Elevated Baseline Cardiac Troponin Levels in the Elderly – Another Variable to Consider?

High-Sensitivity Cardiac Troponin T and Frailty Predict Short-Term Mortality in Patients ≥75 Years Undergoing Emergency Abdominal Surgery: A Prospective Observational Study

BACKGROUND

An elevated cardiac troponin concentration is a prognostic factor for perioperative cardiac morbidity and mortality. In elderly patients undergoing emergency abdominal surgery, frailty is a recognized risk factor, but little is known about the prognostic value of cardiac troponin in these vulnerable patients. Therefore, we investigated the prognostic significance of elevated high-sensitivity cardiac troponin T (hs-cTnT) concentration and frailty in a cohort of elderly patients undergoing emergency abdominal surgery.

METHODS

We included consecutive patients ≥75 years of age who presented for emergency abdominal surgery, defined as abdominal pathology requiring surgery within 72 hours, in a university hospital in Norway. Patients who underwent vascular procedures or palliative surgery for inoperable malignancies were excluded. Preoperatively, frailty was assessed using the Clinical Frailty Scale (CFS), and blood samples were measured for hs-cTnT. We evaluated the predictive power of CFS and hs-cTnT concentrations using receiver operating characteristic (ROC) curves and Cox proportional hazard regression with 30-day mortality as the primary outcome. Secondary outcomes included (1) a composite of 30-day all-cause mortality and major adverse cardiac event (MACE), defined as myocardial infarction, nonfatal cardiac arrest, or coronary revascularization; and (2) 90-day mortality.

RESULTS

Of the 210 screened and 156 eligible patients, blood samples were available in 146, who were included. Troponin concentration exceeded the 99th percentile upper reference limit (URL) in 83% and 89% of the patients pre- and postoperatively. Of the participants, 53% were classified as vulnerable or frail (CFS ≥4). The 30-day mortality rate was 12% (18 of 146). Preoperatively, a threshold of hs-cTnT ≥34 ng/L independently predicted 30-day mortality (hazard ratio [HR] 3.14, 95% confidence interval [CI], 1.13-9.45), and the composite outcome of 30-day mortality and MACE (HR 2.58, 95% CI, 1.07-6.49). In this model, frailty (continuous CFS score) also independently predicted 30-day mortality (HR 1.42, 95% CI, 1.01-2.00) and 30-day mortality or MACE (HR 1.37, 95% CI, 1.02-1.84). The combination of troponin and frailty, 0.14 × hs-cTnT +4.0 × CFS, yielded apparent superior predictive power (area under the receiver operating characteristics curve [AUC] 0.79, 95% CI, 0.68-0.88), compared to troponin concentration (AUC 0.69, 95% CI, 0.55-0.83) or frailty (AUC 0.69, 95% CI, 0.57-0.82) alone.

CONCLUSIONS

After emergency abdominal surgery in elderly patients, increased preoperative troponin concentration and frailty were independent predictors of 30-day mortality. The combination of increased troponin concentration and frailty seemed to provide better prognostic information than troponin or frailty alone. These results must be validated in an independent sample.

Prognostic Value of High-Sensitivity Cardiac Troponin in Women

High-sensitivity cardiac troponin assays have become the gold standard for diagnosing acute and chronic myocardial injury. The detection of troponin levels beyond the 99th percentile is included in the fourth universal definition of myocardial infarction, specifically recommending the use of sex-specific thresholds. Measurable concentrations below the proposed diagnostic thresholds have been shown to inform prognosis in different categories of inpatients and outpatients. However, clinical investigations from the last twenty years have yielded conflicting results regarding the incremental value of using different cut-offs for men and women. While advocates of a sex-specific approach claim it may help reduce gender bias in cardiovascular medicine, particularly in acute coronary syndromes, other groups question the alleged incremental diagnostic and prognostic value of sex-specific thresholds, ultimately asserting that less is more. In the present review, we aimed to synthesize our current understanding of sex-based differences in cardiac troponin levels and to reappraise the available evidence with regard to (i) the prognostic significance of sex-specific diagnostic thresholds of high-sensitivity cardiac troponin assays compared to common cut-offs in both men and women undergoing cardiovascular disease risk assessment, and (ii) the clinical utility of high-sensitivity cardiac troponin assays for cardiovascular disease prevention in women.

Distribution and specificity of high-sensitivity cardiac troponin T in older adults without acute cardiac conditions: cross-sectional results from the population-based AugUR study

OBJECTIVE

European guidelines recommended a uniform upper reference limit of high-sensitivity cardiac troponin T (hsTnT) to rule out non-ST segment elevation myocardial infarction. Our study aimed to provide a hsTnT reference distribution and to assess the specificity of the 14 ng/L cut-off value in the mobile population ≥70 years of age.

DESIGN

A cross-sectional analysis was performed in the German AugUR study (Altersbezogene Untersuchungen zur Gesundheit der University of Regensburg).

SETTING

Study population was the mobile population aged 70+ years living in the city and county of Regensburg, Germany.

PARTICIPANTS

A random sample was derived from the local population registries of residence. Of the 5644 individuals invited, 1133 participated (response ratio=20.1%). All participants came to the study centre and were mentally and physically mobile to conduct the protocol (face-to-face interview, blood draw and standardised transthoracic echocardiography). None of the participants was in an acute state of myocardial infarction.

