Using High-Sensitivity Cardiac Troponin for the Exclusion of Inducible Myocardial Ischemia in Symptomatic Patients: A Cohort Study

Enhancing the diagnosis of functionally relevant coronary artery disease with machine learning

Functionally relevant coronary artery disease (fCAD) can result in premature death or nonfatal acute myocardial infarction. Its early detection is a fundamentally important task in medicine. Classical detection approaches suffer from limited diagnostic accuracy or expose patients to possibly harmful radiation. Here we show how machine learning (ML) can outperform cardiologists in predicting the presence of stress-induced fCAD in terms of area under the receiver operating characteristic (AUROC: 0.71 vs. 0.64, p = 4.0E-13). We present two ML approaches, the first using eight static clinical variables, whereas the second leverages electrocardiogram signals from exercise stress testing. At a target post-test probability for fCAD of <15%, ML facilitates a potential reduction of imaging procedures by 15-17% compared to the cardiologist's judgement. Predictive performance is validated on an internal temporal data split as well as externally. We also show that combining clinical judgement with conventional ML and deep learning using logistic regression results in a mean AUROC of 0.74.

Diagnostic and prognostic value of H-ficolin for functionally relevant coronary artery disease

BACKGROUND

We aimed to test the diagnostic and prognostic ability of H-ficolin, an initiator of the lectin pathway of the complement system, for functionally relevant coronary artery disease (fCAD), and explore its determinants.

METHODS

The presence of fCAD was adjudicated using myocardial perfusion imaging single-photon emission tomography and coronary angiography. H-ficolin levels were measured by a sandwich-type immunoassay at rest, peak stress-test, and 2 h after stress-test. Cardiovascular death and non-fatal myocardial infarction were assessed during 5-year follow-up.

RESULTS

Among 1,571 patients (32.3 % women), fCAD was detected in 462 patients (29.4 %). H-ficolin concentration at rest was 18.6 (15.3-21.8) µg/ml in patients with fCAD versus 17.8 (15.4-21.5) µg/ml, p = 0.33, in patients without fCAD, resulting in an AUC of 0.53 (95 %CI 0.48-0.56). During follow-up, 107 patients (6.8 %) had non-fatal myocardial infarction and 99 patients (6.3 %) experienced cardiovascular death. In Cox regression analysis, H-ficolin was not a predictor of events in the overall cohort. Subgroup analysis suggested a potential link between H-ficolin and non-fatal myocardial infarction in patients without fCAD (adjusted HR 1.03, 95 % CI 1.02-1.15, p = 0.005). H-ficolin concentration showed a weak positive correlation with systolic (r = 0.069, p < 0.001) and diastolic blood pressure (r = 0.111, p < 0.001).

CONCLUSION

H-ficolin concentration did not have diagnostic and/or prognostic value in patients referred for fCAD work-up.

Aconitum carmichaelii Debx. Attenuates Heart Failure through Inhibiting Inflammation and Abnormal Vascular Remodeling

Heart failure (HF) is the most common complication following myocardial infarction, closely associated with ventricular remodeling. Aconitum carmichaelii Debx., a traditional Chinese herb, possesses therapeutic effects on HF and related cardiac diseases. However, its effects and mechanisms on HF-associated cardiac diseases are still unclear. In the present study, a water extraction of toasted Aconitum carmichaelii Debx. (WETA) was verified using UPLC-Q/TOF-MS. The heart function of HF rats was assessed by echocardiography and strain analysis, and myocardial injury was measured by serum levels of CK-MB, cTnT, and cTnI. The pathological changes of cardiac tissues were evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) staining, hematoxylin and eosin (H&E) staining, and Masson's trichrome staining. Additionally, the levels of inflammation-related genes and proteins and components related to vascular remodeling were detected by RT-qPCR, Western blot, and immunofluorescence. WETA significantly inhibited the changes in echocardiographic parameters and the increase in heart weight, cardiac infarction size, the myonecrosis, edema, and infiltration of inflammatory cells, collagen deposition in heart tissues, and also mitigated the elevated serum levels of CK-MB, cTnT, and cTnI in ISO-induced rats. Additionally, WETA suppressed the expressions of inflammatory genes, including IL-1β, IL-6, and TNF-α and vascular injury-related genes, such as VCAM1, ICAM1, ANP, BNP, and MHC in heart tissues of ISO-induced HF rats, which were further confirmed by Western blotting and immunofluorescence. In summary, the myocardial protective effect of WETA was conferred through inhibiting inflammatory responses and abnormal vascular remodeling in ISO-treated rats.

A proteomic surrogate for cardiovascular outcomes that is sensitive to multiple mechanisms of change in risk

A reliable, individualized, and dynamic surrogate of cardiovascular risk, synoptic for key biologic mechanisms, could shorten the path for drug development, enhance drug cost-effectiveness and improve patient outcomes. We used highly multiplexed proteomics to address these objectives, measuring about 5000 proteins in each of 32,130 archived plasma samples from 22,849 participants in nine clinical studies. We used machine learning to derive a 27-protein model predicting 4-year likelihood of myocardial infarction, stroke, heart failure, or death. The 27 proteins encompassed 10 biologic systems, and 12 were associated with relevant causal genetic traits. We independently validated results in 11,609 participants. Compared to a clinical model, the ratio of observed events in quintile 5 to quintile 1 was 6.7 for proteins versus 2.9 for the clinical model, AUCs (95% CI) were 0.73 (0.72 to 0.74) versus 0.64 (0.62 to 0.65), c-statistics were 0.71 (0.69 to 0.72) versus 0.62 (0.60 to 0.63), and the net reclassification index was +0.43. Adding the clinical model to the proteins only improved discrimination metrics by 0.01 to 0.02. Event rates in four predefined protein risk categories were 5.6, 11.2, 20.0, and 43.4% within 4 years; median time to event was 1.71 years. Protein predictions were directionally concordant with changed outcomes. Adverse risks were predicted for aging, approaching an event, anthracycline chemotherapy, diabetes, smoking, rheumatoid arthritis, cancer history, cardiovascular disease, high systolic blood pressure, and lipids. Reduced risks were predicted for weight loss and exenatide. The 27-protein model has potential as a "universal" surrogate end point for cardiovascular risk.

Soluble urokinase plasminogen activator receptor and functionally relevant coronary artery disease: a prospective cohort study

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) is an emerging biomarker associated with anatomical CAD burden and cardiovascular outcomes including myocardial infarction (MI) and death. We aimed at validating previous findings of the prognostic value of suPAR and evaluated its diagnostic potential for functional relevant CAD (fCAD).

METHODS

Consecutive patients with suspected fCAD were enrolled. Adjudication of fCAD was performed blinded to suPAR concentrations by myocardial perfusion single photon emission tomography (MPI-SPECT) and coronary angiography. Prognostic outcome measures included all-cause, cardiovascular death, and incident MI during 2-year follow-up.

RESULTS

Among consecutive 968 patients, SuPAR concentrations were higher in patients with fCAD compared to those without (3.45ng/mL versus 3.20ng/mL, p = 0.007), without acceptable diagnostic accuracy (area under the curve [AUC]: 0.56, 95%CI 0.52-0.60). SuPAR correlated with high-sensitivity cardiac-troponin (hs-cTn) T (Spearman's rho (ρ) 0.393, p < 0.001), NT-proBNP (ρ = 0.327, p < 0.001), age (ρ = 0.364, p < 0.001) and very weakly with coronary atherosclerosis (ρ = 0.123, p < 0.001). Prognostic discrimination of suPAR was moderate for cardiovascular death (AUC =0.72, 95%CI 0.62-0.81) and all-cause death (AUC =0.72, 95%CI 0.65-0.79) at 2-years. SuPAR remained a significant predictor for all-cause death in the full model (HR =1.96, p = 0.001).

CONCLUSIONS

SuPAR was an independent predictor of all-cause death, without diagnostic utility for fCAD.

Gut microbiota-dependent metabolite trimethylamine N-oxide (TMAO) and cardiovascular risk in patients with suspected functionally relevant coronary artery disease (fCAD)

BACKGROUND

Trimethylamine N-oxide (TMAO) has been associated with cardiovascular outcomes. However, the diagnostic value of TMAO and its precursors have not been assessed for functionally relevant coronary artery disease (fCAD) and its prognostic potential in this setting needs to be evaluated.

METHODS

Among 1726 patients with suspected fCAD serum TMAO, and its precursors betaine, choline and carnitine, were quantified using liquid chromatography tandem mass spectrometry. Diagnosis of fCAD was performed by myocardial perfusion single photon emission tomography (MPI-SPECT) and coronary angiography blinded to marker concentrations. Incident all-cause death, cardiovascular death (CVD) and myocardial infarction (MI) were assessed during 5-years follow-up.

RESULTS

Concentrations of TMAO, betaine, choline and carnitine were significantly higher in patients with fCAD versus those without (TMAO 5.33 μM vs 4.66 μM, p < 0.001); however, diagnostic accuracy was low (TMAO area under the receiver operating curve [AUC]: 0.56, 95% CI [0.53-0.59], p < 0.001). In prognostic analyses, TMAO, choline and carnitine above the median were associated with significantly (p < 0.001 for all) higher cumulative events for death and CVD during 5-years follow-up. TMAO remained a significant predictor for death and CVD even in full models adjusted for renal function (HR = 1.58 (1.16, 2.14), p = 0.003; HR = 1.66 [1.07, 2.59], p = 0.025). Prognostic discriminative accuracy for TMAO was good and robust for death and CVD (2-years AUC for CVD 0.73, 95% CI [0.65-0.80]).

CONCLUSION

TMAO and its precursors, betaine, choline and carnitine were significantly associated with fCAD, but with limited diagnostic value. TMAO was a strong predictor for incident death and CVD in patients with suspected fCAD.

CLINICAL TRIAL REGISTRATION

NCT01838148.

The absolute and relative changes in high-sensitivity cardiac troponin I are associated with the in-hospital mortality of patients with fulminant myocarditis

Background

We sought to describe the tendency and extent of high-sensitivity cardiac troponin I (hs-cTnI) changes in patients with fulminant myocarditis (FM) after admission and to explore the relationship between the in-hospital mortality of FM and the absolute and relative changes in hs-cTnI within 24 h and 48 h after admission.

Methods

In the retrospective study, the object are patients diagnosed with FM in our single centre. The value of cardiac troponin was recorded after patients admitted to hospital in succession. The absolute and relative changes in hs-cTnI within 24 h and 48 h were described as range distributions. Receiver operating characteristic (ROC) curve and Cox analyses were performed to determine the relationship between in-hospital mortality of FM and hs-cTnI changes.

Results

A total of 83 FM patients admitted to our centre from January 1, 2010 to December 31, 2019 were included; 69 patients survived and 14 patients died. In the survival group, 78% of patients experienced a decline in hs-cTnI within 24 h, while 36% of the mortality group exhibited a declining tendency in hs-cTnI (P = 0.003). Nearly 60% of survival group had a 0–2000 ng/l reduction in troponin from baseline within 24 h of admission. However, troponin levels of 50% of patients in the mortality group were 0–10,000 ng/ L higher than baseline 24 h after admission. Multivariable logistic analysis revealed that the declining tendency of hs-cTnI within 24 h, in addition to time from onset to admittance to hospital, intravenous immunoglobulin treatment and the abnormal level of creatinine, were associated with the in-hospital mortality of FM (for the declining tendency of hs-cTnI within 24 h, OR = 0.10, 95% CI 0.02–0.68, P = 0.018). The ROC curve revealed optimal cut-off values of − 618 ng/l for absolute change within 24 h (AUC = 0.800, P < 0.01), − 4389 ng/l for absolute change within 48 h (area under the curve = 0.711, P < 0.01), − 28.46% for relative change within 24 h (AUC = 0.810, P < 0.01), and − 52.23% for relative change within 48 h (AUC = 0.795, P < 0.01). Absolute changes and relative changes in hs-cTnI within 24 h and 48 h were strong predictors of in-hospital mortality by Cox regression analysis after adjustment for sex, time from onset to admission, and occurrence of ventricular tachycardia or ventricular fibrillation.

