High VE/VCO2 (>34.0) strongly predicted mortality in CHF patients with preserved exercise capacity (HR 4.3, P<0.0001), with a 3-year survival of 57% compared to 93% in those with normal VE/VCO2.
Cohort (n=123)
Does an elevated ventilatory response to exercise (VE/VCO2) predict mortality in chronic heart failure patients with preserved exercise tolerance?
In chronic heart failure patients with preserved exercise capacity, an elevated VE/VCO2 slope is a strong predictor of mortality and reflects widespread derangement of cardiovascular reflex control, whereas peak VO2 does not predict mortality.
Hazard Ratio: 4.3
Absolute Event Rate: 57% vs 93%
p-value: p=<0.0001
BACKGROUND: In patients with chronic heart failure (CHF) and preserved exercise tolerance, the value of cardiopulmonary exercise testing for risk stratification is not known. Elevated slope of ventilatory response to exercise (VE/VCO(2)) predicts poor prognosis in advanced CHF. Derangement of cardiopulmonary reflexes may trigger exercise hyperpnea. We assessed the relationship between cardiopulmonary reflexes and VE/VCO(2)and investigated the prognostic value of (VE/VCO(2)) in CHF patients with preserved exercise tolerance. METHODS AND RESULTS: Among 344 consecutive CHF patients, we identified 123 with preserved exercise capacity, defined as a peak oxygen consumption (PEAK VO(2)) >/=18 mL. kg(-1). min(-1) (age 56 years; left ventricular ejection fraction 28%; peak VO(2) 23.5 mL. kg(-1). min(-1)). Hypoxic and hypercapnic chemosensitivity (n=38), heart rate variability (n=34), baroreflex sensitivity (n=20), and ergoreflex activity (n=20) were also assessed. We identified 40 patients (33%) with high VE/VCO(2) (ie, >34.0). During follow-up (49+/-22 months, >3 years in all survivors), 34 patients died (3-year survival 81%). High VE/VCO(2) (hazard ratio 4.3, PO(2) (P=0.7) predicted mortality. In patients with high VE/VCO(2), 3-year survival was 57%, compared with 93% in patients with normal VE/VCO(2) P<0.0001). Patients with high VE/VCO(2) demonstrated impaired reflex control, as evidenced by augmented peripheral (P=0.01) and central (P=0.0006) chemosensitivity, depressed low-frequency component of heart rate variability (P<0.0001) and baroreflex sensitivity (P=0.03), and overactive ergoreceptors (P=0.003) compared with patients with normal VE/VCO(2). CONCLUSIONS: In CHF patients with preserved exercise capacity, enhanced ventilatory response to exercise is a simple marker of a widespread derangement of cardiovascular reflex control; it predicts poor prognosis, which VO(2) does not.
Ponikowski et al. (Tue,) conducted a cohort in Chronic heart failure with preserved exercise tolerance (n=123). High VE/VCO2 (>34.0) vs. Normal VE/VCO2 was evaluated on 3-year survival (HR 4.3, p=<0.0001). High VE/VCO2 (>34.0) strongly predicted mortality in CHF patients with preserved exercise capacity (HR 4.3, P<0.0001), with a 3-year survival of 57% compared to 93% in those with normal VE/VCO2.