Introduction: In patients with heart failure (HF), NT-proBNP levels are inversely correlated with the left ven-tricular ejection fraction (LVEF). For HF patients these parameters are independent predictors of mortality.
Objective: To assess if high NT-proBNP values have different prognostic impact for patients with different LVEF.
Methods: We retrospectively included patients with HF admitted to our clinic between January 2011 and December 2014. Only those with NT-proBNP levels determined on admission and a cardiac ultrasound examination during hospitalization were included. Readmissions, in-hospital mortality, acute coronary syndromes, acute pulmonary embolism, and systemic infections were exclusion criteria. Survival status was assessed in June 2018, after a median follow-up of 5.5 years. We documented all-cause mortality. We classi-fied patients as having HF with reduced ejection fracti-on (HFrEF) if LVEF was <40%, HF with mid-range EF (HFmrEF) if LVEF was between 40-50% and HF with preserved EF (HFpEF) if LVEF >50%.
Results: Our sample consisted of 1068 patients with a mean age of 72.3±10.6 years. 53.9% were female. Medi-an (interquartile range) NT-proBNP on admission was 1258 (459.1; 3619) pg/ml. All-cause long-term morta-lity was 45.75%. Patients with HFrEF had the highest median NT-proBNP levels (3777 (1386; 8661) pg/ml), followed by HFmrEF (1283 (625.8; 2846) pg/ml) and then HFpEF (493 (227.2; 1323) pg/ml), p<0.001. Pati-ents with HFrEF had the highest long-term all-cause mortality (60.7%), followed by HFmrEF (42.5%) and then by HFpEF (31.5%), p for trend <0.001. In pati-ents with HFrEF mortality increased with NT-proBNP quartiles from 45.5% to 41.7% to 59.1% to 71.1%, p for trend 0.015. The same tendency was observed for pati-ents with HFmrEF (16.7% – 29.3% – 54.7% – 71.7%), p for trend <0.001 and for patients with HFpEF (21.6% – 5% – 50% – 60.9%), p for trend <0.001. In the first and second NT-proBNP quartile groups, patients with HFrEF had higher mortality compared to HFmrEF and HFpEF. In the last two NT-proBNP quartile groups all patients had similar mortality. Patients with HFrEF in the third and fourth NT-proBNP quartile groups had OR of mortality of 2.6, p=0.001 and 2.4 times higher, p=0.001, those with HFmrEF 4.8, p<0.001 and 4.9 ti-mes higher, p<0.01 and those with HFpEF 3.5, p<0.001 and 3.6 times higher, p=0.005.
Conclusions: NT-proBNP levels and mortality rates are significantly different among patients with HFrEF, HFmrEF and HFpEF. However, high serum concentra-tions of NT-proBNP have the same prognostic impact for all patients, regardless of the ejection fraction.