Early recanalization and plasma brain natriuretic peptide as an indicator of left ventricular function after acute myocardial infarction

Relationship of cardiac biomarkers and reversible and irreversible myocardial injury following acute myocardial infarction as determined by cardiovascular magnetic resonance

BACKGROUND

Cardiovascular magnetic resonance (CMR) can accurately depict myocardial oedema, haemorrhage, infarction and microvascular obstruction. The purpose of this study was to establish the relationships between cardiac biomarkers and reversible and irreversible myocardial injury following AMI, as determined by CMR.

METHODS

Forty-eight patients admitted with AMI and successfully treated with primary percutaneous coronary intervention were studied. A comprehensive CMR protocol was performed at day 2, 1 week, 1 month and 3 months after presentation. Blood samples were taken at the same intervals and analysed for highly sensitive C-reactive protein (hs-CRP), Troponin I, N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) and Heart-type fatty acid binding protein (H-FABP). The CMR end points were the extent of myocardial oedema, haemorrhage and infarction as well as left ventricular function and volumes.

RESULTS

Multiple regression analyses demonstrated that hs-CRP on 'day 2' was the strongest independent predictor of left ventricular ejection fraction (LVEF) (p=0.007) and left ventricular end-systolic volume (LVESV) (p=0.002) at 3 months. Troponin I level on 'day 2' was the only independent predictor of infarct size (p=0.002) at 3 months. Patients with haemorrhagic infarctions had significantly higher biomarker levels at 'day 2'. NT-pro-BNP levels were significantly greater in patients with myocardial haemorrhage at all four time points.

CONCLUSIONS

C-reactive protein measured two days after reperfusion was the strongest independent predictor of left ventricular remodelling at three months. Elevated biomarker levels in patients with haemorrhagic infarction suggest that reperfusion haemorrhage is a marker of more severe myocardial injury and may be associated with adverse ventricular remodelling.

The benefits of repeated measurements of B-type natriuretic peptide in patients with first ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND

Elevated B-type natriuretic peptide levels in patients with acute myocardial infarction are useful in the prediction of poor outcome. It is still not established how often and when assessment of neurohormonal activation provides the best prognostic information.

AIM

To evaluate whether repeated measurements of B-type natriuretic peptide provide additional clinical information in patients with first ST-elevation myocardial infarction.

METHODS

In 96 consecutive patients with first ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, B-type natriuretic peptide concentrations were measured twice: on admission and 24 hours later. A clinical composite endpoint was assessed during hospital stay.

RESULTS

The median B-type natriuretic peptide concentration obtained on admission was 62.9 pg/mL and 24 hours later was 223.6 pg/mL. Thirty-five patients (36.4%) reached composite endpoint, including 3 deaths (3.1%). Both B-type natriuretic peptide levels were related to the clinical and echocardiographic variables, which refer to the large infarct expansion and acute left ventricular dysfunction. The first measurement was better correlated with current patient status (ie, TIMI Risk Score, admission Killip class). B-type natriuretic peptide 24 hours after admission was significantly higher in patients who had an adverse cardiovascular event during hospitalization (P = 0.02). ROC analysis also identified the second B-type natriuretic peptide measurement as significant to estimate adverse outcome (c = 0.64 CI 0.527 - 0.756 P = 0.007).

CONCLUSIONS

Despite there being a time interval of only 24 hours between the two sets of B-type natriuretic peptide sampling, both measurements provide important and different information. Only B-type natriuretic peptide measurement 24 hours after admission identifies patients with a high in-hospital event rate risk.

Insights into the change in brain natriuretic peptide after ST-elevation myocardial infarction (STEMI): why should it be better than baseline?This paper is one of a selection of papers published in this Special Issue, entitled Young Investigators' Forum

