Abstract Body (Do not enter title and authors here): Introduction: Brain natriuretic peptide (BNP) is commonly used for the diagnosis and management of heart failure (HF), as its presence strongly predicts cardiovascular events and risk of death. Detecting HF early has a substantial impact on quality of life and outcomes. Measurement of left ventricular end diastolic pressure (LVEDP) is the gold standard method for diagnosing HF, including early stage HF in the absence of signs and symptoms. BNP has been proposed as another means to screen for early stage HF, specifically in high-risk patients. Here, we compare BNP to elevated LVEDP across a range of LVEDP values to assess its ability to detect HF early.
Methods: The dataset (154 subjects, 66 +/- 10 yrs of age and above; 64% male) consists of patients referred for coronary angiography and left heart catheterization for clinical indications inclusive of direct measurement of LVEDP. LVEDP was measured using high-fidelity Millar Mikro-tip pressure catheters. BNP was measured during the same visit. Mean LVEDP thresholds from 15 mmHg to 25 mmHg were analyzed. The sensitivities and specificities of BNP thresholds of 35 pg/ml and 100 pg/ml were assessed.
Results: The receiver operating characteristic (ROC) curves with the area under the curve (AUC) for the classification models are shown in Fig. 1. AUC appears to increase linearly with the level of measured BNP, displaying only good performance (> 80%) when LVEDP is substantially elevated (AUC = 81%, at 25 mmHg). At a BNP decision threshold of 35 pg/ml (Ambulatory, AHA algorithm for suspected HF) the ROC curves for an LVEDPs >15 mmHg and >25 mmHg yield sensitivities of 74% and 92% and specificities of 47% and 41%, respectively. At a BNP decision threshold of 100 pg/ml (Hospitalized/Decompensated) the ROC curves for LVEDPs >15 mmHg and >25 mmHg yield sensitivities of 43% and 75% and specificities of 74% and 71%, respectively.
Conclusion: While BNP is adept at identifying patients already exhibiting signs and symptoms of HF, these results suggest the diagnostic utility of BNP may be limited in detecting early stage HF.