Topological network analysis of patient similarity for precision management of acute blood pressure in spinal cord injury

  1. Abel Torres-Espín
  2. Jenny Haefeli
  3. Reza Ehsanian
  4. Dolores Torres
  5. Carlos A Almeida
  6. J Russell Huie
  7. Austin Chou
  8. Dmitriy Morozov
  9. Nicole Sanderson
  10. Benjamin Dirlikov
  11. Catherine G Suen
  12. Jessica L Nielson
  13. Nikos Kyritsis
  14. Debra D Hemmerle
  15. Jason F Talbott
  16. Geoffrey T Manley
  17. Sanjay S Dhall
  18. William D Whetstone
  19. Jacqueline C Bresnahan
  20. Michael S Beattie
  21. Stephen L McKenna
  22. Jonathan Z Pan  Is a corresponding author
  23. Adam R Ferguson  Is a corresponding author
  24. The TRACK-SCI Investigators
  1. Weill Institute for Neurosciences; Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco; Zuckerberg San Francisco General Hospital and Trauma Center, United States
  2. Division of Physical Medicine and Rehabilitation, Department of Orthopaedics and Rehabilitation, University of New Mexico School of Medicine, United States
  3. San Francisco Veterans Affairs Healthcare System, United States
  4. Computational Research Division, Lawrence Berkeley National Laboratory, United States
  5. Lawrence Berkeley National Laboratory, United States
  6. Rehabilitation Research Center, Santa Clara Valley Medical Center, United States
  7. Department of Psychiatry and Behavioral Science, and University of Minnesota, United States
  8. Institute for Health Informatics, University of Minnesota, United States
  9. Department of Radiology and Biomedical Imaging, University of California, San Francisco, United States
  10. Department of Emergency Medicine, University of California, San Francisco; Zuckerberg San Francisco General Hospital and Trauma Center, United States
  11. Department of Physical Medicine and Rehabilitation, Santa Clara Valley Medical Center, United States
  12. Department of Neurosurgery, Stanford University, United States
  13. Department of Anesthesia and Perioperative Care, University of California, San Francisco; Zuckerberg San Francisco General Hospital and Trauma Center, United States
5 figures, 12 tables and 3 additional files

Figures

High-frequency monitoring operating room (OR) data.

Flowchart of retrospective study and cohort selection criteria (a). A final cohort of 118 patients were identified and values of mean arterial pressure (MAP) (b) and heart rate (HR), (c) by time …

Figure 2 with 2 supplements
Topological network analysis of intra-operative monitoring.

Intra-operative mean arterial pressure (MAP) and heart rate (HR) sampled every 5 min (Q5) were curated, processed, and formatted in a unique data matrix (a) (Figure 2—figure supplement 1). The …

Figure 2—figure supplement 1
Data preprocessing, dimensionality reduction, and clustering optimization.

The time-series signal between patients is not aligned (changes at specific time point might not reflect the same for each patient) and of different length due to the different duration of surgery (a

Figure 2—figure supplement 2
Exploratory network analysis of AIS (American Spinal Injury Association [ASIA] Impairment Scale) at discharge.

The proportion of AIS grades at discharge for each cluster was mapped into the network and its association with the mean average mean arterial pressure (aMAP) per cluster explored. Clusters with …

Non-linear relationship of average mean arterial pressure (aMAP) with the probability of improving at least one AIS grade.

Logistic regression models were fitted to study the potential non-linearity of the aMAP predictor as suggested by the exploratory analysis. Six different models were studied: naïve, linear, …

Figure 4 with 3 supplements
Range of mean arterial pressure (MAP).

To find the optimal MAP range, a moving MAP range was computed and the time of MAP outside range calculated (a and d, example of the same patient for symmetric and asymmetric map range, …

Figure 4—figure supplement 1
Exploratory network analysis of mean arterial pressure (MAP) out of range.

We further explored the relationship of the distribution of patients in the network and the amount of time their MAP was out of a specific range (Figure 4). For each MAP range, the assortativity …

Figure 4—figure supplement 2
Logistic least absolute shrinkage and selection operator (LASSO) regression with leave-one-out cross-validation (LOOCV) of symmetric range.

(a) The deviance of the binomial model used as cross-validation error (mean and standard deviation) in the LOOCV (see Methods) against the values of l (in log form). The two vertical doted lines …

Figure 4—figure supplement 3
Logistic least absolute shrinkage and selection operator (LASSO) regression with leave-one-out cross-validation (LOOCV) of asymmetric range.
Leave-one-out cross-validation (LOOCV) performance of prediction models.

