Long Term Outcomes of Mechanical Mitral Valve Replacement in ChildrenChizitam Ibezim*, Noor Alshami*, Jessica Knight+, Omar Qayum*, Amber Leila Sarvestani*,

Elizabeth Turk^, Lazaros Kochilas+, James St. Louis^, Geetha Raghuveer^*University of Missouri-Kansas City, +Emory University, ^Children’s Mercy Hospital - Kansas City, MO

•Use of mechanical valves can address congenital mitral valve abnormalities in children; however, children with mechanical mitral valve continue to be at risk for significant morbidity and premature death; long-term outcomes for this unique group of patients with congenital heart diseases have not been well defined.1-2

•We have previously reported that higher prosthetic valve size / body weight ratio is associated with adverse, early hazard for death.3-4

Table 1: Patient and Procedural Characteristics

Total(n= 502)

In-Hospital Deaths(n=55)

Long Term Cohort (n=447)

Age at 1st MVR (years) Mean ± SDMedian

6.3 ± 5.64.5 (1.4 – 10.2)

2.7 ± 4.3*0.9 (0.4 – 3.0)

6.7 ± 5.6*5.1 (1.8 – 10.8)

Age group at 1st MVR n (%)Infant: 0 – 12 monthsChild: 1 – 5 yearsAdolescent: 5 – 21 years

98 (19.5)165 (32.9)239 (47.6)

29 (52.7)*16 (29.1)*10 (18.2)*

69 (15.4)*149 (33.3)*229 (51.2)*

Weight at 1st MVR (kg) Median (IQR) 15.0 (8.0 – 30.1)* 6.0 (4.7 – 10.0)* 16.6 (9.0 - 32.0)*

1st MVR Era Early 1982-1992Middle 1993-1997Late 1998 – 2000s

149 (29.7)179 (35.7)174 (34.7)

23 (41.8)^21 (38.2)^11 (20.0)^

126 (28.2)^158 (35.4)^163 (36.5)^

* p-value <0.0001 ^p-value 0.03

• The course of pediatric patients who have undergone 1st MVR demonstrate the predictive value of age and concomitant valvular operations, at 1st MVR, for long term survival.

• Younger age may be an important predictor of early mortality, including in-hospital and early post-discharge mortality, but after survival to the 1st year after MVR this association no longer remains.

•

Table 2 : Long-term hazard for transplant/death after hospital discharge

Age Groups1 year after first MVR

HR (95% CI)10 year after first MVR

HR (95% CI)

< 1 year 1.59 (0.82 – 3.07) 0.76 (0.35 – 1.66)

1 - <5 years 2.30 (1.38 - 3.86) 1.32 (0.79 - 2.21)

5 - <21 years ref ref

• Largest multi-institutional long-term outcome study in children undergoing 1st MVR performed at age < 21 years.

• Approximately 3/4th of those discharged from hospital were alive at 20 years of follow-up.

• Those that survived to hospital discharge following 1st MVR who had concomitant aortic valve replacement during 1st MVR had a poorer long-term survival.

• Prosthetic valve size / body weight ratio did not predict long-term outcomes, though it remains important for survivability to hospital discharge.

• Patients less than <1 years of age at 1st MVR had increased in-hospital mortality.

• Younger age was associated with lower transplant-free survival in the 1st year after initial MVR, but there was no effect after this time.

SIGNIFICANCE

METHODS

DISCUSSION

CONCLUSION

REFERENCES

CAVC

24%

PAVC

17%SS

17%LTGA

9%

MVA

33%

Figure 2: Underlying Diagnosis

MVA (Mitral Valve Anomaly)CAVC (Complete Atrioventricular Canal)PAVC (Partial Atrioventricular Canal)SS (Shone Syndrome)LTGA (Levo-Transposition of Great Vessels)

0

10

20

30

40

50

< 1

year

1 - 5

years

5 - 20

years

Pe

rce

nta

ge

Age at 1st MVR

Figure 3: Long-Term Transplant free

Survival after 1st MVR

OBJECTIVE

Table 3: Transplants/ deaths after 1st MVR

All MVR n = 502

Transplants, n (%) 22 (4.4)

Deaths, n (%) 170 (33.8)

In-Hospital, n (%) 55 (10.9)

After discharge, n (%) 115 ( 22.9)

After transplant, n (%) 12 (2.4)

Figure 1: Age Distribution at 1st MVR

• Median (IQR) follow-up years post discharge after 1st MVR is 16.4 (11.6 – 21.1).

• When comparing prosthetic valve size/body weight in patients after hospital discharge there was no effect noted on survival (p=0.86).

• Increased hazard in long-term survival in patients undergoing concomitant valve replacement [HR (95% CI): 2.24 (1.26 - 3.97)].

Time from MVR hospital discharge (years)Number at Risk447 383 349 256 138

Tra

nsp

lan

t-Fre

e S

urv

iva

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)

•Define the long-term, transplant-free survival of patients needing their 1st mechanical mitral valve replacement (MVR) at < 21 years of age.

Pediatric MVR long-term outcome studies are limited by:• Small cohort size.• Short-term / single institution observation. • Lack of a systematic method to assess long-term outcomes.

•Pediatric Cardiac Care Consortium (PCCC) - a multi-institutional and multi-era database of patients undergoing interventions for congenital heart disease.•U.S. residents with 1st MVR at age <

21 years between 1980-2010.•Linkage with National Death Index

(88% Sensitivity) and United Network of Organ Sharing (90% Sensitivity) determined survival and cardiac transplant status through 2014.5• Survival compared using

proportional hazard and extended Cox models, for time-dependent terms.

1. Eble BK, Fiser WP, Simpson P, Dugan J, Drummond-Webb JJ, Yetman AT. Mitral valve replacement in children: predictors of long-term outcome. The Annals of Thoracic Surgery. 2003;76(3):853-9.

2. Henaine R, Nloga J, Wautot F, Yoshimura N, Rabilloud M, Obadia J-F, et al. Long-Term Outcome After Annular Mechanical Mitral Valve Replacement in Children Aged Less Than Five Years. The Annals of Thoracic Surgery. 2010;90(5):1570-6.

3. Caldarone CA, Raghuveer G, Hills CB, Atkins DL, Burns TL, Behrendt DM, et al. Long-term survival after mitral valve replacement in children aged <5 years: a multi-institutional study. Circulation. 2001;104(12 Suppl 1):I143-I-7.

4. Raghuveer G, Caldarone CA, Hills CB, Atkins DL, Belmont JM, Moller JH. Predictors of prosthesis survival, growth, and functional status following mechanical mitral valve replacement in children aged <5 years, a multi-institutional study. Circulation. 2003;108 Suppl 1(90101):II174-9.

5. Spector LG, Menk JS, Vinocur JM, Oster ME, Harvey BA, St. Louis JD, et al. In-Hospital Vital Status and Heart Transplants After Intervention for Congenital Heart Disease in the Pediatric Cardiac Care Consortium: Completeness of Ascertainment Using the National Death Index and United Network for Organ Sharing Datasets. Journal of the American Heart Association. 2016;5(8):e003783.

RESULTSRESULTS