Cardiac troponin T as a predictor of cardiac death in patients with left ventricular dysfunction

Prognostic Value of Cardiac Troponin I in Patients with Ventricular Tachyarrhythmias

Besides the diagnostic role in acute myocardial infarction, cardiac troponin I levels (cTNI) may be increased in various other clinical conditions, including heart failure, valvular heart disease and sepsis. However, limited data are available regarding the prognostic role of cTNI in the setting of ventricular tachyarrhythmias. Therefore, the present study sought to assess the prognostic impact of cTNI in patients with ventricular tachyarrhythmias (i.e., ventricular tachycardia (VT) and fibrillation (VF)) on admission. A large retrospective registry was used, including all consecutive patients presenting with ventricular tachyarrhythmias from 2002 to 2015. The prognostic impact of elevated cTNI levels was investigated for 30-day all-cause mortality (i.e., primary endpoint) using Kaplan–Meier, receiver operating characteristic (ROC), multivariable Cox regression analyses and propensity score matching. From a total of 1104 patients with ventricular tachyarrhythmias and available cTNI levels on admission, 46% were admitted with VT and 54% with VF. At 30 days, high cTNI was associated with the primary endpoint (40% vs. 22%; log rank p = 0.001; HR = 2.004; 95% CI 1.603–2.505; p = 0.001), which was still evident after multivariable adjustment and propensity score matching (30% vs. 18%; log rank p = 0.003; HR = 1.729; 95% CI 1.184–2.525; p = 0.005). Significant discrimination of the primary endpoint was especially evident in VT patients (area under the curve (AUC) 0.734; 95% CI 0.645–0.823; p = 0.001). In contrast, secondary endpoints, including all-cause mortality at 30 months and a composite arrhythmic endpoint, were not affected by cTNI levels. The risk of cardiac rehospitalization was lower in patients with high cTNI, which was no longer observed after propensity score matching. In conclusion, high cTNI levels were associated with increased risk of all-cause mortality at 30 days in patients presenting with ventricular tachyarrhythmias.

Redefining Cirrhotic Cardiomyopathy for the Modern Era

Cirrhotic cardiomyopathy (CCM) is cardiac dysfunction in patients with end-stage liver disease in the absence of prior heart disease. First defined in 2005 during the World Congress of Gastroenterology, CCM criteria consisted of echocardiographic parameters to identify subclinical cardiac dysfunction in the absence of overt structural abnormalities. Significant advancements in cardiovascular imaging over the past 14 years, including the integration of myocardial deformation imaging into routine clinical practice to identify subclinical cardiovascular dysfunction, have rendered the 2005 CCM criteria obsolete. Therefore, new criteria based on contemporary cardiovascular imaging parameters are needed. In this guidance document, assembled by a group of multidisciplinary experts in the field, new core criteria based on contemporary cardiovascular imaging parameters are proposed for the assessment of CCM. This document provides a critical assessment of the diagnosis of CCM and ongoing assessment aimed at improving clinical outcomes, particularly surrounding liver transplantation. Key points and practice-based recommendations for the diagnosis of CCM are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

Risk Stratification for Sudden Cardiac Death in Non-Ischaemic Dilated Cardiomyopathy

Purpose of Review

Non-ischaemic dilated cardiomyopathy (DCM) occurs in 1 in 2500 individuals in the general population and is associated with considerable morbidity and mortality. Studies involving large numbers of unselected DCM patients have led to consensus guidelines recommending implantable cardioverter-defibrillator (ICD) implantation for protection against sudden cardiac death (SCD) in those with LVEF ≤35%. The purpose of this article is to review the literature for other potential markers including serological, electrocardiographic, echocardiographic, cardiac magnetic resonance, ambulatory ECG and genetic data, to highlight other potential markers that may optimise risk stratification for SCD in this cohort and thereby allow a more personalized approach to ICD-implantation.

Recent Findings

Recent studies including the Danish study to assess the efficacy of ICDs in patients with non-ischemic systolic heart failure on mortality (DANISH) trial have questioned the benefits of ICD implantation in this group of patients with no changes in all-cause mortality. Recent pooled cohorts of patients with genetic DCM and in particular in those with Lamin A/C (LMNA) mutations have identified patients at increased risk of SCD and allowed the creation of algorithms to prognosticate SCD risk in mutation carriers. Furthermore, genetic testing has identified other DCM-causing genes including filamin C (FLNC) and RBM20 which may be associated with higher rates of ventricular arrhythmia.

