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

Prognostic significance of serial N-terminal pro-B-type natriuretic peptide levels in patients with acute myocardial infarction: A prospective study

OBJECTS

This study aimed to investigate the association between N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels at different sampling times and prognosis in patients with acute myocardial infarction (AMI) undergoing emergency percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Between March 2017 and January 2020, 1,105 patients with AMI who underwent emergency PCI were included. NT-proBNP levels were measured on days 0, 1, 2, 3, and 7. A composite of all-cause death, MI recurrence (reMI), and rehospitalization due to heart failure, known as major adverse cardiovascular events (MACE), was recorded. During the 36.8-month follow-up, 175 patients (15.8%) experienced MACEs. When patients were grouped based on quartiles of NT-proBNP levels on days 0 and 7, the results demonstrated that patients in quartile 4 showed a substantially increased MACE risk compared to those in quartile 1 (hazard ratio [HR] 2.27, 95% confidence interval [CI]:1.27-4.08, P = .006; HR 2.20, 95%CI:1.23-3.94, P = .008). There were U-shaped relationships between the HR for MACE and NT-proBNP levels on days 2, 3, and 7, as well as peak NT-proBNP (P _{for nonlinearity} = .007, .006, .004, and .009, respectively). A similar relationship was observed in the HR for reMI and NT-proBNP levels on days 2 and 3. For MACE at 3 years, serial NT-proBNP levels improved the predictive accuracy of the Global Registry of Acute Coronary Events (GRACE) risk score (concordance index [C-index]: 0.711; continuous net reclassification improvement [NRI]: 0.192, 95% CI: 0.022-0.445; integrated discrimination improvement [IDI]: 0.034, 95% CI: 0.016-0.064). For all-cause death at 3 years, the combination of NT-proBNP and GRACE score showed excellent performance, with C-index, continuous NRI, and IDI values of 0.801, 0.373 (95%CI: 0.072-0.853), and 0.051 (95%CI: 0.025-0.091), respectively.

CONCLUSIONS

Early and sequential measurement of NT-proBNP levels could assist in predicting MACE risk. Moreover, the relationship between MACE risk and NT-proBNP levels was U-shaped.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov NCT: 03593928.

Prognostic Value of Admission Peak NT-proBNP Combined with Culprit Plaque Types for Predicting Cardiovascular Risk in ST-Segment Elevated Myocardial Infarction: An Optical Coherence Tomography Study

OBJECTIVE

Different culprit plaque phenotypes including plaque rupture (PR) and non-plaque rupture (NPR), and N-Terminal prohormone of brain natriuretic peptide (NT-proBNP) have been reported to influence clinical outcomes in patients with acute coronary syndrome (ACS). We aimed to investigate the prognostic implication of the peak and baseline values at admission for NT-proBNP for major adverse cardiovascular events (MACE) in ST-Segment Elevated Myocardial Infarction (STEMI) patients with different plaque phenotype.

METHODS

A total of 428 patients with STEMI undergoing optical coherence tomography (OCT) were enrolled and divided into four groups: PR/Tertile1-2 NT-proBNP (n = 132), PR/Tertile3 NT-proBNP (n = 65), NPR/Tertile1-2 NT-proBNP (n = 154), NPR/Tertlie3 NT-proBNP (n = 77). Baseline and Peak values of NT-proBNP were obtained in the admission period. The MACEs were defined as the composite of all-cause death, recurrence of myocardial infarction and stroke.

RESULTS

High levels for peak NT-proBNP were significantly associated with a higher incidence of MACE and death (Log rank p = 0.037 and 0.0012, respectively). In the subgroup with NPR, a high level for peak NT-proBNP was significantly associated with higher incidence of death (Log rank p = 0.0022) but this association was not significant in the subgroup of PR (Log rank p = 0.24). Though plaque types were not associated with adverse event, the combination of NPR and a higher peak value for NT-proBNP indicated higher incidence of death compared with other groups (Log rank p = 0.0017). The area under the receiver operating characteristic curve for predicting death to evaluate the diagnostic value of the peak value for NT-proBNP and plaque types combined with traditional risk factors was 0.843 (95% CI: 0.805-0.876), which is superior to solely traditional risk factors: NRI (26.8% [95% CI: 0.4-53.1%], p = 0.046) and IDI (5.1% [95% CI: 1.0-9.2%], p = 0.016).

