Determinants and prognostic value of pulmonary arterial pressure in patients with chronic heart failure

Abstract

The epidemiology of pulmonary arterial hypertension (PAH) in patients with heart failure (HF) is poorly described. Our aim was to investigate the determinants and prognostic significance of PAH in a large representative outpatient population with HF. Routine measurement of right ventricular tricuspid pressure gradient (RVTG) was attempted among unselected, consecutive referrals to an HF clinic. The diagnosis of HF was based on symptoms, signs, echocardiography, and N-terminal pro-brain natriuretic peptide (NT-proBNP). Of 2100 patients referred, 1380 were diagnosed as HF, of whom 1026 had left ventricular systolic dysfunction (LVSD) and 354 did not. Right ventricular tricuspid pressure gradient could be measured in 270 (26%) patients with and 143 (40%) without LVSD. The highest RVTG quartile [RVTG > 35 mmHg equivalent to an estimated PA systolic pressure (PASP) > 45 mmHg] constituted 7% of all those with HF and was associated with higher LV filling pressures, LV end-diastolic volume, LVSD, and more severe mitral regurgitation (MR). During a median (inter-quartile range) follow-up of 66 (56–74) months, mortality was 40.3%. Mortality was similar in the lowest quartile of RVTG and in those in whom RVTG could not be measured and rose with increasing RVTG quartile (log-rank: 26.9; P < 0.0001). The highest RVTG quartile, age, blood pressure, and log NT-proBNP independently predicted mortality. Right ventricular tricuspid pressure gradient >35 mmHg had a 96% specificity to discriminate between those with and without HF in patients without LVSD. Using a definition of PASP > 45 mmHg, 7% of the patients with HF have PAH, which is associated with worse LV function, MR, and prognosis. Whether PAH is a target for therapy in this population remains to be elucidated.