Growth hormone for risk stratification and effects of therapy in acute myocardial infarction.

CONTEXT: Excess growth hormone (GH) is associated with early mortality. OBJECTIVES: We assessed the association of GH with prognosis after acute myocardial infarction (AMI), and the effects of secondary prevention therapies. METHODS: GH was measured using a high-sensitivity assay in 953 AMI patients (687 males, mean age 66.1 ± 12.8 years). RESULTS: During 2 years follow-up, there were 281 major adverse cardiac events (MACE). Patients with MACE had higher GH levels (median [range], 0.91 [0.04-26.28] µg/L) compared to event-free survivors (0.59 [0.02-21.6], p < 0.0005). In multivariate Cox survival analysis, GH was a significant predictor of MACE (hazard ratios 1.43, p = 0.026 and 1.49, p = 0.01, respectively) with significant interactions with beta blocker therapy (p = 0.047) and angiotensin converting enzyme inhibitor or angiotensin receptor blocker (ACE/ARB) therapy (p = 0.016). CONCLUSIONS: GH levels post-AMI are prognostic for MACE and may indicate those patients who benefit from beta blocker and ACE/ARB therapy.

Interleukin 33 and ST2 in non-ST-elevation myocardial infarction: comparison with Global Registry of Acute Coronary Events Risk Scoring and NT-proBNP.

BACKGROUND: Soluble ST2 is a marker of biomechanical strain for which the natural ligand is interleukin 33 (IL-33). They have not been studied together in non-ST-elevation myocardial infarction (NSTEMI). We investigated their relationship with death, heart failure (HF) readmission, and reinfarction combined (termed major adverse cardiac events [MACE]) and, separately, in unselected patients using Global Registry of Acute Coronary Events Risk Scoring (GRACE-RS) and n terminal pro B type natriuretic peptide (NT-proBNP) as benchmark comparators. METHODS: ST2 and IL-33 were measured in 577 patients 3 to 5 days after admission. Mean follow-up was 532 (150-1059) days, during which 156 patients (27%) reached the primary end point. RESULTS: ST2 was higher in those who experienced MACE when compared with event-free survivors (median 782 pg/mL vs 596, P < .001), but there was no difference in IL-33 levels across any end point. Multivariate Cox regression analysis reveals that elevated ST2 is independently associated with increased risk of MACE during the long term (hazard ratio [HR] 2.01, P = .005). This relationship continues on further adjustment for either GRACE risk score or NT-proBNP individually but not on adjustment for both. ST2 also independently predicts reinfarction (HR 2.48, P = .03) and 30-day mortality (HR 4.43, P = .02, c-statistic 0.73, P < .001). Adding ST2 to GRACE or to NT-proBNP did not lead to significant improvements in the c-statistic for MACE for long-term follow-up (P = .27 and P = .57, respectively) or the net reclassification index. Neither IL-33 nor its ratio with ST2 was associated with study end points. CONCLUSIONS: Elevated ST2 predicts adverse outcome in non-ST-elevation myocardial infarction but does not significantly improve risk stratification for established markers. Interleukin 33 was not related to adverse events.

Proteinase 3 and prognosis of patients with acute myocardial infarction.

A multimarker approach may be useful for risk stratification in AMI (acute myocardial infarction) patients, particularly utilizing pathways that are pathophysiologically distinct. Our aim was to assess the prognostic value of PR3 (proteinase 3) in patients post-AMI. We compared the prognostic value of PR3, an inflammatory marker, with an established marker NT-proBNP (N-terminal pro-B-type natriuretic peptide) post-AMI. We recruited 900 consecutive post-AMI patients (700 men; age, 64.6±12.4 years) in a prospective study with follow-up over 347 (0-764) days. Plasma PR3 was significantly higher in patients who died [666.2 (226.8-4035.5) ng/ml; P<0.001] or were readmitted with heart failure [598 (231.6-1803.9) ng/ml, P<0.004] compared with event-free survivors [486.9 (29.3-3118.2) ng/ml]. Using Cox modelling, log10 PR3 [HR (hazard ratio), 3.80] and log10 NT-proBNP (HR, 2.51) were significant independent predictors of death or heart failure. When patients were stratified by plasma NT-proBNP (median, 1023 pmol/l), PR3 gave additional predictive value for death or heart failure, in both the patients in whom NT-proBNP level was above the median (log rank for trend, 12.54; P<0.0004) and those with NT-proBNP level below the median (log rank for trend, 3.83; P<0.05). Neither marker predicted recurrent AMI. In conclusion, this is the first report showing a potential role for the serine protease PR3 in determining mortality and incidence of heart failure following AMI, independent of established conventional risk factors. PR3 may represent a clinically useful marker of prognosis after an AMI as part of a multimarker strategy.

