Incidence of elevation of cardiac troponin I prior to and following routine general anaesthesia in dogs

Elevation of cardiac enzymes and B-type natriuretic peptides following venous recanalization and stenting in chronic venous obstruction

BACKGROUND

B-type natriuretic peptides (BNP) and cardiac enzymes are both recognized biomarkers of heart health. Many studies have reported that using these indicators can assess cardiac condition and predict prognosis of patients undergoing surgery. Currently little is known on the effect of increased cardiac input after venous recanalization on cardiac physiology in patients with chronic venous obstruction (CVO).

OBJECTIVES

The aim of this study was to explore the effect of iliocaval recanalization and stenting on cardiac biomarkers in patients with CVO.

METHODS

This was a prospective study involving 60 patients in a single unit. Blood tests were collected 1 day before and 1 day after venous intervention. Three groups as group 1: patients with iliofemoral post-thrombotic syndrome (PTS) but without involvement of inferior vena cava (IVC) (n = 33); group 2: patients with iliofemoral PTS and involvement of IVC (n = 19) and group 3: patients with non-thrombotic vein lesion (NIVL) (n = 8) were compared based on cardiac biomarker levels.

RESULTS

Median concentration of post-operative BNP (259.60 pg/mL) was greater than preoperative levels (49.80 pg/mL) [interquartile range (IQR), 147.15/414.68 versus 29.85/82.88; p < 0.001]. The levels of CK-MB [preop: 3 U/l (IQR, 1.40/11.00) versus postop: 14 U/l (IQR, 12/17), p < 0.001] and troponin T [preop: 3.00 pg/mL (IQR, 3.00/5.25) versus postop: level of 6 pg/mL (IQR, 3.00/9.50), p < 0.001]. Post-procedure increases in cardiac enzymes showed significant differences in BNP (p = 0.023) and troponin T (p = 0.007) across the three groups, while CK-MB levels were not significantly different (p > 0.05). Intergroup comparisons of postoperative BNP: group 1 versus group 2 (p = 0.013), group 2 versus group 3 (p = 0.029), group 1 versus group 3 (p = 0.834); and postoperative troponin T: group 1 versus group 2 (p = 0.018), group 2 versus group 3 (p = 0.002), group 1 versus group 3 (p = 0.282). According to multiple linear regression analysis, length of stenting and level of preoperative BNP were independent determinants of postoperative BNP levels (p < 0.05), and preoperative troponin T affected postoperative troponin T independently (p < 0.05).

CONCLUSIONS

Troponin T, CK-MB and BNP seem to increase after venous recanalization and stent implantation, the elevation being more prominent for longer lesions.

Effect of administering dexmedetomidine with or without atropine on cardiac troponin I level in isoflurane-anesthetized dogs

We aimed to determine whether dexmedetomidine administration with or without atropine increases cardiac troponin I (cTnI) level in healthy dogs. We hypothesized that 10 µg/kg dexmedetomidine + atropine increases the cTnI level, whereas 5 µg/kg dexmedetomidine + atropine does not. Eighteen healthy, pet dogs that underwent an orthopedic surgery or ovariohysterectomy were included in this study. The dogs were randomly assigned to atropine (0.02 mg/kg)–dexmedetomidine (10 µg/kg), saline–dexmedetomidine (10 µg/kg), and atropine (0.02 mg/kg)–dexmedetomidine (5 µg/kg) groups. Each dog was premedicated with atropine or saline intramuscularly (IM). After 10 min, they were IM injected with dexmedetomidine (10 or 5 µg/kg)–morphine (0.5 mg/kg)–midazolam (0.2 mg/kg). Following this, anesthesia was induced after 10 min with propofol and maintained with isoflurane in 100% oxygen. The median plasma cTnI level at 6, 12 and 24 hr after premedication was significantly higher than that at baseline. The cTnI level in the atropine–dexmedetomidine (10 µg/kg) group was significantly higher than that in the saline–dexmedetomidine (10 µg/kg) and atropine–dexmedetomidine (5 µg/kg) groups at 6 and 12 hr after premedication. The cTnI level returned to normal within 72 hr after premedication in all groups. The administration of atropine in combination with 10 µg/kg dexmedetomidine increased the cTnI level, indicating subclinical myocardial damage.