We built three prediction models, one to predict American Spinal Injury Association (ASIA) Impairment Scale (AIS) improvement of at least one grade at discharge (AIS impro., a), one to predict AIS A …

Tables

Table 1
Cohort demographics split by AIS (American Spinal Injury Association [ASIA] Impairment Scale) improvement.
AIS improve. N/A(n = 15)AIS improve. NO(n = 61)AIS improve. YES(n = 42)Univariate p-value
Age (years)0.12
 Mean (SD)46.0 (17.6)45.3 (19.1)51.4 (19.7)
 Median [min, max]45.5 [19.0, 87.0]47.0 [18.0, 82.0]55.0 [18.0, 86.0]
 Missing1 (6.7%)2 (3.3%)1 (2.4%)
AIS admission0.013
 A1 (6.7%)33 (54.1%)18 (42.9%)
 B0 (0%)5 (8.2%)8 (19.0%)
 C0 (0%)5 (8.2%)11 (26.2%)
 D0 (0%)14 (23.0%)5 (11.9%)
 E0 (0%)4 (6.6%)0 (0%)
 Missing14 (93.3%)0 (0%)0 (0%)
AIS discharge<0.0001
 A0 (0%)35 (57.4%)0 (0%)
 B0 (0%)5 (8.2%)5 (11.9%)
 C1 (6.7%)4 (6.6%)15 (35.7%)
 D0 (0%)14 (23.0%)17 (40.5%)
 E1 (6.7%)2 (3.3%)5 (11.9%)
 Missing13 (86.7%)1 (1.6%)0 (0%)
Surgery duration (min)0.66
 Mean (SD)433 (167)392 (146)407 (181)
 Median [min, max]432 [121, 725]389 [120, 728]343 [151, 950]
 Missing1 (6.7%)2 (3.3%)1 (2.4%)
Surgery to discharge (days)0.33
 Mean (SD)9.50 (2.12)18.8 (20.6)23.4 (23.8)
 Median [min, max]9.50 [8.00, 11.0]11.0 [1.00, 128]14.5 [4.00, 120]
 Missing13 (86.7%)4 (6.6%)2 (4.8%)
Dichotomized neurological level of injury at admission0.054
 Cervical2.00 (13.3%)36 (59%)33 (78.6%)
 Non-cervical13.00 (86.7%)25 (41%)9 (21.4%)
Table 2
Logistic regression likelihood ratio test and leave-one-out cross-validation (LOOCV) error (n = 103 patients).
ModelAICResidual dfResidualdevianceDeviancep-ValueLOOCV error
Null model(l=β0)141.26102139.260.246
Linear model(l=β0+β1x)134.8101130.808.46(vs. null model)0.0036**(vs. null model)0.231
Quadratic model(l=β0+β1x+β2x2)128.48100122.488.32(vs. linear model)0.0039**(vs. linear model)0.210
Cubic model(l=β0+β1x+β2x2+β3x3)126.9799118.973.50(vs. quadratic model)0.061(vs. quadratic model)0.213
Natural Spline model (df = 2)(l=β0+f1(x))128.29100122.298.50(vs. linear model)0.0035**(vs. linear model)0.210
Natural Spline model (df = 3)(l=β0+f1(x))127.1399119.133.34(vs. quadratic model)0.067(vs. quadratic model)0.213
  1. ** p < 0.01.

Table 3
Evaluation of logistic regression (Wald test) and leave-one-out cross-validation (LOOCV) error.
Model: l=β0+β1x1+β2x12 where x1: average MAP (n = 103 patients)
LOOCV: average observed accuracy = 0.66; average kappa statistic = 0.334
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= –0.550.242–2.2930.02183*
Average MAP (x1)β1= 8.622.9442.9310.00338**
Average MAP (x12)β2= –7.6013.039–2.5010.0123*
  1. *p < 0.05; **p < 0.01.

Table 4
Evaluation of logistic regression with covariates (Wald test) and leave-one-out cross-validation (LOOCV).
Model: l=β0+β11x1+β12x12+β2x2+β3x3+β4x4+β5x5+β6x6+β7x7+β8x8+β9x9, where x1: average MAP; x2 : average HR; x3: length of surgery (min); x4: days to AIS discharge (days); x5: age; x6: AIS admission D (‘yes’,’no’); x7: AIS admission C (‘yes’,’no’); x8: AIS admission B (‘yes’,’no’); x9: AIS admission A (‘yes’,’no’); (AIS admission E was set as the reference level for AIS admission variable and is part of the intercept) (final n = 93)
LOOCV: average observed accuracy = 0.688; average kappa statistic = 0.362
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= –1.530121.8–0.0130.99
Average MAP (x1)β11= 7.3983.1122.3770.017*
Average MAP (x12)β12= –8.0533.530–2.2810.022*
Average HR (x2)β2= –2.0870.0245–0.8510.394
Length of surgery (x3)β3= 0.00110.00150.7280.466
Days to AIS discharge (x4)β4= 0.00370.01090.3440.730
Age (x5)β5= 0.00820.0130.6340.526
AIS admission D (x6)β6= 1.4541.2180.0120.990
AIS admission C (x7)β7= 1.6451.2180.0140.989
AIS admission B (x8)β8= 1.5851.2180.0130.989
AIS admission A (x9)β9= 1.5271.2180.0130.990
Correlation matrix (Spearman)
Average MAPAverageHRLength of surgeryDays to AIS dischargeAgeAIS admission
Average MAP1
Average HR–0.1261
Length of surgery–0.1520.1011
Days to AIS discharge0.088–0.0590.1651
Age0.006–0.2450.0110.0221
AIS admission0.0240.003–0.010.258–0.131
  1. *p < 0.05.