RESULTS

Among the 1129 individuals with hsTnT measurements (overall median=10.0 ng/L(25th, 75th percentile)=(7.0, 15.0 ng/L)), hsTnT was higher among the older individuals and higher among men (men 70-74 years median=9.6 ng/L (7.2, 13.1 ng/L); men 90-95 years median=21.2 ng/L (14.6, 26.0 ng/L); women 70-74 years median=6.3 ng/L (4.7, 8.7 ng/L); and women 90-95 years median=18.0 ng/L (11.0, 21.0 ng/L)). In participants with impaired kidney function (eGFR_crea <60 mL/min/1.73 m²), hsTnT was elevated (median=13.6 ng/L (9.4, 20.6 ng/L)).Specificity of recommended upper reference limit, 14 ng/L, is 68%. Most false positives were among men aged >79 years (specificity=34%). In a healthy subgroup (n=96, none of the following: overt heart disease, impaired renal function, blood pressure >160/100 mm Hg, left ventricular hypertrophy and diastolic/systolic dysfunction), specificity was 90%.

CONCLUSION

In the elderly population without acute myocardial infarction, hsTnT further increases with age showing different levels for men and women. The specificity of the 14 ng/L cut-off is considerably lower than 99%, even in healthy subjects.

Myocardial injury in noncardiac surgery

Myocardial injury is defined as an elevation of cardiac troponin (cTn) levels with or without associated ischemic symptoms. Robust evidence suggests that myocardial injury increases postoperative mortality after noncardiac surgery. The diagnostic criteria for myocardial injury after noncardiac surgery (MINS) include an elevation of cTn levels within 30 d of surgery without evidence of non-ischemic etiology. The majority of cases of MINS do not present with ischemic symptoms and are caused by a mismatch in oxygen supply and demand. Predictive models for general cardiac risk stratification can be considered for MINS. Risk factors include comorbidities, anemia, glucose levels, and intraoperative blood pressure. Modifiable factors may help prevent MINS; however, further studies are needed. Recent guidelines recommend routine monitoring of cTn levels during the first 48 h post-operation in high-risk patients since MINS most often occurs in the first 3 days after surgery without symptoms. The use of cardiovascular drugs, such as aspirin, antihypertensives, and statins, has had beneficial effects in patients with MINS, and direct oral anticoagulants have been shown to reduce the mortality associated with MINS in a randomized controlled trial. Myocardial injury detected before noncardiac surgery was also found to be associated with postoperative mortality, though further studies are needed.

Prognostic Implications of High-Sensitivity Troponin T Levels Among Patients Attending Emergency Departments and Evaluated for an Acute Coronary Syndrome

BACKGROUND

With increasing age, patients with suspected acute coronary syndromes (ACS) and elevated high-sensitivity troponin T (HsTnT) levels, type-1 myocardial infarction (MI) is diagnosed less often, though associations among these factors, gender, and prognosis is unclear.

METHODS

Patients presenting to the emergency department (ED) with potential ACS who underwent HsTnT testing were prospectively identified and followed. Diagnoses were adjudicated according to the Fourth Universal Definition of MI as follows: type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury, and other diagnoses. Age in years was categorized: younger (<65); elderly (65-79), and very elderly (≥80).

RESULTS

Among 2738 patients with HsTnT measurements, 1611 were suitable for adjudication (42% ages 65 years and younger). Type-2 MI and chronic myocardial injury diagnoses were more common in those ages 65 years and older, whereas younger patients had more type-1 MI diagnoses. Late mortality rates at median 41 months (interquartile range [IQR] 10-57) were 44% (223 out of 506) in those ages 80 years and older, 22% (92 out of 423) in patients 65-79 years, and 7% (46 out of 682) in those 65 years and younger, irrespective of adjudicated diagnoses, log rank P ≤ .001. On multivariable analyses, the adjusted mortality hazard ratios for increasing HsTnT levels irrespective of diagnoses were attenuated in those age 80 years and older compared to younger patients.

CONCLUSIONS

Patients ages 65 years and older constituted ~60% of ED attendances of patients with suspected ACS, and more had type 2 MI and chronic myocardial injury diagnoses compared to younger patients. The relative mortality impact of HsTnT levels was lower among elderly patients irrespective of adjudicated diagnoses.

Predicting peri-operative troponin elevation by advanced electrocardiography

BACKGROUND

Peri-operative mortality remains a global problem and an improved pre-operative risk assessment identifying those at highest risk for peri-operative myocardial injury might improve postsurgical outcomes.

AIMS

To determine whether pre-operative measures of advanced electrocardiography (A-ECG) could predict elevated serum troponin T (TnT) in patients undergoing elective, major non-cardiac surgery.

MATERIAL AND METHODS

This observational cohort study included 257 surgical patients who underwent elective major non-cardiac surgery between the years 2012-2013 and 2015-2016 at Karolinska University Hospital. All selected patients were ≥ 18 years of age [median age 70 (63-75) years], had a pre-operative digital 12‑lead ECG < 6 months prior to the procedure and a postoperative high-sensitivity cardiac TnT (hs-cTnT) sample. A-ECG confounders including atrial fibrillation or flutter, abundant premature atrial or ventricular contractions, bundle branch blocks, QRS duration >110 ms, heart rate > 100 beats/min and paced rhythms were excluded. Previously validated A-ECG diagnostic scores that detect cardiovascular pathologies were calculated and compared in patients with and without peri-operative myocardial injury, defined as hs-cTnT >14 ng l^-1.

RESULTS

Pre-operative left ventricular systolic dysfunction by A-ECG was more probable in patients with than without peri-operative myocardial injury (p = 0.03).

CONCLUSIONS

While a pre-operative A-ECG score for LVSD was able to differentiate between patients with versus without elevated peri-operative TnT levels, it did not add any further utility to standard clinical parameters for predicting troponin-related events in the studied population.

Troponin elevation pattern and subsequent cardiac and non-cardiac outcomes: Implementing the Fourth Universal Definition of Myocardial Infarction and high-sensitivity troponin at a population level

Background

The Fourth Universal Definition of Myocardial Infarction (MI) differentiates MI from myocardial injury. We characterised the temporal course of cardiac and non-cardiac outcomes associated with MI, acute and chronic myocardial injury.

