The present study aimed to determine the association between the blood urea nitrogen (BUN) and creatinine (Cr) ratio and in-hospital mortality in patients with acute myocardial infarction (AMI). The present retrospective cohort study included adult patients (≥18 years of age) who were admitted to the intensive care unit (ICU) with a primary diagnosis of AMI. Medical records were obtained from the electronic ICU collaborative research database, which includes data from throughout continental USA. Data included demographic characteristics, vital signs, laboratory tests and comorbidities. The clinical endpoint was in-hospital mortality. The Cox proportional hazards model was used to evaluate the prognostic values of the basic BUN/Cr ratio and the Kaplan-Meier method was used to plot survival curves. Subgroup analyses were performed to measure mortality across various subgroups. In total, 5,965 eligible patients were included. In the Cox regression analysis, after being adjusted for age, sex, ethnicity and other confounding factors, the BUN/Cr ratio was found to be a significant risk predictor of in-hospital mortality. There was a non-linear relationship between the BUN/Cr ratio and in-hospital mortality after adjusting for potential confounders. A two-piecewise regression model was used to obtain a threshold inflection point value of 18. Furthermore, after adjusting for additional confounding factors (age, sex, ethnicity, BMI, heart rate, oxygen saturation, platelets, total protein, AMI category, heart failure, history of diabetes, history of hypertension, percutaneous coronary intervention, and administration of norepinephrine, dopamine and epinephrine), the BUN/Cr ratio remained a significant predictor of in-hospital mortality (third vs. first tertile: Hazard ratio, 1.50; 95% CI, 1.08-2.09; P<0.05). The Kaplan-Meier curve for tertiles of the BUN/Cr ratio indicated that in-hospital mortality rates were highest when the BUN/Cr ratio was ≥18.34 after adjustment for age, sex and ethnicity (P<0.05). The present findings demonstrated that a higher BUN/Cr ratio was associated with an increased risk of in-hospital mortality in patients with non-ST-segment elevation myocardial infarction. These results support a revision of how the prognosis of patients with AMI is predicted.
Acute myocardial infarction (AMI) is a fatal disease that results in high morbidity and mortality rates. Blood urea nitrogen (BUN) and creatinine (Cr) are the end products of nitrogen metabolism in humans. They are small molecules that can be filtered from nephrons. Usually, 30-40% of BUN is reabsorbed from the kidney tubules (
The BUN/Cr ratio is defined as the ratio of BUN to serum Cr. As a novel biomarker, the BUN/Cr ratio has emerged as an independent prognostic indicator of poor outcomes in different disease conditions, such as chronic and acute heart failure (AHF) (
There is existing research on the risk factors for mortality in patients with HF (
The present study was a multicentre retrospective observational study. Analyses were performed on data subsets (median age, 65.0 years; range, 56.0-75.0 years; 64.2% male) obtained from participants in the electronic ICU collaborative research database (eICU-CRD;
Data on demographics, comorbidities, vital signs, laboratory tests, use of vasoactive drugs and operations were obtained from the eICU-CRD. Used drugs included norepinephrine, dopamine and epinephrine. The serum laboratory variables measured during the first 24 h of ICU admission were used in the present study. If variables were measured multiple times in the first 24 h, the first measure was used in the present study. Records with >10% missing variables were excluded. For records with ≤10% missing variables, the multiple imputation method was used to deal with the missing data. The multiple imputation methods imputes multiple values for each missing value. This results in the creation of multiple complete data sets in which the missing values have been filled in with plausible values. The analysis of scientific interest is then conducted separately in each of these complete data sets and the results are pooled across the imputed data sets. In this way, the multiple imputation allows the user to explicitly incorporate the uncertainty about the true value of imputed variables (
The primary endpoint of the present study was in-hospital mortality. The patients were divided into two groups: Survivors and non-survivors. The intergroup differences in parameters measured in the ICU were then evaluated.