Table 5
Evaluation of logistic regression covariates only (Wald test) and leave-one-out cross-validation (LOOCV).
Model: l=β0+β2x2+β3x3+β4x4+β5x5+β6x6+β7x7+β8x8+β9x9, where x2 : average HR; x3: length of surgery (min); x4: days to AIS discharge (days); x5: age; x6: AIS admission D (‘yes’,’no’); x7: AIS admission C (‘yes’,’no’); x8: AIS admission B (‘yes’,’no’); x9: AIS admission A (‘yes’,’no’); (AIS admission E was set as the reference level for AIS admission variable and is part of the intercept) (final n = 93)
LOOCV: average observed accuracy = 0.612; average kappa statistic = 0.17
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= –1.585138.2–0.0110.991
Average HR (x2)β2= –0.02090.029–0.9110.362
Length of surgery (x3)β3= 0.00160.001411.1510.250
Days to AIS discharge (x4)β4= 0.01050.01060.9930.320
Age (x5)β5= 0.00520.0120.4240.672
AIS admission D (x6)β6= 1.5111.3820.0110.991
AIS admission C (x7)β7= 1.7151.3820.0120.991
AIS admission B (x8)β8= 1.6431.3820.0120.990
AIS admission A (x9)β9= 1.5741.3820.0110.991
Table 6
Evaluation of logistic regression in American Spinal Injury Association (ASIA) Impairment Scale (AIS) A at admission cohort (Wald test) and leave-one-out cross-validation (LOOCV).
Model: l=β0+β11x1+β12x12+β2x2+β3x3+β4x4+β5x5, where x1: average MAP; x2 : average HR; x3: length of surgery (min); x4: days to AIS discharge (days); x5: age (final n = 51)
LOOCV: average observed accuracy = 0.63; average kappa statistic = 0.197
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= –0.9313.433–0.2710.786
Average MAP (x1)β11= 10.795.0142.1530.031*
Average MAP (x12)β12= –6.734.591–1.4680.142
Average HR (x2)β2= –0.0160.035–0.4680.639
Length of surgery (x3)β3= 0.00390.00261.5040.132
Days to AIS discharge (x4)β4= 0.00670.0140.4770.633
Age (x5)β5= –0.0120.020–0.5990.549
  1. *p < 0.05.

Table 7
Neurological level of injury cases.
Cervical (n = 71)Non-cervical (n = 32)
NLIC2C3C4C5C6C7C8T2T3T4T5T6T7T8T9T10T11T12S1S5
Cases3324284811331213132462
Table 8
Evaluation of logistic regression in Cervical cohort (Wald test) and leave-one-out cross-validation (LOOCV).
Model: l=β0+β11x1+β12x12+β2x2+β3x3+β4x4+β5x5+β6x6+β7x7+β8x8, where x1: average MAP; x2 : average HR; x3: length of surgery (min); x4: days to AIS discharge (days); x5: age; x6: AIS admission D (‘yes’,’no’); x7: AIS admission C (‘yes’,’no’); x8: AIS admission B (‘yes’,’no’); (AIS admission A was set as the reference level for AIS admission variable and is part of the intercept, no AIS admission E was present in this cohort) (final n = 93)
LOOCV: average observed accuracy = 0.688; average kappa statistic = 0.362
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= 2.7473.0180.910.363
Average MAP (x1)β11= 7.5943.0562.4850.013*
Average MAP (x12)β12= –7.5283.358–2.2420.025*
Average HR (x2)β2= –0.0550.034–1.6080.108
Length of surgery (x3)β3= 0.00140.00190.7200.472
Days to AIS discharge (x4)β4= 0.00220.0120.1820.855
Age (x5)β5= 0.00790.0160.4820.630
AIS admission D (x6)β6= –0.7470.87–0.8400.730
AIS admission C (x7)β7= 0.7450.800.9250.355
AIS admission B (x8)β8= 0.3010.880.3460.401
  1. *p < 0.05.