C-terminal provasopressin (copeptin) as a prognostic marker after acute non-ST elevation myocardial infarction: Leicester Acute Myocardial Infarction Peptide II (LAMP II) study.

Copeptin, the 39-amino-acid C-terminal portion of provasopressin, has been shown to be an independent predictor for adverse events following STEMI (ST elevation myocardial infarction). We hypothesized that plasma copeptin was an independent predictor for adverse outcomes following acute NSTEMI (non-STEMI) and evaluated whether copeptin added prognostic information to the GRACE (Global Registry of Acute Coronary Events) score compared with NT-proBNP (N-terminal pro-B-type natriuretic peptide). Plasma copeptin and NT-proBNP were measured in 754 consecutive patients admitted to the hospital with chest pain and diagnosed as having NSTEMI in this prospective observational study. The end point was all-cause mortality at 6 months. Upper median levels of copeptin were strongly associated with all-cause mortality at 6 months. Copeptin was a significant predictor of time to mortality {HR (hazard ratio), 5.98 [95% CI (confidence interval, 3.75-9.53]; P < 0.0005} in univariate analysis and remained a significant predictor in multivariate analysis [HR, 3.03 (05% CI, 1.32-6.98); P = 0.009]. There were no significant differences between the area under ROC (receiver operating characteristic) curves of copeptin, NT-proBNP and the GRACE score. Copeptin improved accuracy of risk classification when used in combination with the GRACE score as determined by net reclassification improvement, whereas NT-proBNP did not. The relative utility of the GRACE score was increased more by copeptin than by NT-proBNP over a wide range of risks. Plasma copeptin is elevated after NSTEMI, and higher levels are associated with worse outcomes. Copeptin used in conjunction with the GRACE score improves risk stratification enabling more accurate identification of high-risk individuals.

Kinase requirements in human cells: IV. Differential kinase requirements in cervical and renal human tumor cell lines.

Functional differences among human cells have been difficult to identify by standard biochemical methods. Loss-of-function shRNA screens provide an unbiased method to compare protein requirements across cell lines. In previous work, we have studied kinase requirements in two settings, either among a panel of cells from numerous tissues or between two cell lines that differ only by the expression of a chosen oncoprotein or tumor suppressor protein. Here we examine the patterns of kinase requirements between two unrelated cells, the cervical carcinoma cell line HeLa and the renal carcinoma cell line 786-O. By using time courses of cell proliferation after shRNA transduction and by introducing different levels of the shRNAs, we were able to carefully compare the kinase requirements. These comparisons identified 10 kinases that were required in HeLa but not 786-O, and 5 kinases that were required in 786-O but not HeLa. The patterns of growth inhibition due to particular sets of shRNAs in a tumor cell line were shown to be similar in some but not all cell lines derived from the same tissue-specific cancer type. Differential kinase requirements promise to be useful in distinguishing important cell-to-cell functional variations and may lead to the identification of fingerprints for different physiological cell states.

Kinase requirements in human cells: I. Comparing kinase requirements across various cell types.

shRNA loss-of-function screens were used to identify kinases that were rate-limiting for promoting cell proliferation and survival. Here, we study the differences in kinase requirements among various human cells, including freshly prepared primary cells, isogenic cells, immortalized cells, and cancer cell lines. Closely related patterns of kinase requirements among the various cell types were observed in three cases: (i) in repeat experiments using the same cells, (ii) with multiple populations of freshly prepared primary epithelial cells isolated from the same tissue source, and (iii) between nearly isogenic cells that differ from each other by the expression of a single gene. Other commonly used cancer cell lines were distinct from one another, even when they were isolated from similar tumor types. Even primary cells of different lineages isolated from the same tissue source showed many differences. The differences in kinase requirements among cell lines observed in this study suggest that the control of proliferation and survival may be significantly different between cell lines and that simple comparisons from any one cell to another may be misleading. Although the regulation of cell proliferation and survival are heavily studied areas, we did not see a bias in these screens toward the identification of previously known and well studied kinases, suggesting that our knowledge of molecular events in these areas is still meager.