Patients were diagnosed with AMI according to the ICD-9 code, which was 140. The following inclusion criteria were applied: i) Age ≥18 years; and ii) first ICU admission with a first diagnosis of AMI. AMI was identified from the ICD-9 code in the eICU-CRD. The following exclusion criteria were used: i) Non-first ICU admission; ii) ICU stay <24 h; iii) missing ICU outcome; iv) history of confirmed renal failure; v) blood transfusion received during the 24 h before admission; vi) evidence of thrombocytopenia; vii) coagulopathy; viii) history of injecting cephalosporins or any other drug interfering with BUN or Cr evaluation; ix) both upper and lower gastrointestinal bleeding; and x) missing Cr and BUN measurements after ICU admission or system error (
Clinical evidence of acute myocardial injury was defined as a rise and/or fall in the cardiac troponin I (cTnI) values with at least one value >99th percentile of the upper reference limit and at least one of the following symptoms of myocardial ischemia: Symptoms of acute myocardial ischemia, new ischemic electrocardiogram changes, development of pathological Q waves, and imaging evidence of new loss of viable myocardium or new regional wall motion abnormality in a pattern consistent with an ischemic aetiology (
HF is not a single pathological diagnosis, but a clinical syndrome consisting of cardinal symptoms (e.g., breathlessness, ankle swelling and fatigue) that may be accompanied by signs (e.g., elevated jugular venous pressure, pulmonary crackles and peripheral oedema). HF is due to a structural and/or functional abnormality of the heart that results in elevated intracardiac pressures and/or inadequate cardiac output at rest and/or during exercise. The criteria for diagnosis of HF require evidence of increased left ventricle filling pressures at rest, exercise, or other provocations. The criteria were fulfilled with findings of elevated levels of natriuretic peptides, echocardiographic diastolic parameters such as an E/e' ≥15 or other evidence of elevated filling pressures, or invasive hemodynamic measurement at rest or exercise (
For continuous variables, the Kolmogorov-Smirnov test was used to check the normality of data distribution. Continuous variables with skewed distribution are presented as the median (interquartile range) and comparison among groups was performed using the Kruskal-Wallis H test and Dunn's post hoc test. Categorical or dichotomous variables, which are presented as absolute values and percentages, were compared using the χ2 test.
The cumulative survival rate was calculated using the Kaplan-Meier method and the log-rank test was used for comparison between groups. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% CI of the second and third tertiles relative to the first tertile for in-hospital mortality. Crude regression estimates and estimates adjusted for covariates are presented. After considering the clinical significance, the covariates that were significantly associated with the response variable (P<0.05) or those that changed the effect estimate by ≥10% were retained in the final adjusted model (
Subsequently, a generalized additive model was used to identify the dose-response relationship between the BUN/Cr ratio and in-hospital mortality. If a non-linear association was detected, a two-piecewise linear regression model was used to determine the threshold effect of the BUN/Cr ratio on in-hospital mortality in accordance with the smoothing plot. If the BUN/Cr and in-hospital mortality ratio appeared in the smoothing plot, the inflection point was determined automatically by the recursive method using the maximum model likelihood (
All data were analysed using R software (version 3.42; R Foundation for Statistical Computing) and Empower Stats version 2.17.8 (
The data of a total of 6,616 patients with AMI were extracted from eICU-CRD. Patients without data for BUN (n=328) or Cr (n=50) levels were excluded from the study. Patients with a history of confirmed renal failure, those who had received a blood transfusion during the 24 h before admission, those showing evidence of thrombocytopenia, coagulopathy or having a history of injecting cephalosporins or any other drug interfering with BUN or Cr evaluation, as well as patients with both upper and lower gastrointestinal bleeding (n=273), were excluded from the study. The ICU admission rate of patients without a BUN or Cr level was 5.7% (378 out of 6,616 patients) and a total of 5,965 patients were included in the statistical analysis. A flow chart of the study is shown in
Baseline characteristics according to BUN/Cr tertiles are shown in
The overall in-hospital mortality rate was 8.35% (498 out of 5,965 patients). The in-hospital mortality of different groups based on tertiles of BUN/Cr is shown in
