Enhancing risk stratification post-myocardial infarction: prognostic value of NT-proBNP and fQRS

1. Introduction

Despite significant advancements in the management of myocardial infarction (MI), including reperfusion therapies and medical treatments, patients continue to face a significantly elevated risk of major adverse cardiovascular events (MACE) such as heart failure, recurrent MI, arrhythmias, stroke, and death [1]. This ongoing risk underscores the importance of accurate risk stratification, not only to predict outcomes but also to guide treatment strategies that could improve long-term patient outcomes. Traditional risk stratification models, such as the Global Registry of Acute Coronary Events (GRACE) score, combined with electrocardiographic (ECG) changes, imaging modalities (e.g., echocardiography, cardiac magnetic resonance imaging), and biomarkers like cardiac troponin, have been instrumental but may not fully capture the broader spectrum of hemodynamic stress and ventricular dysfunction [2]. This limitation necessitates additional biomarkers to provide a more comprehensive risk assessment.

2. N-terminal pro-B-type natriuretic peptide as a biomarker in MI

Natriuretic peptides, particularly B-type natriuretic peptide (BNP) and its N-terminal prohormone (NT-proBNP), have become well-established biomarkers in diagnosing and managing heart failure [3–5]. Released in response to myocardial stress and wall tension, these peptides reflect underlying left ventricular dysfunction. In the setting of acute coronary syndromes (ACS), BNP and NT-proBNP offer valuable prognostic insights into the risk of MACE, including heart failure, arrhythmia, and death [5]. Studies have demonstrated that BNP and NT-proBNP levels measured within the first few days following MI provide robust insights for risk stratification in across ACS subtypes, including ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina [6–9]. Moreover, elevated levels of natriuretic peptides retain significant prognostic value, even when adjusted for troponin levels and other clinical predictors [6–9].

The unique value of natriuretic peptides lies in their ability to reflect cardiac neurohormonal activation – a unifying feature in patients at heightened risk of death and heart failure post-MI. Elevated BNP or NT-proBNP levels are especially useful for identifying high-risk patients who may otherwise be classified as lower risk based on traditional clinical assessments [5,7,10]. Serial measurements of BNP and NT-proBNP during follow-up provide crucial information about long-term risks of heart failure and mortality [11,12]. Additionally, these peptides enhance traditional risk assessment tools, such as the GRACE score and echocardiographic evaluations, by providing complementary prognostic information that may not be fully captured by other parameters alone [13–15].

3. Prognostic significance of fQRS and its interplay with NT-proBNP

The study by Sunman et al. adds an important dimension to the growing body of evidence supporting the use of BNP and NT-proBNP in risk stratification by exploring their relationship with fragmented QRS (fQRS) in patients with MI [16]. fQRS is an easily identifiable ECG abnormality that represents conduction delays in the ventricles due to myocardial scarring or ischemia. It has been correlated with larger infarct size, left ventricular dysfunction, and poorer outcomes in MI patients [17–19]. Sunman et al.’s study goes further by investigating the interplay between NT-proBNP levels and fQRS formation during hospitalization in MI patients [16].

Their findings suggest that MI patients who develop de novo fQRS during hospitalization have significantly higher NT-proBNP levels, particularly in the setting of NSTEMI [16]. This association emphasizes the role of NT-proBNP as an independent predictor of de novo fQRS formation, further linking neurohormonal activation to electrical disturbances in the heart. Interestingly, NT-proBNP’s predictive role in fQRS formation is less prominent in patients with STEMI, particularly those with hemodynamic instability (e.g., Killip class III or IV) [16]. This suggests that the relationship between NT-proBNP and fQRS may be influenced by additional factors such as acute hemodynamic stress, making it more complex in STEMI.

While short-term mortality (e.g., in-hospital or 30-day) remains higher in STEMI (2.5–10%) compared to NSTEMI (2–7%), long-term mortality (e.g., one-year) is similar or even worse in NSTEMI, reaching about 8–11% [20–23]. This indicates that despite the higher immediate risk in STEMI patients, those with NSTEMI may face a more prolonged vulnerability, which underscores the importance of long-term risk monitoring. Additionally, Sunman et al. demonstrated that de novo fQRS is also associated with poorer one-year survival rates compared to patients with existing fQRS, further underscoring the importance of this marker in predicting long-term outcomes [16].

4. Clinical implications and future directions

This study aligns with existing literature, which indicates that both NT-proBNP and fQRS are linked to infarct size and myocardial stress [5,9,17–19]. Their combined assessment may improve risk stratification in MI patients, offering clinicians a more nuanced understanding of the patient’s risk profile. Overall, integrating electrical and biochemical markers into clinical practice can lead to more personalized and targeted management strategies [13,14].

However, several limitations should be considered. The study’s retrospective design and limited follow-up data introduce potential biases, and the exclusion of hemodynamically unstable STEMI patients from the subgroup analysis limits the generalizability of the findings [16]. Furthermore, the study does not fully explore the temporal relationship between NT-proBNP and fQRS development, leaving open the question of whether these markers could be used to predict the progression of myocardial injury in real-time [16]. Prospective studies are needed to further elucidate the temporal dynamics between NT-proBNP and fQRS and to explore the potential for combining these markers into real-time risk stratification models.

5. Conclusion

In conclusion, the combined assessment of NT-proBNP and fQRS offers valuable prognostic insights in MI, enhancing traditional risk stratification tools by providing complementary information on myocardial stress and infarct size. Integrating these markers into clinical practice could improve the precision of risk stratification, leading to more tailored treatment strategies and better long-term outcomes for MI patients. Further research is needed to validate these findings and explore the potential for incorporating NT-proBNP and fQRS into prospective risk models.

Funding Statement

The author(s) reported there is no funding associated with the work featured in this article.

Disclosure statement

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Author contributions

Ashok Kumar Pannu: Conceptualization, drafted and revised the manuscript.

Declaration of AI-based tools and technologies in content generation or proofing

I did not use AI-based tools and technologies in content generation or proofing.