Methods

We included all patients presenting to public emergency departments in South Australia between June 2011–Sept 2019. Episodes of care (EOCs) were classified into 5 groups based on high-sensitivity troponin-T (hs-cTnT) and diagnostic codes: 1) Acute MI [rise/fall in hs-cTnT and primary diagnosis of acute coronary syndrome], 2) Acute myocardial injury with coronary artery disease (CAD) [rise/fall in hs-cTnT and diagnosis of CAD], 3) Acute myocardial injury without CAD [rise/fall in hs-cTnT without diagnosis of CAD], 4) Chronic myocardial injury [elevated hs-cTnT without rise/fall], and 5) No myocardial injury. Multivariable flexible parametric models were used to characterize the temporal hazard of death, MI, heart failure (HF), and ventricular arrhythmia.

Results

372,310 EOCs (218,878 individuals) were included: acute MI (19,052 [5.12%]), acute myocardial injury with CAD (6,928 [1.86%]), acute myocardial injury without CAD (32,231 [8.66%]), chronic myocardial injury (55,056 [14.79%]), and no myocardial injury (259,043 [69.58%]). We observed an early hazard of MI and HF after acute MI and acute myocardial injury with CAD. In contrast, subsequent MI risk was lower and more constant in patients with acute injury without CAD or chronic injury. All patterns of myocardial injury were associated with significantly higher risk of all-cause mortality and ventricular arrhythmia.

Conclusions

Different patterns of myocardial injury were associated with divergent profiles of subsequent cardiac and non-cardiac risk. The therapeutic approach and modifiability of such excess risks require further research.

Myocardial Injury After Noncardiac Surgery: Preoperative, Intraoperative, and Postoperative Aspects, Implications, and Directions

Myocardial injury after noncardiac surgery (MINS) differs from myocardial infarction in being defined by troponin elevation apparently from cardiac ischemia with or without signs and symptoms. Such myocardial injury is common, silent, and strongly associated with mortality. MINS is usually asymptomatic and only detected by routine troponin monitoring. There is currently no known safe and effective prophylaxis for perioperative myocardial injury. However, appropriate preoperative screening may help guide proactive postoperative preventative actions. Intraoperative hypotension is associated with myocardial injury, acute kidney injury, and death. Hypotension is common and largely undetected in the postoperative general care floor setting, and independently associated with myocardial injury and mortality. Critical care patients are especially sensitive to hypotension, and the risk appears to be present at blood pressures previously regarded as normal. Tachycardia appears to be less important. Available information suggests that clinicians would be prudent to avoid perioperative hypotension.

High-Sensitivity Cardiac Troponin I Improves Cardiovascular Risk Prediction in Older Men: HIMS (The Health in Men Study)

Background

The Framingham Risk Score estimates the 10‐year risk of cardiovascular events. However, it performs poorly in older adults. We evaluated the incremental benefit of adding high‐sensitivity cardiac troponin I (hs‐cTnI) to the Framingham Risk Score.

Methods and Results

The HIMS (Health in Men Study) is a cohort study of community‐dwelling men aged 70 to 89 years in Western Australia. Participants were identified from the electoral roll, with a subset undergoing plasma analysis. Hs‐cTnI (Abbott Architect i2000SR) was measured in 1151 men without prior cardiovascular disease. The Western Australia Data Linkage System was used to identify incident cardiovascular events. After 10 years of follow‐up, 252 men (22%) had a cardiovascular event (CVE+) and 899 did not (CVE–). The Framingham Risk Score placed 148 (59%) CVE+ and 415 (46%) CVE– in the high‐risk category. In CVE– men, adding hs‐cTnI affected the risk categories of 244 (27.2%) men, with 64.8% appropriately reclassified to a lower and 35.2% to a higher category, which decreased the number of high‐risk men in the CVE– to 39%. In CVE+ men, adding hs‐cTnI affected the risk categories of 61 (24.2%), with 50.8% appropriately reclassified to a higher and 49.2% to a lower category and 82.5% remaining above the 15% risk treatment threshold. The net reclassification index was 0.305 (P<0.001). Adding hs‐cTnI increased the C‐statistic modestly from 0.588 (95% CI, 0.552–0.624) to 0.624 (95% CI, 0.589–0.659) and improved model fit (likelihood ratio test, P<0.001).

Conclusions

Adding hs‐cTnI to the Framingham Risk Score provided incremental prognostic benefit in older men, especially aiding reclassification of individuals into a lower risk category.

Acute Responses of Cardiac Biomarkers to Intermittent and Continuous Exercise Are Related to Age Difference but Not I/D Polymorphism in the ACE Gene

Purpose

The purpose of this study was to determine the (i) cardiac biomarker (cTnI and NT-proBNP) responses to moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) in the middle-aged and young groups, (ii) relationship of post-exercise cardiac biomarker release between these two age groups, and (iii) investigate whether insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene is associated with predisposition to cardiac damage after exercise in Iranian men.

Methods

We examined cTnI and NT-proBNP in 29 middle-aged (54.5 ± 4.6 years) and 28 young (22.7 ± 4.2 years) soccer players before and after HIIE and MICE running tests.

Results

The middle-aged soccer players had higher baseline cTnI (0.015 ± 0.007 ng/ml vs. 0.010 ± 0.006 ng/ml; P = 0.01) and NT-proBNP (30.7 ± 13.6 ng/L vs. 18.4 ± 8.3 ng/L; P < 0.001) values compared with the young group. The changes with exercise (ΔcTnI: 13 vs. 11 ng/ml and ΔNT-proBNP: 18 vs. 11 ng/L) were also higher in the middle-aged group. No subject exceeded the upper reference limit for cTnI and NT-proBNP. Considering three ACE genotypes, the mean cTnI and NT-proBNP values of middle-aged and young groups did not show any significant difference.