While baseline N-terminal brain natriuretic peptide (NT-proBNP) is useful in the prognosis of acute ST-elevation myocardial infarction (STEMI), it is unclear whether a relationship exists between serial NT-proBNP, reperfusion success, and prognosis. We prospectively defined a NT-proBNP analysis in the WEST (Which Early ST-elevation myocardial infarction Therapy) trial that enrolled 304 acute STEMI patients. NT-proBNP (pg/mL) was measured at baseline prior to treatment (n = 258) and 72 to 96 h (n = 247) and 30 days (n = 221) after treatment (ΔNT-proBNP = 72 h value – the baseline NT-proBNP). Reperfusion success was measured by ST-segment resolution at 180 min, infarct size by peak creatine kinase (CK) during the first 24 h, and QRS score at discharge (QRSd). The primary endpoint was a 30 day clinical composite. The ability of either baseline NT-proBNP or ΔNT-proBNP to predict the primary endpoint was compared using single-variable logistic regression and the c-statistic. Median (interquartile range) NT-proBNP in pg/mL was 87 (39–316) at baseline, 864 (338–1857) at 72 h, and 585 (264–1212) at 30 days. ST resolution was inversely correlated with ΔNT-proBNP (r = –0.23, p = 0.002) and 30 day NT-proBNP (30 day NT-proBNP 1016, 828, and 397 for <30%, 30%–70%, ≥70% STR, respectively, p < 0.001). Infarct size was correlated with ΔNT-proBNP by CK (r = 0.41, p < 0.001) and QRSd (r = 0.31, p < 0.001); the 30 day NT-proBNP relationship was similar for CK (r = 0.48, p < 0.001) and QRSd (p = 0.003). The baseline NT-proBNP was associated with an increased 30-day composite endpoint (Q1, 19%; Q2, 20%; Q3, 15%; Q4, 38%; p = 0.03 for trend) as was ΔNT-proBNP (Q1, 16%; Q2, 18%; Q3, 19%; Q4, 37%; p = 0.009 for trend). The c-statistic for baseline, 72 to 96 h, and ΔNT-proBNP was 0.59, 0.61, and 0.62 for the 30-day composite and 0.64, 0.62, and 0.62 for the 90-day composite, respectively. ΔNT-proBNP clearly predicts short-term adverse cardiac events and is superior to baseline NT-proBNP, but similar to the 72 to 96 h NT-proBNP in predicting clinical events after STEMI. This likely reflects the variability in NT-proBNP at presentation and the ability to integrate subsequent important physiologic sequelae of STEMI such as reperfusion and infarct size.

[The role of B type natriuretic peptide in the assessment of post myocardial infarction prognosis]

Recently cardiac peptides have received close attention as cardiovascular markers. Brain (B type) natriuretic peptide is a neurohormone synthesized predominantly in ventricular myocardium. Previous studies have shown that this hormone can provide prognostic information in patients with myocardial infarction. The aim of this review is to evaluate the impact of plasma levels of BNP on prediction of left ventricular ejection fraction and remodelling and major cardiac events after myocardial infarction.

N-terminal pro-brain natriuretic peptide and the timing, extent and mortality in ST elevation myocardial infarction

AIMS

While natriuretic peptides have demonstrated diagnostic and prognostic potential in cardiac disorders, little is known about their relationship with the onset and quantification of myocardial infarction. The relationship of serial N-terminal pro-brain natriuretic peptide (NT-proBNP) with duration from symptom onset, infarct size and prognosis in ST elevation myocardial infarction (STEMI) patients treated with primary percutaneous intervention was examined.

METHODS AND RESULTS

Three hundred thirty-one STEMI patients in the COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial, which evaluated pexelizumab versus placebo, were studied. NT-proBNP (pg/mL) was measured at randomization, 24 h and 72 h; creatine kinase-MB area under the curve was measured at 72 h; and QRS score was assessed at discharge. Prognosis was ascertained from the 90-day composite clinical outcome of death, shock, stroke and congestive heart failure. Multivariate logistical regression was used to adjust for baseline characteristics for models at randomization, 24 h and 72 h. NT-proBNP was higher in patients with longer time from symptom onset (P<0.001) and correlated with measures of infarct size, including the area under the curve (P<0.001) and QRS score (P<0.001). Patients reaching the primary end point had markedly higher NT-proBNP at each sampling period (P<0.001). NT-proBNP at all time points was the strongest independent predictor of the primary end point in the multivariate model: in the 24 h model, only age and 24 h NT-proBNP (C-index 0.83); and only age, Killip class and NT-proBNP was in the 72 h model (C-index 0.85).

CONCLUSIONS

Higher NT-proBNP at 24 h correlated with larger infarct size and worse clinical outcomes. NT-proBNP at baseline, 24 h and 72 h after presentation with acute STEMI, is an independent predictor of a poor outcome and adds clinically useful prognostic information.

