Association Between High Body Mass Index and Mortality Following Myocardial Injury After Noncardiac Surgery.

BACKGROUND: Despite an association between obesity and increased risks for various diseases, obesity has been paradoxically reported to correlate with improved mortality in patients with established cardiovascular disease. However, its effect has not been evaluated to date in patients with myocardial injury after noncardiac surgery (MINS). METHODS: From January 2010 to June 2019, of a total of 35,269 adult patients with postoperative cardiac troponin level data, 5633 (16.0%) patients had MINS as diagnosed by postoperative cardiac troponin I above the 99th-percentile upper reference of 40 ng·L-1 using the TnI-Ultra immunoassay. Patients with MINS were divided into 3 groups according to body mass index (BMI), with 3246 (57.6%) were in the normal (18.5-25 kg·m-2), 425 (7.5%) in the low BMI (<18.5 kg·m-2), and 1962 (34.8%) in the high BMI (≥25 kg·m-2) groups, respectively. The primary outcome was mortality during the first year after surgery, and the mortality during 30 days was also compared. RESULTS: Following adjustment for confounding with inverse probability of treatment weighting, mortality within the first year appeared to be significantly lower in the high BMI group compared with the normal (14.8% vs 20.9%; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.66-0.85; P < .001) and the low BMI (14.8% vs 25.6%; HR: 0.56; 95% CI, 0.48-0.66; P < .001) groups. CONCLUSIONS: High BMI may be associated with decreased mortality following MINS. Further investigations are needed to support this finding.

Preoperative cardiac troponin below the 99th-percentile upper reference limit and 30-day mortality after noncardiac surgery.

Preoperative high-sensitivity cardiac troponin (hs-cTn) above the 99th-percentile upper reference limit (URL) is associated with mortality after noncardiac surgery. This study aimed to evaluate whether preoperative hs-cTn concentrations above the lowest limit of detection (LOD) but below the 99th-percentile URL can predict mortality after noncardiac surgery.From January 2010 to April 2019, a total of 12,415 noncardiac surgical patients with preoperative hs-cTn I below the 99th-percentile URL were enrolled. The patients were divided into two groups according to preoperative hs-cTn I concentration: (1) [hs-cTn] below the LOD (6 ng/L), and (2) mildly elevated [hs-cTn] but below the 99th-percentile URL (40 ng/L). The primary outcome was 30-day mortality. Of the 12,415 patients enrolled, 7958 (64.1%) were in the LOD group whereas 4457 (35.9%) were in the mild elevation group. The incidence of 30-day mortality was significantly greater in the mild elevation group (2.1% vs. 4.0% hazard ratio [HR] 1.73; 95% confidence interval [CI] 1.39-2.16; p < 0.001) in the multivariate analyses. The propensity score matched analyses also produced a similar result (2.6% vs. 4.2% HR 1.61; 95% CI 1.26-2.07; p < 0.001). The threshold at which the risk of mortality increased corresponded to a preoperative hs-cTn I ≥ 12 ng/L. Patients with preoperative hs-cTn I above the LOD and below the 99th-percentile URL had greater 30-day mortality after noncardiac surgery.

Comparison of acute and chronic myocardial injury in noncardiac surgical patients.

PURPOSE: Perioperative myocardial injury is a predictor of postoperative mortality, but the clinical impact of chronic injury during the perioperative period has not been fully investigated. This study aimed to evaluate chronic myocardial injury during the perioperative period in comparison with normal and acute myocardial injury. METHODS: Patients with serial cardiac troponin measurements before and within 30 days following noncardiac surgery were divided into three groups: normal, acute injury, and chronic injury groups. Acute and chronic myocardial injuries were stratified according to 2018 recommendations by the International Federation of Clinical Chemistry and Laboratory Medicine's Task Force on Clinical Applications of Bio-Markers. Thirty-day and one-year mortalities after surgery were compared. RESULTS: Of the 22,969 patients reviewed, 17,671 (76.9%) were classified into the normal, 5,179 (22.5%) into the acute injury, and 119 (0.5%) into the chronic injury groups. The acute and chronic injury groups had higher 30-day mortalities compared with the normal group (0.8% vs. 8.0%; hazard ratio [HR], 11.00; 95% confidence interval [CI], 9.05-13.37; P < 0.001 and 0.8% vs. 7.6%; HR, 10.55; 95% CI, 5.37-20.72; P < 0.001, respectively). In a direct comparison between the acute and chronic injury groups using an inverse probability of weighting adjustments, the 30-day and one-year mortalities were not significantly different. CONCLUSION: Chronic myocardial injury during the perioperative period may show similar clinical impacts on postoperative mortality compared with acute injury. Further studies are needed.