CONCLUSION

STEMI patients with NPR and a high level for peak NT-proBNP showed higher incidence of death. The peak value of NT-proBNP in combination with plaque types can be used in risk stratification and prediction of death in patients with STEMI.

Risk factors and prediction nomogram model for 1-year readmission for major adverse cardiovascular events in patients with STEMI after PCI

To identify risk factors and develop a risk-prediction nomogram model for 1-year readmission due to major adverse cardiovascular events (MACEs) in patients with acute ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PCI). This was a single-center, retrospective cohort study. A total of 526 eligible participants were enrolled, which included 456 non-readmitted and 70 readmitted patients. Multivariate logistical regressions were performed to identify the independent risk factors for readmission, and a prediction nomogram model was developed based on the results of the regression analysis. The receiver operating characteristic curve, Hosmer-Lemeshow test, calibration plot, and decision curve analysis (DCA) were used to evaluate the performance of the nomogram. Female (OR = 2.426; 95% CI: 1.395-4.218), hypertension (OR = 1.898; 95% CI: 1.100-3.275), 3-vessel disease (OR = 2.632; 95% CI: 1.332-5.201), in-hospital Ventricular arrhythmias (VA) (OR = 3.143; 95% CI: 1.305-7.574), peak cTnI (OR = 1.003; 95% CI: 1.001-1.004) and baseline NT-proBNP (OR = 1.001; 95% CI: 1.000-1.002) were independent risk factors for readmission (all P < 0.05). The nomogram exhibited good discrimination with the area under the curve (AUC) of 0.723, calibration (Hosmer-Lemeshow test; χ2 = 15.396, P = 0.052), and clinical usefulness. Female gender, hypertension, in-hospital VA, 3-vessel disease, baseline NT-proBNP, and peak cTnI were independent risk factors for readmission. The nomogram helped clinicians to identify the patients at risk of readmission before their hospital discharge, which may help reduce readmission rates.

Association of N-terminal pro-brain natriuretic peptide level with adverse outcomes in patients with acute myocardial infarction: A meta-analysis

BACKGROUND

Studies evaluating the association of blood level of N-terminal pro-brain natriuretic peptide (NT-proBNP) with adverse prognosis have yielded conflicting results in patients with acute myocardial infarction (AMI). This meta-analysis sought to evaluate the prognostic value of blood level of NT-proBNP in patients with AMI.

METHODS

Two authors independently searched articles in PubMed and Embase databases up to June 13, 2021. Studies evaluating the association of baseline NT-proBNP level with all-cause mortality or major adverse cardiovascular events (MACEs, including death, new or worsening heart failure, recurrent myocardial infarction, revascularization, stroke, etc.) among AMI patients were selected. Multivariable-adjusted risk ratio (RR) with 95% confidence interval (CI) was pooled by the highest vs. lowest category of NT-proBNP level.

RESULTS

A total of 19 studies enrolling 12,158 AMI patients were identified. When compared highest with the lowest category of NT-proBNP level, the pooled RR was 5.28 (95% CI 2.87-9.73) for in-hospital/30-day death, 2.62 (95% CI 2.04-3.37) for follow-up all-cause mortality, and 2.50 (95% CI 1.91-3.28) for follow-up MACEs, respectively. Subgroup analysis further confirmed the value of NT-proBNP in predicting all-cause mortality and MACEs.

CONCLUSIONS

Elevated NT-proBNP level is independently associated with an increased risk of all-cause mortality and MACEs. Determination of blood NT-proBNP level can improve risk stratification of AMI patients.