Therapeutic Potential of Monteplase in Acute Myocardial Infarction as a Powerful Thrombolytic Agent for Pretreatment of Coronary Intervention

Thrombolysis with conventional thrombolytic agents followed by percutaneous coronary intervention (PCI) had no impact on the treatment of acute myocardial infarction (AMI). However, the development of mutant type plasminogen activator (mt-PA) has prompted us to reassess the combination of thrombolysis and PCI. Monteplase (Eisai, Co. Ltd., Tokyo, Japan) is a newly developed mt-PA that can be administrated as a single intravenous bolus injection. We initiated a clinical trial [Combining Monteplase with Angioplasty (COMA)] to evaluate the effectiveness of monteplase followed by PCI. The AMI patients were randomly assigned to receive PCI following pretreatment with a single bolus intravenous injection of monteplase or direct PCI without monteplase. The initial coronary angiography prior to PCI showed that 36.2% of patients in the monteplase group achieved Thrombolysis in Myocardial Infarction (TIMI) 3 flow in the infarct-related artery, compared with in only 7.9% of patients in the direct PCI group (P < 0.0001). During 24 months following PCI, major cardiac events occurred in 27.7% of patients in the monteplase + PCI group, and in 46.7% of patients in the direct PCI group without monteplase (P < 0.05). Thus, the ideal strategy for the treatment of AMI is the administration of monteplase upon arrival at a community hospital with a prompt transfer to a tertiary center for PCI.

Admission N-terminal pro-brain natriuretic peptide and its interaction with admission troponin T and ST segment resolution for early risk stratification in ST elevation myocardial infarction

OBJECTIVE

To assess the long term prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) on admission and its prognostic interaction with both admission troponin T (TnT) concentrations and resolution of ST segment elevation in fibrinolytic treated ST elevation myocardial infarction (STEMI).

DESIGN AND SETTING

Substudy of the ASSENT (assessment of the safety and efficacy of a new thrombolytic) -2 and ASSENT-PLUS trials.

PATIENTS

NT-proBNP and TnT concentrations were determined on admission in 782 patients. According to NT-proBNP concentrations, patients were divided into three groups: normal concentration (for patients < or = 65 years, < or = 184 ng/l and < or = 268 ng/l and for those > 65 years, < or = 269 ng/l and < or = 391 ng/l in men and women, respectively); higher than normal but less than the median concentration (742 ng/l); and above the median concentration. For TnT, a cut off of 0.1 microg/l was used. Of the 782 patients, 456 had ST segment resolution (< 50% or > or = 50%) at 60 minutes calculated from ST monitoring.

MAIN OUTCOME MEASURES

All cause one year mortality.

RESULTS

One year mortality increased stepwise according to increasing concentrations of NT-proBNP (3.4%, 6.5%, and 23.5%, respectively, p < 0.001). In receiver operating characteristic analysis, NT-proBNP strongly trended to be associated more with mortality than TnT and time to 50% ST resolution (area under the curve 0.81, 95% confidence interval (CI) 0.72 to 0.9, 0.67, 95% CI 0.56 to 0.79, and 0.66, 95% CI 0.56 to 0.77, respectively). In a multivariable analysis adjusted for baseline risk factors and TnT, both raised NT-proBNP and ST resolution < 50% were independently associated with higher one year mortality, whereas raised TnT contributed independently only before information on ST resolution was added to the model.

CONCLUSION

Admission NT-proBNP is a strong independent predictor of mortality and gives, together with 50% ST resolution at 60 minutes, important prognostic information even after adjustment for TnT and baseline characteristics in STEMI.

The extent of myocardial damage assessed by contrast-enhanced MRI is a major determinant of N-BNP concentration after myocardial infarction

AIMS

To evaluate the relationship between N-terminal Pro-Brain Natriuretic Peptide (N-BNP) level and contrast-enhanced MRI in patients after acute myocardial infarction (MI).

METHODS

Eighty-two patients were studied. Venous blood samples were obtained 3 days after MI and MRI was performed from 2 to 7 days after MI, with determination of left ventricular function and acquisition of perfusion data after injection of gadolinium-DTPA. First-pass images (FPI) and Delayed contrast-enhanced (CE) images were analyzed using a 17-segment model, and the extent of transmurality was determined by a visual score.

