Abstract 17519: Chronic Kidney Disease Blunts the Prognostic Significance of Chronotropic Incompetence during Exercise in Patients with Left Ventricular Dysfunction
Background: An impaired heart rate response to exercise, chronotropic incompetence (CI), has been reported to be an independent predictor of cardiovascular mortality, but not disclosed elsewhere. This inconsistency may be attributable to multiple factors that are related to autonomic dysfunction. To address this issue, we examined the effect of chronic kidney disease (CKD) on prognostic significance of CI because CKD has been recently implicated to be associated with autonomic nervous dysfunction.
Methods: 316 consecutive patients with left ventricular ejection fraction (LVEF) ≤ 40% who underwent cardiopulmonary exercise testing (CPX) were studied. They were divided into 2 groups with or without CKD [CKD (+), n=149 vs. CKD (-), n=167]. CKD was defined as estimated glomerular filtration rate lower than 60ml/min/1.73m2 for longer than 3months, according to National Kidney Foundation. CI was defined as the peak exercise heart rate (HR) less than 130bpm and the prognostic values of other prognostic parameters were examined. We followed for 4.1±2.2 years, and examined event-free survival (all-cause death or heart failure hospitalization).
Results: Although CKD(+) patients were older (64.8 vs. 55.5 years old, p<0.0001) and with lower peak HR (119 vs. 134 bpm, p<0.0001) than CKD (-) patients, other background was similar (LVEF: 28.7±0.6 vs. 28.3±0.6%, B-type natriuretic peptide: 204±19 vs. 164±18ng/ml, and Use of beta-blockers: 82.6 vs. 75.9%). Event-free survival was significantly lower in patients with CI than those without CI in CKD(-) (p<0.0001), but not different in CKD(+) (Figure). With multivariate analysis (with correction for age, LVEF, peak VO2, VE/VCO2 slope), CI was the strongest and independent prognostic predictor in CKD (-) (χ2 8.13, p value 0.0043, hazard ratio 2.21, 95% confidence interval 1.28-3.88) but not in CKD (+).
Conclusion: Chronotropic incompetence at CPX predicted adverse prognosis in CKD (-), but not in CKD (+) in patients with LV dysfunction.
- © 2010 by American Heart Association, Inc.