NT-proBNP level before primary PCI and risk of poor myocardial reperfusion: Insight from the On-TIME II trial

BACKGROUND

N-terminal fragment of the brain natriuretic peptide prohormone (NT-proBNP), a marker for neurohumoral activation, has been associated with adverse outcome in patients with myocardial infarction. NT-proBNP levels may reflect extensive ischemia and microvascular damage, therefore we investigated the potential association between baseline NT-proBNP level and ST-resolution (STR), a marker of myocardial reperfusion, after primary percutaneous coronary intervention (pPCI).

METHODS

we performed a post-hoc analysis of the On-TIME II trial (which randomized ST-elevation myocardial infarction (STEMI) patients to pre-hospital tirofiban administration vs placebo). Patients with measured NT-proBNP before angiography were included. Multivariate logistic-regression analyses was performed to investigate the association between baseline NTproBNP level and STR one hour after pPCI.

RESULTS

Out of 984 STEMI patients, 918 (93.3%) had NT-proBNP values at baseline. Patients with STR <70% had higher NT-proBNP values compared to patients with complete STR (>70%) [Mean ±SD 375.2 ±1021.7 vs 1007.4 ±2842.3, Median (IQR) 111.7 (58.4-280.0) vs 168.0 (62.3-601.3), P <.001]. At multivariate logistic regression analysis, independent predictors associated with higher risk of poor myocardial reperfusion (STR <70%) were: NT-proBNP (OR 1.17, 95%CI 1.04-1.31, P = .009), diabetes mellitus (OR 1.87, 95%CI 1.14-3.07, P = .013), anterior infarct location (OR 2.74, 95% CI 2.00-3.77, P <.001), time to intervention (OR 1.06, 95%CI 1.01-1.11, P = .021), randomisation to placebo (OR 1.45, 95%CI 1.05-1.99, P = .022).

CONCLUSIONS

In STEMI patients, higher baseline NT-proBNP level was independently associate with higher risk of poor myocardial reperfusion, supporting the potential use of NT-proBNP as an early marker for risk stratification of myocardial reperfusion after pPCI in STEMI patients.

Prognostic Value of MicroRNAs in Patients after Myocardial Infarction: A Substudy of PRAGUE-18

Background

The evaluation of the long-term risk of major adverse cardiovascular events and cardiac death in patients after acute myocardial infarction (AMI) is an established clinical process. Laboratory markers may significantly help with the risk stratification of these patients. Our objective was to find the relation of selected microRNAs to the standard markers of AMI and determine if these microRNAs can be used to identify patients at increased risk.

Methods

Selected microRNAs (miR-1, miR-133a, and miR-499) were measured in a cohort of 122 patients from the PRAGUE-18 study (ticagrelor vs. prasugrel in AMI treated with primary percutaneous coronary intervention (pPCI)). The cohort was split into two subgroups: 116 patients who did not die (survivors) and 6 patients who died (nonsurvivors) during the 365-day period after AMI. Plasma levels of selected circulating miRNAs were then assessed in combination with high-sensitivity cardiac troponin T (hsTnT) and N-terminal probrain natriuretic peptide (NT-proBNP).

Results

miR-1, miR-133a, and miR-499 correlated positively with NT-proBNP and hsTnT 24 hours after admission and negatively with left ventricular ejection fraction (LVEF). Both miR-1 and miR-133a positively correlated with hsTnT at admission. Median relative levels of all selected miRNAs were higher in the subgroup of nonsurvivors (N = 6) in comparison with survivors (N = 116), but the difference did not reach statistical significance. All patients in the nonsurvivor subgroup had miR-499 and NT-proBNP levels above the cut-off values (891.5 ng/L for NT-proBNP and 0.088 for miR-499), whereas in the survivor subgroup, only 28.4% of patients were above the cut-off values (p = 0.001).

Conclusions

Statistically significant correlation was found between miR-1, miR-133a, and miR-499 and hsTnT, NT-proBNP, and LVEF. In addition, this analysis suggests that plasma levels of circulating miR-499 could contribute to the identification of patients at increased risk of death during the first year after AMI, especially when combined with NT-proBNP levels.

