Should Asymptomatic Patients Discharged with Lower Hemoglobin Expect Worse Outcomes After Valve...

Should Asymptomatic Patients Discharged with Lower Hemoglobin Expect Worse Outcomes After Valve Surgery?

Niv Ad, MDSari D. Holmes, PhD

Alan M. Speir, MDGraciela Pritchard, BSLinda Halpin, MSN, RN

Inova Heart and Vascular InstituteFalls Church, VA

Disclosure Information

• Niv Ad, MD• AtriCure: consulting and speaker bureau• Medtronic: consulting and speaker bureau• Left Atrial Appendage Occlusion, LLC: co-owner

• Alan M. Speir, MD• Medtronic: Advisory board

Background

• Blood transfusion has been associated with increased morbidity and cost in cardiac surgery patients

• The decision to transfuse following cardiac surgery is often subjective and based primarily on low Hgb levels, age even in asymptomatic patients

Purpose

Study Purposes:

To determine whether asymptomatic patients discharged with lower Hgb levels are at increased risk for:

• Perioperative complications• Inferior quality of life • Increased 1-year mortality

Methodology

• Data collected prospectively on 1,107 valve-only procedures performed between 2008 and mid-2014

• Patients discharged alive with complete data (N =1,044) and divided into two groups:• Discharge Hgb levels ≤8 g/dL

(n=153)• Discharge Hgb levels >8 g/dL

(n=891)

Methodology

• Asymptomatic Patients: • Clinically stable • Ambulating well • Normal BP & no orthostatic

hypotension • No dizziness, tachycardia, tachypnea,

or shortness of breath

Methodology

• Multivariate analysis with Hgb as a continuous variable supplemented by a propensity score matching (PSM) conducted between Hgb groups (152 patient pairs after PSM)

Primary Research Questions

• Question 1: Does lower discharge Hgb level impact outcomes in the entire sample, adjusting for clinical factors with multivariate analyses?

• Question 2: After PSM based on discharge Hgb, do patients with discharge Hgb ≤8 g/dL have worse outcomes?

• Question 3: What is the role of blood product transfusion on outcomes?

Patient Characteristics Before PSM

CharacteristicHgb >8 g/dL

(n = 891)Hgb ≤8 g/dL

(n = 153) P

Age 62.0 ± 13.8 62.2 ± 15.1 0.924

Female 319 (36) 68 (44) 0.041

Ejection fraction (%) 57.7 ± 10.4 58.3 ± 9.6 0.507

CHF 260 (29) 68 (44) <0.001

Diabetes 132 (15) 43 (28) <0.001

Hypertension 527 (59) 104 (68) 0.039

PVD 51 (6) 13 (9) 0.187

Previous CVA 63 (7) 20 (13) 0.011

CPD 162 (18) 45 (29) 0.001

EuroSCORE II (%) 2.8 ± 4.9 6.0 ± 9.3 <0.001

Preop Hgb (g/dL) 13.1 ± 1.9 11.3 ± 1.8 <0.001

Elective status 793 (89) 119 (78) <0.001

Single valve procedure 802 (90) 116 (76) <0.001

CPB time (mins) 123 ± 44 135 ± 53 0.010

Results – Entire Sample

• Sample included:

• Mean age- 62.1 ± 14.0 Y and 37% female pts

• 918 single-valve,114 double-valve,12 triple-

valve

• MV (n =514), AV (n =593), TV (n =72), PV (n

=3)

• Mean Hgb at discharge = 9.9 ± 1.7 g/dL

Distribution of Discharge Hgb

STS-Defined Outcomes

OutcomeTotal Sample

(N = 1,044)

Prolonged ventilation (>24 hrs) 86 (8%)

Pneumonia 25 (2%)

Stroke/TIA 10 (1%)

Reoperation for bleeding 17 (2%)

Renal failure 12 (1%)

Readmissions <30 days 97 (9%)

Death <30 days 3 (0.3%)

Results – Entire Sample

• Multivariate analyses in entire sample, DC Hgb (continuous variable) not predictive of:

• Post discharge mortality <30 days (OR=1.04, P=0.916)

• Discharge to home (OR=1.07, P=0.435)

• Readmission <30 days (OR=0.92, P=0.307)

• One-year survival (HR=0.87, P=0.363)

Distribution of Propensity Scores

Patient Characteristics by Group

CharacteristicUnmatchedHgb >8 g/dL

(n = 739)

MatchedHgb >8 g/dL

(n = 152)

MatchedHgb ≤8 g/dL

(n = 152)

Age 62.0 ± 13.8 62.1 ± 14.2 62.1 ± 15.1

Female *^ 249 (34) 70 (46) 68 (45)

Ejection fraction (%) 57.6 ± 10.6 58.2 ± 9.6 58.2 ± 9.7

CHF *^ 195 (26) 65 (43) 68 (45)

Diabetes *^ 92 (12) 40 (26) 43 (28)