Ambulatory electrocardiography and serum cardiac troponin I measurement in 21 dogs envenomated by the European adder (Vipera berus)

BACKGROUND

Envenomation by the European adder (Vipera berus) is common in dogs in Europe. Cardiac arrhythmias occur but clinical studies of envenomated dogs are limited.

OBJECTIVES

To describe arrhythmias in dogs within 48 hours of envenomation, and investigate associations between arrhythmia grade, serum troponin I (cTnI), and snakebite severity score (SS score).

ANIMALS

Twenty-one client-owned dogs bitten by V berus.

METHODS

Prospective cohort study of envenomated dogs. Ambulatory electrocardiograms were recorded from presentation to 48 hours after snakebite, and arrhythmias graded 0 to 3 based on frequency and severity. Serum cTnI was measured at presentation, 12 hours, 24 hours, 36 hours, and 14 days after bite. An SS score of 1 to 3 was recorded at admission and based on clinical examination.

RESULTS

All dogs survived. Twelve dogs (57%) developed arrhythmias, all of which were ventricular in origin. Severe complex ventricular arrhythmias (VAs) were observed in 6 dogs (29%). Eighty-one percent of dogs (n = 17) had increased cTnI concentrations at 1 or more time points. Dogs that developed arrhythmias had significantly higher concentrations of cTnI at 12 hours (1.67 [0.04-32.68] versus 0.03 [0.01-0.052]; P = .002), 24 hours (1.88 [0.2-14.23] versus 0.06 [0.01-2.06]; P = .009), and 36 hours (3.7 [0.02-16.62] versus 0.06 [0.01-1.33]; P = .006) after bite compared to those that did not. Contingency table analysis showed that SS score was not significantly associated with arrhythmia grade (P = .9).

CONCLUSIONS AND CLINICAL IMPORTANCE

Myocardial cell injury, reflected by increased cTnI concentrations and VAs, is common after V berus envenomation in dogs. Prolonged electrocardiography monitoring is advised, particularly where cTnI is increased.

Analytical quality assessment and method comparison of two immunoassays for the measurement of serum cardiac Troponin I in dogs and cats

BACKGROUND

Cardiac troponin I (cTnI) is a sensitive and specific biomarker for myocardial injury. Validation of point-of-care (POC) analyzers for cTnI measurement is valuable to the critical care setting, in which rapid results can facilitate prompt diagnoses. An immunoassay for detecting cTnI is available for the POC AIA-360 analyzer (Tosoh Bioscience), but this has not been validated using canine and feline serum.

OBJECTIVES

The objectives were (a) to determine precision, accuracy, and linearity of cTnI measurement using the AIA-360 immunoassay in pooled canine and feline samples, and (b) to compare results for individual canine and feline samples with those obtained using a reference chemiluminescence method (Immulite 1000, Siemens).

METHODS

Intra- and inter-assay repeatability was determined using pooled canine and feline samples, and the coefficient of variation (CV) was calculated for each. Pooled samples were also serially diluted to assess linearity. A modified spike and recovery analysis was performed by mixing pooled samples with different concentrations. Bland-Altman and Deming regression analyses were used to determine bias for individual samples, and the total observed error (TE_obs ) was calculated.

RESULTS

Coefficient of variation values were well within the required maximum of 20%. Linearity was demonstrated over the range of samples tested, and the recovery study showed minimal proportional inaccuracies. Although the correlation between the analyzers was excellent, there was a large mean bias due to relative proportional bias. Total observed error consequently exceeded the total allowable error (TE_A ).

CONCLUSION

Although, in most respects, the analyzer demonstrated adequate performance, pronounced bias contributed to the large TE_obs , indicating a requirement for analyzer-specific reference intervals.

Cardiac troponin I in dogs anaesthetized with propofol and sevoflurane: the influence of medetomidine premedication and inspired oxygen fraction

OBJECTIVE

To investigate changes in serum cardiac troponin I (cTnI) concentrations in dogs in which medetomidine was used for sedation or for premedication prior to anaesthesia with propofol and sevoflurane.

STUDY DESIGN

Prospective clinical study.

ANIMALS

A total of 66 client-owned dogs.

