Early kinetics of cardiac troponin in suspected acute myocardial infarction.

INTRODUCTION AND OBJECTIVES: Release kinetics of high-sensitivity cardiac troponin (hs-cTn) T and I in patients with acute myocardial infarction (AMI) are incompletely understood. We aimed to assess whether hs-cTnT/I release in early AMI is near linear. METHODS: In a prospective diagnostic multicenter study the acute release of hs-cTnT and hs-cTnI within 1 and 2hours from presentation to the emergency department was quantified using 3 hs-cTnT/I assays in patients with suspected AMI. The primary endpoint was correlation between hs-cTn changes from presentation to 1 hour vs changes from presentation to 2hours, among all AMI patients and different prespecified subgroups. The final diagnosis was adjudicated by 2 independent cardiologists, based on serial hs-cTnT from the serial study blood samples and additional locally measured hs-cTn values. RESULTS: Among 2437 patients with complete hs-cTnT data, AMI was the adjudicated diagnosis in 376 patients (15%). For hs-cTnT, the correlation coefficient between 0- to 1-hour change and 0- to 2 hour change was 0.931 (95%CI, 0.916-0.944), P <.001. Similar findings were obtained with hs-cTnI (Architect) with correlation coefficients between 0- to 1-hour change and 0- to 2 hour change of 0.969 and hs-cTnI (Centaur) of 0.934 (P <.001 for both). Findings were consistent among type 1 and type 2 AMI and in the subgroup of patients presenting very early after chest pain onset. CONCLUSIONS: Patients presenting with early AMI showed a near linear release of hs-cTnT and hs-cTnI. This near linearity provides the pathophysiological basis for rapid diagnostic algorithms using 0- to 1-hour changes as surrogates for 0- to 2 hour or 0- to 3 hour changes. Registered at ClinicalTrials.gov (Identifier: NCT00470587).

Surgical hip dislocation with femoral osteotomy and bone grafting prevents head collapse in hips with advanced necrosis.

QUESTIONS: Does surgical hip dislocation with drilling or bone grafting, cartilage treatment and femoral osteotomy in avascular necrosis of the femoral head (AVN) result in: (1) progression of osteonecrosis or osteoarthritis; (2) pain relief and improved function; and (3) subsequent surgery and complications? METHODS: We retrospectively reviewed 12 patients (13 hips, mean age 29 ± 9 years) undergoing surgical hip dislocation for AVN. Preoperative ARCO stages were: 1 hip ARCO II, 8 hips ARCO III early, 4 hips ARCO III late. Drilling was performed in 4 hips, 9 hips underwent curettage, drilling and autologous bone grafting. Cartilage was sutured in 5 hips, autologous matrix-induced chondrogenesis was performed in 3 hips, an osteochondral autograft was used in 1 hip. Femoral osteotomy was performed in 10 hips. Mean follow-up was 3 ± 2 years. Progression of AVN and osteoarthritis was assessed preoperatively and at latest follow-up using Tönnis and ARCO staging. Pain and function were assessed with the Merle d'Aubigné-Postel score. Complications were graded according to Sink et al. RESULTS: 1 hip had AVN progression and converted to THA. 9 hips showed no AVN- or advanced osteoarthritis progression and 3 hips improved at least 1 ARCO stage. The Merle d'Aubigné-Postel score increased from preoperatively 14.1 ± 3.2 to 16.6 ± 1.2 (p = 0.012). Subsequent surgery were performed in 3 hips, complications occurred in 3 hips. CONCLUSION: Although the first results are promising a longer follow-up with more patients is needed to draw a definite conclusion regarding the joint preserving potential in AVN.