Long-term response to calcium channel blockers in idiopathic pulmonary arterial hypertension.
BACKGROUND
Characteristics of patients with idiopathic pulmonary arterial hypertension (IPAH) who benefit from long-term calcium channel blockers (CCB) are unknown.


RESULTS
Acute pulmonary vasodilator testing with epoprostenol or nitric oxide was performed in 557 IPAH patients. Acute responders, defined by a fall in both mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) >20%, received long-term oral CCB. Patients who benefit from long-term CCB were defined as those being in New York Heart Association (NYHA) functional class I or II after at least 1 year on CCB monotherapy. Among the 70 patients who displayed acute pulmonary vasoreactivity (12.6%; 95% CI, 9.8% to 15.3%) and received CCB therapy, only 38 showed long-term improvement (6.8%; 95% CI, 4.7% to 8.9%). Long-term CCB responders had less severe disease at baseline than patients who failed. During acute vasodilator testing, long-term CCB responders displayed a more pronounced fall in mean PAP (-39+/-11% versus -26+/-7%; P<0.0001), reaching an absolute value of mean PAP lower than that measured in patients who failed (33+/-8 versus 46+/-10 mm Hg; P<0.0001). After 7.0+/-4.1 years, all but 1 long-term CCB responders were alive in NYHA class I or II, with a sustained hemodynamic improvement. In the group of patients who failed on CCB, the 5-year survival rate was 48%.


CONCLUSIONS
Long-term CCB responders represent <10% of IPAH patients evaluated in a pulmonary vascular referral center. During acute vasodilator testing, these patients showed significantly lower levels of both mean PAP and PVR, which reached near-normal values.
Sitbon
Olivier
O
Centre des Maladies Vasculaires Pulmonaires, UPRES EA 2705, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine Béclère, AP-HP, Université Paris-Sud, Clamart, France. olivier.sitbon@abc.aphp.fr
Humbert
Marc
M
Jaïs
Xavier
X
Ioos
Vincent
V
Hamid
Abdul M
AM
Provencher
Steeve
S
Garcia
Gilles
G
Parent
Florence
F
Hervé
Philippe
P
Simonneau
Gérald
G
D000328:Adult; D002121:Calcium Channel Blockers / Q000494:pharmacology* / Q000627:therapeutic use; D004341:Drug Evaluation; D011464:Epoprostenol; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide; D011651:Pulmonary Artery / Q000503:physiopathology; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents
D002121:Calcium Channel Blockers; D014665:Vasodilator Agents; D009569:Nitric Oxide; D011464:Epoprostenol