N-terminal pro-B-type natriuretic peptide is associated with severity of the coronary lesions in unstable angina patients with preserved left ventricular function

CircSLC8A1 and circNFIX can be used as auxiliary diagnostic markers for sudden cardiac death caused by acute ischemic heart disease

Sudden cardiac death (SCD) caused by acute ischemic heart disease (IHD) is a major cause of sudden death worldwide. Circular RNAs (circRNAs) are abundant in the heart and play important roles in cardiovascular diseases, but the role of circRNAs as biomarkers in the forensic diagnosis of SCD caused by acute IHD remains poorly characterized. To investigate the potential of two heart-enriched circRNAs, circNFIX and circSLC8A1, we explored the expression of these two circRNAs in different kinds of commonly used IHD models, and further verified their expressions in forensic autopsy cases. The results from both the IHD rat and H9c2 cell models revealed that circSlc8a1 level was upregulated, while the circNfix level was elevated in the early stage of ischemia and subsequently downregulated. The time-dependent expression patterns of the two circRNAs suggested their potential as SCD biomarkers. In autopsy cases, the results showed that the expression of these two circRNAs in the myocardium with acute IHD-related SCDs corresponded to the observations in the ischemic models. Further analysis related to myocardial ischemia indicated that circSLC8A1 showed high sensitivity and specificity for myocardial infarction and was positively correlated with creatine kinase MB in pericardial fluid. Downregulated circNFIX level could indicate the ischemic myocardial damage, and it was negatively correlated with the coronary artery stenosis grade. The combination of circSLC8A1 and circNFIX had better performance to discriminate IHD-related SCDs. The results suggested that circSLC8A1 and circNFIX may be used as auxiliary diagnostic markers for SCD caused by acute IHD in forensic medicine.

Serum Levels of Cystatin C, N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP), and Cardiac Function in Patients with Unstable Angina Pectoris

Background

This study aimed to investigate the association between serum levels of cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac function in patients with unstable angina pectoris (UAP).

Material/Methods

A cross-sectional observational study was conducted at a single center and recruited 300 patients (214 men and 86 women), who were diagnosed with UAP between June 2018 to December 2018. The patients had serum levels of NT-ProBNP measured and were divided into four groups according to the serum levels of cystatin C: Q1, 0.49–0.83 mg/L; Q2, 0.84–1.04 mg/L; Q3, 1.05–1.38 mg/L; Q4, 1.39–4.21 mg/L. Cardiac function was graded according to the New York Heart Association (NYHA) class I to IV criteria.

Results

In the 300 patients with UAP, there were significant differences in cardiac function and NT-ProBNP levels between the four study groups (Q1 to Q4) (p<0.05). Univariate analysis showed that body weight, heart rate, treatment with aspirin, ticagrelor, angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker (ACE/ARB), diuretic use, uric acid level, and serum cystatin C levels were significantly associated with increased levels of NT-ProBNP. After adjusting for confounding factors screened in univariate analysis, multivariate regression analysis showed that increased serum cystatin C levels were significantly associated with increased levels of NT-ProBNP.

Conclusions

Increased serum levels of cystatin C were associated with poor cardiac function and increased levels of NT-ProBNP in patients with UAP.

N-Terminal Pro-B-Type Natriuretic Peptide Levels Inversely Correlated With Heart Rate Variability in Patients With Unstable Angina Pectoris