Conclusion

Most FM patients who survived experienced a decline in hs-cTnI within 24 h. The absolute and relative changes in hs-cTnI within 24 h and 48 h were strong predictors of in-hospital mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02386-8.

Influence of renin-angiotensin-aldosterone system inhibitors on plasma levels of angiotensin-converting enzyme 2

AIMS

Concern has been raised that treatment with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may increase the expression of angiotensin-converting enzyme 2 (ACE2), which acts as the entry receptor for SARS-CoV-2, and lead to an increased risk of death from SARS-CoV-2. We aimed to address this concern by evaluating the in vivo relationship of treatment with ACE inhibitors and angiotensin receptor blockers (ARB) with circulating plasma concentrations of ACE2 in a large cohort of patients with established cardiovascular disease (n = 1864) or cardiovascular risk factors (n = 2144) but without a history of heart failure.

METHODS AND RESULTS

Angiotensin-converting enzyme 2 was measured in 4008 patients (median age 68, 33% women, 31% on ACE-inhibitors, 31% on ARB) using the SOMAscan proteomic platform (SomaLogic Inc, Colorado, USA). Plasma concentration of ACE2 was comparable in 1250 patients on ACE inhibitors (mean 5.99) versus patients without ACE inhibitors (mean 5.98, P = 0.54). Similarly, plasma concentration of ACE2 was comparable in 1260 patients on ARB (mean 5.99) versus patients without ARB (mean 5.98, P = 0.50). Plasma concentration of ACE2 was comparable in 2474 patients on either ACE inhibitors or ARB (mean 5.99) versus patients without ACE inhibitors or ARB (mean 5.98, P = 0.31). Multivariable quantile regression model analysis confirmed the lack of association between treatment with ACE inhibitors or ARB and ACE2 concentrations. Body mass index showed the only positive association with ACE2 plasma concentration (effect 0.015, 95% confidence interval 0.002 to 0.028, P = 0.024).

CONCLUSIONS

In a large cohort of patients with established cardiovascular disease or cardiovascular risk factors but without heart failure, ACE inhibitors and ARB were not associated with higher plasma concentrations of ACE2.

Analytical performance of cardiac troponin assays - Current status and future needs

Concurrent with the introduction of cardiac troponin measurements into the diagnostic definition of myocardial infarction (MI), clinicians and laboratory professionals signaled a clear clinical need for improved analytical quality. This was an important precipitant for developing high-sensitivity cardiac troponin (hs-cTn) assays, currently used in rapid algorithms guiding investigations of patients presenting to the emergency department with possible MI. The hs-cTn assays were also important for the detection and monitoring of low-grade chronic myocardial injury, a condition that has been linked to increased long-term risk of cardiovascular morbidity and mortality. This review summarizes the general recommendations for defining analytical performance specifications while providing relevant clinical situations related to analytical performance. Importantly, outcome studies suggest analytical quality performance for hs-cTn is sufficient for early discharge of patients investigated for possible MI. However, bias due to change in calibrators or reagents may significantly affect the percentage of patients discharged. Biological variation data is suitable for defining performance specifications when hs-cTn measurements are used for diagnosing and monitoring chronic myocardial injury. Further improvement in analytical performance for hs-cTn testing may result in even faster decision making in the emergency setting; while also identifying those with chronic injury at risk for an adverse cardiac event.