We found that in people with diabetes, lower 1,5-AG (<6 μg/mL) was cross-sectionally associated with elevated hs-cTnT (prevalence ratio 2.06, 95% CI 1.23-3.46) compared with higher 1,5-AG (≥10 μg/mL). Associations in people without diabetes and with thick CIMT or the presence of carotid plaque were less robust. Low 1,5-AG was prospectively associated with the 6-year incident elevation in hs-cTnT (relative risk 2.90, 95% CI 1.23-6.85) in people with diabetes. All associations were strongly attenuated with further adjustment for HbA1c.

CONCLUSIONS

In people with diabetes, 1,5-AG was associated with subclinical cardiovascular disease, particularly chronic subclinical myocardial damage. Nonetheless, whether observed associations are truly independent of average glycemia is unclear.

Biomarkers and degree of atherosclerosis are independently associated with incident atherosclerotic cardiovascular disease in a primary prevention cohort: The ARIC study

BACKGROUND AND AIMS

Biomarkers and atherosclerosis imaging have been studied individually for association with incident cardiovascular disease (CVD); however, limited data exist on whether the biomarkers are associated with events with a similar magnitude in the presence of atherosclerosis. In this study, we assessed whether the presence of atherosclerosis as measured by carotid intima media thickness (cIMT) affects the association between biomarkers known to be associated with coronary heart disease (CHD) and incident cardiovascular disease (CVD) in a primary prevention cohort.

METHODS

8127 participants from the ARIC study (4th visit, 1996-1998) were stratified as having minimal, mild, or substantial atherosclerosis by cIMT. Levels of C-reactive protein, lipoprotein-associated phospholipase A2, cardiac troponin T, N-terminal pro-brain natriuretic peptide, lipoprotein(a), cystatin C, and urine albumin to creatinine ratio were measured in each participant. Hazard ratios were used to determine the relationship between the biomarkers and incident CHD, stroke, and CVD in each category of atherosclerosis.

RESULTS

While each of the biomarkers was significantly associated with risk of events overall, we found no significant differences noted in the strength of association of biomarkers with CHD, stroke, and CVD when analyzed by degree of atherosclerosis.

CONCLUSIONS

These findings suggest that the level of atherosclerosis does not significantly influence the association between biomarkers and CVD.

Troponin assay use in the emergency department for management of patients with potential acute coronary syndrome: current use and future directions

Troponins are proteins commonly found in cardiac tissue that are released during myocardial ischemia or necrosis. These troponins can be detected by assays that can then be used to guide clinical decision-making and disposition, especially if the suspected insult is related to acute coronary syndrome. Timing of troponin measurement can be important as elevations may not be detectible immediately after an insult. New assays have been designed to detect troponin con-centrations previously too low to be detected by conventional assays. These tests are known as high-sensitivity cardiac troponin assays. Current research is aimed at evaluating the clinical sig-nificance of troponin elevations detected by these new assays especially in management of pa-tients with suspected acute coronary syndrome. A number of risk-stratification scores exist to assist physicians with evaluating chest pain in the emergency department in the context of de-tection (or absence) of troponins in systemic circulation. Additionally, investigators are working to integrate data generated by hs-cTn measurements into existing and new risk-stratification scores.

Effect of Remote Ischaemic Conditioning in Oncology Patients Undergoing Chemotherapy: Rationale and Design of the ERIC-ONC Study--A Single-Center, Blinded, Randomized Controlled Trial

Cancer survival continues to improve, and thus cardiovascular consequences of chemotherapy are increasingly important determinants of long‐term morbidity and mortality. Conventional strategies to protect the heart from chemotherapy have important hemodynamic or myelosuppressive side effects. Remote ischemic conditioning (RIC) using intermittent limb ischemia‐reperfusion reduces myocardial injury in the setting of percutaneous coronary intervention. Anthracycline cardiotoxicity and ischemia‐reperfusion injury share common biochemical pathways in cardiomyocytes. The potential for RIC as a novel treatment to reduce subclinical myocyte injury in chemotherapy has never been explored and will be investigated in the Effect of Remote Ischaemic Conditioning in Oncology (ERIC‐ONC) trial (clinicaltrials.gov NCT 02471885). The ERIC‐ONC trial is a single‐center, blinded, randomized, sham‐controlled study. We aim to recruit 128 adult oncology patients undergoing anthracycline‐based chemotherapy treatment, randomized in a 1:1 ratio into 2 groups: (1) sham procedure or (2) RIC, comprising 4, 5‐minute cycles of upper arm blood pressure cuff inflations and deflations, immediately before each cycle of chemotherapy. The primary outcome measure, defining cardiac injury, will be high‐sensitivity troponin‐T over 6 cycles of chemotherapy and 12 months follow‐up. Secondary outcome measures will include clinical, electrical, structural, and biochemical endpoints comprising major adverse cardiovascular clinical events, incidence of cardiac arrhythmia over 14 days at cycle 5/6, echocardiographic ventricular function, N‐terminal pro‐brain natriuretic peptide levels at 3 months follow‐up, and changes in mitochondrial DNA, micro‐RNA, and proteomics after chemotherapy. The ERIC‐ONC trial will determine the efficacy of RIC as a novel, noninvasive, nonpharmacological, low‐cost cardioprotectant in cancer patients undergoing anthracycline‐based chemotherapy.

Troponin elevation predicts critical care needs and in-hospital mortality after thrombolysis in white but not black stroke patients

INTRODUCTION

Stroke patients undergoing intravenous thrombolysis (IVT) are at increased risk for critical care interventions and mortality. Cardiac troponin elevation is common in stroke patients; however, its prognostic significance is unclear. The present study evaluates troponin elevation as a predictor of critical care needs and mortality in post-IVT patients and describes racial differences in its predictive accuracy.

METHODS

Logistic regression and receiver operating characteristics (ROC) analysis were used to determine racial differences in the predictive accuracy of troponin elevation for critical care needs and mortality in post-IVT patients.

RESULTS

Troponin elevation predicted critical care needs in white (odds ratio [OR] 29.40, 95% confidence interval [CI] 4.86-177.81) but not black patients (OR 0.50, 95% CI 0.14-1.78; P value for interaction < .001). Adding troponin elevation to a prediction model for critical care needs in whites improved the area under the curve from 0.670 to 0.844 (P = .006); however, addition of troponin elevation did not improve the model in blacks (area under the curve 0.843 vs 0.851, P = .54). Troponin elevation was associated with in-hospital mortality in whites (OR 21.94, 95% CI 3.51-137.11) but not blacks (OR 1.10, 95% CI 0.19-6.32, P value for interaction .022).

CONCLUSION

Troponin is a useful predictor of poor outcome in white but not black post-IVT stroke patients.