Incidence of Pulmonary Hypertension in the Echocardiography Referral Population.

Rationale: Incidence rates for pulmonary hypertension using diagnostic data in patients with cardiopulmonary disease are not known.

Objectives: To determine incidence rates of, risk factors for, and mortality hazard associated with pulmonary hypertension among patients referred for transthoracic echocardiography.

Methods: Retrospective cohort study using data from the Veterans Health Administration (1999-2020) and Vanderbilt University Medical Center (1994-2020). Pulmonary hypertension was defined as pulmonary artery systolic pressure >35mmHg with prevalent cases excluded. Heart failure and chronic obstructive pulmonary disease were the primary exposures of interest. The primary outcome was incident pulmonary hypertension. Secondarily, we examined mortality rate following incident diagnosis.

Measurements and main results: We identified 245,067 VA patients (94% male, 20% Black) and 117,526 Vanderbilt patients (46% male, 11% Black) without pulmonary hypertension, of whom 38,882 VA patients and 8,061 Vanderbilt patients developed pulmonary hypertension. Only 18-19% of patients with echo-based pulmonary hypertension also had a diagnostic code. Hazard of pulmonary hypertension was 4-fold higher in patients with heart failure and chronic obstructive pulmonary disease compared to patients without either. Mortality rates increased from pulmonary artery systolic pressure of 35mmHg to 45mmHg then plateaued. Independent risk factors for incident pulmonary hypertension included older age, male sex, black race, and cardiometabolic comorbidities.

Conclusions: Pulmonary hypertension incidence rates estimated by diagnostic data are higher than code-based rates. Heart failure and chronic obstructive pulmonary disease strongly associate with incident pulmonary hypertension. Pulmonary artery systolic pressure >45mmHg at diagnosis is associated with high mortality. New pulmonary hypertension on echocardiography is an important prognostic sign.