Abstract
Background: Bone morphogenetic protein receptor type 2 (BMPR2) mutations occur in idiopathic and familial pulmonary arterial hypertension (IPAH, FPAH); however, the impact of these mutations on clinical assessment and,disease severity remains unclear. We investigated the role of BMPR2 mutations on acute vasoreactivity and disease severity in IPAH/FPAH children and adults.
Methods: BMPR2 mutation types were determined in 147 IPAH/FPAH patients. Hemodynamics were obtained at baseline and with acute vasodilator testing.
Results: Of 147 patients (69 adults, 78 children; 114 with IPAH, 33 with FPAH), 124 (84%) were BMPR2 mutation-negative, and 23 (16%) were mutation-positive. BMPR2 mutation-positive patients were less likely to respond to acute vasodilator testing than mutation-negative patients (4% vs 33%; p < 0.003; n = 147). BMPR2 mutation-positive children also appeared less likely to respond to acute vasodilator testing than mutation-negative children. BMPR2-positive patients had lower mixed venous saturation (57 +/- 9% vs 62 +/- 10%; p < 0.05) and cardiac index (CI; 2.0 +/- 1.1 vs 2.4 +/- 1.5 liters/min; p < 0.05) than BMPR2-negative patients.
Conclusions: Patients with BMPR2 mutations are less likely to respond to acute vasodilator testing than mutation-negative patients and appear to have more severe disease at diagnosis. Determination of BMPR2 mutations appears to help identify IPAH/FPAH children and adults who are unlikely to respond to acute vasodilator testing and, thus, unlikely to benefit from calcium channel blockade (CCB) treatment.