Elevated Cardiac Troponin Levels in Geriatric Patients Without ACS: Role of Comorbidities.

BACKGROUND: Elevated levels of cardiac troponin T as measured by a high-sensitivity test (hscTnT) are common in geriatric patients with a large spectrum of comorbidities but without acute coronary syndrome (ACS). However, the relative contribution of individual comorbidities has never been clearly addressed. This study aimed to determine the relationship between hscTnT elevation as a response variable and individual comorbidities, and to estimate the impact of individual comorbidities on hscTnT elevation in geriatric patients free of ACS. METHODS: A nonexperimental, retrospective, matched, longitudinal cohort study was designed to evaluate the files of 7062 geriatric patients (aged ≥ 65 years) without ACS. The hscTnT levels of the patients have already been measured in all evaluated medical records. The dataset was split into 2 groups (0 and 1) based on the individual comorbidity (0 and 1) and hscTnT levels (≤ 14 ng/L = 0 and > 14 ng/L = 1). RESULTS: Our results show that although age was positively and significantly correlated with hscTnT (r = 0.17, P < 0.0001), the likelihood of experiencing elevated hscTnT levels in older individuals after having excluded ACS was related to the presence of comorbidities independently of their number (P < 0.0001). The regression coefficients (ß) associated with renal insufficiency (0.71), cardiomyopathy (0.63), chronic obstructive pulmonary disease (0.30), diabetes (0.25), and anemia (0.22) indicated that there exists a significant association between these comorbidities and the elevated hscTnT levels (P < 0.001). The receiver operating characteristic curve for predictive modeling was estimated at 71% (P < 0.0001). CONCLUSIONS: Elevated hscTnT levels were mostly associated with renal insufficiency, cardiac myopathies, chronic obstructive pulmonary disease, diabetes, and anemia in geriatric patients without ACS. Developing guidelines to accurately evaluate hscTnT elevation in geriatric patients with comorbidities, without ACS, is clinically essential.

CONTEXTE: Il arrive fréquemment que les patients âgés présentant un grand éventail d'affections concomitantes, mais pas de syndrome coronarien aigu (SCA), aient un taux élevé de troponine T cardiaque mesuré par un test de haute sensibilité (TnTc-hs). La contribution relative des différentes affections concomitantes prises individuellement n'a toutefois jamais été clairement évaluée. Cette étude a tenté de déterminer la relation entre l'élévation du taux de TnTc-hs en tant que variable réponse et différentes affections concomitantes, et d'estimer l'effet individuel de ces affections concomitantes sur le taux de TnTc-hs chez les patients âgés exempts de SCA. MÉTHODOLOGIE: Nous avons conçu une étude de cohorte longitudinale, non expérimentale, rétrospective et avec appariement afin d'évaluer les dossiers de 7 062 patients âgés (≥ 65 ans) ne présentant pas de SCA. Les taux de TnTc-hs des patients avaient déjà été mesurés et figuraient dans tous les dossiers médicaux examinés. Les données ont été séparées en 2 groupes (0 et 1) en fonction de la présence d'une affection concomitante particulière (0 et 1) et du taux de TnTc-hs (≤ 14 ng/l = 0 et > 14 ng/l = 1). RÉSULTATS: Nos résultats indiquent que bien que l'âge soit corrélé de manière positive et significative avec le taux de TnTc-hs (r = 0,17, p < 0,0001), la probabilité qu'une personne âgée présente un taux de TnTc-hs élevé alors qu'un SCA a été exclu est liée à la présence d'affections concomitantes, indépendamment de leur nombre (p < 0,0001). Les coefficients de régression (ß) associés à l'insuffisance rénale (0,71), à la cardiomyopathie (0,63), à la maladie pulmonaire obstructive chronique (0,30), au diabète (0,25) et à l'anémie (0,22) indiquent qu'il existe un lien significatif entre ces affections et un taux élevé de TnTc-hs (p < 0,001). La courbe caractéristique de la performance d'un test correspondant à la modélisation prédictive a été estimée à 71 % (p < 0,0001). CONCLUSIONS: Chez les patients âgés exempts de SCA, les taux élevés de TnTc-hs étaient principalement associés à l'insuffisance rénale, à la cardiomyopathie, à la maladie pulmonaire obstructive chronique, au diabète et à l'anémie. Il est donc essentiel, sur le plan clinique, d'établir des lignes directrices permettant de mesurer avec précision l'élévation du taux de TnTc-hs chez les patients âgés présentant des affections concomitantes, mais exempts de SCA.

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.

Transient high level mammalian reovirus replication in a bat epithelial cell line occurs without cytopathic effect.

Mammalian reoviruses exhibit a large host range and infected cells are generally killed; however, most studies examined only a few cell types and host species, and are probably not representative of all possible interactions between virus and host cell. Many questions thus remain concerning the nature of cellular factors that affect viral replication and cell death. In the present work, it was observed that replication of the classical mammalian reovirus serotype 3 Dearing in a bat epithelial cell line, Tb1.Lu, does not result in cell lysis and is rapidly reduced to very low levels. Prior uncoating of virions by chymotrypsin treatment, to generate infectious subviral particles, increased the initial level of infection but without any significant effect on further viral replication or cell survival. Infected cells remain resistant to virus reinfection and secrete an antiviral factor, most likely interferon, that is protective against the unrelated encephalomyocarditis virus. Although, the transformed status of a cell is believed to promote reovirus replication and viral "oncolysis", resistant Tb1.Lu cells exhibit a classical phenotype of transformed cells by forming colonies in semisolid soft agar medium. Further transduction of Tb.Lu cells with a constitutively active Ras oncogene does not seem to affect cell growth or reovirus effect on these cells. Infected Tb1.Lu cells can produce low-level of infectious virus for a long time without any apparent effect, although these cells are resistant to reinfection. The results suggest that Tb1.Lu cells can mount an unusual antiviral response. Specific properties of bat cells may thus be in part responsible for the ability of the animals to act as reservoirs for viruses in general and for novel reoviruses in particular. Their peculiar resistance to cell lysis also makes Tb1.Lu cells an attractive model to study the cellular and viral factors that determine the ability of reovirus to replicate and destroy infected cells.