Usefulness of High-Sensitivity Cardiac Troponin T to Predict Long-Term Outcome in Patients with Hypertrophic Cardiomyopathy

Since the first report of an association between cardiac troponin (cTn) and adverse outcome in hypertrophic cardiomyopathy (HD), there is a paucity in confirmative data. We performed a prospective, prespecified 5-year follow-up cohort study of 135 HC patients who participated in a national multicenter project and underwent clinical evaluation, MRI (cine, LGE and T2-weighted imaging) and biomarker assessment (high-sensitivity cTnT (hs-cTnT), N-terminal pro-B-type natriuretic peptide, soluble tumorgenicity suppressor-2, Galectin-3, Growth differentiation factor-15, C-terminal Propeptide of Type I Collagen (CICP)). An elevated hs-cTnT concentration was defined as ≥14ng/L. Follow-up was systematically performed for the primary endpoint: a composite of sudden cardiac death, heart failure related death, stroke-related death, heart failure hospitalization, hospitalization for stroke, spontaneous sustained ventricular tachycardia (VT) or appropriate ICD discharge, and progression to NYHA class III-IV. Elevated hs-cTnT was present in 33 of 135 (24%) HC patients. During a median follow-up of 5.0 years (IQR: 4.9-5.1) 18 patients reached the primary endpoint. Using Cox regression analysis, elevated hs-cTnT was univariately associated with the primary endpoint (HR: 3.4 (95%CI: 1.4-8.7, p=0.009). Also female sex, previous syncope, previous non-sustained VT, reduced LV ejection fraction (&lt;50%) and CICP were associated with the primary endpoint. In multivariable analysis, elevated hs-cTnT remained independently associated with outcome (aHR: 4.7 (95%CI: 1.8-12.6, p = 0.002). In conclusion, this 5-year follow-up study is the first to prospectively confirm the association of elevated hs-cTnT and adverse outcomes. In addition to established clinical variables, cTn seems the biomarker of interest to further improve risk prediction in HC, which should be evaluated in larger prospective registries.</p

Exercise and myocardial injury in hypertrophic cardiomyopathy

Objective: Troponin and high signal intensity on T2-weighted (HighT2) cardiovascular magnetic resonance imaging (CMRi) are both markers of myocardial injury in hypertrophic cardiomyopathy (HCM). The interplay between exercise and disease development remains uncertain in HCM. We sought to assess the occurrence of postexercise troponin rises and its determinants. Methods: Multicentre project on patients with HCM and mutation carriers without hypertrophy (controls). Participants performed a symptom limited bicycle test with hs-cTnT assessment pre-exercise and 6 hours postexercise. Pre-exercise CMRi was performed in patients with HCM to assess measures of hypertrophy and myocardial injury. Depending on baseline troponin (13 ng/L), a rise was defined as a >50% or >20% increase, respectively. Results: Troponin rises occurred in 18% (23/127) of patients with HCM and 4% (2/53) in mutation carriers (p=0.01). Comparing patients with HCM with and without a postexercise troponin rise, maximum heart rates (157±19 vs 143±23, p=0.004) and maximal wall thickness (20 mm vs 17 mm, p=0.023) were higher in the former, as was the presence of late gadolinium enhancement (85% vs 57%, p=0.02). HighT2 was seen in 65% (13/20) and 19% (15/79), respectively (p<0.001). HighT2 was the only independent predictor of troponin rise (adjusted odds ratio 7.9; 95% CI 2.7 to 23.3; p<0.001). Conclusions: Postexercise troponin rises were seen in about 20% of patients with HCM, almost five times more frequent than in mutation carriers. HighT2 on CMRi may identify a group of particularly vulnerable patients, supporting the concept that HighT2 reflects an active disease state, prone to additional injury after a short episode of high oxygen demand

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

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, t 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,

High T2-weighted signal intensity for risk prediction of sudden cardiac death in hypertrophic cardiomyopathy

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