METHODS

The dogs were sedated with medetomidine (0.04 mg kg^-1) intravenously (IV) (group M; n = 20) and left to breath room air or anaesthetized with propofol (6.5 ± 0.76 mg kg^-1 IV) and sevoflurane (4.5% vaporizer setting) in oxygen (group P + S; n = 20) or with medetomidine (0.04 mg kg^-1 IV), propofol (1.92 ± 0.63 mg kg^-1) and sevoflurane (3% vaporizer setting) in oxygen (group M + P + S; n = 26), respectively. After 35 minutes, medetomidine was antagonized with atipamezole (0.1 mg kg^-1 intramuscularly). Blood samples for serum cTnI determination were taken before sedation or anaesthesia, 6 and 12 hours and 4 days thereafter. Serum cTnI concentrations were measured with the Architect STAT Troponin-I assay.

RESULTS

Before sedation or anaesthesia, cTnI concentrations were above the detection limit in 22 out of 66 (33%) of dogs. Compared to basal values, cTnI concentrations significantly increased at 6 and 12 hours in all groups and at day 4 in group M. There were no differences in cTnI concentration between groups at baseline, at 6 hours and at 4 days. At 12 hours, cTnI concentrations were significantly higher in groups M and P + S, respectively, compared to group M + P + S.

CONCLUSIONS AND CLINICAL RELEVANCE

Oxygenation during anaesthesia and reduction of propofol and sevoflurane dose due to the sparing effects of medetomidine might have played a role in alleviation of myocardial hypoxic injury as indicated by the less severe and short-lived increase of cTnI in the M + P + S group.

Biologic variability of cardiac troponin I in healthy dogs and dogs with different stages of myxomatous mitral valve disease using standard and high-sensitivity immunoassays

BACKGROUND

Biologic variability (BV) is one aspect of interpreting changes in biomarker concentrations known to be clinically important in people with cardiac disease, but it has not been adequately addressed in dogs so far.

OBJECTIVES

The purpose of the study was to determine BV of cardiac troponin I (cTnI) in healthy dogs and dogs with 3 stages of myxomatous mitral valve disease (MMVD).

METHODS

Healthy dogs and dogs with 3 stages of MMVD were prospectively assigned to groups based on comprehensive clinical evaluation using current guidelines. Concentrations of cTnI were measured hourly, daily, and weekly using standard and high-sensitivity immunoassays. Within- (CV_I ) and between-subject (CV_G ) coefficients of variability, percent reference change value (RCV), and index of individuality (IoI) were calculated.

RESULTS

All 10 healthy dogs and 76/112 (68%) of samples from 28 MMVD dogs had cTnI concentrations below the limit of detection (LOD) using a standard sensitivity immunoassay. Only 49/160 (31%) of healthy dog samples and no MMVD samples had cTnI below the high-sensitivity immunoassay LOD. Data analysis for the high-sensitivity immunoassay revealed CV_I of 48.1%, CV_G of 60.1%, RCV of 134.0%, and IoI of 0.804 in healthy dogs. In MMVD dogs, CV_I was 39.6%, CV_G was 80.7%, RCV was 110%, and IoI was 0.494. Of all MMVD dogs, those with Stage B2 had the lowest RCV of 91%.

CONCLUSIONS

Biologic variability affects cTnI concentrations in healthy dogs and dogs with MMVD. Consideration of BV may be clinically relevant when monitoring individual changes in cTnI values, using high-sensitivity immunoassays.

Cardiac Troponin I and Amino-Terminal Pro B-Type Natriuretic Peptide in Dogs With Stable Chronic Kidney Disease

Background

Increased concentrations of N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) and cardiac troponin I (cTnI) in dogs with azotemia have been documented. Knowledge of mechanisms behind increased concentrations of cardiac biomarkers in dogs with azotemia is warranted for correct interpretation of test results.

Objectives

The aim of the article was to investigate possible associations between plasma concentrations of cTnI and NT‐proBNP, respectively, and patient characteristics, glomerular filtration rate (GFR), a plasma volume factor (PVF) derived from scintigraphic examination (PVf), systolic blood pressure (SBP), selected hematologic and biochemical variables, and echocardiographic measurements in dogs with stable chronic kidney disease (CKD) and in healthy dogs.

Animals

Fifty student‐, staff‐, and client‐owned dogs were included. Twenty‐three of the dogs were healthy and 27 were diagnosed with CKD.