The Kaplan-Meier curves for the tertiles of the BUN/Cr ratio are shown in
A total of three different models, the non-adjusted model and adjusted models I and II, were constructed to analyse the independent effects of the BUN/Cr ratio on the in-hospital mortality of critically ill patients with AMI that were grouped according to the BUN/Cr ratio tertiles. As shown in
In addition, cTnI is a heart-specific protein released in the circulation upon myocardial injury and serves a role in the regulation of muscle contraction and cTns (
The present study (
The results of the subgroup analyses are presented in
The results of the present study revealed that an elevated BUN/Cr ratio indicated an increased risk of in-hospital death in patients with AMI. Even after adjusting for confounding factors in the multivariate models, the BUN/Cr ratio was associated with adverse outcomes. The findings of the present study not only are in agreement with those of the aforementioned previous studies but also demonstrate a non-linear relationship between the BUN/Cr ratio and in-hospital mortality in patients with AMI (
BUN is not a specific marker of renal insufficiency. Cr is affected by extra-renal factors, such as muscle mass, sex, age, nutrition and ethnicity (
Brisco
There is a close bidirectional relationship between the heart and the kidney. HF is a complex syndrome that affects almost all organs and systems of the body. Renal dysfunction is one of the most important comorbidities in patients with chronic HF and is accentuated, or becomes more evident, during episodes of acute HF. This relationship is reflected in cardiorenal syndrome (CRS) (
The present study has several strengths. To the best of our knowledge, it is the first to investigate the relationship between the BUN/Cr ratio and in-hospital mortality in patients with AMI based on a large and diverse population from the publicly available eICU-CRD (
The Global Registry of Acute Coronary Events (GRACE) risk score was initially established to predict in-hospital mortality in patients with ACS (
Although the present study is based on a large multicentre critical care database, it still has some limitations. This was a retrospective study derived from an observational study, which cannot definitively establish causality. As this was an observational study, although a multifactor analysis was performed, other confounding factors may still exist. Furthermore, the data were from the United States, and thus, the results may not apply fully to ICUs elsewhere with different practices or resources. In addition, only data from a single BUN/Cr test were available at admission and repeated measures data were not analysed. Different blood collection times would also affect the results of BUN/Cr, which may have resulted in biases in the study results. Furthermore, the present study did not include clinical follow-up data and could not predict the long-term outcomes of these patients with AMI. Finally, data on the use of intra-aortic balloon pump and left ventricular assist device were not available.
In conclusion, the present findings demonstrated that the BUN/Cr ratio had a strong association with in-hospital mortality in patients with non-STEMI, but not in patients with STEMI. These results may motivate the revision of how the prognosis of patients with AMI should be predicted. Importantly, these findings suggest that the BUN/Cr ratio may be a useful risk stratification factor for critically ill patients with AMI. The effect of the BUN/Cr ratio on in-hospital mortality should be recorded and investigated in future prospective studies.
Not applicable.
The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.
SH and LG confirm the authenticity of all the raw data. SH, LL and XD conceived the study. SH, NG and LL performed the research. XD, LG, LL, ZZ and QZ analyzed the data. SH, LL and LG wrote the paper. All authors read and approved the final manuscript.
The establishment and use of this database was approved by the Massachusetts Institute of Technology (Cambridge, MA, USA) and permission was obtained for the original data collection. The database is released under the Health Insurance Portability and Accountability Act (HIPAA) safe harbour provision. The re-identification risk was certified as meeting safe harbour standards by Privacert (HIPAA certification no. 1031219-2). Since all protected health information was de-identified, the requirement for individual patient consent for publication was waived. In addition, they waived the need for informed consent due to the retrospective nature of the study. The study was performed in accordance with the Declaration of Helsinki. All methods were performed in accordance with the relevant guidelines and regulations.
