Background: Pulmonary hypertension (PH) with pulmonary vascular resistance (PVR) 320-480 ARU resistant to therapy is a contraindication for orthotopic heart transplantation (HTX).
Aim of the study: evaluation of pulmonary hypertension in candidates for heart transplantation.
Study population and methods: 44 patients (pts) with dilated cardiomyopathy (Group I) and 34 patients with ischemic heart disease (Group II) were assessed. Evaluation of PH was done according to the following protocol: 1st measurement (cardiac catheterization): PVR (pulmonary vascular resistance) > or = 320 ARU--infusion of NTG (nitroglycerine) 1 microg/kg/min. (during 10 min.), 2nd measurement: PVR > or = 320 ARU--infusion of NTG 2 microg/kg/min. (during 10 min.), 3rd measurement: final PVR evaluation. If PVR was less than 320 ARU in 2nd or 3rd measurement, the reversibility of PH was diagnosed, and when PVR > or = 320 ARU was observed in 3rd measurement, fixed PH was diagnosed.
Results: No significant difference in baseline PVR between the groups was observed (Group I--332,7 ARU and Group II--327.6 ARU). In 23 patients with PVR > or = 320 ARU reduction of mean values of PVR, MPAP (mean pulmonary artery pressure) and TPG (transpulmonary gradient) was seen (p < 0.001), significantly more prominent in 11 pts from Group I. There was no correlation between duration of the disease and degree of PH. HTX was performed in 25 patients. PVR at 72 hours after HTX was similar in 7 pts with reversible PH and 18 pts with PVR < 320 ARU in 1st measurement.
Conclusions: 1. Nitroglycerine used according to the protocol is sufficient in determining PH. 2. The reversibility of PH could depend on type of cardiomyopathy but not directly on symptom duration.