Cardiac Biomarkers and Prediction of Early Outcome After Heart Valve Surgery: A Prospective Observational Study.

OBJECTIVES: Circulating cardiac biomarkers may improve the prediction of long-term outcomes after cardiac surgery. The authors sought to assess if cardiac biomarkers also help better predict short-term morbidity. DESIGN: Prospective observational study. SETTING: Single academic hospital. PARTICIPANTS: A total of 250 patients undergoing aortic or mitral valve surgery with or without associated coronary artery bypass grafts. INTERVENTION: None MEASUREMENT AND MAIN RESULTS: Relationships between preoperative plasma concentrations of four cardiac biomarkers (sST2, Galectin-3, GDF-15, and NT-proBNP) and postoperative outcome were assessed using logistic regressions and Cox proportional hazards models. The primary outcome was a composite of 30-day mortality, an inotropic support longer than 48 hours and an initial length of stay in the intensive care >five days. Secondary outcome measures were postoperative acute kidney injury, inotropic support duration, lengths of intensive care unit and hospital stays, and 30-day and one-year mortality. No association was observed between any of the four cardiac biomarkers and the primary outcome. The preoperative levels of Galectin-3 (hazard ratio = 1.2; p < 0.001) and sST2 (hazard ratio = 1.01, p < 0.001) were significantly associated with one-year survival, and their addition to the EuroSCORE II significantly improved the prediction of one-year mortality (p < 0.001). Similarly, Galectin-3 was associated with postoperative acute kidney injury (odds ratio = 1.15, p = 0.001) and improved the prediction of this complication when added to the EuroSCORE II (p = 0.002). CONCLUSIONS: These results suggested that the ability of cardiac biomarkers to predict short-term outcome after cardiac surgery, though of interest, appears limited. Conversely, cardiac biomarkers may have the potential to refine the prediction of long-term outcome. Admittedly, all positive results were obtained on secondary outcomes and must be regarded with caution.

The clinical challenge of concomitant aortic and mitral valve stenosis.

The coexistence of mitral and aortic stenosis is not exceptional. Whereas rheumatic fever is currently plummeting in the Western countries, the incidence of degenerative disease is inversely increasing. The haemodynamic interactions which may interfere both with the usual echocardiographic parameters and with the invasive assessment may render the diagnosis difficult. The therapeutic challenges raised by this entity should not be underestimated. The increased morbidity and mortality of multivalvular surgery has to be balanced with the risk of a second operation down the line if one valvular involvement, deemed of a lesser importance, is neglected. This complex situation requires the multidisciplinary approach of a heart team involving surgeons, cardiologists, geriatrists if need be and imaging specialists.

Creatinine-based formulae for the estimation of glomerular filtration rate in heart transplant recipients.

Chronic renal failure (CRF) is a common complication in heart transplant patients. Serum creatinine has clear limitations for the detection and estimation of glomerular filtration rate (GFR). Various creatinine-based formulae are classically used for GFR estimation, but little scientific evidence exists for such use in a heart transplant population. GFR was measured using the plasmatic clearance of the glomerular tracer (51)Cr-EDTA in 27 heart transplant patients with two measures for 22 of the patients. Forty-nine measures were thus available for analysis. The precision and accuracy (Bland and Altman analysis) of the Cockcroft, simplified Modified Diet in Renal Diseases (MDRD) and new Mayo Clinic formulae were compared. The mean GFR of the population was 39 +/- 15 mL/min/1.73 m(2). All formulae were well correlated with the GFR. With the Bland and Altman analysis, the accuracy of the MDRD formula appeared higher than that of the Cockcroft or the Mayo Clinic formulae (bias of +12 mL/min/1.73 m(2), vs. +19.9 mL/min/1.73 m(2), and +22.1 mL/min/1.73 m(2), respectively). The difference between the estimated and measured GFR was higher than 20 mL/min/1.73 m(2) in 51% and 55% cases when using the Cockcroft and the Mayo Clinic formulae respectively, whereas the difference was only noted in 14% cases when the MDRD was used. Among creatinine-based formulae, the MDRD appears the most precise and accurate for estimating the GFR in heart transplant patients. However, when the GFR must be measured with high accuracy, we recommend the use of a reference method like inulin or (51)Cr-EDTA plasma clearance techniques.