Not applicable.
The authors declare that they have no competing interests.
Flow diagram of the screening and enrolment of study patients. A total of 5,965 patients were included in the analysis. AMI, acute myocardial infarction; BUN, blood urea nitrogen; Cr, creatinine; eICU-CRD, electronic ICU collaborative research database; ICU, intensive care unit.
Kaplan-Meier curves of the BUN/Cr ratio for predicting in-hospital mortality with acute myocardial infarction. A high BUN/Cr ratio was significantly associated with a higher mortality than a medium or low BUN/Cr ratio (P<0.05). BUN, blood urea nitrogen; Cr, creatinine; T, tertile.
Non-linear relationship between BUN/Cr ratio and in-hospital mortality. There was a non-linear relationship rather than a linear interaction between the BUN/Cr ratio and in-hospital mortality after adjusting for confounding factors. BUN, blood urea nitrogen; Cr, creatinine; RR, relative risk.
Baseline characteristics of patients.
Tertiles of BUN/Cr | |||||
---|---|---|---|---|---|
Characteristics | All patients | Tertile 1 (10.00-16.27) | Tertile 2 (16.28-18.33) | Tertile 3 (18.34-20.65) | P-value |
No. of participants | 5,965 | 1,931 | 2,025 | 2,009 | |
Age, years | 65.00 (56.00-75.0) | 60.00 (52.00-69.00) | 65.00 (56.00-73.00) | 71.00 (63.00-79.00) | <0.001 |
Sex, n (%) | <0.001 | ||||
Female | 2,133 (35.68) | 662 (34.28) | 650 (32.10) | 821 (40.87) | |
Male | 3,832 (64.24) | 1,269 (65.72) | 1,375 (67.90) | 1,188 (59.13) | |
Ethnicity, n (%) |
<0.001 | ||||
Caucasian | 4,642 (77.82) | 1,442 (75.78) | 1,604 (80.32) | 1,596 (80.40) | |
Non-Caucasian | 1,243 (20.84) | 461 (24.22) | 393 (19.68) | 389 (19.60) | |
BMI, kg/m2 | 28.34 (24.79-32.97) | 28.52 (25.05-32.82) | 28.67 (25.14-33.39) | 27.93 (24.20-32.75) | <0.001 |
Length of hospital stay, days | 3.80 (2.26-7.59) | 3.04 (2.08-6.05) | 3.43 (2.20-7.14) | 5.21 (2.90-9.07) | <0.001 |
BUN/Cr | 17.39 (15.87-18.92) | 15.38 (14.52-15.79) | 17.35 (16.85-17.93) | 19.35 (18.92-19.88) | <0.001 |
Estimated glomerular filtration rate, ml/min per 1.73 m2 | 71.81 (47.36-93.10) | 70.05 (43.48-89.07) | 73.85 (50.73-93.52) | 71.72 (47.79-96.72) | <0.001 |
White blood cells, x109 | 10.80 (8.40-14.00) | 10.44 (8.18-13.20) | 10.80 (8.34-13.70) | 11.28 (8.70-15.20) | <0.001 |
Red blood cells, x109 | 4.17 (3.65-4.62) | 4.31 (3.84-4.73) | 4.25 (3.74-4.63) | 3.95 (3.47-4.42) | <0.001 |
Red blood cell distribution width, % | 13.90 (13.20-14.90) | 13.70 (13.10-14.60) | 13.70 (13.20-14.70) | 14.30 (13.50-15.40) | <0.001 |
Platelets, x109 | 207.00 (169.00-252.00) | 208.00 (173.00-253.00) | 208.00 (169.00-250.00) | 205.50 (164.00-254.00) | 0.165 |
Aspartate transaminase, U/l | 66.50 (32.00-163.00) | 70.00 (32.00-155.00) | 66.00 (31.00-169.50) | 64.00 (33.00-171.25) | 0.977 |
Alanine transaminase, U/l | 35.00 (22.00-65.50) | 34.00 (22.00-59.00) | 36.00 (23.00-65.00) | 36.00 (22.00-73.00) | 0.165 |