Activation of a novel natriuretic endocrine system in humans with heart failure.

Proguanylin and prouroguanylin are the inactive precursors of guanylin and uroguanylin, natriuretic peptides involved in the regulation of sodium balance. Urinary uroguanylin levels have been found previously to be elevated in patients with HF (heart failure). The aim of the present study was to investigate whether plasma proguanylin and prouroguanylin levels are increased in patients with HF and to evaluate their relationship with cardiac and renal function. In this prospective observational study, we recruited 243 patients with HF (151 men) and 72 healthy controls. In patients with HF, plasma levels of proguanylin [median, 7.2 (range, 0.9-79.0) microg/l] and prouroguanylin [8.3 (1.7-53.0 microg/l)] were both significantly (P<0.0005) higher compared with levels in healthy controls [5.5 (0.4-22.3 microg/l) for proguanylin and 6.3 (2.5-16.9) microg/l for prouroguanylin]. In patients with HF, increased age, a history of hypertension, diabetes and atrial fibrillation, use of diuretics, a higher NYHA (New York Heart Association) class and a lower eGFR (estimated glomerular filtration rate) were significant univariate predictors of proguanylin and prouroguanylin levels. In multivariate analysis, a history of hypertension and low eGFR both had strong independent associations with proguanylin and prouroguanylin levels. Proguanylin and prouroguanylin varied significantly between NYHA class with a trend of increasing plasma concentrations with worsening severity of symptoms. In conclusion, plasma proguanylin and prouroguanylin are elevated in patients with HF. Elevated plasma proguanylin and prouroguanylin levels are associated with hypertension, renal impairment and increasing severity of HF. This novel endocrine system may contribute to the pathophysiology of HF.

Procalcitonin as a prognostic marker in patients with acute myocardial infarction.

BACKGROUND: Procalcitonin is involved in the inflammatory response and is associated with adverse prognosis in certain conditions. AIMS: To investigate the association between procalcitonin and major adverse cardiac events (MACE), left ventricular (LV) function and remodelling following acute myocardial infarction (AMI). METHODS: Plasma procalcitonin was measured in 977 patients with AMI. Subjects were followed for MACE (median 671 days). A subgroup underwent echocardiography at discharge and follow-up LV function and volume assessment. RESULTS: Procalcitonin was associated with MACE on uni- and multivariable analysis. Kaplan-Meier assessment revealed an adverse outcome in subjects with procalcitonin above the median. Procalcitonin was related to markers of LV dysfunction and remodelling. CONCLUSION: Procalcitonin is associated with MACE, LV dysfunction and remodelling post-AMI.

Growth differentiation factor-15 as a prognostic marker in patients with acute myocardial infarction.