Conclusion

Marked differences in baseline and post-exercise cTnI and NT-proBNP values were observed, which were related to age differences but not to ACE genotypes.

Mortality at 5 Years Among Very Elderly Patients Undergoing High Sensitivity Troponin T Testing for Suspected Acute Coronary Syndromes

BACKGROUND

Patients aged ≥80 years old often present to Emergency Departments (ED) with symptoms potentially due to an acute coronary syndrome (ACS). This study aimed to evaluate associations between baseline level(s) of high sensitivity troponin T (HsTnT), adjudicated diagnoses and outcomes.

METHODS

Consecutive patients aged ≥80 years were studied, who presented to the ED at Liverpool Hospital, NSW, Australia during the 4 months period March to June 2014 (inclusive) with symptoms suggestive of an ACS, and who had at least one HsTnT assay performed. Diagnoses were based on the fourth universal definition of MI (myocardial infarction) including type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury; the rest were termed "other diagnoses". Patients were categorised by baseline HsTnT levels 1) ≤14 ng/L, 2) 15-29 ng/L, 3) 30-49 ng/L and 4) ≥50 ng/L.

RESULTS

Of 2,773 patients screened, 545 were aged ≥80 years (median age 85 [IQR 82-88]); median follow-up was 32 months (IQR 5-56). The respective rates of adjudicated diagnoses were type-I MI 3.1%, type-2 MI 13%, acute myocardial injury 9.5%, chronic myocardial injury 56% and 18.6% had other diagnoses. Mortality rates increased, irrespective of adjudicated diagnoses with increasing HsTnT levels (ng/L): 17% (16/96) for ≤14; 35% (67/194) for 15-29; 51% (65/127) for 30-49; and 64% (82/128) for ≥50 ng/L; log rank p≤0.001. On multi-variable analyses, after adjusting for potential confounding factors including age, hypertension, chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), MI type was not associated with late mortality.

CONCLUSIONS

Among patients aged ≥80 years higher HsTnT levels, irrespective of adjudicated diagnoses, were associated with increased mortality. Most very elderly patients presenting with symptoms suggestive of an ACS undergoing HsTnT testing in EDs had elevated levels most commonly due to chronic myocardial injury. Whether any interventions can modify outcomes require prospective evaluation.

[Control of ventricular rate in permanent atrial fibrillation: cardio-protec-tion and tissue hemodynamics]

Objective To evaluate myocardial injury and tissue hemodynamics in elderly patients with permanent atrial fibrillation (AF) based on the achieved range of ventricular contraction rate (VCR).Materials and Methods This prospective, randomized, blind study included 75 patients aged ≥60 with permanent AF. All patients were prescribed bisoprolol as a VCR-reducing therapy. Patients were randomized to two groups according to the permuted-block design based on the range of resting VCR goal: group 1, 60-79 bpm (n=38) and group 2, 80-100 bpm (n=37). All patients also received perindopril and apixaban. Troponin I concentration was measured using the high-sensitivity assay (hsTn); parameters of tissue hemodynamics, including the mean blood flow velocity (Vm) and pulsatility index (PI), were measured using high-frequency ultrasound doppler flowmetry; echocardiographic indexes of left heart remodeling were recorded at baseline and after 6 month of VCR monitoring.Results Mean age of patients was 74±7 years. Medians [25th percentile; 75th percentile] of baseline hsTn concentrations were 10.2 [5.25; 21.2] ng / l in group 1 and 10.3 [5.4; 20.4] ng / ml in group 2 (p=0.91). 89.5 % of patients in group 1 and 100 % of patients in group 2 achieved the VCR range goal. At 6 month, resting VCRs were 70±4 bpm in group 1 (n=34) and 88±5 bpm in group 2 (n=37) (p1, p2&lt;0.001). According to echocardiographic data significant progression of myocardial remodeling was not observed. Concentrations of hsTn significantly decreased in both groups but the decrease was more pronounced in group 1, to 8.0 [4.13; 17.23; p1&lt;0.001] ng / l vs. 9.2 [4.8, 17.5] ng / l in group 2 (р1, p2&lt;0.001). A weak direct correlation was found between the VCR decrease and hsTn concentration (rs=0.44; p=0.009 in group 1, and rs=0.41; p=0.01 in group 2); regression coefficient was 0.78 at 95 % confidence interval (CI), from 0.21 to 1.3 (p=0.009) in group 1, and 0.14 at 95 % CI, from 0.04 to 0.24 (p=0.007) in group 2. Vm values were increased to 2.93±0.10 (p&lt;0.001) and 3.21±0.09 cm / sec (p&lt;0.001) and PIs were decreased to 1.42±0.03 conv. units (p&lt;0.01) and to 1.34±0.02 conv. units (p&lt;0.001) in groups 1 and 2, respectively.Conclusion The treatment aimed at VCR control in patients older than 60 with permanent AF was associated with a positive dynamics of myocardial injury (hsTn) and tissue hemodynamics indexes (Vm и РI). This indicates a possibility for using these indexes for further improvement of managing such patients.

