Pathophysiology and Diagnosis of Pulmonary Hypertension Due to Left Heart Disease

Abstract

Pulmonary hypertension due to left heart disease (PH-LHD) is the most common type of pulmonary hypertension, although an accurate prevalence is challenging. PH-LHD includes PH due to systolic or diastolic left ventricular dysfunction, mitral or aortic valve disease and congenital left heart disease. In recent years a new and distinct phenotype of “combined post-capillary and pre-capillary PH,” based on diastolic pulmonary gradient and pulmonary vascular resistance, has been recognized. The roles of right ventricular dysfunction and pulmonary vascular compliance in PH-LHD have also been elucidated recently and they appear to have significant clinical implications. Echocardiography continues to play a seminal role in diagnosis of PH-LHD and heart failure with preserved LV ejection fraction, as it can identify valve disease and help to distinguish PH-LHD from pre-capillary PH. Right, and occasionally left heart catheterization, remains the gold-standard for diagnosis and phenotyping of PH-LHD, although Cardiac Magnetic Resonance Imaging is emerging as a useful alternative tool in non-invasive diagnostic and prognostic assessment of PH-LHD. In this review, the latest evidence for more recent advances will be discussed, including the role of fluid challenge and exercise during cardiac catheterization to unravel occult post-capillary and the role of vasoreactivity testing. The use of many or all of these diagnostic techniques will undoubtedly provide key information about sub-groups of patients with PH-LHD that might benefit from medical therapy previously considered to be only suitable for pulmonary arterial hypertension.

Circulating Relaxin-1 Level Is a Surrogate Marker of Myocardial Fibrosis in HFrEF

“…Interestingly, average values of pulmonary arterial pressures and pulmonary vascular resistance were increased, referring to chronic pathological remodeling in the pulmonary arterial vasculature, which is common in HFrEF. According the definition of pre-, post-capillary and combined pulmonary arterial hypertension most of our patients had combined pulmonary hypertension (pulmonary capillary wedge pressure: 21.76 ± 7.15 mmHg, Wood units: 2.69 ± 1.8, diastolic pulmonary arterial pressure: 20.65 ± 6.5 mmHg) in keeping with the long-standing LV dysfunction, maximal compensatory mechanisms and end-stage HF (Charalampopoulos et al, 2018).…”

Effects of Sacubitril/Valsartan on the Right Ventricular Arterial Coupling in Patients with Heart Failure with Reduced Ejection Fraction

“…In patients with HFrEF, an increase in the left atrial (LA) pressure and a reduction in LA compliance [ 17 , 18 ] leads to LA remodelling (increase in LA size, impaired LA contractility, and interstitial fibrosis), resulting in an increase in LA stiffness, which is a major determinant of pulmonary hypertension [ 19 ]. In fact, an increase in the LAVI and left atrial pressure ensures that LA no longer acts as a barrier between the high left ventricular pressure and the pulmonary vessels, thus resulting in a passive transmission of the left ventricular pressure into the pulmonary vascular tree [ 20 ].…”

Myocardial proteomic profile in pulmonary arterial hypertension

“…Although advances in the understanding of the pathobiology of PAH have been seen in recent years, molecular processes underlying heart remodeling over the course of PAH are still insufficiently understood 8 , 9 . In particular, there is still incomplete knowledge regarding the mechanisms of LV mass loss and dysfunction, which was completely avoided by researchers until recently 10 , 11 .…”