Elevated plasma levels of cardiac troponin-I predict left ventricular systolic dysfunction in patients with myotonic dystrophy type 1:A multicentre cohort follow-up study

Objective: High sensitivity plasma cardiac troponin-I (cTnI) is emerging as a strong predictor of cardiac events in a variety of settings. We have explored its utility in patients with myotonic dystrophy type 1 (DM1). Methods: 117 patients with DM1 were recruited from routine outpatient clinics across three health boards. A single measurement of cTnI was made using the ARCHITECT STAT Troponin I assay. Demographic, ECG, echocardiographic and other clinical data were obtained from electronic medical records. Follow up was for a mean of 23 months. Results: Fifty five females and 62 males (mean age 47.7 years) were included. Complete data were available for ECG in 107, echocardiography in 53. Muscle Impairment Rating Scale score was recorded for all patients. A highly significant excess (p = 0.0007) of DM1 patients presented with cTnI levels greater than the 99th centile of the range usually observed in the general population (9 patients; 7.6%). Three patients with elevated troponin were found to have left ventricular systolic dysfunction (LVSD), compared with four of those with normal range cTnI (33.3% versus 3.7%; p = 0.001). Sixty two patients had a cTnI level < 5ng/L, of whom only one had documented evidence of LVSD. Elevated cTnI was not predictive of severe conduction abnormalities on ECG, or presence of a cardiac device, nor did cTnI level correlate with muscle strength expressed by Muscle Impairment Rating Scale score. Conclusions: Plasma cTnI is highly elevated in some ambulatory patients with DM1 and shows promise as a tool to aid cardiac risk stratification, possibly by detecting myocardial involvement. Further studies with larger patient numbers are warranted to assess its utility in this setting

Metabolic impairments in patients with myotonic dystrophy type 2

Objectives: metabolic syndrome (MetS) increases risk of cardiovascular diseases and diabetes mellitus type 2. Aim of this study was to investigate frequency and features of MetS in a large cohort of patients with DM2. Materials & methods: this cross-sectional study included 47 DM2 patients. Patients were matched with 94 healthy controls (HCs) for gender and age. MetS was diagnosed according to the new worldwide consensus criteria from 2009. Results: mean age of DM2 patients was 52 ± 11 years, 15 (32%) were males, and mean disease duration was 15 ± 14 years. MetS was present in 53% of DM2 patients and 46% of HCs (p > 0.05). All components of the MetS appeared with the similar frequency in DM2 and HCs, respectively: hypertension 64 vs 52%, central obesity 62 vs 74%, hypertriglyceridemia 49 vs 39%, hyperglycemia 42 vs 33% and low HDL cholesterol 30 vs 42% (p > 0.05). DM2 patients were more commonly on lipid lowering therapy compared to HCs (12 vs 3%, p = 0.05). Fifteen (32%) patients with DM2 and only one (1%) subject from control group had diabetes mellitus (p 0.05). Conclusions: more than half of DM2 subjects met the criteria for the MetS. We suppose that treatment of metabolic disturbances may reduce cardiovascular complications and improve quality of life in patients with DM2, which is progressive and still incurable disorder