Determinants and prognostic implications of the negative diastolic pulmonary pressure gradient in patients with pulmonary hypertension due to left heart disease

Abstract

AimsThe diastolic pulmonary pressure gradient (DPG) has recently been introduced as a specific marker of combined pre-capillary pulmonary hypertension (Cpc-PH) in left heart disease (LHD). However, its diagnostic and prognostic superiority compared with traditional haemodynamic indices has been challenged lately. Current recommendations explicitly denote that in the normal heart, DPG values are greater than zero, with DPG ≥7 mmHg indicating Cpc-PH. However, clinicians are perplexed by the frequent observation of DPG <0 mmHg (DPG NEG ), as its physiological explanation and clinical impact are unclear to date. We hypothesized that large V-waves in the pulmonary artery wedge pressure (PAWP) curve yielding asymmetric pressure transmission might account for DPG NEG Methods and resultsRight heart catheterization and echocardiography were performed in 316 patients with LHD due to primary myocardial dysfunction or valvular disease. A total of 256 patients had PH-LHD, of whom 48% demonstrated DPG NEG . The V-wave amplitude inversely correlated with DPG (r = −0.45, P < 0.001) in patients with low pulmonary vascular resistance (PVR), but not in those with elevated PVR (P > 0.05). Patients with large V-waves had negative and lower DPG than those without augmented V-waves (P < 0.001) despite similar PVR (P >0.05). Positive, but normal DPG (0-6 mmHg) carried a worse 2-year prognosis for death and/or heart transplantation than DPG NEG (hazard ratio 2.97; P < 0.05). ..................................................................................................................................................................... ConclusionOur results advocate against DPG NEG constituting a measurement error. We propose that DPG NEG can partially be ascribed to large V-waves and carries a better prognosis than DPG within the normal positive range.

Haemodynamic mechanisms and long‐term prognostic impact of pulmonary hypertension in patients with severe aortic stenosis undergoing valve replacement

“…Importantly, CpcPH and IpcPH patients exhibited a clearly distinct exercise response, indirectly justifying the practice of preferring the PVR criterion. Interestingly, we found a high proportion of patients with negative DPG (as evident from the data in Table ), which is in line with the findings from patients with mitral stenosis and PH due to HF with reduced or preserved ejection fraction as reported by Nagy et al . They showed that negative DPG values were associated with the presence of large V waves in patients with PVR < 3 WU.…”

“…They showed that negative DPG values were associated with the presence of large V waves in patients with PVR < 3 WU. In our study, as in the study by Nagy et al ., mPAWP was obtained from the entire cardiac cycle including V waves. This probably has resulted in higher mPAWP values compared to a practice of not including V waves, which in turn has resulted in lower DPG, TPG, and PVR values.…”

February 2018 at a glance: heart and brain interaction, prognostic variables, and acute heart failure and post‐discharge outcomes

“…Pulmonary vascular resistance differentiated patients at high and low risk. In contrast, no difference in survival was found based on the diastolic pressure gradient, consistently with previous data regarding this parameter …”

Hemodynamic Phenotyping of Pulmonary Hypertension in Left Heart Failure

“…At present, an almost equal number of studies have confirmed [41][42][43] or refuted [44][45][46] the prognostic relevance of DPG. These discrepancies are explained by the fact that the DPG represents a small number, is exposed to instability, as shown in studies where high DPGs were sometimes found in patients with a normal PVR 44 or where DPG was reported as negative in a proportion of patients, 47 conditions which are both physiologically impossible. TPG or PVR have to increase in proportion of the DPG, 7 while reported negative DPG values may be because of improper incorporation of V waves in the reading of PAWP tracings or simply because of a lack of precision of the measurement.…”