Total cholesterol, mmol/l | 158.00 (131.00-188.00) | 165.00 (138.00-197.00) | 158.00 (131.00-186.00) | 150.00 (121.00-181.00) | <0.001 |
Triglyceride, mmol/l | 117.00 (83.00-170.00) | 122.00 (89.00-177.00) | 114.00 (84.00-171.00) | 113.00 (78.00-163.50) | 0.002 |
High-density lipoprotein, mmol/l | 38.00 (31.00-46.00) | 38.00 (31.00-46.00) | 37.00 (31.00-46.00) | 39.00 (31.00-48.00) | 0.020 |
Low-density lipoprotein, mmol/l | 92.00 (67.00-120.00) | 97.00 (71.00-126.00) | 92.00 (68.50-117.00) | 82.50 (59.00-111.75) | <0.001 |
Potassium, mmol/l | 4.00 (3.80-4.40) | 4.00 (3.70-4.30) | 4.00 (3.80-4.30) | 4.10 (3.80-4.50) | <0.001 |
Sodium, mmol/l | 138.00 (136.00-140.00) | 138.00 (135.00-140.00) | 138.00 (136.00-140.00) | 138.00 (136.00-140.00) | 0.025 |
Prothrombin time international normalized ratio | 1.20 (1.09-1.40) | 1.20 (1.10-1.40) | 1.20 (1.09-1.40) | 1.20 (1.07-1.40) | 0.369 |
Heart rate, beats/min | 81.00 (70.00-94.00) | 81.00 (70.00-94.00) | 81.00 (70.00-94.00) | 80.00 (69.00-93.00) | 0.610 |
Systolic blood pressure, mmHg | 122.00 (103.00-142.00) | 122.00 (102.00-142.50) | 122.00 (103.00-143.00) | 123.00 (104.00-142.00) | 0.866 |
Diastolic blood pressure, mmHg | 62.00 (51.00-74.00) | 61.00 (50.00-72.00) | 63.00 (51.00-74.00) | 61.00 (51.00-74.00) | 0.440 |
Percutaneous coronary intervention, n (%) | <0.001 | ||||
No | 3,788 (63.50) | 1,140 (59.04) | 1,241 (61.28) | 1,407 (70.03) | |
Yes | 2,177 (36.50) | 791 (40.96) | 784 (38.72) | 602 (29.97) | |
Coronary artery bypass grafting, n (%) | 0.023 | ||||
No | 5,199 (87.16) | 1,714 (88.76) | 1,760 (86.91) | 1,725 (85.86) | |
Yes | 766 (12.84) | 217 (13.09) | 265 (13.09) | 284 (14.14) | |
Heart failure, n (%) | <0.001 | ||||
No | 5,168 (86.99) | 1,738 (90.19) | 1,822 (90.47) | 1,605 (80.40) | |
Yes | 773 (13.01) | 189 (9.81) | 192 (9.53) | 392 (19.60) | |
History of diabetes n (%) | <0.001 | ||||
No | 4,057 (68.29) | 1,449 (75.19) | 1,392 (69.12) | 1,216 (60.80) | |
Yes | 1,884 (31.71) | 478 (24.81) | 622 (30.88) | 784 (39.20) | |
History of hypertension, n (%) | <0.001 | ||||
No | 2,596 (43.70) | 980 (50.86) | 871 (43.25) | 745 (37.25) | |
Yes | 3,345 (56.30) | 947 (49.14) | 1,143 (56.75) | 1,255 (62.75) | |
Acute myocardial infarction category,n (%) | <0.001 | ||||
Non-STEMI | 3,010 (50.46) | 875 (45.31) | 920 (45.43) | 1,215 (60.48) | |
STEMI | 2,955 (49.54) | 1,056 (54.69) | 1,105 (54.57) | 794 (39.52) | |
Norepinephrine, n (%) | <0.001 | ||||
No | 4,223 (85.52) | 1,455 (89.48) | 1,428 (85.56) | 1,340 (81.56) | |
Yes | 715 (14.48) | 171 (10.52) | 241 (14.44) | 303 (18.44) | |
Dopamine, n (%) | 0.004 | ||||
No | 4,661 (94.39) | 1,555 (95.63) | 1,578 (94.55) | 1,528 (93.00) | |
Yes | 277 (5.61) | 71 (4.37) | 91 (5.45) | 115 (7.00) | |
Epinephrine, n (%) | 0.001 | ||||
No | 4,603 (93.22) | 1,547 (95.14) | 1,533 (91.85) | 1,523 (92.70) | |
Yes | 335 (6.78) | 79 (4.86) | 136 (8.15) | 120 (7.30) |
