Right Ventricular Volume Predicts Changes in Clinically-Stable PAH
Although right heart catheterization is an invasive procedure, it can detect changes in right ventricular volume that predict clinical worsening of pulmonary arterial hypertension. A study from the Department of Pulmonary Diseases at VU University Medical Center in Amsterdam, “Signs of Right Ventricular Deterioration in Clinically Stable Patients with Pulmonary Arterial Hypertension,” showed that even patients with unchanged pulmonary arterial hypertension are at risk for disease progression, but these risks can be foreseen by clinical testing.
During the study, the authors followed 22 patients with clinically stable idiopathic pulmonary arterial hypertension. All had stable or improving NYHA-class II-III pulmonary arterial hypertension and showed improvements during five years of follow-ups following initial diagnosis. Baseline right heart catheterization and cardiac MRIs were taken for each patient.
Over time, 10 of the 22 patients showed late-stage clinical progression that led to lung transplantation or death after a follow-up time of eight years. During these eight years, right heart catheterization and cardiac MRIs were repeated after 1.5, 3.5, and 6.5 years; for patients who were still alive, the two procedures were also conducted 10 years after baseline.
Although hemodynamic parameters were similar between the two groups at baseline and throughout the entire follow-up period, right ventricular volumes began to differ. For the late-progressive patients, baseline right ventricular end-systolic volume (RVESV) was higher and right ventricular ejection fraction (RVEF) was lower than those of stable patients. During the study, late-progressive patients’ volumes became more exaggerated, with RVESV and right ventricular diastolic volume (RVEDV) increasing and RVEF decreasing. The same was not true for the stable patients, whose volumes remained unchanged.
“Our results implicate that monitoring of right ventricular volumes allows the anticipation to clinical worsening, even at the time of apparent clinical stability,” noted the authors in the abstract of the study. If a patient shows signs of irregular right ventricular volumes, his or her clinician may be alerted to possible changes in disease stability in the future and be able to recommend interventions to prevent disease worsening for the patient with apparently stable pulmonary arterial hypertension.