Troponin elevation is very common in patients with infective endocarditis and is associated with a poor outcome

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Epidemiology, Diagnosis, Treatment, and Prognosis of Infective Endocarditis

Infective endocarditis (IE) has experienced enormous changes in recent decades [...].

Procedure-Specific Relationships Between Postoperative Troponin T and a Composite of Mortality and Low Cardiac Output Syndrome: A Retrospective Cohort Analysis

BACKGROUND

Myocardial injury after coronary artery bypass grafting (CABG) is defined as troponin concentrations >10 times 99th percentile upper reference limit (URL) according to the Fourth Universal Definition. However, troponin concentrations after non-CABG cardiac surgery which indicate greater-than-expected myocardial injury and increased risk for complications remain unclear. Our goal was to assess procedure-specific relationships between troponin T and a composite outcome of low cardiac output syndrome and in-hospital mortality in cardiac surgical patients.

METHODS

Patients having cardiac surgery between January 2010 and December 2017 were categorized into 4 groups by procedure: (1) CABG; (2) mitral valve repair; (3) aortic valve repair/replacement (AVR); (4) mitral valve replacement (MVR) or CABG + valve surgeries. Exclusion criteria were elevated preoperative troponin T, preoperative kidney failure, circulatory arrest, or preoperative/planned mechanical circulatory support. Logistic regression was used to assess the association between troponin T and composite outcome, both overall and by procedure, including assessment of the interaction between procedure and troponin T on outcome.

RESULTS

Among 10,253 patients, 37 (0.4%) died and 393 (3.8%) developed the primary outcome. Troponin T concentrations differed by procedure (P < .001). Compared to CABG, AVR had 0.53 (99.2% confidence interval [CI], 0.50-0.56; unadjusted P < .001) times lower troponin T concentrations, while MVR/CABG + valve were 1.54 (99.2% CI, 1.45-1.62, unadjusted P < .001) times higher. There were linear relationships between log2 troponin T concentration and log odds mortality/low cardiac output syndrome. The (unadjusted) relationships were parallel for various types of surgery (interaction P = .59), but at different levels of the outcome.

CONCLUSIONS

The relative increase in odds for mortality/low cardiac output syndrome per a similar increase in troponin T concentrations did not differ among cardiac surgical procedures, but the absolute troponin T concentrations did. Troponin concentrations should thus be interpreted in context of surgical procedure.

C-Reactive Protein at Hospital Discharge and 1-Year Mortality in Acute Infective Endocarditis: A Prospective Observational Study

Background: An accurate biomarker at hospital discharge is needed to identify patients with acute infective endocarditis (IE) who are at high risk of mortality. This prospective observational study evaluated the prognostic value of C-reactive protein (CRP).

Methods: Patients with acute IE (n = 343) and hospitalized at 2 university-affiliated medical centers from January 2014 to December 2019 were enrolled. Patients were categorized as having low or high CRP (n = 217 and 126, respectively) at hospital discharge according to the optimal cutoff (CRP = 6.5 mg/L) determined via receiver-operating characteristic curve analysis. The primary endpoint was all-cause death, from hospital discharge to 1 year. The secondary endpoint was the cumulative rate of rehospitalization or paravalvular abscess at 1 year.

Results: At the 12-month follow-up, the mortality rate of the high-CRP group (21.43%) was significantly higher than that of the low-CRP group (2.76%, log-rank P < 0.0001). The multivariate regression analysis indicated that the high-CRP group had a higher excess mortality hazard risk (HR = 4.182; 95% CI: 2.120, 5.211; P < 0.001). The cumulative 1-year incidence of paravalvular abscess of the high-CRP group (11.90%) was significantly higher than that of the low-CRP (5.07%; P = 0.022). The cumulative rate of heart rehospitalizations of the 2 groups were similar (18.25% cf. 14.29%, P = 0.273).

Conclusion: For hospitalized patients with acute IE, a high CRP at discharge suggests a poor prognosis for 1-year mortality and paravalvular abscess.

Cardiac troponin and infective endocarditis prognosis: a systematic review and meta-analysis

AIMS

Infective endocarditis (IE) is associated with high mortality and morbidity. Cardiac troponin (Tn) elevation seems to be common in patients with IE and could be associated with a poor prognosis. The aim of this study was to synthesize the prognostic value of Tn in patients with IE.

METHODS AND RESULTS

We searched in MEDLINE, EMBASE, and the Cochrane library, including the Cochrane Central Register of Controlled Trials (CENTRAL) until February 2020. Observational studies reporting on the association between Tn and in-hospital and 1-year mortality, and IE complications were considered eligible. As each centre uses different conventional or ultra-sensitive Tn, with different normality threshold, we considered them as normal or elevated according to the criteria specified in each article. Articles were systematically selected, assessed for bias, and, when possible, meta-analysed using a random effect model. After retrieving 542 articles, 18 were included for qualitative synthesis and 9 for quantitative meta-analysis. Compared with patients with normal Tn levels, patients with Tn elevation presented higher in-hospital mortality [odds ratio (OR) 5.96, 95% confidence interval (CI) 3.46-10.26; P < 0.0001], 1-year mortality (OR 2.67, 95% CI 1.42-5.02; P = 0.002), and surgery rates (OR 2.34, 95% CI 1.42-3.85; P = 0.0008). They also suffered more frequent complications: central nervous system events (OR 8.85, 95% CI 3.23-24.26; P < 0.0001) and cardiac abscesses (OR 4.96, 95% CI 1.94-12.70; P = 0.0008).

CONCLUSION

Tn elevation is associated with a poor prognosis in patients with IE. Troponin determination seems to provide additional help in the prognostic assessment of these patients.