Aims The diastolic pressure gradient (DPG) has been proposed as a marker pulmonary
vascular disease in the setting of left heart failure (HF). However, its diagnostic
utility is compromised by the high prevalence of physiologically incompatible negative
values (DPG(NEG)) and the contradictory evidence on its prognostic value. Pressure
pulsatility impacts on DPG measurements, thus conceivably, pulmonary artery wedge
pressure (PAWP) measurements insusceptible to the oscillatory effect of the V-wave
might yield a more reliable DPG assessment. We set out to investigate how the instantaneous
PAWP at the trough of the Y-descent (PAWP(Y)) influences the prevalence of DPG(NEG)
and the prognostic value of the resultant DPG(Y). Methods Hundred and fifty-three
consecutive HF patients referred for right heart catheterisation were enrolled prospectively.
DPG, as currently recommended, was calculated. Subsequently, PAWP(Y) was measured
and the corresponding DPG(Y) was calculated. Results DPG(Y) yielded higher values
(median, IQR: 3.2, 0.6-5.7 mmHg) than DPG (median, IQR: 0.9, - 1.7-3.8 mmHg); p <
0.001. Conventional DPG was negative in 45% of the patients whereas DPG(Y) in only
15%. During follow-up (22 +/- 14 months) 58 patients have undergone heart-transplantation
or died. The predictive ability of DPG(Y) >= 6 mmHg for the above defined end-point
events was significant [HR 2.1; p = 0.007] and independent of resting mean pulmonary
artery pressure (PAP(M)). In contrast, conventional DPG did not comprise significant
prognostic value following adjustment for PAP(M). Conclusion Instantaneous pressures
at the trough of Y-descent yield significantly fewer DPG(NEG) than conventional DPG
and entail superior prognostic value in HF patients with and without PH.