an=5885 as ethnicity was not recorded for all patients at the time of admission. Continuous variables with skewed distribution are presented as the median (interquartile range) and comparison among groups was performed using the Kruskal-Wallis H test and Dunn's post hoc test. Categorical or dichotomous variables, which are presented as absolute values and percentages, were compared using the χ2 test. P-values refer to comparisons among all three tertile groups. STEMI, ST-segment elevation myocardial infarction; BUN, blood urea nitrogen; Cr, creatinine.
Association between the BUN/Cr ratio and in-hospital mortality in patients with acute myocardial infarction in different models.
Exposure | Non-adjusted model HR (95% CI) | P-value | Adjusted model I HR (95% CI) | P-value | Adjusted model II HR (95% CI) | P-value |
---|---|---|---|---|---|---|
BUN/Cr | 1.09 (1.04-1.16) | 0.0002 | 1.06 (1.00-1.11) | 0.0447 | 1.07 (1.00-1.13) | 0.0510 |
BUN/Cr tertiles | ||||||
Tertile 1 | Reference | Reference | Reference | |||
Tertile 2 | 1.02 (0.77-1.34) | 0.8974 | 0.99 (0.74-1.32) | 0.9467 | 1.07 (0.73-1.55) | 0.7328 |
Tertile 3 | 1.63 (1.28-2.08) | <0.0001 | 1.35 (1.04-1.75) | 0.0220 | 1.50 (1.08-2.09) | 0.0170 |
P-value for trend | <0.0001 | 0.0094 | 0.0077 |
Models were derived from Cox proportional hazards regression models. Adjusted model I adjusted for: Age, sex and ethnicity. Adjusted model II adjusted for: Age, sex, ethnicity, BMI, heart rate, oxygen saturation, platelets, total protein, acute myocardial infarction category, heart failure, history of diabetes, history of hypertension, percutaneous coronary intervention, and administration of norepinephrine, dopamine and epinephrine. P-value for trend was obtained from the median value of each BUN/Cr tertile as a continuous variable in the models. BUN, blood urea nitrogen; Cr, creatinine; HR, hazard ratio.
Threshold effect analysis of the relationship between the BUN/Cr ratio and mortality using a two-piecewise regression model.
BUN/Cr ratio inflection point | In-hospital mortalityhazard ratio (95% CI) | P-value |
---|---|---|
<18 | 0.99 (0.91-1.08) | 0.836 |
≥18 | 1.34 (1.17-1.54) | <0.001 |
Likelihood-ratio test | 0.003 |
The model adjusted for age, sex, ethnicity, BMI, heart rate, high- and low-density lipoproteins, alanine transaminase, acute myocardial infarction category, coronary artery bypass grafting, heart failure, history of diabetes, history of hypertension, and percutaneous coronary intervention. If the BUN/Cr and in-hospital mortality ratio appeared in the smoothing plot, the inflection point was determined automatically by the recursive method using the likelihood ratio test. The likelihood ratio test has been widely adopted for assessing the goodness of fit of two competing statistical models based on the ratio of their likelihoods. BUN, blood urea nitrogen; Cr, creatinine.
