The relationship between symptom burden and myocardial fibrosis in patients with hypertrophic cardiomyopathy

Abstract Background In hypertrophic cardiomyopathy (HCM) patients, determining the risk of sudden cardiac death and developing strategies to prevent it can be challenging, and myocardial fibrosis is one of the parameters used in this regard. Late gadolinium enhancement (LGE) is the most important marker of myocardial fibrosis detected by cardiac magnetic resonance imaging (CMR). The most recent guidelines do not provide a unified recommendation on ICD implantation for primary prevention in HCM patients with over %15 LGE. However, accurate LGE quantification requires specialized software, often unavailable in many centers. Symptom severity often correlates with disease severity, linking these two parameters closely. The presence and severity of symptoms in HCM patients are essential for both treatment and prognosis, and the Kansas City Cardiomyopathy Questionnaire (KCCQ) is the most commonly used tool in clinical studies to assess symptom burden. Purpose This study investigates the relationship between symptom burden and high fibrosis in HCM patients. Methods HCM patients from our cardiomyopathy clinic who underwent CMR between October 2021 and May 2023 were included. Symptom burden was assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ), where lower scores indicate higher symptom burden. High fibrosis was defined as LGE of 15% or more, evaluated by two radiologists. Results Among 193 patients, 57 had high fibrosis. Demographic data showed no significant difference between groups. However, the high fibrosis group had significantly lower KCCQ scores, higher troponin and NT-proBNP levels, lower LVEF, and greater wall thickness and LV mass index (LVMI). Logistic regression identified KCCQ score, LVEF derived from CMR, and CMR-LVMI as independent predictors of high fibrosis. A KCCQ score cut-off of 57.9 predicted high fibrosis with 77.1% sensitivity and 33.3% specificity (AUC: 0.717). Conclusions This study finds that a lower KCCQ score, reflecting higher symptom burden, is an independent predictor of high fibrosis in HCM patients, highlighting its potential utility for fibrosis risk assessment.Late gadolinium enhancement in CMR