(P182) THE DIAGNOSTIC AND PROGNOSTIC ROLE OF CARDIAC BIOMARKERS IN PREDICTING MAJOR ADVERSE CARDIAC EVENTS IN PATIENTS WITH SUSPECTED GENETIC CARDIOMYOPATHIES

Background: Patients with genetic cardiomyopathies experience high morbidity and mortality. These patients require prompt cardiac assessments and early interventions to prevent progression to advanced heart failure. Plasma biomarkers, such as B-type natriuretic peptide (BNP), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and high-sensitive troponin T (hsTropT) may be able to prognosticate major adverse cardiac events (MACE) in this group of patients. Notably, plasma biomarkers have been used to predict the risk of cardiovascular death in traditional heart failure populations, but the role of these biomarkers in patients with genetic cardiomyopathies is not yet well established.

METHODS AND RESULTS: We prospectively enrolled 421 patients (median age 58 years, IQR: 44 – 69) at the multidisciplinary Cardiomyopathy Clinic at the Mazankowski Alberta Heart Institute. This included 224 patients with dilated cardiomyopathy (DCM), 72 with hypertrophic cardiomyopathy (HCM), 79 with infiltrative cardiomyopathy, and 46 patients who were stage A/at-risk for genetic cardiomyopathy. A prospective chart review was performed to collect patient demographics and comorbidities, symptom status, medication/device utilization, medical history, genetic testing results, plasma biomarkers (BNP, NT-proBNP, hsTropT), electrocardiogram (ECG), transthoracic echocardiography (TTE), and cardiac magnetic resonance imaging (CMR) data. Outcome data was collected in collaboration with the Alberta SPOR support unit and included cardiovascular (CV) emergency department (ED) visits, heart failure (HF) ED visits, HF hospitalizations, and CV death with MACE defined as the composite of these outcomes. BNP and NT-proBNP, were predictors of MACE [area under the curve (AUC) 0.72, P  < 0.001 and AUC 0.60, P =0.043; respectively]. ROC curves and the corresponding Youden’s indices were utilized to determine a priori cut-off values for increased risk of MACE for BNP and NT-proBNP of 213.5 pg/mL and 243.0 ng/L, respectively. Over a median follow-up period of 31.5 months (IQR: 14.0 – 51.8), there were a total of 73 MACE (2 deaths, 35 ED visits, 36 hospitalizations). Kaplan-Meier survival analyses showed that patients with BNP >213.5 pg/mL and NT-proBNP >243.0 ng/L had a lower probability of survival (χ2=18.540, P< 0.001 and χ2=12.355, P< 0.001, respectively).

Conclusion: This study demonstrates the prognostic value of BNP and NT-proBNP in the prediction of MACE in patients with genetic cardiomyopathies.