RESULTS

Univariate analysis showed that age (P<0.001), sex (P<0.02), Left Ventricular Ejection Fraction (LVEF) <45% (P<0.002), creatinine (P<0.05) and delayed CE-MR images (P<0.006) were predictors of a supramedian N-BNP level. FPI was not a predictor in this univariate analysis (P<0.078). In a multivariate model, only age, LVEF <45% and delayed CE-MRI were associated with an increased N-BNP level.

CONCLUSION

After MI, high N-BNP levels are dependent on the LVEF but also on the myocardial infarct size derived from the delayed CE-MR images.

Evaluation of neurohumoral activation (adrenomedullin, BNP, catecholamines, etc.) in patients with acute myocardial infarction

OBJECTIVE

The object of our study was to identify the most useful predictor of patient prognosis in acute myocardial infarction (AMI), from 7 acute-phase cardiovascular peptides which take part in neurohumoral activation [brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP), renin, aldosterone, adrenomedullin, epinephrine and norepinephrine].

METHODS

In 141 consecutive AMI patients, 24 hours from onset, we evaluated plasma concentration levels of the 7 types of cardiovascular peptides and the relationships between the values of these peptides and short-term clinical prognosis, including mortality.

RESULTS

Plasma levels of all cardiovascular peptides were significantly higher in patients who suffered mortality than in surviving patients (BNP: 1,267+/-997 pg/ml vs. 293+/-327 pg/ml, p<0.0001; ANP: 164+/-186 pg/ml vs. 64+/-76 pg/ml, p<0.001; adrenomedullin: 13.61+/-3.29 Fmol/l vs. 3.45+/-1.52 Fmol/I, p<0.0001; renin: 8.79+/-7.15 ng/ml/h vs. 4.34+/-5.10 ng/ml/h, p<0.01; aldosterone: 249+/-210 pg/ml vs. 68+/-74 pg/ml, p<0.0001; epinephrine: 3,191+/-8,360 pg/ml vs. 68+/-74 pg/ml, p<0.0001; norepinephrine: 21.8+/-46.2 ng/ml vs. 0.9+/-0.8, ng/ml p<0.0001). Multivariate analysis identified only high levels of adrenomedullin as an independent related factor of cardiogenic shock (risk ratio: 5.84, 95% C.I.: 1.80-18.95, p=0.003), and as an independent predictor of short-term mortality (risk ratio: 16.16, 95% C.I.: 1.38-189.71, p=0.03).

CONCLUSIONS

Acute-phase neurohumoral activation, involving renin, aldosterone, epinephrine, norepinephrine, BNP, ANP, and adrenomedullin may be closely related to poor patient outcomes, including mortality. Our results suggest that acute-phase plasma adrenomedullin concentrations may be the most useful predictor of patient prognosis in the setting of AMI, out of the 7 types of cardiovascular peptides involved in neurohumoral activation.

Serum B-type natriuretic peptide levels on admission predict not only short-term death but also angiographic success of procedure in patients with acute ST-elevation myocardial infarction treated with primary angioplasty

BACKGROUND

B-type natriuretic peptide (BNP) levels are predictive of short-term death in patients with acute coronary syndromes. Few data are available for BNP levels obtained on admission in patients with acute ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI).

METHODS

Blood samples for BNP estimation, obtained on admission in 126 consecutive patients (mean age, 58.8 +/- 10.7 years) with STEMI, were measured at the bedside by using a simple point-of-care test in a 15-minute period before PCI. Follow-up up to 42 days was performed.

RESULTS

A baseline BNP value of 331 pg/mL had a sensitivity of 87.9% and a specificity of 90% for predicting death in a follow-up study. There was no difference in subgroups by median BNP (100 pg/mL) in Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 before PCI, although higher BNP levels were observed among patients with TIMI <3 after PCI than among those with TIMI 3 (356.7 +/- 350.8 vs 144.9 +/- 191.2 pg/mL; P <.0001). In multivariate logistic regression analysis, admission BNP was the independent predictor for the following: death (odds ratio [OR], 16.3; 95% confidence interval [CI], 1.4 to 186.7; P =.03), TIMI grade <3 after PCI (OR, 3.4; 95% CI, 1.2 to 9.6; P =.02), and the no-reflow phenomenon (OR, 6.2; 95% CI, 1.7 to 23; P =.007) after adjusting for other variables.