Methods

In this cross‐sectional observational study, dogs with a previous diagnosis of CKD and healthy control dogs were included. At inclusion, all dogs were characterized by physical examination, repeated blood pressure measurements, complete urinalysis, hematology and biochemistry panel, echocardiography, abdominal ultrasound examination of the entire urinary tract, and scintigraphic examination for measurement of GFR.

Results

Plasma volume factor and PCV were independently associated with NT‐proBNP (Radj2 = 0.42; P < .0001). Age, body weight (BW), and SBP were independently associated with cTnI (Radj2 = 0.50; P < .0001).

Conclusions and Clinical Importance

Neither NT‐proBNP nor cTnI concentrations were independently associated with measured GFR. Thus, findings were not suggestive of passive accumulation of either marker, suggesting that increased circulating concentrations of cTnI and NT‐proBNP can be interpreted similarly in dogs with stable CKD as in dogs without CKD.

Avaliação dos valores de troponina I, eletrocardiograma e ecocardiograma em felinos sedados com cetamina e midazolam, suplementados ou não com oxigênio

Lesões no miocárdio, causadas por baixa perfusão e oxigenação cardíaca, podem ser ocasionadas por fármacos anestésicos, como a cetamina. Essas lesões podem ser identificadas por meio de biomarcadores específicos e, dentre estes, destaca-se a troponina I. O objetivo deste estudo foi avaliar as alterações cardiovasculares com base nos valores de troponina I (TnI), eletrocardiograma (ECG) e ecocardiograma em gatos sedados com cetamina e midazolam, suplementados ou não com oxigênio. Utilizaram-se 12 gatos machos, hígidos, nos quais se avaliaram os valores de troponina I, eletro e ecocardiografia, frequência cardíaca (FC) e pressão arterial sistólica (PAS) no momento basal (M0). Na sequência, os animais foram sedados com a associação de 10mg.kg-1 de cetamina e 0,5mg.kg-1 de midazolam pela via intramuscular. Decorridos aproximadamente 10 minutos, os animais foram alocados aleatoriamente em dois grupos: com e sem suplementação de oxigênio via máscara facial (GCO e GSO, respectivamente), sendo submetidos novamente aos exames citados. Foram coletadas amostras sanguíneas, para dosagem de TnI em seis, 12 e 24 horas após a administração dos agentes anestésicos. Não foram observadas alterações significativas na FC, na PAS e no ECG após a administração dos tratamentos em ambos os grupos. Os valores médios de TnI elevaram-se significativamente em T6 quando comparados ao basal em ambos os grupos, com médias de 0,507±0,335ng/mL no GSO e 0,777±0,505ng/mL no GCO. Na ecocardiografia, o débito cardíaco (DC) reduziu em M1 em ambos os grupos, quando comparados aos valores basais, sendo M0 0,472±0,115 e M1 0,234±0,08 no GSO e M0 0,356±0,095 e M1 0,222±0,09 no GCO, expressos em L/min. Conclui-se que a administração de cetamina e midazolam em gatos hígidos não promove alterações eletrocardiográficas, aumenta os valores de troponina I, com pico de seis horas após a administração, reduz o débito cardíaco, e que a suplementação de oxigênio 100% via máscara facial não atenua tais alterações.

Effect of general anesthesia on plasma cardiac troponin I concentrations in healthy horses

OBJECTIVE

To evaluate the effect of general anesthesia on plasma cTnI concentrations in horses.

ANIMALS, MATERIALS AND METHODS

Thirty-two horses undergoing general anesthesia and either elective surgery or MRI without surgery were prospectively studied. Twenty-nine horses (22 surgical, 7 imaging) completed the study. Plasma cTnI concentrations were determined prior to anesthesia and at 6, 12 and 24 h following discontinuation of the inhalant anesthetic.

RESULTS

All horses had cTnI values within the reference range at all time points. Six horses (21%) developed detectable cTnI 6 or 12 h following anesthesia. Risk factors for detectable cTnI include increasing age and dorsal recumbency. Horses with detectable cTnI had significantly lower mean and diastolic arterial blood pressures than those without detectable cTnI.

CONCLUSION

Uncomplicated general anesthesia with or without surgery does not result in cardiac troponin I elevations above the reference range in the first 24 h postoperatively.