Pulmonary pressures and death in heart failure: a community study

Abstract

Objectives: The purpose of this study was to determine among community patients with heart failure (HF) whether pulmonary artery systolic pressure (PASP) assessed by Doppler echocardiography was associated with death and improved risk prediction over established factors, using the integrated discrimination improvement and net reclassification improvement.

Background: Although several studies have focused on idiopathic pulmonary arterial hypertension, less is known about pulmonary hypertension among patients with HF, particularly about its prognostic value in the community.

Methods: Between 2003 and 2010, Olmsted County residents with HF prospectively underwent assessment of ejection fraction, diastolic function, and PASP by Doppler echocardiography.

Results: PASP was recorded in 1,049 of 1,153 patients (mean age 76 ± 13; 51% women). Median PASP was 48 mm Hg (25th to 75th percentile: 37.0 to 58.0). There were 489 deaths after a follow-up of 2.7 ± 1.9 years. There was a strong positive graded association between PASP and mortality. Increasing PASP was associated with an increased risk of death (hazard ratio [HR]: 1.45, 95% confidence interval [CI]: 1.13 to 1.85 for tertile 2; HR: 2.07, 95% CI: 1.62 to 2.64 for tertile 3 vs. tertile 1), independently of age, sex, comorbidities, ejection fraction, and diastolic function. Adding PASP to models including these clinical characteristics resulted in an increase in the c-statistic from 0.704 to 0.742 (p = 0.007), an integrated discrimination improvement gain of 4.2% (p < 0.001), and a net reclassification improvement of 14.1% (p = 0.002), indicating that PASP improved prediction of death over traditional prognostic factors. All results were similar for cardiovascular death.

Conclusions: Among community patients with HF, PASP strongly predicts death and provides incremental and clinically relevant prognostic information independently of known predictors of outcomes.

Figure 1. Overall survival by PASP tertiles among HF patients

Overall survival by pulmonary artery systolic pressure (PASP) tertiles among heart failure (HF) patients. N=1049. p<0.001.

Figure 2. The association between PASP tertiles and all-cause mortality

The unadjusted and adjusted hazard ratios for risk of all-cause mortality using Cox proportional hazards regression. Adjusted*=adjusted for age and sex; Adjusted**=adjusted for age, sex incident HF status, comorbidity index, anemia, ejection fraction (EF), diastolic function and chronic obstructive pulmonary disease (COPD). Other abbreviations as in Figure 1.

Figure 3. Survival from CV death by PASP tertiles among HF patients

Survival from cardiovascular (CV) death by PASP tertiles among HF patients. N=975. p<0.001. Other abbreviations as in Figure 1.

Figure 4. The association between PASP tertiles and CV mortality

The unadjusted and adjusted hazard ratios for risk of CV mortality using Cox proportional hazards regression. Adjusted*=adjusted for age and sex; Adjusted**=adjusted for age, sex incident HF status, comorbidity index, anemia, EF, diastolic function and COPD. Other abbreviations as in Figures 1, 2 and 3.