Complement activation products in acute heart failure: Potential role in pathophysiology, responses to treatment and impacts on long-term survival.

BACKGROUND: Previous studies have indicated a correlation between heart failure, inflammation and poorer outcome. However, the pathogenesis and role of inflammation in acute heart failure (AHF) is incompletely studied and understood. The aim of our study was to explore the potential role of innate immunity - quantified by complement activation products (CAPs) - in pathophysiology, responses to treatment and impacts on long-term survival in AHF. METHODS: In a prospective study enrolling 179 unselected patients with AHF, plasma concentrations of C4d, C3a and sC5b-9 were measured in a blinded fashion on the first day of hospitalisation and prior to discharge. The final diagnosis, including the AHF phenotype, was adjudicated by two independent cardiologists. Long-term follow-up was obtained. Findings in AHF were compared to that obtained in 75 healthy blood donors (control group). RESULTS: Overall, concentrations of all three CAPs were significantly higher in patients with AHF than in healthy controls (all p < 0.001). In an age-adjusted subgroup analysis, significant differences could be confirmed for concentrations of C4d and sC5b-9, and these parameters further increased after 6 days of in-hospital treatment ( p < 0.001). In contrast, C3a levels in AHF patients did not differ from those of the control group in the age-adjusted subgroup analysis and remained constant during hospitalisation. Concentrations of C4d, C3a and sC5b-9 were significantly higher when AHF was triggered by an infection as compared to other triggers ( p < 0.001). In addition, CAP levels significantly correlated with each other ( r = 0.64-0.76), but did not predict death within 2 years. CONCLUSIONS: Activation of complement with increased plasma levels of C4d and sC5b-9 at admission and increasing levels during AHF treatment seems to be associated with AHF, particularly when AHF was triggered by an infection. However, CAPs do not have a prognostic value in AHF.

Prediction of mortality using quantification of renal function in acute heart failure.

BACKGROUND: Renal function, as quantified by the estimated glomerular filtration rate (eGFR), is a predictor of death in acute heart failure (AHF). It is unknown whether one of the clinically-available serum creatinine-based formulas to calculate eGFR is superior to the others for predicting mortality. METHODS AND RESULTS: We quantified renal function using five different formulas (Cockroft-Gault, MDRD-4, MDRD-6, CKD-EPI in patients<70 years, and BIS-1 in patients≥70 years) in 1104 unselected AHF patients presenting to the emergency department and enrolled in a multicenter study. Two independent cardiologists adjudicated the diagnosis of AHF. The primary endpoint was the accuracy of the five eGFR equations to predict death as quantified by the time-dependent area under the receiver-operating characteristics curve (AUC). The secondary endpoint was the accuracy to predict all-cause readmissions and readmissions due to AHF. In a median follow-up of 374 days (IQR: 221 to 687 days), 445 patients (40.3%) died. eGFR as calculated by all equations was an independent predictor of mortality. The Cockcroft-Gault formula showed the highest prognostic accuracy (AUC 0.70 versus 0.65 for MDRD-4, 0.55 for MDRD-6, and 0.67 for the combined formula CKD-EPI/BIS-1, p<0.05). These findings were confirmed in patients with varying degrees of renal function and in three vulnerable subgroups: women, patients with severe left ventricular dysfunction, and the elderly. The prognostic accuracy for readmission was poor for all equations, with an AUC around 0.5. CONCLUSIONS: Calculating eGFR using the Cockcroft-Gault formula assesses the risk of mortality in patients with AHF more accurately than other commonly used formulas.

Prospective validation of a 1-hour algorithm to rule-out and rule-in acute myocardial infarction using a high-sensitivity cardiac troponin T assay.

BACKGROUND: We aimed to prospectively validate a novel 1-hour algorithm using high-sensitivity cardiac troponin T measurement for early rule-out and rule-in of acute myocardial infarction (MI). METHODS: In a multicentre study, we enrolled 1320 patients presenting to the emergency department with suspected acute MI. The high-sensitivity cardiac troponin T 1-hour algorithm, incorporating baseline values as well as absolute changes within the first hour, was validated against the final diagnosis. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data and serial measurements of high-sensitivity cardiac troponin T levels. RESULTS: Acute MI was the final diagnosis in 17.3% of patients. With application of the high-sensitivity cardiac troponin T 1-hour algorithm, 786 (59.5%) patients were classified as "rule-out," 216 (16.4%) were classified as "rule-in" and 318 (24.1%) were classified to the "observational zone." The sensitivity and the negative predictive value for acute MI in the rule-out zone were 99.6% (95% confidence interval [CI] 97.6%-99.9%) and 99.9% (95% CI 99.3%-100%), respectively. The specificity and the positive predictive value for acute MI in the rule-in zone were 95.7% (95% CI 94.3%-96.8%) and 78.2% (95% CI 72.1%-83.6%), respectively. The 1-hour algorithm provided higher negative and positive predictive values than the standard interpretation of highsensitivity cardiac troponin T using a single cut-off level (both p < 0.05). Cumulative 30-day mortality was 0.0%, 1.6% and 1.9% in patients classified in the rule-out, observational and rule-in groups, respectively (p = 0.001). INTERPRETATION: This rapid strategy incorporating high-sensitivity cardiac troponin T baseline values and absolute changes within the first hour substantially accelerated the management of suspected acute MI by allowing safe rule-out as well as accurate rule-in of acute MI in 3 out of 4 patients. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00470587.