Rise and fall of B-type natriuretic peptide levels in patients with coronary artery disease and normal left ventricular function after cardiac revascularization

B-type natriuretic peptide trumps other prognostic markers in patients assessed for coronary disease

BACKGROUND

Risk prediction for patients with suspected coronary artery disease is complex due to the common occurrence of prior cardiovascular disease and extensive risk modification in primary care. Numerous markers have the potential to predict prognosis and guide management, but we currently lack robust 'real-world' evidence for their use.

METHODS

Prospective, multicentre observational study of consecutive patients referred for elective coronary angiography. Clinicians were blinded to all risk assessments, consisting of conventional factors, radial artery pulse wave analysis, 5-minute heart rate variability, high-sensitivity C-reactive protein and B-type natriuretic peptide (BNP). Blinded, independent adjudication was performed for all-cause mortality and the composite of death, myocardial infarction or stroke, analysed with Cox proportional hazards regression.

RESULTS

Five hundred twenty-two patients were assessed with median age 66 years and 21% prior revascularization. Median baseline left ventricular ejection fraction was 64%, and 62% had ≥ 50% stenosis on angiography. During 5.0 years median follow-up, 30% underwent percutaneous and 16% surgical revascularization. In multivariate analysis, only age and BNP were independently associated with outcomes. The adjusted hazard ratio per log unit increase in BNP was 2.15 for mortality (95% CI 1.45-3.19; p = 0.0001) and 1.27 for composite events (1.04-1.54; p = 0.018). Patients with baseline BNP > 100 pg/mL had substantially higher mortality and composite events (20.9% and 32.2%) than those with BNP ≤ 100 pg/mL (5.6% and 15.5%). BNP improved both classification and discrimination of outcomes (p ≤ 0.003), regardless of left ventricular systolic function. Conversely, high-sensitivity C-reactive protein, pulse wave analysis and heart rate variability were unrelated to prognosis at 5 years after risk modification and treatment of coronary disease.

CONCLUSIONS

Conventional risk factors and other markers of arterial compliance, inflammation and autonomic function have limited value for prediction of outcomes in risk-modified patients assessed for coronary disease. BNP can independently identify patients with subtle impairment of cardiac function that might benefit from more intensive management.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT00403351 Registered on 22 November 2006.

NT-proANP and NT-proBNP circulating levels as predictors of cardiovascular outcome following coronary stent implantation

BACKGROUND

Natriuretic peptides are diagnostic/prognostic biomarkers in major cardiovascular diseases. We aimed at assessing the predictive role of N-terminal pro-A-type (NT-proANP) and pro-B-type (NT-proBNP) natriuretic peptides levels toward cardiovascular outcome in both stable and unstable coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI) in a non-primary PCI setting.

METHODS

A total of 395 patients undergoing PCI with stent implantation for either stable angina (SA) or non ST-elevation acute coronary syndrome (NSTE-ACS) were enrolled. Pre-procedural NT-proANP and NT-proBNP levels were measured. Occurrence of major adverse cardiac events (MACEs), composite of cardiac death, non-fatal myocardial infarction, and clinically driven target lesion revascularization (c-TLR), was the endpoint of the study. Follow up mean time was 48.53±14.69months.

RESULTS

MACEs occurred in forty-four patients (11%) during follow up. Both NT-proANP levels [3170 (2210-4630) vs 2283 (1314-3913) fmol/mL, p=0.004] and NT-proBNP levels [729 (356-1353) vs 511 (267-1006) fmol/mL, p=0.04] were significantly higher in patients with MACEs compared to patients without MACEs. Similar results were found when considering hard MACEs (myocardial infarction and cardiac death). NT-proANP levels were significantly higher in patients with c-TLR compared with patients without c-TLR [3705 (2766-5184) vs 2343 (1340-3960) fmol/mL, p=0.021]. At multivariate analysis, NT-proANP levels were a significant predictor of MACEs (HR 1.09, 95% CI 1.03-1.18, p=0.04). Kaplan-Meyer curves revealed that patients with elevated NT-proANP levels (>2.100fmol/mL) had a lower MACE free survival (p=0.003).

