Utility of NT-proBNP for detecting heart failure and assessing prognosis in elderly myocardial infarction survivors: insights from the OMEMI trial
P Myhre, K Berge, A Kalstad, S Tveit, K Laake, A Tveit, S Solheim, T Omland, I Lunde, H RosjoAbstract
Background
Elderly myocardial infarction (MI) survivors face a high risk of developing heart failure (HF), but diagnosis is challenging due comorbidities and inactivity after discharge masking symptoms. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a robust cardiac stress marker and a defining feature of HF.
Aims
To evaluate NT-proBNP concentrations in elderly post-MI patients without clinically diagnosed HF and assess their association with cardiovascular event risk.
Methods
The OMEMI trial, a randomized controlled study across four Norwegian academic hospitals, included 1014 elderly (range 70-82 years) patients with a recent MI between 2012 and 2020. Participants were randomized to omega-3 fatty acids or placebo for two years and monitored for cardiovascular events. The overall trial was neutral. NT-proBNP was analyzed at baseline (2-8 weeks post-MI) using the Roche Elecsys assay. The age-adjusted NT-proBNP threshold of 500 ng/L for HF rule-in was applied (ref). Patients with pre-existing HF (n=65) or new-onset HF between MI and baseline (n=22) were excluded. Cox proportional hazards regression was used to analyze time to event data for HF hospitalization and mortality, with adjustment for age, sex, BMI, hypertension, diabetes, previous MI, atrial fibrillation, eGFR, and NYHA-class at baseline, in addition to index MI peak troponin T concentration and ST-elevation MI (STEMI).
Results
Among 937 patients without HF diagnosis, median NT-proBNP was 494 (224-1159) ng/L. NT-proBNP ≥500 ng/L was present in 49.7% (n=466), and associated with older age, lower BMI, and more atrial fibrillation. The index MI being STEMI and higher peak troponin T during the MI (r=0.51) also predicted higher NT-proBNP at the baseline visit 2-8 weeks later. At baseline, patients with NT-proBNP ≥500 ng/L showed significantly higher rates of NYHA class ≥2 (41.8%) and peripheral edema (34.7%). During two-year follow-up, this group accounted for 81.0% of deaths (30/37) and 92.8% of HF hospitalizations (26/28). After multivariable adjustment, NT-proBNP ≥500 ng/L remained associated with increased risk of death (HR 3.16, 95%CI 1.28-7.84, p=0.013); HF hospitalization (HR 6.34, 95%CI 1.88-21.35, p=0.003) and a composite of the two outcomes (HR 4.21, 95%CI 2.03-8.90, p<0.001). The risk of HF hospitalization or death increased significantly and progressively across ascending quartiles of NT-proBNP levels (log-rank p<0.001; Figure)
Conclusion
Half of the elderly post-MI patients without clinical HF diagnosis had NT-proBNP levels above the HF rule-in threshold, exhibiting HF signs/symptoms and significantly increased risk of HF hospitalization or death. These findings support NT-proBNP screening for HF in elderly patients in the months following MI, especially in patients with large troponin elevations during the MI.Baseline characteristicsFor image description, please refer to the figure legend and surrounding text.Nelson-Aalen plotFor image description, please refer to the figure legend and surrounding text.