Hypertension *^ 425 (58) 102 (67) 103 (68)

PVD * 36 (5) 15 (10) 13 (9)

Previous CVA *^ 46 (6) 17 (11) 19 (13)

CPD *^ 120 (16) 42 (28) 44 (29)

EuroSCORE II (%) *^ 2.5 ± 4.6 4.3 ± 6.0 6.0 ± 9.3

Preop Hgb (g/dL) *^ 13.4 ± 1.7 11.4 ± 2.0 11.3 ± 1.8

Elective status *^ 675 (91) 118 (78) 118 (78)

Single valve procedure *^ 682 (92) 120 (79) 116 (76)

CPB time (mins) *^ 121 ± 41 131 ± 53 134 ± 52

* Unmatched vs. Matched Hgb >8 g/dL groups (P < 0.05)^ Unmatched Hgb > 8 g/dL vs. Matched Hgb ≤8 g/dL groups (P <0.05)

Patient Characteristics After PSM

CharacteristicHgb >8 g/dL

(n = 152)Hgb ≤8 g/dL

(n = 152) P

Age 62.1 ± 14.2 62.1 ± 15.1 0.994

Female 70 (46) 68 (45) 0.818

Ejection fraction (%) 58.2 ± 9.6 58.2 ± 9.7 0.994

CHF 65 (43) 68 (45) 0.729

Diabetes 40 (26) 43 (28) 0.699

Hypertension 102 (67) 103 (68) 0.903

PVD 15 (10) 13 (9) 0.692

Previous CVA 17 (11) 19 (13) 0.723

CPD 42 (28) 44 (29) 0.799

EuroSCORE II (%) 4.3 ± 6.0 6.0 ± 9.3 0.063

Preop Hgb (g/dL) 11.4 ± 2.0 11.3 ± 1.8 0.651

Elective status 118 (78) 118 (78) >0.999

Single valve procedure 120 (79) 116 (76) 0.582

CPB time (mins) 131 ± 53 134 ± 52 0.680

Results – PSM Groups

• Matched Hgb ≤ 8 grp similar to Hgb > 8 grp on:

• Post-DC mortality <30 days (0% vs. 0.7%, P>0.999)

• Discharge to home (81% vs. 80%, P=0.667)

• Readmission <30 days (14% vs. 16%, P=0.522)

• One-year survival (89% vs. 91%, P=0.67)

Cumulative One-Year Survival

Months

Patients at Risk (95% CI)

Hgb ≤8 g/dL Hgb >8 g/dL

6 118 (0.91–0.98) 108 (0.90–0.98)

9 106 (0.88–0.97) 100 (0.89–0.98)

12 96 (0.84–0.95) 89 (0.86–0.97)

HRQL Improvement at 6 Months

Hgb > 8 g/dL

Hgb ≤ 8 g/dLP

HY

SIC

AL

CO

MP

OS

ITE

HR

QL

SC

OR

E

PRESURGERY 6 MONTHS

Physical (28% vs. 18% increase; P=0.268)Mental (7% vs. 6% increase; P=0.943)

Results – Blood Transfusion

• Multivariate analyses in entire sample found blood product transfusion (22%):

• Poorer 1-year survival (HR=2.27, P=0.036)

• Not related to readmissions (OR=1.51, P=0.244)

Results – Blood Transfusion

• In matched sample, pts with transfusions were (46%): • Similar in 30-day mortality (0.7% vs. 0%,

P=0.461)• Similar on readmissions (17% vs. 13%,

P=0.366)• Less likely to be discharged to home (69% vs.

89%, P<0.001)• Worse on 1-year cumulative survival (85.7%

vs. 94.8%, P=0.012) even after adjusting for discharge Hgb level (HR=3.00, P=0.021)

Summary

• In both multivariate and PSM analyses lower discharge Hgb in asymptomatic patients was not associated with increased post discharge complications and inferior survival

• Blood transfusion was associated with increased mortality at one year, however this was not the primary focus of the study

Conclusions

• We found that symptomatic patients with lower Hgb levels can be safely discharged following valve surgery without being transfused just to correct anemia.

• Based on our consistent experience in a busy center, it is imperative to change the culture around transfusion.

• Implementation of blood conservation protocols has been associated with improved outcomes and cost savings.

Inova Heart & Vascular InstituteCardiac Surgery Research

Research Team Members:• Niv Ad, MD• Rabia R. Ali, BS• Katherine Armstrong, BS• Jill C. Bennick• Hester Dean, BS• Linda Halpin, MSN, RN• Sari D. Holmes, PhD• Deborah Lamont, BSN, RN• Lisa M. Martin, PhD• Paul S. Massimiano, MD• Casey E. Miller, BS, CCRP• Graciela Pritchard, BS• Deborah J. Shuman, BS• Alan M. Speir, MD

Thank you!

Should Asymptomatic Patients Discharged with Lower Hemoglobin Expect Worse Outcomes After Valve...

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