Contemporary NSTEMI management: the role of the hospitalist

Non-ST-segment elevation myocardial infarction (NSTEMI) is defined as elevated cardiac biomarkers of necrosis in the absence of persistent ST-segment elevation in the setting of anginal symptoms or other acute event. It carries a poorer prognosis than most ST-segment elevation events, owing to the typical comorbidity burden of the older NSTEMI patients as well as diverse etiologies that add complexity to therapeutic decision-making. It may result from an acute atherothrombotic event ('Type 1') or as the result of other causes of mismatch of myocardial oxygen supply and demand ('Type 2'). Regardless of type and other clinical factors, the hospital medicine specialist is increasingly responsible for managing or coordinating the care of these patients. Following published guidelines for risk stratification and basing anti-anginal, anticoagulant, antiplatelet, other pharmacologic therapies, and overall management approach on that individualized patient risk assessment can be expected to result in better short- and long-term clinical outcomes, including near-term readmission and recurrent events. We present here a review of the evidence basis and expert commentary to assist the hospitalist in achieving those improved outcomes in NSTEMI. Given that the Society for Hospital Medicine cites care of patients with acute coronary syndrome as a core competency for hospitalists, it is essential that those specialists stay current on optimal NSTEMI care.Abbreviations: ACC: American college of cardiology; ACCOAST: comparison of prasugrel at the time of diagnosis in patients with non-ST elevation myocardial infarction; ACS: acute coronary syndrome; ADP: adenosine diphosphate; AHA: American heart association; ARB: angiotensin II receptor blocker; ASA: acetylsalicylic acid; CABG: coronary artery bypass graft: CAD: coronary artery disease; CCTA: coronary computed tomography angiography; cTn: cardiac troponin; CRUSADE: can rapid risk stratification of unstable angina patients suppress adverse outcomes with early implementation of the ACC/AHA guidelines; CURE: clopidogrel in unstable angina to prevent recurrent events; CURRENT: OASIS-7 clopidogrel and aspirin optimal dose usage to reduce recurrent events-seventh organization to assess strategies in ischemic syndromes; ECG: electrocardiogram; ED: emergency department; ESRD: endstage renal disease; ESC: European society of cardiology; FDA: food and drug administration; GRACE: global registry of acute coronary events; LVEF: left ventricular ejection fraction; MACE: major adverse cardiac event; MI: myocardial infarction; MVO₂: myocardial oxygen demand; NSTEMI: non-ST-segment-elevation myocardial infarction; NTG: Nitroglycerin; PCI: percutaneous coronary intervention; plato: platelet inhibition and patient outcomes; PPI: proton pump inhibitor; PURSUIT: platelet glycoprotein IIb/IIIa in unstable angina: Receptor Suppression Using Integrilin Therapy; RAAS: Renin-Angiotensin-Aldosterone System; SHM: society of hospital medicine; STEMI: ST-segment-elevation myocardial infarction; TIMI: Thrombolysis in Myocardial Infarction; TRITON-TIMI:trial to assess improvement in therapeutic outcomes by optimizing platelet inhibition with prasugrel-thrombolysis in myocardial infarction.

Revisiting the Biological Variability of Cardiac Troponin: Implications for Clinical Practice

The diagnosis of acute myocardial injury requires a rise and/or fall of cardiac troponin (cTn) on serial testing, with at least one concentration above the 99th percentile value of a normal reference population according to the recently published Fourth Universal Definition of Myocardial Infarction.1 However, the magnitude of change in cTn that constitutes a significant rise and/or fall was again not specified in detail. High-sensitivity cardiac troponin (hs-cTn) assays can measure ten-fold lower concentrations of cTn with more precision than older assays, and can accurately quantify cTn in more than 50% of healthy individuals with a coefficient of variation of less than 10% at the 99th percentile. These hs-cTn assays are also able to detect the normal variations in cTn results that are due to biological variability. Understanding and quantifying the normal variations in cTn is important as this would allow significant changes to be better defined. Numerous studies have sought to investigate the biological variability of cTn over the last ten years. Such studies are usually conducted in healthy individuals, however individuals with chronic cardiac disease or chronic renal failure have also been examined. These studies have yielded varying results in regards to significant change values for cTn. In light of the recent redefinition for myocardial infarction, the purpose of this mini-review is to revisit the biological variability of cTn. In particular, we outline concepts for determining a significant change value, review the results of previous studies on the biological variation of cTn and discuss potential considerations for clinical practice.

Increased level of high-sensitivity cardiac Troponin T in a geriatric population is determined by comorbidities compared to age

High level of cardiac Troponin T (hs-cTnT) in geriatric population has been considered as an age-related phenomenon, which may question the interpretation of the increase of hs-cTnT in this population. The challenge is what is the primary cause of the increased hs-cTnT levels in elderly patients without AMI.

Objective

The aim of the current study was to determine the impact of aging on hs-cTnT levels in elderly patients without acute cardiac events but in the presence of comorbidities.

Methods

Sociodemographic and clinical data were collected from 6977 medical records of patients aged ≥65 years without acute coronary events but for whom hs-cTnT measurements were available. The patients were stratified based on age, troponin levels and the number of comorbidities.

Results

The results suggested that the likelihood of increased hs-cTnT was related to the presence of comorbidities independently of their number (p < 0.05). The adjusted odds ratio (AOR) for both advanced age and having comorbidity was statistically significant, however for the old group (74 ≥ age ≥ 84 years) the chance of having elevated troponin regarding age compared to the presence of comorbidity was 1.070 vs. 1.216, whereas for the old-old group (≥85 years) it was found to be 1.071 vs. 1.311. Besides statistical significance for age, from a clinical standpoint, the AOR of 1.070 may not be considered clinically relevant.

Conclusion

Increased hs-cTnT levels were associated with the presence of pre-existing comorbidities independently of age. Increased hs-cTnT levels in the elderly should always be considered as pathological, and a specific etiology should be searched.

Prognostic value of cardiac troponin I assay in hospitalized elderly patients

BACKGROUND

Cardiac troponin I (cTnI) has been poorly studied in elderly inpatients.