AIMS: Our aim was to assess the long-term prognostic value of growth differentiation factor-15 (GDF-15) in patients post-acute myocardial infarction (AMI). Growth differentiation factor-15 is a member of the transforming growth factor beta family. Growth differentiation factor-15 is expressed in the myocardium and upregulated due to 'stress' and has been shown to have antiapoptotic actions. Its role in the cardiovascular system however is not well defined. We were interested to see if GDF-15 could provide long-term prognostic value in post-AMI patients. We compared GDF-15 with N-terminal pro-B-type natriuretic peptide (NT-proBNP). METHODS AND RESULTS: We recruited 1142 consecutive post-AMI patients [820 men, median (range) age 67 (24-97) years] in a prospective study with a follow-up period of 505 (range 1-2837) days. Growth differentiation factor-15 levels increased with increasing Killip class (P < 0.001) and were correlated with NT-proBNP (r = 0.47, P < 0.001). Using a multivariable Cox proportional hazards model, log GDF-15 (HR 1.77), log NT-proBNP (HR 2.06), age (HR 1.03) Killip class above 1, (HR 1.62), use of beta-blockers (HR 0.54) and past history of MI (HR 1.44) were significant independent predictors of death or heart failure (HF). Predictors of death were log NT-proBNP, log GDF-15, age, eGFR, past history of MI, use of beta-blockers, and use of ACE inhibitors or angiotensin receptor blockers. The C-statistic for GDF-15 for predicting death or HF at 1 year was 0.73 (95% CI: 0.70-0.76, P < 0.001) and was 0.76 (95% CI: 0.70-0.80, P < 0.001) for NT-proBNP. Combining these markers yielded an AUC of 0.81 (95% CI: 0.77-0.85), which exceeded that of GDF-15 (P < 0.001) and NT-proBNP (P = 0.004) alone. The Kaplan-Meier analysis revealed that those patients with above median GDF-15 and NT-proBNP had the highest event rate for death and HF (log rank 50.22, P < 0.001). CONCLUSION: Growth differentiation factor-15 is a new marker for predicting death and HF in post-AMI patients. GDF-15 provides prognostic information over and above clinical factors and the established biomarker NT-proBNP. Combined levels of GDF-15 with NT-proBNP can identify a high-risk group of patients.

Gender and renal function influence plasma levels of copeptin in healthy individuals.

The present study sought to identify confounding factors for the interpretation of copeptin levels in healthy individuals. The natriuretic peptides are recognized as diagnostic and prognostic tools in HF (heart failure). Interpretation of BNP (brain natriuretic peptide) and NTproBNP (N-terminal pro-BNP) levels is multifaceted as their secretion is influenced by many variables. A newly identified glycopeptide called copeptin is comparable with the natriuretic peptides in the diagnosis and prognosis of HF and as a prognostic biomarker after AMI (acute myocardial infarction). Copeptin, derived from the C-terminal portion of the precursor to AVP (arginine vasopressin), is secreted stoichiometrically with vasopressin, hence it can be used as a surrogate marker of the AVP system. In the present study, 706 healthy volunteers were recruited from a local HF screening study. Participants with a history of cardiovascular disease and those with echocardiographic abnormalities were excluded from the study. Copeptin and NTproBNP levels were assayed using in-house immunoluminometric assays. Median copeptin levels were significantly higher in the male volunteers compared with the females [median (range): 4.3 (0.4-44.3) compared with 3.2 (1.0-14.8) pmol/l; P<0.001]. In males, copeptin was correlated with eGFR (estimated glomerular filtration rate; r(s)=-0.186, P<0.001). In females, the correlation of copeptin with eGFR was weak (r(s)=-0.097, P=0.095). DT (deceleration time) and left atrial size correlated with higher copeptin levels (r(s)=0.085, P=0.029 and r(s)=0.206, P<0.001 respectively). Only gender (P<0.001), eGFR (P<0.001), left atrial size (P=0.04) and DT (P=0.02) remained independently predictive of plasma copeptin. The present study suggests that gender and renal function specific partition values should be used to interpret copeptin values in future studies of this biomarker in HF or ischaemic heart disease.

N-terminal pro-B-type natriuretic peptide complements the GRACE risk score in predicting early and late mortality following acute coronary syndrome.

The GRACE (Global Registry of Acute Coronary Events) risk score has been shown to offer predictive power with regard to death and AMI (acute myocardial infarction) in patients with ACS (acute coronary syndromes). NT-proBNP (N-terminal pro-B-type natriuretic peptide) has also been found to be useful in predicting mortality following ACS. In the present study, we sought to investigate the use of the GRACE score and NT-proBNP levels at predicting risk of early and late deaths following ACS. We studied 1033 patients (740 men, mean age 66.5+/-12.7 years) with AMI. Blood was drawn once within 24 h following the onset of chest pain. The plasma concentration of NT-proBNP was determined using an in-house non-competitive immunoassay. Patients were GRACE risk scored. The 30-day mortality was 3.7% and the 6-month mortality was 7.8%, and all were related to higher GRACE risk scores (P=0.001 for trend). Higher NT-proBNP levels were also related to increased mortality (P<0.0001). In a Cox proportional hazards model, independent predictors of 30-day and 6-month mortality included NT-proBNP levels and the GRACE risk score. The receiver-operating curve for the GRACE risk score was complemented by NT-proBNP levels for prediction of 30-day mortality [AUC (area under the curve), 0.85] and 6-month mortality (AUC, 0.81). NT-proBNP gives complementary information to the GRACE risk score for predicting early and late mortality. The inclusion of the NT-proBNP blood test is useful in risk-stratifying patients after ACS.

