Background-Heart failure with preserved ejection fraction (HFPEF) is a common and increasing public health problem.Myocardial fibrosis is a key pathological feature of HFPEF. Peripheral collagen markers may reflect this excess fibrosis; however, the relation of these markers to prognosis in patients with HFPEF has not as yet been determined. Methods and Results-This substudy of the Irbesartan in Heart Failure With Preserved Systolic Function (I-PRESERVE) trial measured plasma levels of procollagen type I amino-terminal peptide, procollagen type III amino-terminal peptide, and osteopontin in 334 patients with HFPEF. Measurements were performed at baseline and 6 months after randomization to placebo or irbesartan 300 mg/day. The relation of baseline collagen markers to the I-PRESERVE primary end point (all-cause death and hospitalization for prespecified cardiovascular causes) was evaluated by single and multivariable analysis. Similar evaluations were performed for all-cause death alone as well as heart failure events (death or hospitalization because of heart failure). Increased plasma levels of collagen markers at baseline were associated with increased frequency of the study primary end point for all collagen markers. For each 10-g/L increase in procollagen type I amino-terminal peptide, the hazard ratio (HR) for the primary end point was 1.09 (95% CI, 1.052 to 1.13; PϽ0.0001); for each 10-g/L increase in procollagen type III amino-terminal peptide procollagen type I amino-terminal peptide, the HR was 2.47 (95% CI, 0.97 to 6.33; Pϭ0.059); and for each 10-nmol/L increase in osteopontin, the HR was 1.084 (95% CI, 1.026 to 1.15; Pϭ0.004). No variable remained significant as an independent predictor when introduced into a multivariable model. Both treatment groups tended to reduce collagen markers, with the reduction significantly greater for placebo versus irbesartan for procollagen type III amino-terminal peptide only (Pϭ0.0185). Conclusions-Increased peripheral collagen turnover markers were not independently associated with increased mortality and cardiovascular hospitalization in an HFPEF population on multivariable analysis but were associated on single-variable analysis. These findings provide some support to the hypothesis that pathological fibrosis in the heart, and possibly the peripheral vasculature, may be contributory to adverse clinical outcomes in patients with HFPEF. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00095238.(Circ Heart Fail. 2011;4:561-568.)

Background: Cardiac troponins are specific biochemical markers of myocardial injury used in the diagnosis of acute myocardial disease and cardiac risk stratification. To avoid misclassification of patients, troponin assays must demonstrate precision at the low end of the measuring range. We report our evaluation of the Architect STAT Troponin-I assay (Abbott Diagnostics), comparison of low-positive results with 2 other assays, and occurrence of heterophile antibody interference in the assay. Methods:We assessed analytical performance on the ci8200 according to CLSI protocols, using quality-control and patient samples. Our healthy reference population included 480 blood donors. For correlation studies against the AxSYM first-generation cTnI (Abbott Diagnostics) and Access second-generation AccuTnI (Beckman Coulter) assays, we used 339 samples from hospital patients. Results: The CV of the Architect STAT Troponin-I assay was 10% near the 99th percentile for the reference population (0.03 g/L). Comparison with the AxSYM first-generation cTnI assay showed good correlation at higher concentrations, but better sensitivity of the Architect cTnI assay at low concentrations, which were clinically relevant as shown by review of patient histories. Correlation was good at the low end of the measuring range with the Access second-generation AccuTnI. Over the last 12 months we have identified 6 patients with heterophile antibodies causing positive interference. Conclusions: The Architect STAT Troponin-I assay provides highly sensitive measurement of cTnI with a CV of 10% near the upper limit of a reference population; however, heterophile antibodies can interfere with this assay.

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The aim of our review is to identify the reconstruction technique that has a superior functional outcome and decreased number of complications for the anterior cruciate ligament (ACL). We have divided our review into 2 sections. Our primary question evaluates the functional results and complications of autografts compared to allografts for ACL reconstruction. Our subsidiary question evaluates the functional results and complications of bone-patellar tendon-bone (BPTB) autografts compared to hamstring tendon autografts. We conducted a systematic review (SR) based on high quality evidence provided by Cochrane, PubMed and National Health Service evidence searches for papers comparing different ACL reconstruction techniques. Results from 2 primary studies, 1 SR and 1 meta-analysis showed no significant statistical difference when comparing clinical outcomes such as pain, range of motion, laxity, International Knee Documentation Committee score, single assessment numerical evaluation score, Tegner activity score and patient reported satisfaction with regards to autografts vs allografts. Allografts had worse outcomes for postoperative tibial tunnelling and graft failure. Results of 3 SRs showed statistically significant differences in incidence of anterior knee pain, kneeling pain and knee stability, which were all found to be greater amongst those who had received a BPTB autograft. Knee extension was significantly reduced in patients with BPTB grafts when compared to patients with Hamstring tendon autografts. However, with regards to return to prior levels of activity, there was no statistically significant difference between those that received BPTB autografts and those that received Hamstring tendon autografts. Autograft reconstruction of the ACL was shown to provide better postoperative outcomes when compared to allograft reconstruction, although the difference was not statistically significant. When researching different autograft options BPTB autografts were associated with greater pain but also greater stability of the knee joint postoperatively when compared to hamstring tendon autografts.