Abstract 10157: Prognostic Value of Heart Rate Recovery Testing in Addition to Brain Natriuretic Peptide Levels in Ambulatory Patients with Nonischemic Dilated Cardiomyopathy
Introduction: Heart rate recovery (HRR) after exercise is related to autonomic function and is a prognostic marker in cardiovascular disease. Meanwhile, the diagnostic and prognostic value of plasma brain natriuretic peptide (BNP) levels has been established in chronic heart failure. However, little is known regarding the potential relationship between the HRR and BNP in heart failure patients.
Hypothesis: We assessed the hypothesis that HRR and BNP levels in combination would be a good prognostic marker in ambulatory outpatients with non-ischemic dilated cardiomyopathy (NICM).
Methods: Seventy-nine NICM outpatients who were clinically stable, in New York Heart Association functional class I or II, were enrolled. They underwent cardiopulmonary exercise testing and echocardiography and measurement of plasma BNP levels. HRR was defined as the difference in heart rate between at the peak exercise and at 1 min after stopping exercise. We prospectively followed up all patients for the occurrence of cardiac events, that were defined as cardiac death or unscheduled admission for decompensated heart failure for a mean of 19 months.
Results: Mean plasma BNP level was 174 pg/mL; peak oxygen uptake (peakVO2) was 18.4 mL kg-1 min-1, left ventricular ejection fraction was 38.4%; and HRR was 15.6 bpm. On the basis of the ROC curve, we divided the patients into two groups: with HRR >12 bpm (n = 48, abnormal) and with HRR ≤12 bpm (n = 31, normal). The probability of cardiac event-free survival was significantly lower in the abnormal HRR group than in the normal HRR group (P = 0.002). Stepwise multivariate analysis revealed that plasma BNP and HRR were independent predictors of cardiac events. The risk of cardiac events in patients with HRR of ≤12 bpm and plasma BNP of ≥200 pg/mL was significantly higher than in those with HRR >12 bpm and BNP <200 pg/mL (hazard ratio 32.4; 95% CI, 3.75-280.96).
Conclusions: Assessment of the parasympathetic nervous activity by HRR, in combination with plasma BNP level testing, might be a useful prognostic measure in ambulatory outpatients with NICM.
- © 2011 by American Heart Association, Inc.