We evaluate the predictive value of patient-reported functional status on hospital length of stay (LOS) and morbidity/mortality for PHTN patients undergoing non-cardiac, non-obstetric procedures at our institution.

1. Self-Reported Exercise
Tolerance and
Perioperative Morbidity in
Pulmonary Hypertension
***July 2016 UPDATE***
Aalap C. Shah, MD
Clinical Fellow in Anesthesia
Boston Children’s Hospital
Harvard Medical School

2.  Pulmonary Hypertension (PHTN)
◦ Progressive increase in mean pulmonary
arterial pressure (PAP) > 25 mmHg at rest;
◦ 30mmHg during exercise
 PAP > 30/15
 Estimated PASP > 0.5 SBP
◦ Symptoms
 Dyspnea
 Dizziness / Fatigue
 Arrhythmias
 Edema
Background

3. Pulmonary Hypertension (PHTN)
◦ Prevalence: 15-50 cases/1 million 1
◦ Incidence: 2.4  5-15 cases/1 million/year 1
◦ Average age: 53 +/- 14 yrs 1
◦ Overall survival: ~2.8 yrs (no treatment) 2
 1 yr: 68%; 2 yr: 48%; 3 yr 34%
◦ Postoperative Mortality : 3.5-18%3-6
- Current risk stratification studies are
underpowered (<100 patients)
- RCRI criteria analogue for PHTN patients?

4. Background
Pathogenesis
◦ Vasodilator/
vasoconstrictor
imbalance

5. PHTN Evaluation
 Pre-Anesthesia Clinic (PAC) evaluation
◦ Increasing chronic disease / comorbidity in
PHTN patients
◦ Increasing # of treatments / survival
◦ Expensive
diagnostic and
monitoring
workup (+TTE)
◦ No consensus
on severity
assessment

6. PHTN: Outcomes Study
 Retrospective chart review of all PHTN
patients receiving elective procedures at
UWMC (April 2007 – September 2013)
 Outcome Measures
◦ LOS (< or ≥ 7 days)
◦ Mortality/Morbidity (< 30d after DOS)
◦ Hospital Readmissions
◦ Unplanned ICU Stay

7. Self-Reported Exercise Tolerance:
Functional Status
During the pre-anesthesia clinic,
all patients asked to estimate,
without symptomatic limitation:
- # number of blocks they could
walk
- # flights of stairs they could
climb
Functional Status (FS) < 4 METs -
- Patients who could not walk 4
blocks or climb 2 flights of stairs.
Climbing 1 flight of stairs
1 metabolic equivalent of task (MET) = 3.5 ml O2/kg/min

8. Objective
 Does self-reported functional status (FS)
identify PHTN patients at risk for
complications and increased hospital
resource use?
“Can you climb 1 flight of stairs without
getting short of breath?”

9. Data Collection / Selection
N=1922 N=661
N=550 cases/
370 patients
INCLUSION CRITERIA
1) PHTN diagnosis
(ECHO or CATH)
2) ECHO data
(<1 year prior to DOS)
3) elective non-CPB/non-OB
procedures
(GA or MAC)
EXCLUSION CRITERIA
1)Multiple procedure during the
same hospital stay (n=43)
2) admissions >24h prior to surgery
(n=34)
3) missing/incomplete FS data
(n=31)
4) Procedure cx after induction
(n=3)

10. Statistics
 SPSS
◦ Χ2 statistic
◦ T-tests vs. Mann-Whitney U (ranked sums)
◦ Bivariate logistic regression (ENTER) -> OR,
95% CI
 LOS
 Morbidity/Mortality by discharge
 Morbidity/Mortality by 30d

11. PHTN: Demographics vs LOS
Variables Overall
(N=550)
LOS £ 7
days
(N = 433)
LOS > 7
days
(N = 117)
P value
Male (%) 298 (54) 229 (53) 69 (59) .252
Age (years) 60 +/- 14 60 +/- 14 60 +/- 16 .850
Body Weight (kg) 91 +/- 34 92 +/- 33 89 +/- 34 .448
Height (cm) 170 +/- 10 170 +/- 10 171 +/- 10 .259
BMI (kg/m
2
) 32 +/- 12 32 +/- 12 31 +/- 12
.288
ASA Classification
II
III
IV
43 (8)
377 (69)
130 (24)
39 (9)
311(72)
83 (19)
4 (3)
66 (56)
47 (40) .001
Poor Functional Status
< 4 METs (%)
273 (50) 197 (46) 76 (65) <.001

12. Variables Overall
(N=550)
LOS £ 7
days
(N = 433)
LOS > 7
days
(N = 117)
P value
Hypertension (%) 365 (66) 298 (69) 67 (57) .021
Angina (%) 40 (7) 32 (7) 8 (7) 1.000
Coronary artery disease (%) 183 (34) 139 (32) 44 (38) .224
Congestive heart failure (%) 175 (32) 135 (31) 40 (34) .576
Arrhythmia (%) 245 (45) 191 (44) 54 (46) .753
VTE (%) 34 (6) 24 (6) 10 (9) .277
Asthma (%) 78 (14) 64 (15) 14 (12) .550
COPD (%) 74 (14) 53 (12) 21 (18) .125
Obstructive sleep apnea (%) 142 (26) 119 (28) 23 (20) .096
Diabetes (%) 156 (28) 130 (30) 26 (21) .106
Renal failure (%) 136 (25) 104 (24) 32 (27) .470
PAH medical therapy (%) 17 (3) 13 (3) 4 (3) .767
PHTN: Comorbidities vs. LOS

