Efficacy of Pulmonary Artery Pulsatility Index as a Measure of Right Ventricular Dysfunction in Stable Phase of Dilated Cardiomyopathy

Obesity Modifies Clinical Outcomes of Right Ventricular Dysfunction

BACKGROUND

Right ventricular (RV) dysfunction is associated with increased mortality across a spectrum of cardiovascular diseases. The role of obesity in RV dysfunction and adverse outcomes is unclear.

METHODS

We examined patients undergoing right heart catheterization between 2005 and 2016 in a hospital-based cohort. Linear regression was used to examine the association of obesity with hemodynamic indices of RV dysfunction (pulmonary artery pulsatility index, right atrial pressure:pulmonary capillary wedge pressure ratio, RV stroke work index). Cox models were used to examine the association of RV function measures with clinical outcomes.

RESULTS

Among 8285 patients (mean age, 63 years; 40% women), higher body mass index was associated with worse indices of RV dysfunction, including lower pulmonary artery pulsatility index (β, -0.23; SE, 0.01; P<0.001), higher right atrium:pulmonary capillary wedge pressure ratio (β, 0.25; SE, 0.01; P<0.001), and lower RV stroke work index (β, -0.05; SE, 0.01; P<0.001). Over median of 7.3 years of follow-up, we observed 3006 mortality and 2004 heart failure hospitalization events. RV dysfunction was associated with a greater risk of mortality (eg, pulmonary artery pulsatility index:hazard ratio, 1.11 per 1-SD increase [95% CI, 1.04-1.18]), with similar associations with risk of heart failure hospitalization. Body mass index modified the effect of RV dysfunction on all-cause mortality (Pinteraction≤0.005 for PAPi and RA:PCWP ratio), such that the effect of RV dysfunction was more pronounced at higher body mass index.

CONCLUSIONS

Patients with obesity had worse hemodynamic measured indices of RV function across a broad hospital-based sample. While RV dysfunction was associated with worse clinical outcomes including mortality and heart failure hospitalization, this association was especially pronounced among individuals with higher body mass index.

Obesity Modifies Clinical Outcomes of Right Ventricular Dysfunction

Introduction

Right ventricular (RV) dysfunction is associated with increased mortality across a spectrum of cardiovascular diseases. The role of obesity in RV dysfunction and adverse outcomes is unclear.

Methods

We examined patients undergoing right heart catheterization between 2005-2016 in a hospital-based cohort. Linear regression was used to examine the association of obesity with hemodynamic indices of RV dysfunction [pulmonary artery pulsatility index (PAPi), right atrial pressure: pulmonary capillary wedge pressure ratio (RAP:PCWP), RV stroke work index (RVSWI)]. Cox models were used to examine the association of RV function measures with clinical outcomes.

Results

Among 8285 patients (mean age 63 years, 40% women), higher BMI was associated with worse indices of RV dysfunction, including lower PAPi (β -0.26, SE 0.01, p <0.001), higher RA:PCWP ratio (β 0.25, SE 0.01, p-value <0.001), and lower RVSWI (β -0.05, SE 0.01, p-value <0.001). Over 7.3 years of follow-up, we observed 3006 mortality and 2004 heart failure (HF) hospitalization events. RV dysfunction was associated with greater risk of mortality (eg PAPi: HR 1.11 per 1-SD increase, 95% CI 1.04-1.18), with similar associations with risk of HF hospitalization. BMI modified the effect of RV dysfunction on outcomes (P-interaction <=0.005 for both), such that the effect of RV dysfunction was more pronounced at higher BMI.

Conclusions

Patients with obesity had worse hemodynamic measured indices of RV function across a broad hospital-based sample. While RV dysfunction was associated with worse clinical outcomes including mortality and HF hospitalization, this association was especially pronounced among individuals with higher BMI.

A Novel Hemodynamic Index of Post-operative Right Heart Dysfunction Predicts Mortality in Cardiac Surgical Patients

INTRODUCTION

This study aimed to investigate whether mortality following cardiac surgery was associated with the pulmonary artery pulsatility index (PAPi): pulmonary artery pulse pressure divided by central venous pressure (CVP), and a novel index: mean pulmonary artery pressure (mPAP) minus CVP.

METHODS

This retrospective analysis investigated all cardiac surgery patients in the Society of Thoracic Surgeons registry at a single academic medical center from January 2017 through March 2020 (n = 1510). The primary and secondary outcomes were mortality at 1 year and serum creatinine increase during index surgical admission, respectively. CVP, mPAP, PAPi, mPAP-CVP gradient, mean arterial pressure (MAP), and cardiac index (CI) were sampled continually from invasive hemodynamic monitors post-operatively. Associations with mortality were tested with univariate and multivariate analyses. The relationship with serum creatinine was investigated with Pearson's correlation at alpha = .05.

RESULTS

One-year mortality was observed in 44/1200 patients (3.7%). On univariate analysis, mortality was associated with minimums for mPAP, MAP, and CI and maximums for CVP, mPAP, PAPi, mPAP-CVP gradient, and CI (all P < .10). Model selection revealed that the only independently predictive parameters were minimum MAP (AOR = .880 [.819-.944]), maximum mPAP-CVP gradient (AOR = 1.082 [1.031-1.133]), and maximum CI (AOR = 1.421 [.928-2.068]), with model c-statistic = .770. A maximum mPAP-CVP gradient >20.5 predicted mortality with 54.5% sensitivity and 79.30% specificity, maintaining significance on survival analysis (P < .001). Peak increase in serum creatinine from baseline demonstrated a weak association with all parameters (max |r| = .33).

CONCLUSIONS

Mortality was not predicted by the post-operative PAPi; rather, it was independently predicted by the mPAP-CVP gradient, MAP, and CI.

Association of Pulmonary Artery Pulsatility Index With Adverse Cardiovascular Events Across a Hospital-Based Sample

BACKGROUND

The pulmonary artery pulsatility index (PAPi), calculated from the ratio of the pulmonary artery pulse pressure to right atrial pressure, is a predictor of right ventricular failure after inferior myocardial infarction and left ventricular assist device implantation. Whether PAPi is associated with adverse outcomes across a heterogeneous population is unknown.

METHODS

We examined consecutive patients undergoing right heart catheterization between 2005 and 2016 in a hospital-based cohort. Multivariable Cox models were utilized to examine the association between PAPi and all-cause mortality, major adverse cardiac events, and heart failure hospitalizations.

RESULTS

We studied 8285 individuals (mean age 63 years, 39% women) with median PAPi across quartiles 1.7, 2.8, 4.2, and 8.7, who were followed over a mean follow-up of 6.7±3.3 years. Patients in the lowest PAPi quartile had a 60% greater risk of death compared with the highest quartile (multivariable-adjusted hazard ratio, 1.60 [95% CI, 1.36-1.88], P<0.001) and a higher risk of major adverse cardiac events and heart failure hospitalizations (hazard ratio, 1.80 [95% CI, 1.56-2.07], P<0.001 and hazard ratio, 2.08 [95% CI, 1.76-2.47], P<0.001, respectively). Of note, patients in quartiles 2 and 3 also had increased risk of cardiovascular events compared with quartile 4 (multivariable P<0.05 for all).

CONCLUSIONS

Compared with the highest PAPi quartile, patients in PAPi quartiles 1 to 3 had a greater risk of all-cause mortality, major adverse cardiac events, and heart failure hospitalizations, with greatest risk observed in the lowest quartile. A low PAPi, even at values higher than previously reported, may serve an important role in identifying high-risk individuals across a broad spectrum of cardiovascular disease.