NT-proBNP during and after primary PCI for improved scheduling of early hospital discharge

Background

The Zwolle Risk Score (ZRS) identifies primary percutaneous coronary intervention (PPCI) patients at low mortality risk, eligible for early discharge. Recently, this score was improved by adding baseline NT-proBNP. However, the optimal timepoint for NT-proBNP measurement is unknown.

Methods

PPCI patients in the On-Time 2 study were candidates. The ZRS and NT-proBNP levels on admission, at 18–24 h, at 72–96 h, and the change in NT-proBNP from baseline to 18–24 h (delta NT-proBNP) were determined. We investigated whether addition of the different NT-proBNP measurements to the ZRS improves the prediction of 30-day mortality. Based on cut-off values reflecting zero mortality at 30 d, patients who potentially could be discharged early were identified and occurrence of major adverse cardiac events (MACE) and major bleeding until 10 d was registered.

Results

845 patients were included. On multivariate analyses, NT-proBNP at baseline (HR 2.09, 95% CI 1.59–2.74, p < 0.001), at 18–24 h (HR 6.83, 95% CI 2.94–15.84), and at 72–96 h (HR 3.32, 95% CI 1.22–9.06) independently predicted death at 30 d. Addition of NT-proBNP to the ZRS improved prediction of mortality, particularly at 18–24 h (net reclassification index 29%, p < 0.0001, integrated discrimination improvement 17%, p < 0.0001). Based on ZRS (<2) or NT-proBNP at 18–24 h (<2500 pg/ml) 75% of patients could be targeted for early discharge at 48 h, with expected re-admission rates of 1.2% due to MACE and/or major bleeding.

Conclusions

NT-proBNP at different timepoints improves prognostication of the ZRS. Particularly at 18–24 h post PPCI, the largest group of patients that potentially could be discharged early was identified.

Electronic supplementary material

The online version of this article (doi: 10.1007/s12471-016-0935-2) contains supplementary material, which is available to authorized users.

Predictive value of NT-proBNP for 30-day mortality in patients with non-ST-elevation acute coronary syndromes: a comparison with the GRACE and TIMI risk scores

Background

The biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP) predicts outcome in patients with non-ST-elevation acute coronary syndromes (NSTE-ACS). Whether NT-proBNP has incremental prognostic value beyond established risk strategies is still questionable.

Purpose

To evaluate the predictive value of NT-proBNP for 30-day mortality over and beyond the Global Registry of Acute Coronary Events (GRACE) and Thrombolysis In Myocardial Infarction (TIMI) risk scores in patients with NSTE-ACS.

Methods

Patients included in our ACS registry were candidates. NT-proBNP levels on admission were measured and the GRACE and TIMI risk scores were assessed. We compared the predictive value of NT-proBNP to both risk scores and evaluated whether NT-proBNP improves prognostication by using receiver operator curves and measures of discrimination improvement.

Results

A total of 1324 patients were included and 50 patients died during follow-up. On logistic regression analysis NT-proBNP and the GRACE risk score (but not the TIMI risk score) both independently predicted mortality at 30 days. The predictive value of NT-proBNP did not differ significantly compared to the GRACE risk score (area under the curve [AUC]) 0.85 vs 0.87 p=0.67) but was considerably higher in comparison to the TIMI risk score (AUC 0.60 p<0.001). Adjustment of the GRACE risk score by adding NT-proBNP did not improve prognostication: AUC 0.86 (p=0.57), integrated discrimination improvement 0.04 (p=0.003), net reclassification improvement 0.12 (p=0.21).

Conclusion

In patients with NSTE-ACS, NT-proBNP and the GRACE risk score (but not the TIMI risk score) both have good and comparable predictive value for 30-day mortality. However, incremental prognostic value of NT-proBNP beyond the GRACE risk score could not be demonstrated.

A Clinical Study of the N-Terminal pro-Brain Natriuretic Peptide in Myocardial Injury after Neonatal Asphyxia

BACKGROUND

We aimed to study the changes of serum N-terminal pro-brain natriuretic to peptide (NT-proBNP) levels after asphyxia-induced myocardial injury in children and explore the relationship between serum NT-proBNP levels and neonatal asphyxia.