CONCLUSIONS

Both NT-proANP and NT-proBNP levels were higher in CAD patients experiencing MACEs following PCI in a non-primary setting. Notably, only NT-proANP levels significantly affected prognosis after PCI.

Cross-sectional study: CagA-positive Helicobacter pylori infection, acute coronary artery disease and systemic levels of B-type natriuretic peptide

BACKGROUND

B-type natriuretic peptide (BNP) determination is routinely used to evaluate the severity of congestive heart failure, a possible consequence of coronary artery disease (CAD). CAD originates from vascular atherosclerotic processes and is stimulated by inflammatory events, which may also be triggered by chronic bacterial infections.

AIM

To explore the effect of Helicobacter pylori infection upon systemic BNP, tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels and linear homology between cardiac peptides and H pylori.

METHODS

A group of 103 consecutive patients with a diagnosis of non-ST elevation acute CAD (ACAD) and no other concomitant pathology was examined. BNP was measured by a commercial solid-phase sandwich immunoradiometric assay. H pylori infection, CagA serological status and circulating levels of IL-6 and TNF-α, were determined by ELISA assays. Amino acid sequence homology between human cardiac and H pylori peptides was investigated by Basic Local Alignment Search Tool (BLAST) analysis.

RESULTS

Circulating levels of BNP and IL-6, in pg/mL (interquartile difference), among infected patients with anti-CagA serum antibodies, respectively 781 (1899) and 37.7 (137.6), were significantly increased in respect to those measured in uninfected patients, respectively 325 (655) and 7.7 (23.5), (p<0.01 and p=0.025), and, with regard to BNP alone, also in patients infected by CagA negative H pylori strains, 305 (593), (p<0.01). TNF-α levels were raised in CagA positive in respect to uninfected patients. Tropomyosin and Ca2+ transporting ATPases showed strong similarities to H pylori proteins, suggesting the existence of molecular mimicry phenomena.

CONCLUSIONS

Chronic infection by H pylori expressing CagA correlates with high circulating levels of BNP and IL-6 in patients with ACAD.

N-terminal pro-B-type natriuretic peptide as a predictor of repeat coronary revascularization

BACKGROUND

Recent studies suggest that natriuretic peptides are potential biomarkers for myocardial ischemia. However, little is known about the value of NT-proBNP as a predictor of repeat revascularization (RR) at follow-up angiography in patients with normal LV systolic function.

METHODS

We collected and analyzed the clinical and angiographic data from 445 consecutive patients (62.5+/-10.1 years; 73% males) who showed normal LV systolic function and no regional wall motion abnormalities on transthoracic echocardiogram performed at baseline and follow-up angiography.

RESULTS

Overall, NT-proBNP level on admission for follow-up angiography was significantly higher in patients with RR (n=55) than those without RR (n=390) [92.4 (47.5-178.5) pg/ml vs. 54.8 (30.6-93.1) pg/ml, P<0.001]. In asymptomatic patients, NT-proBNP did not show significant difference between patients with RR and those without RR (P=0.42). An elevated NT-proBNP level, especially in symptomatic patients (n=77) (>87.5 pg/ml as an optimal cut off value) was a strong independent predictor for RR at follow-up angiography (OR, 12.3; 95% CI, 3.25-46.2; P=0.001). NT-proBNP (>122.9 pg/ml) showed high specificity (85.9%) and negative predictive value (91.0%) for predicting RR in overall patients. However, NT-proBNP (>97.0 pg/ml) showed low sensitivity (49.1%) and positive predictive value (23.5%). The areas under the receiver operator characteristic (ROC) curve in predicting RR in overall patients and symptomatic patients were 0.648 (95% CI; 0.564-0.732, P<0.001) and 0.768 (95% CI; 0.653-0.884, P<0.001), respectively.

CONCLUSION

Our data show that NT-proBNP level at follow-up is a strong independent predictor for RR especially in symptomatic patients. Although routine measurement may be not useful for predict RR, NT-proBNP may help to identify patients with low risk of repeat revascularization.