Matrix metalloproteinase-2 predicts mortality in patients with acute coronary syndrome.

The aim of the present study was to investigate the predictive value of MMP (matrix metalloproteinase)-2, MMP-3 and MMP-9 levels in patients with acute coronary syndrome for death, readmission with HF (heart failure) or recurrent MI (myocardial infarction) and to compare them with established markers, NT-proBNP (N-terminal pro-B-type natriuretic peptide) and the GRACE (Global Registry of Acute Coronary Events) score. A single blood test was taken 4 days after admission in 1024 consecutive patients with acute MI with end points observed over 519 (134-1059) days [value is median (range)]. MMP-2 and MMP-3 were increased in patients who died (n=111) compared with survivors (P<0.006 and P=0.01 respectively), but were similar in patients with HF (n=106) or MI (n=138). MMP-9 levels were similar across study end points. Using Cox proportional hazards modelling, MMP-2 demonstrated an independent prediction of death [HR (hazard ratio) 6.60, P=0.001], along with NT-proBNP (HR 4.62, P<0.001) and the GRACE score (HR 1.03, P<0.001), but MMP-3, MMP-9 or log10-troponin I did not. For 1 year mortality, the areas under the receiver operating characteristic curves were 0.60 and 0.58 for MMP-2 and MMP-3 respectively, compared with 0.82 for NT-proBNP and 0.84 for the GRACE score (all P<0.001). Kaplan-Meier analysis revealed that MMP-2 levels in the top quartile were associated with higher mortality rates (log rank 12.49, P=0.006). On univariate analysis, MMP-2 and MMP-3 had a weak association with HF readmission, which was lost after adjustment for clinical factors. None of the MMPs tested predicted MI. In conclusion, this is the first single centre study that identifies MMP2 as an independent predictor of all-cause mortality post-ACS (acute coronary syndrome); however, NT-proBNP and the GRACE score are superior for risk stratification in this cohort.

Clinical outcome of a simplified technique for aortic valve replacement with stentless bioprostheses.

BACKGROUND AND AIM OF THE STUDY: Aortic stentless bioprostheses provide good clinical and hemodynamic results, but may be difficult to implant. Their use is also contraindicated in the presence of a severely calcified aortic root. The study aim was to assess the mid-term results of a simplified implant technique of the Sorin Pericarbon Freedom stentless bioprosthesis (SPF), that allows its use in the presence of severe aortic root calcification. METHODS: Between 2001 and 2007, a total of 51 patients underwent aortic valve replacement (AVR) with the SPF, using a new technique which consisted of standard annular fixation and the fixation of each strut with a single 'U' stitch. The perioperative characteristics, early and late mortality and occurrence of valve-related events were evaluated. The overall mean cross-clamp and cardiopulmonary bypass times were 91.5 +/- 30.2 and 125.3 +/- 44.9 min, respectively, and 77.8 +/- 17.7 and 105.6 +/- 22.8 min, respectively, for AVR (these times were comparable to those required in patients receiving stented valve bioprostheses). The mean follow up period was 40.5 months (range: 3-75 months), and was 100% complete. RESULTS: Hospital mortality was 4% and survival 76.5 +/- 14.5% at six years. Late deaths occurred in eight patients; in four cases this was valve-related (1.9%/patient-year). Freedom from valve-related death and reoperation was 91 +/- 9% and 98 +/- 2% respectively, at six years. The mean transprosthetic gradients were 12.0 +/- 3.4, 9.9 +/- 2.6, 8.7 +/- 4.2, 5.2 +/- 3.9, 4.5 +/- 3.0 and 3.2 +/- 2.7 mmHg for the 19, 21, 23, 25, 27 and 29 mm valve sizes, respectively. No valvular or paravalvular regurgitation was recorded. CONCLUSION: This new implantation technique for the aortic SPF stentless bioprosthesis is simple, effective and versatile, and showed good early results. It may be applicable to other stentless bioprostheses, and also be particularly useful in patients with small aortic annulus and in those with a calcified aortic root.