We explored the relationships between heart rate variability (HRV) and levels of N-terminal Pro-B-type natriuretic peptide (NT-proBNP) in patients with unstable angina pectoris (UA).A total of 90 consecutive patients admitted < 48 hours for UA were included. Serum levels of NT-proBNP were measured from blood samples. The cohort was divided into tertiles according to NT-proBNP levels. HRV parameters including SDNN, RMSSD, LF, HF, TP, and VLF were assessed by 24-hour Holter ECG monitoring.The median (IQR) NT-proBNP level was 177.02 (64.76, 740.70) pg/mL. Patients with SDNN < 100 ms had higher levels of NT-proBNP than those with SDNN > 100 ms (P = 0.003). With increasing levels of NT-proBNP, both the 24hour monitoring HRV and night-monitoring HRV showed that SDNN and VLF gradually decreased (P < 0.01), and patients in the NT-proBNP lowest tertile group had higher LF values than the other two groups (P < 0.05); however, no difference was found in RMSSD, HF, and TP. During the daytime, the LF, VLF, and TP values were lower in the NTproBNP highest group compared with the lowest tertile group (P < 0.05). NT-proBNP levels correlated negatively with SDNN (r = -0.314, P = 0.003) and VLF (r = -0.397, P < 0.001) but not with other HRV parameters. Multiple regression analysis showed that serum levels of NT-proBNP remained predictive of SDNN (β = -0.060, P = 0.001) and VLF (β = -0.145, P < 0.001), even after adjustment for confounders.Our study showed that the elevated serum levels of NT-proBNP predict reduced HRV parameters, and the increased NT-proBNP levels combined with decreased HRV represent the degree of neurohormonal dysfunction and may be better prognostic predictors for risk stratification in UA patients.

Coronary artery calcium score and N-terminal pro-B-type natriuretic peptide as potential gatekeepers for myocardial perfusion imaging

Myocardial perfusion imaging (MPI) holds an important place as non-invasive risk assessment in patients with intermediate risk of coronary heart disease (CHD). However, as much as 60-70% of MPI scans are normal. This study evaluates the role of coronary artery calcium scoring (CAC score) and NT-proBNP as potential gatekeepers for MPI. Patients with intermediate risk of CHD referred for standard MPI were included. CAC score and NT-proBNP were both assessed at the day of the stress study. Sensitivity, specificity and NPV for prediction of abnormal MPI scans were calculated for CAC, NT-proBNP and the combination hereof. A total of 190 patients were included (mean age 61 ± 12 years, 55% female) of whom 24% had known CHD. In all 30% of the scans were abnormal. CAC score achieved the highest AUC regardless of whether patients with known CHD were included or not [AUC 0·75 95% CI (0·66-0·84) and AUC 0·79 (0·68-0·91)]. As a singular variable, CAC score was the most potent predictor with a sensitivity of 85%, specificity of 39% and NPV 88%. The combination of CAC score<10 and NT-proBNP>26 reached a sensitivity of 98% and NPV 94%, where 8% of scans tentatively could be avoided. In patients referred for MPI with intermediate risk for CHD, a combination of CAC score and NT-proBNP could be used to identify a group of patients where MPI could be averted with a high degree of diagnostic safety.

The severity of coronary artery disease and reversible ischemia revealed by N-terminal pro-brain natriuretic peptide in patients with unstable angina and preserved left ventricular function

The association between the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the severity of coronary artery disease (CAD) diagnosed by coronary angiography and other approaches has been investigated. The clinical application of NT-proBNP is restricted by the drawbacks of these techniques now available in screening out patients who need intensive or conservative treatment. Fractional flow reserve (FFR) is superior to coronary angiography and other functional indicators. Accordingly, we designed to investigate the association between NT-proBNP and myocardial ischemia from the perspective of anatomy and physiology in patients with unstable angina and preserved left ventricular function. Plasma samples were collected from 110 patients and NT-proBNP levels were measured by radioimmunoassay. The severity of coronary artery stenosis in patients was measured by coronary angiography and FFR. Stenosis ≥50% in the left main artery or stenosis of 70%, and fractional flow reserve (FFR) ≤0.80 in one or more coronary branches with diameter ≥2mm were defined as "positive", which require revascularization. NT-proBNP levels increased progressively between patients with negative and positive angiographic results (p<0.05), and between FFR-negative and FFR-positive patients (p<0.05). A significant correlation was observed between logNT-proBNP and logGS (GS=Gensini score, p<0.001). NT-proBNP level serves as a predictor of positive results of angiographic stenosis and FFR, with the area under the receiver operating characteristic curve being 0.697 and 0.787, respectively. NT-proBNP levels are correlated with the severity of anatomic coronary obstruction and inducible myocardial ischemia, but NT-proBNP per se is insufficient to identify clinically significant angiographic and physiological stenoses.