METHODS

One hundred and six cases of neonatal asphyxia were randomly selected for the study, including 46 severe cases with myocardial injury and 60 mild cases with no cardiac injury. Sixty-three healthy newborns were selected as the control group. The serum NT-proBNP level was detected using electrochemiluminescence. Creatine kinase MB (CK-MB) and serum sodium and calcium were measured simultaneously.

RESULTS

The serum NT-proBNP level in the myocardial injury group was significantly higher than that of the noncardiac injury and control groups (p < 0.01). Asphyxia serum NT-proBNP and cardiac enzymes were significantly correlated. The median value of neonatal NT-proBNP was 1491 pg/mL at postnatal Day 3 (P3) and 1077 pg/mL at postnatal Day 14 (P14). The cutoff value for children with myocardial injury was 3612.5 pg/mL; the area under the receiver operating characteristic curve was 0.80 (p < 0.001), with a sensitivity of 83.3%, a specificity of 80.5%, a positive predictive value of 82.8%, and a negative predictive value of 79.4%. After treatment, the serum NT-proBNP level in children with myocardial damage showed a significant decrease.

CONCLUSION

The serum NT-proBNP level can reflect myocardial injury in neonates with asphyxia and can guide its diagnosis.

Prognostic implications of left ventricular end-diastolic pressure during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: Findings from the Assessment of Pexelizumab in Acute Myocardial Infarction study

BACKGROUND

Left ventricular end-diastolic pressure (LVEDP) is frequently measured during primary percutaneous coronary intervention (PCI). However, little is known of this measurement's utility in predicting outcomes or informing treatment decisions. We sought to determine the prognostic value of LVEDP measured during primary PCI for ST-segment elevation myocardial infarction (STEMI).

METHODS

We studied 1,909 (33.2%) of 5,745 STEMI patients in whom LVEDP was measured during primary PCI in the APEX-AMI trial. Cox regression analysis was used to evaluate whether LVEDP was an independent predictor of mortality and the composite of death, cardiogenic shock, or congestive heart failure (CHF) at 90 days.

RESULTS

The median (25th, 75th percentiles) LVEDP level was 22 mm Hg (16, 29); compared with patients with LVEDP ≤ 22 mm Hg, those with LVEDP > 22 mm Hg had higher rates of CHF (7.3% vs 3.1%, P < .001), cardiogenic shock (4.6% vs 1.7%, P < .001), and death (4.1% vs 2.2%, P = .014) at 90 days. After multivariable adjustment, LVEDP was associated with increased risk of mortality through 90 days (adjusted hazard ratio 1.22, 95% CI 1.02-1.46, per 5-mmHg increase, P = .044) and the composite of death, cardiogenic shock, or CHF within the first 2 days (adjusted hazard ratio 1.40, 95% CI 1.23-1.59, per 5-mm Hg increase, P < .001), but not from day 3 to 90 (P = .25).

CONCLUSIONS

Left ventricular end-diastolic pressure measured during primary PCI for STEMI is an independent predictor of inhospital and longer term cardiovascular outcomes. Measuring LVEDP may be useful to stratify patient risk and guide postinfarct treatment.

Pexelizumab fails to inhibit assembly of the terminal complement complex in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. Insight from a substudy of the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial

BACKGROUND

Reasons for pexelizumab lack of benefit in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention remain unclear. In a substudy of the APEX-AMI trial, we explored the hypothesis that early complement activation preceding drug administration explained the failure.

METHODS

A panel of terminal complement complex proteins and fragments and biomarkers of inflammation, apoptosis, and high-risk features were assessed in serum obtained before and 24 hours after administration of placebo or pexelizumab and primary percutaneous coronary intervention (n = 356) and in human umbilical vein endothelial cell cultures coincubated with serum (n = 45).

