Pulmonary Hypertension Due to Left Heart Disease: an Update.

PURPOSE OF REVIEW: Pulmonary hypertension (PH) frequently complicates heart failure and portends a worse prognosis. This review will summarize and discuss recent updates in the classification and management of patients with PH due to left heart disease. RECENT FINDINGS: Careful hemodynamic assessment is critical to the classification of patients with PH and heart failure. Two hemodynamic subgroups of PH in heart failure patients have been described: isolated post-capillary pulmonary hypertension and combined post- and precapillary pulmonary hypertension. The cornerstone in management of PH due to left heart disease is the treatment of the underlying left heart pathology; however, ongoing trials have been designed to test pulmonary vasodilators in this cohort. PH-specific therapies have not demonstrated a benefit in patients with pulmonary hypertension due to left heart disease. Understanding the distinct pathobiology of each hemodynamic subgroup may lead to the development of useful biomarkers and effective targeted therapies.

Left Ventricular Assist Devices in Pulmonary Hypertension Group 2 With Significantly Elevated Pulmonary Vascular Resistance: A Bridge to Cure.

BACKGROUND: Pulmonary hypertension secondary to left heart disease (WHO Group 2) is a known risk factor in patients with heart failure. The favourable effect of left ventricular assist devices (LVAD) on pulmonary hypertension has been demonstrated before, although this effect has not been well-studied in advanced pulmonary arterial bed disease with a significant elevation in pulmonary vascular resistance. METHODS: We reviewed the records of 258 LVAD patients in our institution. Patients with elevated mean pulmonary artery pressure (mPAP>25mmHg) and elevated pulmonary vascular resistance (PVR ≥3 Wood units) were included in the study. Patients were divided into two groups based on their baseline PVR (PVR=3-5 Wood units (WU) vs. PVR>5WU). The groups were studied for the changes in their pulmonary haemodynamics after the placement of LVAD. RESULTS: Fifty-one (51) patients were included in the study. All patients showed a significant improvement in their pulmonary haemodynamic parameters post LVAD placement. In the group with the higher PVR, mPAP dropped from a baseline of 43±7mmHg to 22±6mmHg post LVAD placement (p<0.001), while PVR dropped from 6.3±1.2 Wood units to 2.2±1.1 Wood units (p<0.001). In a subgroup of patients who underwent cardiac transplantation post LVAD (n=14), all patients maintained a normalised PVR (<3WU) one year post cardiac transplantation. CONCLUSIONS: Left ventricular assist devices can reverse pulmonary hypertension WHO Group 2 with significantly elevated PVR; this effect is not dependent on the baseline PVR, and is maintained up to one year post cardiac transplantation.

Pulmonary Hypertension Due to Left Ventricular Cardiomyopathy: Is it the Result or Cause of Disease Progression?

PURPOSE OF REVIEW: The purpose of this review is to define pulmonary hypertension in the setting of left heart disease (PH-LHD), discuss its epidemiology and pathophysiology, and highlight the cause and effect relationship it has with disease progression in the setting of cardiomyopathy. RECENT FINDINGS: Both pulmonary hypertension (PH) and heart failure are becoming increasingly common. As such, PH-LHD is now the most common form of PH. The pathophysiology of the condition relates to backward transmission of elevated left ventricular filling pressures into the pulmonary circulation and, ultimately, right ventricular (RV) strain/dysfunction. It is evident that these pathophysiologic processes are both the effect and cause of left heart disease progression. In this review, we describe the complex relationship between disease progression in left ventricular cardiomyopathy and PH-LHD. Clinicians and researchers should take note of the importance of PH-LHD and RV dysfunction to appropriately risk stratify patients and develop therapies for the condition.