Pulmonary vascular remodeling in pulmonary hypertension due to chronic heart failure

Pulmonary hypertension (PHT) associated with chronic heart failure (CHF) is a risk factor of right ventricular failure after heart transplantation (HT). Our aim was to study pulmonary vascular changes in patients with CHF and to assess any correlation with haemodynamic data.

We studied 17 HT recipients with preoperative CHF who died shortly after HT. Preoperative haemodynamic information was obtained immediately before HT. Vascular lesions in muscular arteries were assessed by linear morphometry. Haemodynamic data were correlated with the morphologic changes.

Mean transpulmonary gradient (TPG) was 8.9+/-4.5 mm Hg and pulmonary vascular resistance (PVR) was 2.25+/-1.34 Wu. According to the threshold for at-risk PHT (TPG>12 mm Hg or PVR>2.5 Wu), six patients had at-risk PHT. Medial thickness was 23.82+/-7.23% in patients with at-risk PHT and 17.16+/-3.24% in patients without at-risk PHT (p=0.018).

Medial hypertrophy of muscular pulmonary arteries is more common and severe than expected in patients with CHF, even in patients without at-risk PHT. This structural change could explain why PHT, even in range of values not excluding HT, is a risk factor for right ventricular failure after HT and influences post-HT haemodynamic behaviour.