CONCLUSIONS

BNP levels obtained on admission are a powerful, independent predictor of short-term death and angiographic success after PCI in patients with STEMI. The no-reflow phenomenon may be predicted in STEMI on the basis of high serum BNP values on admission.

The utility of BNP in clinical practice

Brain natriuretic peptide (BNP) is a cardiac neurohormone of increasing interest over recent years, with research applications expanding at a rapid rate and new data published on a monthly basis. Initially developed as a diagnostic aid for those with acute shortness of breath, clinical applications are now increasing, and this article reviews these clinical applications of BNP and the evidence for effectiveness of the synthetic BNP analogue nesiritide.

Is measurement of plasma brain natriuretic peptide levels a useful test to detect for surgical timing of valve disease?

BACKGROUND

The optimal timing of valve surgery is very important. In patients who are severely symptomatic, the marked improvement in symptomatic status observed following successful valve surgery. However, in patients with no or only mild symptoms, the decision is more difficult. The aim of this retrospective study was to determine whether the measurement of plasma brain natriuretic peptides (BNP) levels is useful to decide surgical timing for valve disease.

METHODS

Fifty-one patients with valve disease underwent single valve surgery (mitral stenosis, MS, 13; mitral regurgitation, MR, 16; aortic stenosis, AS, 14; aortic regurgitation, AR, 8 patients). Blood samples, echocardiographic and cardiac catheterization data were obtained before operation and echocardiographic examination were performed after 1-year of operations.

RESULTS

In patients subjected to single heart valve surgery, plasma BNP mean levels were 214.6+/-48.5 pg/ml. In plasma BNP levels, there was only significant difference between MS and AS group (MS 67.5+/-9.7 vs. AS 314.3+/-112.0 pg/ml, P=0.04). There were no relationships between plasma BNP levels and pre-operative cardiac functions. After 1-year of the valve surgery, NYHA functional class was reduced in 36 patients (70.6%) and plasma BNP levels before the surgery significantly correlated with post-operative NYHA functional class.

CONCLUSIONS

In this retrospective study, patients with high plasma BNP levels significantly impaired the improvement of clinical symptoms after surgery. We have suggested that plasma BNP levels is useful for detecting asymptomatic valvular disease, and is a clinical marker useful in determining the optimal surgical timing.

The role and assessment of ventricular peptides in heart failure

Although heart failure may be diagnosed readily in its advanced stages, it may be difficult to diagnose clinically in its early stages.Thus, there is a critical need for an inexpensive, simple, rapid,and objective test for heart failure. This article discusses the role and assessment of ventricular natriuretic peptides and related pep-tides in heart failure.

Diagnostic accuracy and prognostic relevance of the measurement of cardiac natriuretic peptides: a review

BACKGROUND

The pathophysiologic and clinical relevance of cardiac natriuretic hormone (CNH) assays has been investigated in numerous experimental and clinical studies. Authors have sought to evaluate the diagnostic accuracy and prognostic relevance of the measurement of CNHs according to evidence-based laboratory medicine principles.

METHODS

In June 2003, we ran a computerized literature search on National Library of Medicine using keywords "ANP" and "BNP" and found more than 12 300 and 1200 articles, respectively. A more refined search with keywords "ANP or BNP assay" extracted approximately 7000 and 800 articles, respectively. Only studies specifically designed to evaluate the diagnostic accuracy and prognostic relevance of CNH measurements were selected from this huge mass of articles to be discussed in this review.

CONTENT

Several studies suggested that CNH assays may be clinically useful for the screening and classification of patients with heart failure, as a prognostic marker in cardiovascular disease, in the follow-up of patients with heart failure, and because they may reduce the need for further cardiac investigation. However, it is difficult to compare even the best-designed studies because not only did the authors evaluate different populations, they also used different gold standards.

CONCLUSIONS

CNH assays and conventional diagnostic work-ups provide complementary information for evaluation of the presence and severity of cardiac dysfunction and clinical disease. Several aspects of CNH assays are still to be elucidated, and further work is needed to carefully assess their diagnostic accuracy and prognostic value in cardiac disease.