Association of Mild Echocardiographic Pulmonary Hypertension With Mortality and Right Ventricular Function

Key PointsQuestionDo patients with mild echocardiographic pulmonary hypertension have worse right ventricular function and mortality than patients with pulmonary pressures in the normal range? FindingsIn this cohort study of 47784 patients, those with mild echocardiographic pulmonary hypertension (right ventricular systolic pressure of 33 to 39 mm Hg) had higher mortality, reduced right ventricular function, and impaired right ventricular-pulmonary arterial coupling compared with patients with right ventricular systolic pressure less than 33 mm Hg. MeaningIn a clinical referral population, mildly elevated pulmonary pressures were associated with adverse right ventricular compensation and increased adjusted mortality. This cohort study evaluates if mild echocardiographic pulmonary hypertension is associated with reduced right ventricular function and increased risk of mortality. ImportanceCurrent guidelines recommend evaluation for echocardiographically estimated right ventricular systolic pressure (RVSP) greater than 40 mm Hg; however, this threshold does not capture all patients at risk. ObjectivesTo determine if mild echocardiographic pulmonary hypertension (ePH) is associated with reduced right ventricular (RV) function and increased risk of mortality. Design, Setting, and ParticipantsIn this cohort study, electronic health record data of patients who were referred for echocardiography at Vanderbilt University Medical Center, Nashville, Tennessee, from March 1997 to February 2014 and had recorded estimates of RVSP values were studied. Data were analyzed from February 2017 to May 2019. ExposuresMild ePH was defined as an RVSP value of 33 to 39 mm Hg. Right ventricular function was assessed using tricuspid annular plane systolic excursion (TAPSE), and RV-pulmonary arterial coupling was measured using the ratio of TAPSE to RVSP. Main Outcomes and MeasuresAssociations of mild ePH with mortality adjusted for relevant covariates were examined using Cox proportional hazard models with restricted cubic splines. ResultsOf the 47784 included patients, 26758 of 47771 (56.0%) were female and 6040 of 44763 (13.5%) were black, and the mean (SD) age was 59 (18) years. Patients with mild ePH had worse RV function compared with those with no ePH (mean [SD] TAPSE, 2.0 [0.6] cm vs 2.2 [0.5] cm; P<.001) and nearly double the prevalence of RV dysfunction (32.6% [92 of 282] vs 16.7% [170 of 1015]; P<.001). Compared with patients with RVSP less than 33 mm Hg, those with mild ePH also had reduced RV-pulmonary arterial coupling (mean [SD] ratio of TAPSE to RVSP, 0.55 [0.18] mm/mm Hg vs 0.93 [0.39] mm/mm Hg; P<.001). An increase in adjusted mortality began at an RVSP value of 27 mm Hg (hazard ratio, 1.32; 95% CI, 1.02-1.70). Female sex was associated with increased mortality risk at any given RVSP value. Conclusions and RelevanceMild ePH was associated with RV dysfunction and worse RV-pulmonary arterial coupling in a clinical population seeking care. Future studies are needed to identify patients with mild ePH who are susceptible to adverse outcomes.