Prognostic significance of repeated brain natriuretic peptide measurements after percutaneous transluminal septal myocardial ablation in patients with drug-refractory hypertrophic obstructive cardiomyopathy

OBJECTIVES: To evaluate whether repeated brain natriuretic peptide (BNP) measurements after percutaneous transluminal septal myocardial ablation (PTSMA) provide prognostic information regarding the response to PTSMA in patients with drug-refractory hypertrophic obstructive cardiomyopathy (HOCM). BACKGROUND: Plasma BNP levels are associated with clinical outcomes in patients with HOCM. However, the prognostic value of plasma BNP level changes before and after PTSMA remains unclear. METHODS: We measured the plasma BNP levels serially before and after PTSMA, and evaluated the relationship between the changes in plasma BNP levels and clinical improvement in 47 patients. The patients were assigned to two groups based on the reduction in the New York Heart Association class ≥1 (good responder) or <1 (poor responder) before and after PTSMA. The Kansas City Cardiomyopathy Questionnaire (KCCQ) was used to measure health status. RESULTS: The plasma BNP levels gradually decreased after PTSMA, although the levels plateaued 3 months until 12 months after PTSMA. Although the plasma BNP levels and resting left ventricular outflow tract peak pressure gradient before PTSMA were comparable between the groups, the ratio of the BNP levels before and after PTSMA in the good responder group was significantly lower than that in the poor responder group (0.43 (range, 0.24–0.68) vs 0.78 (range, 0.62–0.93), p=0.002). The KCCQ score changes in the good responder group were significantly higher than those in the poor responder group. CONCLUSIONS: The plasma BNP level ratio was associated with long-term clinical improvement of heart failure after PTSMA for drug-refractory HOCM.