Effect size of BUN/Cr on in-hospital mortality in prespecified and exploratory subgroups.
Characteristics | No. of participants | Hazard ratio (95% CI) | Subgroup P-value | P-value |
---|---|---|---|---|
BUN/Cr ratio | 0.0013 | |||
<18 | 3,462 | 1.03 (0.93, 1.14) | 0.6817 | |
≥18 | 2,503 | 1.44 (1.20, 1.73) | 0.0001 | |
Estimated glomerular filtration rate, ml/min per 1.73 m2 | 0.1943 | |||
<60 | 2,098 | 1.01 (1.00, 1.03) | 0.0008 | |
≥60 | 3,867 | 1.03 (1.02, 1.04) | <0.0001 | |
Sex | 0.1901 | |||
Female | 2,133 | 0.97 (0.77, 1.22) | 0.0607 | |
Male | 3,832 | 1.19 (0.96, 1.47) | 0.0031 | |
Age, years | 0.2092 | |||
<65 | 2,711 | 1.12 (1.01, 1.20) | 0.0183 | |
≥65 | 3,067 | 1.09 (1.01, 1.18) | 0.2078 | |
BMI, kg/m2 | 0.5280 | |||
<28 | 2,770 | 1.12 (1.05, 1.19) | 0.0005 | |
≥28 | 3,076 | 1.06 (0.99, 1.15) | 0.0981 | |
Heart failure | 0.0522 | |||
No | 4,465 | 1.10 (0.91,1.32) | 0.0562 | |
Yes | 645 | 0.75 (0.53.1.05) | 0.1089 | |
History of diabetes | 0.3897 | |||
No | 4,057 | 1.24 (1.00, 1.53) | <0.0001 | |
Yes | 1,884 | 1.038 (0.87, 1.35) | 0.4147 | |
History of hypertension | 0.6017 | |||
No | 2,596 | 1.12 (1.02, 1.17) | 0.0025 | |
Yes | 3,345 | 1.09 (1.02, 1.17) | 0.0252 | |
Coronary artery bypass grafting | 0.6173 | |||
No | 5,199 | 1.11 (1.05, 1.17) | <0.0001 | |
Yes | 766 | 1.16(0.91, 1.24) | 0.6480 | |
Percutaneous coronary intervention | 0.1418 | |||
No | 3,788 | 1.08 (1.02, 1.14) | 0.0005 | |
Yes | 2,177 | 1.20 (1.06, 1.35) | 0.0021 | |
Glucose, mg/dl | 0.4315 | |||
<128 | 2,847 | 1.09 (1.01, 1.17) | 0.0407 | |
≥128 | 2,858 | 1.113 (1.05, 1.22) | 0.0030 | |
Acute myocardial infarction group | <0.0001 | |||
STEMI | 3,010 | 1.02 (0.97, 1.09) | 0.3638 | |
Non-STEMI | 2,955 | 1.31 (1.19, 1.44) | <0.0001 | |
Heart rate, beats/min | 0.6369 | |||
<80 | 2,806 | 1.12 (1.04, 1.20) | 0.0102 | |
≥80 | 3,115 | 1.09 (1.09, 1.17) | 0.0172 | |
Alanine transaminase, U/l | 0.6116 | |||
<36 | 1,585 | 0.98 (0.78, 1.23) | 0.0008 | |
≥36 | 1,570 | 1.06 (0.86, 1.32) | 0.4424 | |
Low density lipoprotein, mmol/l | 0.7413 | |||
<90 | 1,119 | 1.225 (1.06, 1.46) | 0.0071 | |
≥90 | 1,186 | 1.31 (1.05, 1.63) | 0.0175 |
P-values were generated by Cox regression analysis. BUN, blood urea nitrogen; Cr, creatinine; STEMI, ST-segment elevation myocardial infarction.