For patients with severe aortic stenosis, the left ventricular unloading provided by transcatheter aortic valve replacement (TAVR) was shown to also improve right ventricular function and right ventricular-pulmonary artery coupling, according to a study published in JACC Cardiovascular Interventions.
The aim of this prospective, single-center study was to assess whether the unloading effects of TAVR on the left ventricle would also improve right ventricular function and right ventricular-pulmonary artery coupling in patients with severe aortic stenosis. The study sample (n=44) included patients scheduled for percutaneous transfemoral TAVR who were 40 years of age or older and had a diagnosis of severe aortic stenosis. Invasive hemodynamic evaluation and assessment of vascular and ventricular function with simultaneous echocardiography, as well as clinical assessments, were performed for all patients both before and immediately after the procedure.
The invasive hemodynamic assessments included left ventricle end-systolic pressure, aortic valve assessments, cardiac output, and stroke volume. Invasive vascular assessments included transpulmonary gradient, pulmonary vascular resistance, pulmonary arterial elastance, total pulmonary resistance, ventricle stroke work, precapillary pulmonary hypertension, postcapillary pulmonary hypertension, and systemic vascular resistance. Clinical assessments included frailty evaluations, New York Heart Association functional class assessments, plasma N-terminal pro–B-type natriuretic peptide evaluations, and follow-up echocardiograms.
The mean age of the patients was 80.7 years old, and the mean body mass index was 30.2 kg/m². Exactly 30% of patients were women. At baseline, pulmonary hypertension was present in 61% of the patients, abnormal right ventricular function was present in 50% of the patients. Overall, aortic valve area was severely reduced (mean 0.8 cm²), pulmonary vascular resistance was mildly elevated (mean 222 dynes s/cm⁵), pulmonary arterial compliance was reduced (mean 3.4 ml/mm Hg), and pulmonary arterial elastance was increased (mean 0.63 mm Hg/ml).
After TAVR, significant increases were observed in aortic valve area (P <.001), cardiac index (P =.03), aortic systolic pressure (P =.007), and aortic pulse pressure (P <.001), with significant decreases in aortic valve resistance (P <.001), systolic ejection period (P <.001), circumferential end-systolic wall stress (P <.001), and valvuloarterial impedance (P <.001). Left ventricular unloading was associated with left ventricular ejection fraction and global longitudinal strain improvements (P =.02), and left ventricular stroke work reduction (P <.001).
Right ventricular function improved through an increase in right ventricular stroke work (P =.04) and a 10% increase in tricuspid lateral annular systolic velocity (P =.01). Of the patients with right ventricular dysfunction (n=22), 18% experienced acute normalization of right ventricular function. Of the patients with improved pulmonary artery compliance (n=24), greater improvements were found in pulmonary capillary wedge pressure (P =.07), mean pulmonary artery pressure (P =.001), and pulmonary vascular resistance (P =.01) than in patients without improved pulmonary artery compliance.
There was no mortality in patient sample at 30-day follow up, 5 patients required a permanent pacemaker, and improvements were noted in the New York Heart Association functional class (P <.001) and N-terminal pro–B-type natriuretic peptide (P =.03).
Limitations of this study included the potential confounders of sedatives used during the TAVR procedure, the prone position of the patient during the transthoracic echocardiogram, and the use of only tricuspid lateral annular systolic velocity to assess right ventricular function. Additionally, the study only included short-term follow-up, which did not allow assessment of long-term improvements.
The researchers concluded that “[left ventricular] unloading with TAVR is associated with acute improvements in [right ventricular] function and [right ventricular-pulmonary artery] coupling. Patients demonstrating acute increases in [pulmonary artery compliance] with TAVR experience the greatest improvements in cardiac ejection and intracardiac filling pressures.”
Disclosure: Charanjit S. Rihal, MD, has served as a consultant and done research with Edwards Lifesciences.
Eleid MF, Padang R, Pislaru SV, et al. Effect of transcatheter aortic valve replacement on right ventricular-pulmonary artery coupling. JACC Cardiovasc Interv. 2019;12(21):2145-2154.