RESULTS

In the placebo group, C5a and sC5b-9 levels increased by 37% (7.9-14.2 ηg/mL, P = .007) and 96% (442-845 ηg/mL, P < .0001), respectively, during the first 24 hours. Pexelizumab prevented the increase in C5a (P = .01 vs placebo), but not that of sC5b-9 (502-1,157 ηg/mL, not significant vs placebo). Levels of C-reactive protein, interleukin (IL) 6, IL-1ß, Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) or Chemokine C-C motif ligand 5 (CCL5), and N-terminal probrain natriuretic peptide increased significantly in both groups; those of IL-10, IL-12, IL-1ra, and Interferon gamma-induced protein 10 (IP-10) or C-X-C motif chemokine 10 (CXCL10) decreased. Pexelizumab halved the increase in IL-6 (+92% vs 156%, P = .01) without effects on other markers, including C-reactive protein and N-terminal probrain natriuretic peptide. In cell culture, pexelizumab inhibited C5a, sC5b-9, and membrane-bound C5b-9 by 92%, 75%, and 78%, respectively (all P < .0001), without influencing cytokine levels and cell apoptosis.

CONCLUSIONS

The blockage of both C5a and terminal complement in cell culture, but of C5a only in vivo with minimal effects on inflammation and risk biomarkers, supports the hypothesis that late administration of pexelizumab after the ischemia/reperfusion insult precluded adequate myocardial protection, resulting in a negative trial.

Established and novel biomarkers in ST-elevation myocardial infarction

Cardiac biomarkers assist in the diagnosis of and risk stratification in acute coronary syndromes. In ST-elevation myocardial infarction (STEMI), rapid diagnosis and initiation of reperfusion via primary percutaneous coronary intervention or fibrinolysis is often based on the clinical history and presenting ECG, but measurement of biomarkers in the early and/or late phases of STEMI may allow the selection of patients who are at increased or decreased risk of subsequent complications. Although the measurement of only three biomarkers (troponin, natriuretic peptides and C-reactive protein) are currently included in practice guidelines, more than 20 other novel cardiac biomarkers have been proposed to provide improved risk stratification after a STEMI.

Natriuretic peptides in heart failure: where we are, where we are going

Tremendous advances have been made in understanding the pathophysiology and treatment of congestive heart failure (CHF). However, diagnosis still remains difficult, even with a comprehensive physical examination. Symptoms such as dyspnea are non-specific and poorly sensitive indicators for early CHF that can be largely undetected. The discovery of natriuretic peptides (BNP) as diagnostic biomarkers has been one of the most critical advances for heart failure diagnosis. Therefore, both B-type and N-terminal pro-B-type have potential role in the diagnosis of heart failure, as well as in prognostic risk assessment. A single determination of BNP at any time during the progression of chronic HF provides a clinically useful tool for risk stratification. The hypothesis that repeated measurements might carry prognostic information beyond a single measure was confirmed in different settings. One of the main interests is given to the values of repeated determinations for monitoring progression of disease, and for the evaluation of the clinical effects of medical therapy. Nevertheless, despite thousands of papers describing their potential utility, current guidelines have not endorsed the highest level of recommendation for their use, in part, because the application in clinical practice is often limited for the absence of well codified cut off. Recently, European guidelines emphasized the role of natriuretic peptides as potential laboratory markers. In the near future, algorithm building will take into consideration clinical and echocardiographic parameters as well as NP measurements, and this may lead to a correct diagnosis and identification of patients at high risk. The purpose of this review is to discuss the clinical approaches and future applications of natriuretic peptides in heart failure and coronary disease.

Predicting chronic left ventricular dysfunction 90 days after ST-segment elevation myocardial infarction: An Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) Substudy

OBJECTIVES

The purpose of this study was to determine predictors of 90-day left ventricular function following acute ST-segment elevation myocardial infarction (STEMI) using variables from clinical presentation, biomarker testing, and cardiovascular magnetic resonance imaging (CMR).

BACKGROUND

Identifying patients with acute STEMI who experience adverse remodeling and develop left ventricular dysfunction 3 months post-MI is a priority for guiding subsequent therapy.

