Kidney Function Alters the Relationship between Postoperative Troponin T Level and Death

Abstract

Cardiac troponin T (cTnT), even at low concentrations, is a risk factor for 30-day mortality in patients undergoing noncardiac surgery, but it is uncertain whether that risk is generalizable to patients with poor kidney function. We, therefore, evaluated the relationship between cTnT concentration and kidney function on the outcome of 30-day mortality in a post hoc analysis of a prospective cohort study of patients undergoing noncardiac surgery. cTnT was measured for 3 days after surgery and considered abnormal if the peak was $0.02 ng/ml. Of the included 14,037 patients, 267 (1.9%) patients died within 30 days of surgery. The adjusted hazard ratios for death with an abnormal cTnT concentration were 4.37 (95% confidence intervals [95% CI], 3.21 to 6.22), 6.15 (95% CI, 2.95 to 140.9), 6.30 (95% CI, 3.12 to 21.23), 1.33 (95% CI, 0.56 to 4.85), and 1.46 (95% CI, 0.46 to 9.21) for eGFR$60, 45 to ,60, 30 to ,45, 15 to ,30, and ,15 ml/min per 1.73 m 2 or on dialysis, respectively. Compared with patients with eGFR$60 ml/min per 1.73 m 2 , the adjusted hazard ratio was significantly lower for patients with eGFR=15 to ,30 ml/min per 1.73 m 2 (interaction P value=0.02). Redefining abnormal cTnT concentration as $0.03 ng/ml or a change of $0.02 ng/ml did not alter results. Because the risk associated with postoperative cTnT levels may be different for patients with eGFR,30 ml/min per 1.73 m 2 , additional research is required to determine how to interpret perioperative cTnT values for patients with low kidney function.

Prognostic value of postoperative high-sensitivity troponin T in patients with different stages of kidney disease undergoing noncardiac surgery

“…Our study confirmed similar results in patients with CKD using the fifth generation hsTnT assay and furthermore demonstrates an increased risk of long-term mortality, which was unclear in patients with severe CKD. Similar to Walsh and colleagues, 36 patients with severe CKD in our cohort were more subject to undergo emergency procedures. Observing the same trend in a larger cohort than ours, suggests that this is a selection bias for which we cannot fully adjust.…”

“…Additionally, they found no interaction between eGFR and postoperative hsTnT. The study by Walsh and colleagues 36 displays the same increased risk of 30-day all-cause mortality between the different strata of CKD when postoperative troponin T was elevated (!0.02 ng ml À1 fourth generation assay) up to CKD with an eGFR !30 ml min À1 1.73 m À2 . Our study confirmed similar results in patients with CKD using the fifth generation hsTnT assay and furthermore demonstrates an increased risk of long-term mortality, which was unclear in patients with severe CKD.…”

Biomarkers of Cardiovascular Disease and Mortality Risk in Patients with Advanced CKD

“…Thus, we could not, for example, adequately study the effect of residual renal function on the observed relationships and test the hypothesis that reduced tubular metabolism is an important determinant of the observed elevation in biomarker concentrations. Second, our epidemiologic study does not address the direct clinical usefulness of the biomarkers in diagnosing acute events, such as cardiac ischemia, although it was recently shown that residual renal function is an important confounder when using TnT for that purpose (45,46). Third, because we measured the circulating biomarkers using commercial ELISA kits, the unknown epitopes of most of these makes any meaningful interpretation difficult.…”

The Stockholm CREAtinine Measurements (SCREAM) project: protocol overview and regional representativeness

“…CKD also has a substantial impact on societal costs, by increasing per se the need for healthcare services [ 3 ] and contributing to work disability [ 4 ]. Further, the consequences of CKD are of importance for many other aspects of healthcare, including the incidence of other comorbidities [ 1 , 5 ] or impairment on the diagnostic accuracy of laboratorial analyses and medical devices [ 6 – 8 ] dependent on protein or fluid retention by the failing kidneys. Notwithstanding that creatinine is a very common and low-cost assessment in healthcare [ 9 , 10 ], systematic screening programs are lacking and, in most societies, the awareness of CKD among both physicians and patients remains very low [ 11 , 12 ].…”