An mPAP/CO slope >3 Wood units during exercise is associated with impaired survival, and a PAWP/CO slope >2 Wood units differentiates pre- from post-capillary causes of PAP elevation.
Systematic Review (n=5,598)
Do pulmonary haemodynamic parameters during exercise provide diagnostic and prognostic value in evaluating pulmonary vascular and cardiac diseases?
An mPAP/CO slope >3 WU and PAWP/CO slope >2 WU during exercise are prognostically relevant cut-offs for survival and can effectively differentiate pre- from post-capillary causes of pulmonary hypertension.
BACKGROUND: The cardiopulmonary haemodynamic profile observed during exercise may identify patients with early-stage pulmonary vascular and primary cardiac diseases, and is used clinically to inform prognosis. However, a standardised approach to interpreting haemodynamic parameters is lacking. METHODS: We performed a systematic literature search according to PRISMA guidelines to identify parameters that may be diagnostic for an abnormal haemodynamic response to exercise and offer optimal prognostic and differential-diagnostic value. We performed random-effects meta-analyses of the normal values and report effect sizes as weighted mean±sd. Results of diagnostic and prognostic studies are reported descriptively. RESULTS: We identified 45 eligible studies with a total of 5598 subjects. The mean pulmonary arterial pressure (mPAP)/cardiac output (CO) slope, pulmonary arterial wedge pressure (PAWP)/CO slope and peak cardiac index (or CO) provided the most consistent prognostic haemodynamic parameters during exercise. The best cut-offs for survival and cardiovascular events were a mPAP/CO slope >3 Wood units (WU) and PAWP/CO slope >2 WU. A PAWP/CO slope cut-off >2 WU best differentiated pre- from post-capillary causes of PAP elevation during exercise. Upper limits of normal (defined as mean+2sd) for the mPAP/CO and PAWP/CO slopes were strongly age-dependent and ranged in 30-70-year-old healthy subjects from 1.6 to 3.3 WU and 0.6 to 1.8 WU, respectively. CONCLUSION: An increased mPAP/CO slope during exercise is associated with impaired survival and an independent, prognostically relevant cut-off >3 WU has been validated. A PAWP/CO slope >2 WU may be suitable for the differentiation between pre- and post-capillary causes of PAP increase during exercise.
Zeder et al. (Thu,) conducted a systematic review in Early-stage pulmonary vascular and primary cardiac diseases (n=5,598). Pulmonary haemodynamic parameters during exercise was evaluated on Survival, cardiovascular events, and differentiation of pre- from post-capillary causes of PAP elevation. An mPAP/CO slope >3 Wood units during exercise is associated with impaired survival, and a PAWP/CO slope >2 Wood units differentiates pre- from post-capillary causes of PAP elevation.