Proenkephalin and prognosis in heart failure with preserved ejection fraction: a GREAT network study.

BACKGROUND: Proenkephalin (PENK), a stable endogenous opioid biomarker related to renal function, has prognostic utility in acute and chronic heart failure. We investigated the prognostic utility of PENK in heart failure with preserved ejection fraction (HFpEF), and its relationship to renal function, Body Mass Index (BMI), and imaging measures of diastolic dysfunction. METHODS: In this multicentre study, PENK was measured in 522 HFpEF patients (ejection fraction > 50%, 253 male, mean age 76.13 ± 10.73 years) and compared to 47 age and sex-matched controls. The primary endpoint was 2-years composite of all-cause mortality and/or heart failure rehospitalisation (HF). A subset (n = 163) received detailed imaging studies. RESULTS: PENK levels were raised in HFpEF (median [interquartile range] 88.9 [62.1-132.0]) compared to normal controls (56.3 [47.9-70.5]). PENK was correlated to urea, eGFR, Body Mass Index and E/e' (rs 0.635, - 0.741, - 0.275, 0.476, respectively, p < 0.0005). During 2 years follow-up 144 patients died and 220 had death/HF endpoints. Multivariable Cox regression models showed PENK independently predicted 2 year death/HF [hazard ratio (for 1 SD increment of log-transformed biomarker) HR 1.45 [95% CI 1.12-1.88, p = 0.005]], even after adjustment for troponin (HR 1.59 [1.14-2.20, p = 0.006]), and Body Mass Index (HR 1.63 [1.13-2.33, p = 0.009]). PENK showed no interaction with ejection fraction status for prediction of poor outcomes. Net reclassification analyses showed PENK significantly improved classification of death/HF outcomes for multivariable models containing natriuretic peptide, troponin and Body Mass Index (p < 0.05 for all). CONCLUSIONS: In HFpEF, PENK levels are related to BMI, and measures of diastolic dysfunction and are prognostic for all-cause mortality and heart failure rehospitalisation.

C-terminal provasopressin (copeptin) as a novel and prognostic marker in acute myocardial infarction: Leicester Acute Myocardial Infarction Peptide (LAMP) study.

BACKGROUND: The role of the vasopressin system after acute myocardial infarction is unclear. Copeptin, the C-terminal part of the vasopressin prohormone, is secreted stoichiometrically with vasopressin. We compared the prognostic value of copeptin and an established marker, N-terminal pro-B-type natriuretic peptide (NTproBNP), after acute myocardial infarction. METHODS AND RESULTS: In this prospective single-hospital study, we recruited 980 consecutive post-acute myocardial infarction patients (718 men, median [range] age 66 [24 to 95] years), with follow-up over 342 (range 0 to 764) days. Plasma copeptin was highest on admission (n=132, P<0.001, day 1 versus days 2 to 5) and reached a plateau at days 3 to 5. In the 980 patients, copeptin (measured at days 3 to 5) was elevated in patients who died (n=101) or were readmitted with heart failure (n=49) compared with survivors (median [range] 18.5 [0.6 to 441.0] versus 6.5 [0.3 to 267.0] pmol/L, P<0.0005). With logistic regression analysis, copeptin (odds ratio, 4.14, P<0.0005) and NTproBNP (odds ratio, 2.26, P<0.003) were significant independent predictors of death or heart failure at 60 days. The area under the receiver operating characteristic curves for copeptin (0.75) and NTproBNP (0.76) were similar. The logistic model with both markers yielded a larger area under the curve (0.84) than for NTproBNP (P<0.013) or copeptin (P<0.003) alone, respectively. Cox modeling predicted death or heart failure with both biomarkers (log copeptin [hazard ratio, 2.33], log NTproBNP [hazard ratio, 2.70]). In patients stratified by NTproBNP (above the median of approximately 900 pmol/L), copeptin above the median (approximately 7 pmol/L) was associated with poorer outcome (P<0.0005). Findings were similar for death and heart failure as individual end points. CONCLUSIONS: The vasopressin system is activated after acute myocardial infarction. Copeptin may predict adverse outcome, especially in those with an elevated NTproBNP (more than approximately 900 pmol/L).