AIM

This study wanted to assess factors influencing the increase in cTnI and its prognostic value in hospitalized elderly patients.

METHODS

354 elderly (mean age of 84.8 ± 6.9 years) patients consecutively admitted in the Geriatrics Division in Padua were tested for cTnI levels assay during the hospital stay. Number of subsequent patient deaths at 6 months and 2 years were registered.

RESULTS

Of the 354 patients, 27 (7.6%) died in hospital; their levels were not significantly higher or more frequently positive on cTnI than those of the remainder of the sample. 71 (20.01%) patients died within 6 months of being discharged, and in-hospital positive cTnI levels emerged as a mortality risk factor in this group [unadjusted HR 1.13 (1.04-1.23); p = 0.004]. At 2 years, a total of 174 patients (49.2%) had died, but in-hospital pathological cTnI levels were not a mortality risk factor in this group.

DISCUSSION

It should be noted that cTnI level was a risk factor for mortality at 6 months but no longer at 2 years after an elderly patient's hospitalization. This finding may relate to patients' limited physiological reserves or be driven by the fact that the elderly tend to receive fewer evidence-based treatments, and to be managed more conservatively than younger patients.

CONCLUSIONS

In the multidimensional analysis of older patients, troponin I can be used to stratify patients and assess mortality risk at 6 months, but not at 2 years.

Association between troponin-I levels and outcome in critically ill patients admitted to non-cardiac intensive care unit with high prevalence of cardiovascular risk factors

Background

The association of troponin-I levels and outcome in medical-surgical ICU patients has been studied before in populations with low to moderate prevalence of cardiovascular risk factors. The objective in this article is to examine the association of troponin-I levels with hospital mortality in patients with high prevalence of cardiovascular risk factors who were admitted with medical-surgical indications to a non-cardiac intensive care unit.

Methods

This was a retrospective study of adult patients admitted to a tertiary medical-surgical ICU between July 2001 and November 2011. Data were extracted from prospectively collected ICU and clinical laboratory databases. Patients were stratified based on the highest troponin-I level in the first 72 h of admission into four groups (Group I < 0.03, Group II = 0.03–0.3, Group III = 0.3–3 and Group IV > 3 ng/mL). Hospital mortality was the primary outcome. To study the association between elevated troponin-I and hospital mortality, we carried out multivariate logistic regression analyses with Group I as a reference group.

Results

During the study period, 3368 patients had troponin-I levels measured in the first 72 h, of whom 1293 (38.3%) were diabetic and 1356 (40.2%) were chronically hypertensive. Among the study population, 2719 (81%) had elevated troponin-I levels (0.03 ng/mL and higher). Hospital mortality increased steadily as the troponin-I levels increased. Hospital mortality was 23.4% for Group I, 33.2% for Group II (adjusted odds ratio (aOR) 1.08, 95% confidence interval (CI) 0.84, 1.38), 49.6% for Group III (aOR = 1.64, 95% CI 1.24, 2.17), and 57.4% for Group IV (aOR 1.80, 95% CI 1.30, 2.49). The association of increased mortality with increased troponin level was observed whether patients had underlying advanced heart failure or not. Subgroup analysis showed an increased mortality in patients aged < 50 years, non-diabetics and not on vasopressors.

Conclusion

In a population with high prevalence of diabetes and hypertension, elevated troponin-I was frequently observed in medical-surgical critically ill patients, and showed a level-dependent association with hospital mortality.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0515-7) contains supplementary material, which is available to authorized users.

Relationship between Cardiac Troponin and Thrombo-Inflammatory Molecules in Prediction of Outcome after Acute Ischemic Stroke

BACKGROUND

In patients with acute ischemic stroke (AIS) without cardiovascular complications, we investigated the association of serum concentration of cardiac troponin (high-sensitivity cardiac troponin T [hs-cTnT]) with thrombo-inflammatory markers.

METHODS

Thirty-five patients with first-ever AIS were prospectively examined. Serum hs-cTnT was measured 6 and 24 hours after stroke, whereas S100B, high-sensitivity C-reactive protein (hsCRP), soluble CD40 ligand, tissue plasminogen activator (tPA), monocyte chemoattractant protein-1 (MCP-1), and P-selectin were measured 6 and 72 hours after stroke. Severity of stroke was assessed by the National Institutes of Health Stroke Scale (NIHSS) on admission, 24 hours later, and at discharge.

RESULTS

Concentration of MCP-1 at 6 hours was higher in the serum of patients with worsened NIHSS by 24 hours (P = .009). Concentration of hs-cTnT at both 6 and 24 hours was higher, if NIHSS worsened by discharge (P = .026 and P = .001). A cutoff value for hs-cTnT measured at T24 greater than or equal to  9.4 predicted worsened NIHSS on discharge with a sensitivity of 81% and a specificity of 74% (area: .808, P = .002). Concentration of hs-cTnT at both 6 and 24 hours was also higher in nonsurvivors compared with survivors (P = .03, respectively), and correlated with (1) tPA levels at 6 hours (P = .001 and P = .002, respectively); (2) MCP-1 concentration at 6 hours (P = .01 and P = .015, respectively); and increased hsCRP levels at 72 hours (P = .01, respectively). Concentration of hs-cTnT at 24 hours was an independent predictor of worsened NIHSS at discharge (odds ratio: 1.58, 95% confidence interval: 1.063-2.370, P = .024).

CONCLUSIONS

Elevated concentration of hs-cTnT measured 24 hours after AIS is an independent predictor of progressing neurologic deficit in patients without apparent myocardial damage, and also correlates with acute elevation of tPA and MCP-1.

