{
  "abstract": "Introduction Mavacamten, a first-in-class cardiac myosin inhibitor, received NICE approval in September 2023 for adults with symptomatic obstructive HCM (oHCM). Clinical studies have shown mavacamten reduces left ventricular outflow tract (LVOT) gradient, improves New York Heart Association (NYHA) functional class, and lowers biomarkers such as NT-proBNP. As we explore real-world effectiveness, accessible tools like the six-minute walk test (6MWT) may offer practical insights into treatment response. This study evaluated changes in 6MWT distance alongside established clinical outcomes following mavacamten initiation.Methods All patients commencing Mavacamten therapy between May and August 2024 at Belfast Inherited Cardiac Services Centre were included. Baseline assessments included echocardiography, biomarkers, Kansas City Cardiomyopathy Questionnaire (KCCQ), and 6MWT and assessments then repeated after 16 weeks continuous therapy. Paired Student’s t-tests were used for comparison of continuous variables. Analyses were performed using SPSS.Results Among the ten patients initiated on Mavacamten therapy; 30% were female, median age 55 years (± 15), and 60% NYHA class III. At baseline, mean peak LVOT gradient was 133 mmHg (± 50.7mmHg), NT-proBNP mean was 1951 pg/mL (range 62–5571 pg/mL), and mean KCCQ score was 38. After 16 weeks, peak LVOT gradient mean reduction was 103 mmHg (95% CI: 70–136; p < 0.0001). NT-proBNP decreased by 1596 pg/mL (95% CI: 244–2948; p = 0.03), and KCCQ improved by 22.3 (95% CI: 1.7–43.0; p = 0.04). Notably, 6MWT distance increased with a mean gain of 93m (95% CI: 21–164m; p = 0.016), figure 1.Conclusion These findings support the early real-world effectiveness and safety of mavacamten in oHCM, showing improvements in haemodynamics, biomarkers, and QoL metrics. The significant increase in 6MWT distance highlights its potential utility as an accessible and objective measure of functional response to therapy. Further real-world studies are required to optimise delivery and deepen our understanding of mavacamten.Abstract 1 Figure 1Bar graphs showing paired student t-test results at baseline (week 0) and following 16 weeks treatment with mavacamten therapy in patients with symptomatic obstructive hypertrophic cardiomyopathy (A) 6-minute walk test with significant improvement in distance travelled (p= 0.02) (B) significant reduction in cardiac biomarker NT-pro",
  "authors": [
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "M Todd"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "A Muir"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "K Linden"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "D McCall"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "J McOsker"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "T Jardine"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "H Connolly"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "A Devlin"
    },
    {
      "affiliations": [
        "Belfast City Hospital, Belfast, UK"
      ],
      "name": "P Savage"
    }
  ],
  "title": "1 Evaluating real-world effectiveness of mavacamten in hypertrophic cardiomyopathy using accessible functional testing",
  "uid": "ca473c63-0e82-5b9b-827a-f5c8c445f308"
}