Evaluation of the branched-chain DNA assay for measurement of RNA in formalin-fixed tissues.

We evaluated the branched-chain DNA (bDNA) assay QuantiGene Reagent System to measure RNA in formalin-fixed, paraffin-embedded (FFPE) tissues. The QuantiGene Reagent System does not require RNA isolation, avoids enzymatic preamplification, and has a simple workflow. Five selected genes were measured by bDNA assay; quantitative polymerase chain reaction (qPCR) was used as a reference method. Mixed-effect statistical models were used to partition the overall variance into components attributable to xenograft, sample, and assay. For FFPE tissues, the coefficients of reliability were significantly higher for the bDNA assay (93-100%) than for qPCR (82.4-95%). Correlations between qPCR(FROZEN), the gold standard, and bDNA(FFPE) ranged from 0.60 to 0.94, similar to those from qPCR(FROZEN) and qPCR(FFPE). Additionally, the sensitivity of the bDNA assay in tissue homogenates was 10-fold higher than in purified RNA. In 9- to 13-year-old blocks with poor RNA quality, the bDNA assay allowed the correct identification of the overexpression of known cancer genes. In conclusion, the QuantiGene Reagent System is considerably more reliable, reproducible, and sensitive than qPCR, providing an alternative method for the measurement of gene expression in FFPE tissues. It also appears to be well suited for the clinical analysis of FFPE tissues with diagnostic or prognostic gene expression biomarker panels for use in patient treatment and management.

C-terminal provasopressin (copeptin) is associated with left ventricular dysfunction, remodeling, and clinical heart failure in survivors of myocardial infarction.

BACKGROUND: Acute myocardial infarction (AMI) is associated with left ventricular (LV) dysfunction and clinical heart failure. Arginine vasopressin is elevated in heart failure and the C-terminal of provasopressin (Copeptin) is associated with adverse outcome post-AMI. The aim of this study was to describe the association between Copeptin with LV dysfunction, volumes, and remodeling and clinical heart failure post-AMI. METHODS AND RESULTS: We studied 274 subjects with AMI. Copeptin was measured from plasma at discharge and subjects underwent echocardiography at discharge and follow-up (median 155 days). Subjects were followed for clinical heart failure for a median of 381 days. Remodeling was assessed as the change (Delta) in LV volumes between echo examinations. Copeptin correlated directly with wall motion index score (WMIS) and inversely with LV ejection fraction (LVEF) at discharge (WMIS, r=0.276, P < .001; LVEF, r=-0.188, P=.03) and follow-up (WMIS, r=0.244, P < .001; LVEF, r=-0.270, P < .001) and with ventricular volumes at follow-up (LVEDV, r=0.215, P=.002; LVESV, r=0.299, P < .001). Copeptin was associated with ventricular remodeling; DeltaEDV; r=0.171, P=0.015, DeltaESV; r=0.186, P=.008. Subjects with increasing LVESV had higher levels of Copeptin (median 6.30 vs. 5.75 pmol/L, P=.012). Subjects with clinical heart failure (n=30) during follow-up had higher Copeptin before discharge (median 13.55 vs. 5.80, P < .001). In a Cox proportional hazards model, Copeptin retained association with clinical heart failure. Kaplan-Meier assessment revealed increased risk in subjects with Copeptin >6.31 pmol/L. CONCLUSIONS: Copeptin is associated with LV dysfunction, volumes, and remodeling and clinical heart failure post-AMI. Measurement of Copeptin may provide prognostic information and the AVP system may be a therapeutic target in post-MI LV dysfunction.

A rapid and efficient branched DNA hybridization assay to titer lentiviral vectors.

A robust assay to titer lentiviral vectors is imperative to qualifying their use in drug discovery, target validation and clinical applications. In this study, a novel branched DNA based hybridization assay was developed to titer lentiviral vectors by quantifying viral RNA genome copy numbers from viral lysates without having to purify viral RNA, and this approach was compared with other non-functional (p24 protein ELISA and viral RT-qPCR) and a functional method (reporter gene expression) used commonly. The RT-qPCR method requires purification of viral RNA and the accuracy of titration therefore depends on the efficiency of purification; this requirement is ameliorated in the hybridization assay as RNA is measured directly in viral lysates. The present study indicates that the hybridization based titration assay performed on viral lysates was more accurate and has additional advantages of being rapid, robust and not dependent on transduction efficiency in different cell types.

