Increased Pulmonary-Systemic Pulse Pressure Ratio Is Associated With Increased Mortality in Group 1 Pulmonary Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterised by remodelling of the pulmonary vasculature leading to right ventricular (RV) failure. The failing RV, through interventricular uncoupling, deleteriously impacts the left ventricle and overall cardiac efficiency. We hypothesised that the ratio of the pulmonary artery pulse pressure to the systemic pulse pressure ("pulmonary-systemic pulse pressure ratio", or PS-PPR) would be associated with mortality in PAH. METHODS: We conducted a retrospective analysis of 262 patients in the National Institute of Health Primary Pulmonary Hypertension Registry (NIH-PPH). We evaluated the association between the PS-PPR and mortality after adjustment for the Pulmonary Hypertension Connection (PHC) risk equation. RESULTS: Among 262 patients (mean age 37.5±15.8years, 62.2% female), median PS-PPR was 1.04 (IQR 0.79-1.30). In the Cox proportional hazards regression model, each one unit increase in the PS-PPR was associated with more than a two-fold increase in mortality during follow-up (HR 2.06, 95% CI 1.40-3.02, p=0.0002), and this association of PS-PPR with mortality remained significant in the multivariable Cox model adjusted for the PHC risk equation, mean pulmonary artery pressure, and body mass index (BMI) (adjusted HR 1.81, 95% CI 1.13-2.88, p=0.01). Furthermore, PS-PPR in the upper quartile (>1.30) versus quartiles 1-3 was associated with a 68% increase in mortality after adjustment for these same covariates (adjusted HR 1.68, 95% CI 1.13-2.50, p=0.01). CONCLUSIONS: Pulmonary-systemic pulse pressure ratio, a marker of biventricular efficiency, is associated with survival in PAH even after adjustment for the PHC risk equation. Further studies are needed on the wider applications of PS-PPR in PAH patients.

Right atrial to left atrial volume index ratio is associated with increased mortality in patients with pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is characterized by increased pulmonary vascular resistance leading to right heart failure. Elevated right atrial (RA) pressure reflects right ventricular (RV) pressure overload and is an established risk factor for mortality in PH. We hypothesized that PH patients with an increased ratio of RA to LA volume index (RAVI/LAVI), would have increased mortality. METHODS: We evaluated the association of RAVI/LAVI with mortality in 124 patients seen at a single academic center's PH clinic after adjusting for the REVEAL risk score, an established risk score in PH. LA and RA volume indices were measured in the four-and two-chamber views by two independent researchers. Multivariable logistic regression was used to model the independent association of RAVI/LAVI with survival. RESULTS: Among 124 patients (mean age 62 ± 12.7 years, 68.6% female), each unit increase in RAVI/LAVI was associated with a nearly twofold increase in mortality (OR: 1.91, 95% CI: 1.20-3.04). In a multivariable logistic regression, each unit increase in RAVI/LAVI was associated with a nearly twofold increase in mortality (OR: 1.73, 95% CI: 1.003-2.998). Furthermore, RAVI/LAVI in the highest quartile (>1.42) was significantly associated with elevated right atrial pressure (RAP) to pulmonary artery wedge pressure ratio (RAP/PAWP) (0.76 ± 0.41, P = 0.02) compared with the lowest quartile (<0.77), suggesting an interaction between invasive hemodynamic data, atrial structural changes, and mortality in PH. CONCLUSIONS: Increased RAVI/LAVI in PH is associated with decreased survival and accounts for atrial structural remodeling related to invasive hemodynamics. These findings support further study of this index in predicting outcomes in PH.

Isolated Marked Inferior Vena Cava Dilatation: Unusual Presentation or Underrecognized Common Phenomenon?

Inferior vena cava (IVC) diameter and respirophasic variation are commonly used echocardiographic indices to estimate right atrial pressure. While dilatation of the IVC and reduced collapsibility have traditionally been associated with elevated right heart filling pressures, the significance of isolated IVC dilatation in the absence of raised filling pressures remains poorly understood. We present a case of an asymptomatic 28-year-old male incidentally found to have IVC dilatation, reduced inspiratory collapse, and normal right heart pressures.