1. A Validated Practical Risk Score to Predict the Need for RVAD after Continuous-flow LVAD SK Singh MD MSc, DK Pujara MBBS, J Anand MD, WE Cohn MD, OH Frazier MD, HR Mallidi MD Division of Transplant & Assist Devices, Baylor College of Medicine Houston, Texas, USA 95th Annual AATS Meeting, Seattle, WA April 28th, 2015

2. Disclosures
The authors have NO disclosures relevant to this research project.

3. Background RV failure after LVAD implant occurs in 20-50% of patients.
Severe RV failure post-LVAD, requiring RVAD support has an incidence of 10-25%.
The causes are multi-factorial.
RV failure & RVAD after LVAD are well described as significant, independent risk factors for morbidity & mortality.
Kormos et al. JTCVS 2010;139:

4. Background
Identifying patients high risk for RVAD after LVAD, may improve outcomes via:
• Peri-operative RV optimization
• Lower threshold for RVAD support
• Alternate strategies (Transplant, TAH, planned BiVAD)
Existing risk scores are limited:
• RV failure outcome, vs RVAD
• Inconsistent variables
• Few reproduced
• Small sample sizes
• Based on univariate analyses
• Include obsolete pulsatile LVADs
• None have been robustly validated

5. Objective
To review the largest single-center experience with CF LVADS to create a simple, portable & robustly validated risk score, that accurately predicts patients at risk for a RVAD after CF LVAD.

6. Methods
A retrospective review of consecutive patients implanted with a CF LVAD at our single institution (1999–2013)
N = 469 patients.
Stratified by RVAD required during admission for CF LVAD.
n = 42 RVADs (9.0%)
Univariate summary statistics & Kaplan-Meier survival.
Multivariable logistic regression identified predictors of requiring RVAD.

7. Methods
Risk Score:
Predictors dichotomized at clinically relevant thresholds; weighted odds ratios
Created simple acronym & simple to remember risk coefficients
ROC AUC c-statistics were calculated for accuracy
Validated internally – Bootstrapping (case resampling)
Validated prospectively patient cohort (N=78)

8. Results

9. RVAD Incidence – Era

10. RVAD Survival .

11. Baseline Characteristics
CF LVAD (n=427)
+RVAD (n=42)
Age (years)
Ischemic Etiology
175 (41%)
20 (48%)
Bridge-to-transplant
254 (59%)
26 (62%)
INTERMACS 1 or 2
219 (53%)*
31 (77%)*
Inotropic Support
361 (84%)*
41 (98%)*
Vasopressor Support
59 (14%)*
12 (29%)*
Pre-operative temporary circulatory support
Extra-corporal membrane oxygenation (ECMO)**
Abiomed Impella or TandemHeart**
Intra-aortic balloon pump (IABP)**
214 (50%)*
1 (0.2%)
63 (14.8%)*
184 (43.1%)*
30 (71%)*
2 (4.8%)
12 (28.6%)*
24 (57.1%)*

12. Baseline Characteristics
CF LVAD (n=427)
+RVAD (n=42)
Diabetes
178 (42%)
15 (36%)
Chronic Obstructive Pulmonary Disease
55 (13%)
3 (7%)
Renal Replacement Therapy
20 (5%)*
9 (21%)*
Hemoglobin (g/dL)
White blood count (106/mL) * *
Sodium (mEq/L)
Creatinine (mg/dL)
Albumin (g/dL) * *

13. Hemodynamics CF LVAD (n=427) +RVAD (n=42) CI (L/min/m2) 1.9 + 0.6
CF LVAD (n=427)
+RVAD (n=42)
CI (L/min/m2)
PCWP (mmHg)
23 + 9
CVP (mmHg)
12 + 7
14 + 9
PVR (Wood’s Units)
LVEDD (cm) * *
TR (mod–sev)
170 (43%)*
24 (60%)*
MR (mod–sev)
230 (57%)
25 (63%)
RV depression (mod-sev)
287 (73%)
32 (86%)

14. Operative CF LVAD (n=427) +RVAD (n=42) Previous Sternotomy 144 (34%)*
CF LVAD (n=427)
+RVAD (n=42)
Previous Sternotomy
144 (34%)*
21 (50%)*
Operative Approach
Sternotomy
Thoracotomy
Subcostal/Other
366 (86%)
37 (9%)
19 (5%)
35 (83%)
6 (14%)
1 (2%)
CPB (minutes) * *
Concomitant Procedure
Atrial septal defect repair**
Tricuspid valve repair/replacement**
Mitral valve repair/replacement**
Aortic valve repair/replacement**
Left ventricle geometry restoration**
Coronary artery bypass grafting**
159 (37%)
45 (10.5%)
7 (1.6%)*
49 (11.5%)
16 (3.7%)
29 (6.8%)
14 (3.3%)
22 (52%)
7 (16.7%)
3 (7.1%)*
4 (9.5%)
2 (4.8%)
3 (7.1%)

15. Predictors of RVAD OR (95% CI) P-value Tricuspid regurgitation (1-4)
1.6 ( )
0.03
Renal Replacement Therapy (yes/no)
2.9 ( )
0.04
Albumin (g/dL)
0.3 ( )
<0.001
LVEDD (cm)
0.6 ( )
0.01
Previous sternotomy
1.7 ( )
0.2
Vasopressor use preoperatively
1.4 ( )
0.5
Logistic Regression

16. “TRAPPS” Predictor Odds Ratio TRAPPS Score (Total = 27)
Predictor
Odds Ratio
TRAPPS Score
(Total = 27)
Tricuspid regurgitation (any)
2.5 5
Renal Replacement Therapy (yes/no)
3.5 7
Albumin (low; <3.5 g/dL)
2.6
Previous sternotomy (yes/no)
1.7 3
VasoPressor required (yes/no)
1.8 4
Small LV cavity size (LVEDD <6 cm)
1.5
 TRAPPS SCORE
Probability of RVAD
Low risk (0-5)
Intermediate risk (6-16)
High risk (17-27)
2.5%
10%
25%
Logistic Regression

17. Accuracy (N=469) TRAPPS (continuous) TRAPPS (risk groups)
Logistic Regression

18. Validation - Bootstrapping
Logistic Regression

19. Validation – Prospective (n=78)
TRAPPS (continuous) TRAPPS (risk groups)
Logistic Regression

20. Conclusions
Severe RV failure requiring RVAD after CF LVAD is a significant risk factor for considerable early mortality.
This review of the largest, single-center CF LVAD experience found a 9% incidence of RVAD after CF LVAD.
The TRAPPS risk score, is a simple, portable, accurate & validated, pre-operative score to identify patients at risk for RVAD after CF LVAD.
TR (any)
Renal replacement therapy
Albumin (<normal)
Previous sternotomy Pressor requirement
Small LV cavity (<6cm)

21. Conclusions
The TRAPPS variables are intuitive & reproduced in literature.
The score is novel in its robust validation retrospectively, prospectively & derived from a large cohort of solely CF LVADs.
Limitations include external validation (pending), and exclusion of important intra-operative variables (i.e. transfusions).
While TRAPPS accurately identifies those at risk for RVAD, there remains a large margin where further aspects of a heart failure program’s practice may impact RVAD incidence.

22. A Validated Practical Risk Score to Predict the Need for RVAD after Continuous-flow LVAD SK Singh MD MSc, DK Pujara MBBS, J Anand MD, WE Cohn MD, OH Frazier MD, HR Mallidi MD Division of Transplant & Assist Devices, Baylor College of Medicine Houston, Texas, USA 95th Annual AATS Meeting, Seattle, WA April 28th, 2015