Summary

To date, risk-stratification for SCD has been hampered by the utilisation of heterogenous subsets of idiopathic DCM patients and by use of static risk models where predictions are based on a single time point with a lack of consideration of disease progression. The current focus of personalised risk-stratification for SCD is shifting towards better characterisation of underlying DCM aetiology and the development of multi-parametric risk-stratification models that incorporate time-dependent disease characteristics and novel biomarkers.

Is Cardiac Troponin I Valuable to Detect Low-Level Myocardial Damage in Congestive Heart Failure?

Objectives:

Congestive heart failure (CHF) is a heart disease with a growing incidence and prevalence. Creatine kinase-myocardial base (CK-MB) is generally used to determine myocardial damage; however, it is insufficiently sensitive to measure the relatively low level of myocardial damage that typically occurs in heart failure (HF). The use of cardiac troponins, which are far more sensitive and specific, has become common to identify myocardial damage and permits the detection of even minute amounts of damage. The aim of this study was to ascertain whether cardiac troponin I (cTnI) can be used to detect low-level myocardial damage occurring in CHF in real-life conditions.

Methods:

Fifty patients with CHF symptoms (Group I) and 20 patients who were evaluated as normal (Group II) were included in this prospective study. The Framingham criteria were used to diagnose HF. Group I was divided into 3 subgroups according to the New York Heart Association classification of functional capacity: Class II, Group A; Class III, Group B, and Class IV, Group C. On the first day of admission, CK-MB and cTnI levels were measured and assessed quantitatively. The cTnI level was compared between these 3 subgroups and between Groups I and II. Linear regression analysis was performed to investigate the relationship between ejection fraction (EF) and cTnI.

Results

The mean cTnI value was 0.084±0.07 ng/mL in Group I and 0.018±0.012 ng/mL in Group II (p=0.0001). The mean cTnI value was 0.047±0.016 ng/mL, 0.080±0.048 ng/mL, and 0.175± 0.102 ng/mL in Groups A, B, and C, respectively. The difference between the subgroups of Group I was statistically significant. In addition, it was observed that there was a significant difference in the EF (%) value between Groups I and II and between Groups A, B, and C. Linear regression analysis revealed an inverse relationship between EF and cTnI (r: -0.66) (p=0.0001).

Conclusion

As the severity of HF increased, the cTnI serum level also increased. This increase was inversely related to the EF value. These results are consistent with other studies in the literature, suggesting that the cTnI level may be a useful marker in the diagnosis and evaluation of severity of HF.

Postoperative high-sensitivity troponin T as a predictor of sudden cardiac arrest in patients undergoing cardiac surgery

BACKGROUND

The usefulness of high-sensitivity troponin T (hs-TnT) as a predictor of sudden cardiac arrest (SCA) in patients undergoing valve surgery is currently unknown.

METHODS

A prospective study was conducted on a group of 815 consecutive patients with significant valvular heart disease that underwent elective valve surgery. The primary end-point was postoperative SCA.

RESULTS

The postoperative SCA occurred in 26 patients. At multivariate analysis of hs-TnT measured immediately after surgery (hs-TnT I) and age remained independent predictors of the primary end-point.

CONCLUSIONS

Elevated postoperative hs-TnT was associated with a higher risk of postoperative SCA.

Risk Stratification of Sudden Cardiac Death in Patients with Heart Failure: An update

Heart failure (HF) is a complex clinical syndrome in which structural/functional myocardial abnormalities result in symptoms and signs of hypoperfusion and/or pulmonary or systemic congestion at rest or during exercise. More than 80% of deaths in patients with HF recognize a cardiovascular cause, with most being either sudden cardiac death (SCD) or death caused by progressive pump failure. Risk stratification of SCD in patients with HF and preserved (HFpEF) or reduced ejection fraction (HFrEF) represents a clinical challenge. This review will give an update of current strategies for SCD risk stratification in both HFrEF and HFpEF.