METHODS

The Assessment of Pexelizumab in Acute Myocardial Infarction trial tested pexelizumab treatment in STEMI patients presenting within 6 hours of symptom onset who were to undergo primary percutaneous coronary intervention. We studied 64 patients within this trial according to a prespecified substudy that included paired core laboratory delayed-enhancement CMR at days 3 and 90 as well as plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP; in picograms per milliliter) measured at randomization and 24 hours. A multivariable model predicting day 90 left ventricular ejection fraction (LVEF) was developed from clinical, biomarker, and imaging findings.

RESULTS

Patients had a median age of 60 years (52-68), 89% were male, and 60% had anterior STEMI. Time from symptom onset to percutaneous coronary intervention was 3 hours. The median baseline LVEF was 48% (38%-56%) and was 50% (40%-54%) at 90 days: 7 patients (11%) had an LVEF <35% at 90 days. Patients with a lower 90-day LVEF (as a continuous variable) had a higher 24-hour NT-proBNP (P = .02) and a larger baseline infarct size by CMR (median 15% LV [8%-20% LV]) (P < .01). Microvascular obstruction (no reflow) was greater as measured by CMR (median 2.8% [1.4%-6.1%]) in patients with a lower 90-day LVEF (P < .01). Median baseline and 24-hour NT-proBNP levels were 94 pg/mL (54-292 pg/mL) and 1,448 pg/mL (958-2,599 pg/mL), respectively. In a multivariable model with clinical, biomarker, and imaging variables, only 3 variables independently predicted 90-day LVEF: 24-hour NT-proBNP, baseline CMR infarct size, and microvascular obstruction.

CONCLUSIONS

Three key pathophysiologic variables of the post-STEMI myocardium measuring baseline infarct size and the extent of microvascular obstruction on CMR and wall tension (24-hour NT-proBNP) independently predicted 90-day LVEF. Further studies linking these measures with earlier use of clinical therapies may be warranted.

Plasma N-terminal fragment of the prohormone B-type natriuretic peptide concentrations in relation to time to treatment and Thrombolysis in Myocardial Infarction (TIMI) flow: a substudy of the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT IV-PCI) trial

BACKGROUND

We investigated the prognostic significance of plasma N-terminal fragment of the prohormone B-type natriuretic peptide (Nt-proBNP) concentrations in addition to time to reperfusion and Thrombolysis in Myocardial Infarction (TIMI) flow before and after coronary intervention in patients with ST elevation myocardial infarction (STEMI) from the database of the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT IV-PCI) trial.

METHODS

Plasma Nt-proBNP was available in 1,037 patients with STEMI. Patients were randomized either to primary (p-PCI) or to full-dose tenecteplase before PCI (f-PCI).The study end point was the composite of death, cardiogenic shock, or congestive heart failure at 90 days.

RESULTS

According to classification tree analysis, patients with Nt-proBNP levels >694 pg/mL had the highest primary end point rates (33.8% vs 11%, P < .001). In Cox regression analysis, Nt-proBNP >694 pg/mL strongly predicted 90-day survival even among patients with short treatment delay (f-PCI < or =3 hours: hazard ratio [HR] 2.63, P = .002 and p-PCI < or =3 hours: HR 4.87, P < .001, respectively). Patients with TIMI 3 flow after coronary intervention were at significantly higher risk of the primary end point if admission Nt-proBNP exceeded 694 pg/mL (f-PCI: HR 2.88, P < .001 and p-PCI: HR 3.84, P < .001, respectively). In multivariable analysis, Nt-proBNP >694 pg/mL significantly (P = .001) predicted 90-day survival in addition to age (P < .001), TIMI flow after PCI (P < .001), body mass index (P = .026), anterior wall infarction (P = .035), and systolic blood pressure at randomization (P = .036), respectively.

CONCLUSION

Elevated plasma concentrations of Nt-proBNP in the early phase of STEMI determine in-hospital and 90-day outcome after infarction irrespective of time to treatment and pre- or postinterventional TIMI flow.

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.