Prediction of Extensive Myocardial Fibrosis in Nonhigh Risk Patients With Hypertrophic Cardiomyopathy

Abstract

In nonhigh risk patients with hypertrophic cardiomyopathy (HC), the presence of extensive late gadolinium enhancement (LGE_ext) at cardiovascular magnetic resonance (CMR) imaging has been proposed as a risk modifier in the decision process for implantable cardioverter defibrillator implantation. With a pretest risk of about 10%, a strategy that alters the likelihood of LGE_ext could markedly affect efficacious CMR imaging. Our aim was to study the potential of clinical variables and biomarkers to predict LGE_ext. In 98 HC patients without any clear indication for implantable cardioverter defibrillator implantation, we determined the discriminative values of a set of clinical variables and a panel of biomarkers (hs-cTnT, NTproBNP, GDF-15, and Gal-3, CICP) for LGE_ext, that is, LGE ≥15% of the left ventricular mass. LGE_ext was present in 10% (10/98) of patients. The clinical prediction model contained a history of nonsustained ventricular tachycardia, maximal wall thickness and reduced systolic function (c-statistic: 0.868, p <0.001). Of all biomarkers, only hs-cTnT was associated with LGE_ext, in addition to the improved clinical model of diagnostic accuracy (p = 0.04). A biomarker-only strategy allowed the exclusion of LGE_ext in half of the cohort, in case of a hs-cTnT concentration less than the optimal cutoff (Youden index; 8 ng/L-sensitivity 100%, specificity 54%). In conclusion, in this nonhigh risk HC cohort, the pretest likelihood of LGE_ext can be altered using clinical variables and the addition of hs-cTnT. The promising findings with the use of hs-cTnT only call for new initiatives to study its impact on efficacious CMR imaging in a larger HC population, either with or without additional use of clinical variables.