PURPOSE: The prediction of early death in CHF patients remains challenging. As our reports(1-2), some powereful predictors, derived from cardiopulmonary exercise tests (CPET), were confirmed, but commonly used cardiovascular measurements at rest were excluded as predictor of early death in patients with chronic left ventricular heart failure (CHF). Our goal was to identify prognosis importance of peak cardiac output (CO) and stoke volume (SV) in CHF for early death.
METHODS: 508 patients with CHF due to systolic dysfunction had resting cardiovascular measurements, and CPET. Outcomes were six-month mortality (all cause death).The peak O2 uptake (VO2), peak O2 pulse, anaerobic threshold (AT), ratio of ventilation to CO2 output (VE/VCO2), VE-vs-VCO2 slope, oxygen uptake efficiency plateau (OUEP, i.e. Highest VO2/VE) and presence or absence of a distinctive oscillatory breathing pattern (OB) were ascertained for comparisons. Noninvasive peak CO and SV were calculated by following equations based previous report with adjustment by HB and SpO2(3):Peak CO=peak VO2÷(0.57+1.52x100)÷15.4xHB÷97.1%xSpO2% Peak SV=peak CO÷heart rate.
RESULTS: During six-month follow-up, 19 patients died and 489 patients survived. The noninvasive peak CO and SV were 6.6±2.7L/min and 62±24ml/beat in CHF. The best cut-off values for peak CO and SV were 5.5L/min and 60ml/beat. The odds ratios of lower peak CO and SV predictor of early mortality were 6.85 (95%CI:5.72-7.97) and 5.72 (4.47-6.96). They were slightly higher than those of peak V. O2, OB, AT and peak O2 pulse; but lower than OUEP, lowest V. E/V. CO2 and V. E-vs-V. CO2 slope.
CONCLUSION: Although none of non-exercise measurements (i.e. NYHA, QRS duration, ejection fraction, blood pressure, cardiac output and stroke volume at rest) and exercise blood pressure, heart rate and double produce significantly prognosticate early mortality; the lower peak CO and SV are powerful predictors.
CLINICAL IMPLICATIONS: CPET is a useful functional evaluation tool for cardiovascular diseases. The reduced noninvasive peak CO and SV parameters are powerful prognosticators of early mortality in CHF patients.
DISCLOSURE: Xingguo Sun, No Financial Disclosure Information; No Product/Research Disclosure Information