Age-related remodeling of the JAK/STAT/SOCS signaling pathway and associated myocardial changes: From histological to molecular level

BACKGROUND

The cellular and molecular mechanisms implicated in age-associated changes in myocardial structure are of paramount importance since they cause profound alterations in the functional response and represent targets for alleviating age-related pathologies. One of these mechanisms is the JAK/STAT/SOCS signaling pathway.

AIM OF THE STUDY

The present study is designed to elucidate age-dependent changes of the myocardium to provide morphological basis displaying the pathogenesis of myocardial hypertrophy, fibrosis and inflammation with aging.

MATERIAL AND METHODS

Thirty male Sprague Dawley rats aged; 6, 30 and 36 months were used in this study. The animals were divided into three age groups, young adult, senile and very senile rats, respectively. The heart weight/body weight ratio was determined. The heart was subjected to gross morphologic examination, microscopic examination using H&E and Masson's trichrome stains and immunohistochemical examination for detection of JAK, pSTAT3, α-SMA, β-MHC and CD45. Western blotting was also carried out to detect SOCS genes. Real-time PCR was used to detect the inflammatory markers TNFα and IL1β and the hypertrophy marker α-SKA. Biochemical analysis of cardiac troponin I and creatine kinase-MB was done. Quantitative histomorphometric estimations included estimation of cardiac myocyte cross sectional area, estimation of the area percent of collagen fibers in Masson's trichrome stained sections and determination of optical density in immunostained sections. Electron microscopic examination was done to determine capillary density.

RESULTS

Jak and pSTAT3 were predominantly localized to the nuclei and exhibited progressive decline with aging, while SOCS3 activity displayed an age-related increase. The aged myocardium displayed profound age associated structural changes as well as myocardial hypertrophy, fibrosis and inflammation in senile and very senile rats.

CONCLUSION

The age-related modifications in the JAK/STAT/SOCS signaling as well as the age-associated pathological changes in myocardial structure are of particular interest as they provide further insight in age-associated heart pathologies and represent potential targets for cardioprotective and therapeutic approaches.

Association Between Subclinical Cardiac Biomarkers and Clinically Manifest Cardiac Diseases With Cortical Cerebral Microinfarcts

Importance

Subclinical and clinical cardiac diseases have been previously linked to magnetic resonance imaging (MRI) manifestations of cerebrovascular disease, such as lacunes and white matter hyperintensities, as well as dementia. Cortical cerebral microinfarcts (CMIs), a novel MRI marker of cerebral vascular disease, have not been studied, to date, in relation to subclinical and clinical cardiac diseases.

Objective

To examine the association of blood biomarkers of subclinical cardiac disease and clinically manifest cardiac diseases with CMIs graded on 3-T MRI in a memory clinic population.

Design, Setting, and Participants

This baseline cross-sectional analysis of a cohort study performed from August 12, 2010, to July 28, 2015, included 464 memory clinic participants. All participants underwent collection of blood samples, neuropsychological assessment, and 3-T MRI.

Exposures

N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) concentrations were measured by electrochemiluminescence immunoassays. Cardiac disease was defined as a history of atrial fibrillation, ischemic heart diseases, or congestive heart failure.

Main Outcomes and Measures

The CMIs were graded according to a previously validated protocol.

Results

Of 464 participants, 124 had insufficient blood plasma samples and 97 had no CMI grading (none, incomplete, or ungradable MRI), leaving a sample size of 243 for final analysis (mean [SD] age, 72.8 [9.1] years; 116 men [42.9%]). Seventy participants (28.8%) had cortical CMIs (median, 1; range, 0-43). Compared with participants with no CMIs, those with CMIs had a significantly higher prevalence of atrial fibrillation (rate ratio [RR], 1.62; 95% CI, 1.20-21.8), ischemic heart disease (RR, 4.31; 95% CI, 3.38-5.49), and congestive heart failure (RR, 2.05; 95% CI, 1.29-3.25). Significantly higher levels of NT-proBNP (RR, 3.16; 95% CI, 2.33-4.27) and hs-cTnT (RR, 2.17; 95% CI, 1.00-4.74) were found in participants with CMIs. In multivariate models adjusted for demographics and vascular risk factors, higher levels of NT-proBNP (RR, 3.19; 95% CI, 2.62-3.90) and hs-cTnT (RR, 4.86; 95% CI, 3.03-7.08) were associated with CMIs. These associations persisted even after excluding patients with clinically manifest cardiac disease.

Conclusions and Relevance

This study found that biomarkers of subclinical cardiac disease and clinically manifest cardiac diseases were associated with CMIs on 3-T MRI in patients attending a memory clinic, suggesting that cardiac disease may contribute to the development of CMIs. Hence, cardiac dysfunction should be targeted as a potentially modifiable factor to prevent CMI-related brain injury.

High-sensitivity cardiac troponin T levels in the emergency department in patients with chest pain but no myocardial infarction

BACKGROUND

High-sensitivity cardiac troponin T (hs-cTnT) was recently introduced into clinical practice. The increased sensitivity has decreased the specificity. We aimed to determine the predictors for and prevalence of hs-cTnT levels above the 99th percentile in a stable population of patients without myocardial infarction (MI) who sought medical attention for chest pain in the emergency department.

METHODS

We included 11,847 patients with chest pain and at least one hs-cTnT measurement during 2011 and 2012. Patients with any acute reasons for an elevated hs-cTnT level were excluded. We used logistic regression to calculate adjusted odds ratios with 95% confidence intervals for the association between patient characteristics and hs-cTnT levels of >14ng/L. We also determined 50th, 75th, 97.5th, and 99th percentile values of hs-cTnT levels in relation to age, sex, estimated glomerular filtration rate (eGFR), and presence or absence of comorbidities.

