Plasma N-terminal protype-B natriuretic peptide and restrictive mitral flow to risk-stratify patients with stage B heart failure

Abstract

Background: The prognostic role of echocardiography is well established in patients with previous or current symptoms of heart failure (HF). Less is understood about patients with stage B HF, who have structural heart disease but no symptoms at any stage. This study investigated the role of plasma N-terminal protype-B natriuretic peptide (NT-proBNP) and Doppler-echo parameters of diastolic and systolic function for risk stratification in stage B HF patients.

Hypothesis: We investigated whether plasma NT-proBNP and Doppler-echo parameters of diastolic and systolic function have a role in risk stratification of stage B HF patients.

Methods: Doppler echocardiography was performed in 155 outpatients with asymptomatic left ventricular (LV) dysfunction (ejection fraction [EF] < 50%) and comprised conventional diastolic variables, including pulsed-Doppler mitral E-wave deceleration time (EDT). Plasma NT-proBNP was assessed at the time of the echocardiogram. The prespecified end point was cardiac death or HF hospitalization or any new HF episode requiring a change in medication.

Results: Mean EF was 35% +/- 7%. Median NT-proBNP was 745 pg/mL (interquartile range [IQR], 442-1672). Patients with events at follow-up (n = 46) had higher prevalence of risk factors for developing HF. Plasma NT-proBNP, EDT, and EF were independently associated with cardiac events at multivariable analysis and receiver operating characteristic curves were used to determine the optimal prognostic cut points for each: NT-proBNP > or = 831 pg/mL, EDT < 145 msec, and EF < 37%. When used in combination, event-free survival was incrementally worse with each additional abnormality.

Conclusion: Plasma NT-proBNP, EDT, and EF are independently useful for prognostic stratification of stage B HF patients and suggest an incremental prognostic deficit is associated with the combination of each. This study supports the complementary role of comprehensive echocardiography and natriuretic peptide assay in asymptomatic LV dysfunction.