Outpatient Chronic Heart Failure Diagnosis Missed in 52.4% of Elderly Type 2 Diabetics with Elevated Nt-proBNP

Diagnosing Chronic Heart Failure (CHF) in elderly patients with Type 2 Diabetes Mellitus (DM2) is challenging due to often erased clinical symptoms that can mimic other age-related conditions. This diagnostic difficulty leads to delayed intervention and poorer outcomes. Current outpatient diagnostic practices frequently miss early-stage CHF, especially Heart Failure with Preserved Ejection Fraction (HFpEF), which is common in this population. Objective biomarkers like N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and instrumental methods such as echocardiography are crucial for early detection, yet their routine application in this high-risk group is often inconsistent.

This single-stage observational study included 83 elderly patients with Type 2 Diabetes Mellitus (DM2), aged 60 to 74.9 years, who were hospitalized for planned endocrinology care. All participants underwent a standard physical examination, including clinical assessment for Chronic Heart Failure (CHF). Laboratory analysis involved determining Nt-proBNP concentration using a semi-quantitative method. Instrumental examination included comprehensive echocardiography to assess cardiac function and structure, particularly ejection fraction and other parameters relevant to CHF diagnosis. The study aimed to compare outpatient CHF diagnoses with objective biomarker and imaging findings.

The study revealed a significant discrepancy between clinical and objective Chronic Heart Failure (CHF) diagnoses in elderly Type 2 Diabetes Mellitus (DM2) patients. The frequency of outpatient CHF diagnosis was only 43%. However, 76% of the study participants had Nt-proBNP levels exceeding 125 pg/ml, a common diagnostic threshold for CHF. Notably, 97.6% of these patients retained ejection fraction, indicating a high prevalence of Heart Failure with Preserved Ejection Fraction (HFpEF).

52.4% (n=33) of patients with Nt-proBNP ≥125 pg/ml had not been diagnosed with CHF prior to the study. Among these previously undiagnosed patients, 24.2% (n=8) had Nt-proBNP in the 125-449 pg/ml range, 45.5% (n=15) were in the 450-899 pg/ml range, 18.2% (n=6) in the 900-1799 pg/ml range, and 12.1% (n=4) had levels ≥1800 pg/ml. Paradoxically, 30% of patients with Nt-proBNP below the diagnostic threshold had already been clinically diagnosed with Stage 1 CHF.