13. PHTN: Procedure/Echo vs. LOS
Variables Overall
(N=550)
LOS £ 7
days
(N = 433)
LOS > 7
days
(N = 117)
P value
Number of procedures (n) 2 (2) 2 (2) 2 (2) .725
Most recent procedure (%) 370 (67) 298 (69) 72 (62) .149
Procedure Length (hours)
(mean +/- st. dev)*
1.9 +/- 1.9 1.6 +/- 1.4 3.0 +/- 2.8
<.001
Echocardiography finding
RAP ≥ 10mmHg** 169 (42) 130 (42) 39 (44)
.716
PASP (mean, st. dev)*** 44 +/- 12 44 +/- 12 47 +/- 13
.035
Severe PHTN*** 50 (10) 37 (9) 13 (11)
.470

14. Regression:
Independent Associations
Variables Beta (SE) OR 95% CI P value
ASA Classification IV 1.09 (.24) 2.43 1.56-3.78 <.001
Open Surgical Approach .98 (.26) 2.67 1.60-4.44 <.001
Poor Functional Status
(< 4 METS)
.78 (.25) 2.19 1.35-3.56 .002
No systemic HTN .67 (.26) 1.94 1.18-3.20 .008
Preoperative PASP .01 (.01) 1.00 .99-1.02 .649
Procedure Length .36 (.07) 1.44 1.27-1.64 <.001

15. PHORS and Predicted LOS
1.8%
8.4%
18.0%
41.0%
0.0%
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
35.0%
40.0%
45.0%
0 1 2 3+
ProbabilityofLOs>7days(%)
PHORS Risk Score

16. ROC and PHORS Accuracy
Assessment of Multivariate Predictive model accuracy
(a) Area Under Curve (AUC of 0.775 [95% CI: .728-.822])
(b) Adding echocardiogram variables such as PASP and RAP to the regression
model did not significantly change the predictive value of the model
(PASP: 782 [95% CI: .735-.828]; RAP: .770 [95% CI: .715-.824])

17. PHORS and Outcomes
0.5%
15.6%
2.0%
14.0%
2.6%
30.4%
8.9%
17.4%
0.0% 5.0% 10.0% 15.0% 20.0% 25.0% 30.0% 35.0%
Mortality
Any
Complication
UnplannedICU
AdmissionReadmission
Prevalence (%)
PHORS ≥ 2
PHORS < 2p=.001
p=.102
p<.001
p=.336

18. Complications
10 deaths
(mortality rate: 2.3%)
137 cases
(complication rate: 25.0%)
35 unplanned
ICU admissions (6.4%)
89 readmissions <30d (16.2%)
Complications PHORS < 2
(N = 200)
PHORS ³ 2
(N = 350)
MI (%) 0 (0) 1 (0.3)
Cardiac Arrest (%) 0 (0) 2 (0.6)
CHF (%) 2 (1.0) 6 (1.7)
ARDS (%) 1 (0.5) 3 (0.9)
Respiratory Depression (%) 0 (0) 3 (0.9)
Reintubation (%) 1 (0.5) 6 (1.7)
Stroke/TIA (%) 1 (0.5) 0 (0)
VTE (%) 2 (1.0) 3 (0.9)
Arrhythmia (%) 7 (3.5) 21 (6.0)
Persistent Hypotension (%) 2 (1.0) 8 (2.3)
Acute renal failure (%) 3 (1.5) 9 (2.6)
Hemorrhage à tx or re-op (%) 2 (1.0) 6 (1.7)
Hematoma (%) 1 (0.5%) 1 (0.3)
Wound Debridement/Revision
(%)
1 (0.5) 8 (2.3)
Re-operation for bleeding (%) 1 (0.5) 4 (1.1)
Syncope (%) 1 (0.5) 2 (0.6)
Delirium (%) 4 (2.0) 13 (3.7)
PNA (%) 2 (1.0) 6 (1.7)
Sepsis (%) 3 (1.5) 2 (0.6)
UTI (%) 1 (0.5) 2 (0.6)
SSI (%) 1 (0.5) 2 (0.6)
Other abx 5 (2.5) 5 (1.4%)
Other 11 (5.5) 27 (7.7)

19. Limitations
 Retrospective Study (Causation vs.
Association)
 Left-sided cardiac dysfunction patients
included
 Lacking non-PHTN case control group
◦ Outcome comparisons
◦ External Validity
 Very few patients with severe PHTN
 More likely to experience severe outcomes

20. Conclusions
 Poor functional status is an independent
predictor of increased length of stay
 Pre-operative echocardiogram (PASP and
RAP) offers restricted additional prognostic
value
 Future Directions:
◦ External Validation of Predictive Model vs non-
PHTN comparison
◦ Interface with large data consortiums
 National Registries
 Multicenter Perioperative Outcomes Group (MPOG)
◦ Cost analyses

21. Acknowledgements
• Gail Van Norman, MD – Professor and
Director of Compliance
• G. Alec Rooke, MD, PhD – Professor
• David Faraoni, MD – Research Assocaite
• Kevin Ma, BA – Clinical Research
Coordinator
• Jessica Wang Olivia Wang Se Won An
• Edmond Lai Jacob DeBerry Daniel Masin
• Tammy Tarhini Shilpa Santhosh Ruby Chen
• Asha Melootu Jonathon Dang Zoe Ferguson-Steele

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23. Questions?
Thank You!