RESULTS

In total, 1360 (11%) patients had hs-cTnT levels of >14ng/L. Men had higher troponin levels than women, and older patients had higher levels than younger patients. The strongest predictor of an elevated troponin level was a reduced eGFR. The 99th percentile for hs-cTnT among all men and among women <50years of age with normal renal function was 20 and 12ng/L, respectively; this level increased to 44 and 36ng/L, respectively, at the age of 70-79years.

CONCLUSIONS

A hs-cTnT level above the 99th percentile in patients with chest pain but no MI is common and is related to sex, age, and eGFR.

The role of cardiac troponin I in prognostication of patients with isolated severe traumatic brain injury

BACKGROUND

Cardiac dysfunction is frequently observed after severe traumatic brain injury (sTBI); however, its significance is poorly understood. Our study sought to elucidate the association of cardiac troponin I (cTnI) elevation with all-cause in-hospital mortality following isolated sTBI (brain Abbreviated Injury Scale score ≥3 and admission Glasgow Coma Scale score ≤8, no Abbreviated Injury Scale score ≥3 to any other bodily regions).

METHODS

We retrospectively reviewed all adult patients (aged ≥18 years) with isolated sTBI admitted to a Level I trauma center between June 2007 and January 2014. Patients must have cTnI values within 24 hours of admission. Mortality risks were examined by Cox proportional hazard model.

RESULTS

Of 580 patients identified, 30.9% had detectable cTnI in 24 hours of admission. The median survival time was 4.19 days (interquartile range, 1.27-11.69). When adjusted for potential confounders, patients in the highest cTnI category (≥0.21 ng/mL) had a significantly higher risk of in-hospital mortality (hazard ratio, 1.39; 95% confidence interval, 1.04-1.88) compared with patients with undetectable cTnI. Mortality risk increased with higher troponin levels (p < 0.0001). This association was more pronounced in patients aged 65 years or younger (hazard ratio, 2.28; 95% confidence interval, 1.53-3.40; p < 0.0001) while, interestingly, insignificant in those older than 65 years (p = 0.0826).

CONCLUSION

Among patients with sTBI, cTnI elevation is associated with all-cause in-hospital mortality via a nonlinear positive trend. Age modified the effect of cTnI on mortality.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Troponin I levels in permanent atrial fibrillation-impact of rate control and exercise testing

BACKGROUND

High-sensitivity troponin I (hs-TnI) and troponin T (hs-TnT) are moderately correlated and independently related to outcome in atrial fibrillation (AF). Rate controlling therapy has been shown to reduce hs-TnT, however the potential impact on hs-TnI levels, and whether this differs from the effects on hs-TnT, has not been investigated previously.

METHODS

Sixty patients with stable, permanent AF without heart failure or known ischemic heart disease were included in a randomised crossover study (mean age 71 ± 9 years, 18 women). Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered once daily for three weeks, in a randomised sequence. At baseline and on the last day of each treatment period, hs-TnI was measured at rest and after a maximal exercise test and compared to hs-TnT.

RESULTS

Hs-TnI and hs-TnT correlated moderately at baseline (rs = 0.582, p < 0.001). All drugs reduced both the resting and the peak exercise levels of hs-TnI compared with baseline (p < 0.001 for all). The decline in resting hs-TnI and hs-TnT values relative to baseline levels was similar for all drugs except for verapamil, which reduced hs-TnI more than hs-TnT (p = 0.017). Levels of hs-TnI increased significantly in response to exercise testing at baseline and at all treatment regimens (p < 0.001 for all). The relative exercise-induced increase in hs-TnI was significantly larger compared to hs-TnT at baseline (p < 0.001), on diltiazem (p < 0.001) and on verapamil (p = 0.001).

CONCLUSIONS

In our population of stable, permanent AF patients, all four rate control drug regimens reduced hs-TnI significantly, both at rest and during exercise. The decline in hs-TnI and hs-TnT levels associated with beta-blocker and calcium channel blocker treatment was similar, except for a larger relative decrease in hs-TnI levels following verapamil treatment.

TRIAL REGISTRATION

www.clinicaltrials.gov ( NCT00313157 ).

Markers of cardiac dysfunction in cognitive impairment and dementia

Markers of cardiac dysfunction such as amino terminal pro-brain natriuretic peptide (NTpro-BNP) and high sensitivity cardiac troponin T (hs-cTnT) may be associated with dementia. However, limited data exist on their association with either pre-dementia stages, that is, cognitive impairment no dementia (CIND), or the burden of cerebrovascular diseases (CeVD).We therefore, examined the association of these biomarkers of cardiac dysfunction with CeVD in both CIND and dementia.A case-control study, with cases recruited from memory clinics and controls from memory clinics and community. All subjects underwent collection of blood samples, neuropsychological assessment, and neuroimaging. Subjects were classified as CIND and dementia based on clinical criteria whilst significant CeVD was defined as the presence of cortical infarcts and/or more than 2 lacunes and/or confluent white matter lesions in two regions of brain on Age-Related White Matter Changes Scale.We included a total of 35 controls (mean age: 65.9 years), 78 CIND (mean age: 70.2 years) and 80 cases with dementia (mean age: 75.6 years). Plasma concentrations of hs-cTnT were associated significantly with CeVD in both CIND (odds ratios [OR]: 9.05; 95% confidence interval [CI]: 1.64-49.79) and dementia (OR: 16.89; 95%CI: 2.02-142.67). In addition, NTpro-BNP was associated with dementia with CeVD (OR: 7.74; 95%CI: 1.23-48.58). These associations were independent of other vascular risk factors.In this study, we showed that plasma NTproBNP and hs-cTnT are associated with dementia and CIND, only when accompanied by presence of CeVD.