Table 9
Evaluation of logistic regression in non-cervical cohort only (Wald test) and leave-one-out cross-validation (LOOCV).
Model: l=β0+β11x1+β12x12+β2x2+β3x3+β4x4+β5x5+β6x6+β7x7+β8x8+β9x9, where x1: average MAP; x2 : average HR; x3: length of surgery (min); x4: days to AIS discharge (days); x5: age; x6: AIS admission D (‘yes’,’no’); x7: AIS admission C (‘yes’,’no’); x8: AIS admission B (‘yes’,’no’); x9: AIS admission A (‘yes’,’no’); (AIS admission E was set as the reference level for AIS admission variable and is part of the intercept) (final n = 93)
LOOCV: average observed accuracy = 0.688; average kappa statistic = 0.362
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= –1.883352.4–0.0050.996
Average MAP (x1)β11= –0.2064.713–0.0440.965
Average MAP (x12)β12= –8.0647.643–1.0550.291
Average HR (x2)β2= –0.00020.06490.0040.997
Length of surgery (x3)β3= 0.00180.00540.3360.737
Days to AIS discharge (x4)β4= 0.0760.06131.2400.215
Age (x5)β5= –0.00470.051–0.9210.357
AIS admission D (x6)β6= 1.7273.5240.0050.996
AIS admission C (x7)β7= 3.5575.7820.0050.996
AIS admission B (x8)β8= 1.7383.5240.0050.995
AIS admission A (x9)β9= 1.6863.5240.0050.996
Table 10
Least absolute shrinkage and selection operator (LASSO) solution and logistic regression of most predictive symmetric range with leave-one-out cross-validation (LOOCV).
Model: l=β0+β1x1, where x1: time of MAP outside range 76–104 mmHg (n = 103 patients)
LOOCV: average observed accuracy = 0.61; average kappa statistic = 0.158
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= 0.3680.3331.1030.269
Time MAP out 76–104 (x1)β1= –0.0060.0026–2.5660.0103*
  1. *p < 0.05.

Table 11
Least absolute shrinkage and selection operator (LASSO) solution and logistic regression of most predictive asymmetric range with leave-one-out cross-validation (LOOCV).
Model: l=β0+β1x1, where x1: time of MAP outside range 76–117 mmHg (n = 103 patients)
LOOCV: average observed accuracy = 0.5728; average kappa statistic = 0.102
PredictorCoef. estimate (logit)Std. errorz-Valuep-Value
Interceptβ0= 0.28810.2871.0020.316
Time MAP out 76–117 (x1)β1= –0.007880.0027–2.8280.00468**
  1. **p < 0.01.

Table 12
Best prediction models of outcome.
Model predicting AIS improvement:l=β0+β11x1+β12x12+β2x2+β3x3+β4x4+β5x5
Model predicting AIS A:l=β0+β11x1+β12x12+β2x2+β3x3+β4x4+β5x5+β6x6+β7x7
Model predicting AIS D:l=β0+β2x2+β3x3+β4x4+β5x5+β8x8+β9x9
where x1: average MAP; x2 : AIS admission A (‘yes’, ‘no’); x3 : AIS admission B (‘yes’, ‘no’); x4 : AIS admission C (‘yes’, ‘no’); x5 : AIS admission D (‘yes’, ‘no’); x6 : NLI non-cervical; x7 : Time MAP out 76–117; x8 : Length of surgery; x9 : Age; (AIS admission E and NLI cervical were set as the reference levels for the corresponding variable and are part of the intercept). All metrics are on LOOCV prediction (n = 93)
Model AIS improv.Model AIS AModel AIS D
PredictorCoef. estimate (logit)Coef. estimate (logit)Coef. estimate (logit)
Interceptβ0= –16.24β0= 20.466β0= 1.558
Average MAP (x1)β11= 7.374β11= 27.031
Average MAP (Cohn et al., 2010) (x1)β12= –8.215β12= –17.138
AIS admission A (x2)β2= 15.54β2= –22.814β2= 2.324
AIS admission B (x3)β3= 16.1818β3= –20.38β3= 0.41
AIS admission C (x4)β4= 16.752β4= –19.01β4= –2.591
AIS admission D (x5)β5= 14.828β5= 0.217β5= –2.624
NLI non-Cervical (x6)β6= –1.228
Time MAP out 76–117 (x7)β7= 0.017
Length of Surgery (x8)β8= –0.0044
Age (x9)β9= 0.03
Model performance metricMetric valueMetric valueMetric value
Accuracy (95% CI)0.73 (0.629, 0.818)0.82 (0.735, 0.898)0.806 (0.71, 0.881)
AUC0.7430.880.87
Kappa0.450.6290.573
Sensitivity0.710.8120.793
Specificity0.740.8360.812
Positive predicted value0.6580.720.657
Negative predicted value0.7880.890.896

Additional files

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