Associations of right ventricular pulsatile load and cardiac power output to clinical outcomes in heart failure: Difference from systemic circulation.

BACKGROUND

Although left ventricular (LV) cardiac power output (CPO) is a powerful prognostic indicator in heart failure (HF), the significance of right ventricular (RV) CPO is unknown. In contrast, RV pulsatile load is a key prognostic marker in HF. We investigated the impact of RV-CPO and pulsatile load on cardiac outcome and the prognostic performance of the combined systemic and pulmonary circulation parameters in HF.

METHODS

Right heart catheterization and echocardiography were performed in 231 HF patients (62 ± 16 years, LV ejection fraction 42 ± 18 %). Invasive and noninvasive CPOs were calculated from mean systemic or pulmonary arterial pressure and cardiac output. LV-CPO was then normalized to LV mass (LV-P/M). Pulmonary arterial capacitance and the ratio of acceleration time to ejection time (AcT/ET) of RV outflow were used as parameters of RV pulsatile load. The primary endpoints, defined as a composite of cardiac death, HF hospitalization, ventricular arrythmia, and LVAD implantation after the examination, were recorded.

RESULTS

Noninvasive CPOs were moderately correlated with invasive ones (LV: ρ = 0.787, RV: ρ = 0.568, and p < 0.001 for both). During a median follow-up period of 441 days, 57 cardiovascular events occurred. Lower LV-P/M and higher RV pulsatile load were associated with cardiovascular events; however, RV-CPO was not associated with the outcome. Echocardiographic LV-P/M and AcT/ET showed significant incremental prognostic value over the clinical parameters.

CONCLUSIONS

RV pulsatile load assessed by AcT/ET may be a predictor of clinical events in HF patients. The combination of echocardiographic LV-P/M and AcT/ET could be a novel noninvasive prognostic indicator in HF patients.