C-terminal pro-endothelin-1 offers additional prognostic information in patients after acute myocardial infarction: Leicester Acute Myocardial Infarction Peptide (LAMP) Study.

BACKGROUND: Endothelin-1 is elevated in heart failure (HF) and after acute myocardial infarction (AMI) and gives prognostic information on mortality. Another part of its precursor, C-terminal pro-endothelin-1 (CT-proET-1), is more stable in circulation and ex vivo. We investigated the cardiovascular prognostic value post-AMI of CT-proET-1 and compared it to N-terminal pro-B-type natriuretic peptide (NTproBNP), a marker of death and HF. METHODS: We measured plasma CT-proET-1 and NTproBNP in 983 consecutive post-AMI patients (721 men, mean age 65.0 +/- [SD] 12.2 years), 3 to 5 days after chest pain onset. RESULTS: There were 101 deaths and 49 readmissions with HF during follow-up (median 343, range 0-764 days). C-terminal pro-endothelin-1 was raised in patients with death or HF compared to survivors (median [range] [pmol/L], 119.0 [14.0-671.0] vs 73.0 [4.6-431.0], P < .0001). Using a Cox proportional hazards logistic model, log CT-proET-1 (HR 6.82) and log NTproBNP (HR 2.62) were significant independent predictors of death or HF (along with age, sex, history of AMI, and therapy with beta-blockers). The areas under the receiver operating curve for CT-proET-1, NTproBNP, and the logistic model with both markers were 0.76, 0.76, and 0.81 respectively. Findings were similar for death and HF as individual end points. CONCLUSION: The endothelin system is known to be activated post AMI. C-terminal pro-endothelin-1 is a powerful predictor of adverse outcome, along with NTproBNP. CT-proET-1 may represent a clinically useful marker of prognosis after AMI.

Myotrophin is a more powerful predictor of major adverse cardiac events following acute coronary syndrome than N-terminal pro-B-type natriuretic peptide.

Myotrophin is a 12 kDa protein initially isolated from hypertrophied hearts of spontaneously hypertensive rats and acts by modulating NF-kappaB (nuclear factor kappaB) activity. We have reported previously the presence of myotrophin in patients with human systolic heart failure; however, its role as a predictor of MACE (major adverse cardiac events) in patients with ACS (acute coronary syndrome) is unclear. In the present study, we sought to investigate this and compared myotrophin with NTproBNP (N-terminal pro-B-type natriuretic peptide), a marker of MACE. We studied 356 patients with ACS {276 men; mean age, 63.0+/-12.8 years; 80.6% STEMI [ST segment elevation MI (myocardial infarction)]; and 19.4% NSTEMI (non-STEMI)}. Blood measurement was made at 25-48 h after the onset of chest pain. The plasma concentration of myotrophin and NTproBNP was determined using in-house non-competitive immunoassays. Patients were followed-up for the combined end point of death, MI or need for urgent revascularization. Over the median follow-up period of 355 (range 0-645) days, there were 28 deaths, 27 non-fatal MIs and 73 patients required urgent revascularization. Myotrophin was raised in patients with MACE compared with survivors [510.7 (116.0-7445.6) fmol/ml compared with 371.5 (51.8-6990.4) fmol/ml respectively; P=0.001; values are medians (range)]. Using a Cox proportional hazards model, myotrophin {HR (hazard ratio), 1.64 [95% CI (confidence interval), 0.97-2.76]; P=0.05} and Killip class above 1 [HR, 1.52 (95% CI, 0.93-2.42); P=0.10] were the only independent predictors of MACE. A Kaplan-Meier survival curve revealed a significantly better clinical outcome in patients with myotrophin below the median compared with those with myotrophin above the median (log rank, 7.63; P=0.006). In conclusion, after an ACS, levels of myotrophin are more informative at predicting MACE than NTproBNP and may be useful to risk stratify patients.