Chronic sildenafil lowers transpulmonary gradient and improves cardiac output allowing successful heart transplantation.
BACKGROUND
For patients undergoing heart transplantation, an elevated pulmonary vascular resistance (PVR) increases mortality in the early post-heart transplant period. This study aimed to assess the effects of chronic sildenafil administration on the PVR, transpulmonary gradient (TPG), and cardiac output (CO) in patients with heart failure awaiting heart transplantation.


METHODS
The data from serial right heart catheterizations (RHC) of six patients were analyzed. All patients demonstrated a reaction to the vasodilators glyceryl trinitrate or inhaled iloprost at initial RHC before commencing sildenafil. A follow-up RHC was performed as required to guide management.


RESULTS
The average total daily dose of sildenafil was 100 mg for a period of 68+/-58 days (4-145). The average TPG at baseline was 23.7 mmHg and fell in 4 of the 6 patients (67%) with an average reduction of 4.5+/-7.3 mmHg (-5 to 14). The average PVR at baseline was 571 dyn s cm(-5) and fell in 5 of 6 patients (83%), with an average reduction of 167+/-266 dyn s cm(-5) (74-518). The CO at baseline was 3.95 L/min and rose in 5 of 6 patients (83%) with an average improvement of 0.58 L/min (-1.1 to 1.3). The mean pulmonary capillary wedge pressure (MPCWP) at baseline was 26.3 mmHg and fell in 5 of 6 patients (83%) with an average fall of 5.5 mmHg (-1 to 17). Four of the six patients achieved a final TPG<15 mmHg, which we consider to be acceptable for orthotopic heart transplantation, average 11 mmHg (8 to 13). Three of these patients have already undergone successful, uncomplicated heart transplantation.


CONCLUSIONS
Chronic sildenafil use is safe and effective in reducing an elevated TPG and PVR in patients with heart failure requiring heart transplantation and allows patients to be transplanted who may otherwise have been excluded because of pulmonary hypertension.
Jabbour
Andrew
A
Heart Transplant Unit, St Vincent's Hospital, Sydney, New South Wales, Australia. jabbourandrew@hotmail.com <jabbourandrew@hotmail.com>
Keogh
Anne
A
Hayward
Christopher
C
Macdonald
Peter
P
D000328:Adult; D006328:Cardiac Catheterization; D002302:Cardiac Output / Q000187:drug effects* / Q000502:physiology; D009202:Cardiomyopathies / Q000503:physiopathology / Q000601:surgery*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000601:surgery*; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D010879:Piperazines / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000503:physiopathology; D011379:Prognosis; D011669:Pulmonary Wedge Pressure / Q000187:drug effects* / Q000502:physiology; D011687:Purines / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000627:therapeutic use*; D014655:Vascular Resistance / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000627:therapeutic use*; D014850:Waiting Lists
D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate