Diastolic Pulmonary Gradient Does Not Predict Survival in Pulmonary Hypertension | Journal Scan

Study Questions:

How does the diastolic pressure gradient (DPG = dPA-PCW) compare with the transpulmonary gradient (TPG = mPA-PCW) and the pulmonary vascular resistance (PVR = TPG/CO) for predicting survival in patients with pulmonary hypertension (PH) due to left heart disease (PH-LHD)?

Methods:

A retrospective cohort of 1,174 patients evaluated for unexplained cardiomyopathy (CM) at The Johns Hopkins Hospital was studied. Each of them had a complete right heart catheterization and were followed until death, cardiac transplantation, or the end of the study period (mean time 4.4 years). The relationships between DPG, TPG, or PVR and survival in subjects with PH-LHD (n = 469) were evaluated with Cox proportional hazards regression and Kaplan-Meier analyses.

Results:

Of the 1,174 patients, about 50% had an elevated PCW >15 mm Hg, 40% had PH defined as an mPA ≥25 mm Hg, and 13% of those with PH had a DPG ≥7, which is often used as a measure of precapillary PH. Mean age in the group with PH was 49 years, body mass index (BMI) was about 27 kg/m2, and 44% were “idiopathic” and 34% were “other CMs.” DPG was not significantly associated with mortality (hazard ratio [HR], 1.02; p = 0.10) in PH-LHD, whereas elevated TPG and PVR adjusted for age, gender, race, and BMI predicted death (per unit increase HR, 1.02; p = 0.046; and HR, 1.11; p = 0.002, respectively). Similarly, DPG did not differentiate survivors from nonsurvivors at any selected cut points including a DPG of 7 mm Hg.

Conclusions:

In this retrospective study of patients with CM and PH-LHD, an elevated DPG was not associated with worse survival.

Perspective:

The debate about the utility of the DPG versus the TPG and PVR for predicting outcome in a large cohort of middle-aged persons with CMs appears to be settled. However, the recommendation to use the DPG rather than the TPG has been promoted primarily by PH experts to help define the degree to which patients with heart failure with preserved ejection fraction, hypertrophic CM, and valvular heart disease have precapillary PH that might preclude successful surgery or be amenable to novel pulmonary arterial hypertension–specific therapies.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Pulmonary Hypertension and Venous Thromboembolism, Valvular Heart Disease, Acute Heart Failure, Chronic Heart Failure, Pulmonary Hypertension, Hypertension

Keywords: Blood Pressure, Hypertension, Hypertension, Pulmonary, Cardiac Catheterization, Vascular Resistance, Heart Failure, Heart Valve Diseases, Cardiomyopathies, Heart Failure, Diastolic, Retrospective Studies, Survivors


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