Evaluation of variables responsible for hospital mortality in patients with rheumatic heart disease undergoing double valve replacement

Abstract

To describe the hospital mortality and associated clinical and echocardiographic variables in patients with rheumatic disease who underwent double valve replacement surgery.
This is a cross sectional descriptive study of mortality, performed in a referral hospital in Salvador, Bahia. Records from patients with rheumatic disease who underwent double valve replacement surgery during the years 2007-2011 were analyzed.
The studied sample comprises 104 patients and 60 (57.7%) were male. The mean age was 38.04±14.45. Sixty five bioprostheses and 38 mechanical prostheses were used in these patients at the time of surgery. There were statistically significant differences between the two groups, when we analyzed the following variables: the mean age (36.30±13.03 vs. 45.35±17.8 years-old, P=0.011), mean hemoglobin (11.10±2.19 vs. 9.22±2.26 g/dL, P=0.002), mean hematocrit (34.22±5.86 vs. 28.44±6.62%, P<0.001). New York Heart Association functional class III and IV (NYHA) (P=0.022) was statistically associated with mortality.
We concluded that the mean hemoglobin/hematocrit level and the NYHA functional class was the major variables associated to the mortality among these patients. Based on these data one may concern about the patient best moment for surgery and the patient hemoglobin level.

Full text

537
Rev Bras Cir Cardiovasc | Braz J Cardiovasc Surg
Rev Bras Cir Cardiovasc 2014;29(4):537-42
Fernandes AMS, et al. - Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease undergoing double valve
replacement
RBCCV 44205-1586DOI 10.5935/1678-9741.20140044
Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease
undergoing double valve replacement
Avaliação de variáveis responsáveis pela mortalidade hospitalar em pacientes portadores de doença
reumática submetidos à dupla troca valvar
André Maurício Souza Fernandes1, MsC; Gustavo Maltez de Andrade2; Rafael Marcelino Oliveira2;
Gabriela Tanajura Biscaia2; Francisco Farias Borges dos Reis2, MsC, PhD; Cristiano Ricardo
Macedo1, MsC; Andre Rodrigues Durães1, PhD; Roque Aras Junior1, PhD
1. Universidade Federal da Bahia (UFBA), Salvador, BA, Brazil.
2. Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brazil.
This study was carried out at Hospital Ana Nery, Salvador, BA, Brazil and
Escola Bahiana de Medicina e Saúde Pública, Salvador, BA, Brazil.
No nancial support.
Correspondence address:
Gustavo Maltez de Andrade
Hospital Ana Nery, Escola Bahiana de Medicina e Saúde Pública
Rua Saldanha Marinho, S/N - Caixa D’água - Salvador, BA, Brazil
Zip code: 40320-010
E-mail: maltezgustavo@yahoo.com.br
Article received on September 22nd, 2013
Article accepted on January 13th, 2014
ORIGINAL ARTICLE
Abstract
Objective: To describe the hospital mortality and associat-
ed clinical and echocardiographic variables in patients with
rheumatic disease who underwent double valve replacement
surgery.
Methods: This is a cross sectional descriptive study of
mortality, performed in a referral hospital in Salvador, Bahia.
Records from patients with rheumatic disease who underwent
double valve replacement surgery during the years 2007-2011
were analyzed.
Results: The studied sample comprises 104 patients and
60 (57.7%) were male. The mean age was 38.04±14.45. Sixty
ve bioprostheses and 38 mechanical prostheses were used in
these patients at the time of surgery. There were statistically
signicant differences between the two groups, when we an-
alyzed the following variables: the mean age (36.30±13.03 vs.
45.35±17.8 years-old, P=0.011), mean hemoglobin (11.10±2.19
vs. 9.22±2.26 g/dL, P=0.002), mean hematocrit (34.22±5.86 vs.
28.44±6.62%, P<0.001). New York Heart Association functional
class III and IV (NYHA) (P=0.022) was statistically associated
with mortality.
Conclusion: We concluded that the mean hemoglobin/hemato-
crit level and the NYHA functional class was the major variables
associated to the mortality among these patients. Based on these
data one may concern about the patient best moment for surgery
and the patient hemoglobin level.
Descriptors: Rheumatic Fever. Heart Valve Diseases. Hospital
Mortality. Preoperative Period.
Resumo
Objetivo: Descrever a mortalidade hospitalar em pacientes
reumáticos submetidos à cirurgia de dupla troca valvar e sua
relação com variáveis clínicas e ecocardiográcas.
Métodos: Trata-se de um estudo de corte transversal. Fo-
ram estudados pacientes maiores que 18 anos, com valvopatia
reumática que foram submetidos à cirurgia de DTV do período
de janeiro de 2007 a dezembro de 2011 no Hospital Ana Nery -
Salvador - Bahia. A coleta de dados se deu por meio de consulta
aos prontuários dos pacientes.
Resultados: Foram estudados 104 pacientes, 60 (57,7%) eram
do sexo masculino. A média de idade da população estudada foi
de 38,04±14,45 anos. Foram utilizadas 65 próteses biológicas e
38 próteses metálicas. Houve diferença estatisticamente signi-
cante entre os grupos comparados, pacientes que obtiveram
alta versus pacientes que foram a óbito, em relação às seguintes

538
Rev Bras Cir Cardiovasc | Braz J Cardiovasc Surg
Rev Bras Cir Cardiovasc 2014;29(4):537-42
Fernandes AMS, et al. - Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease undergoing double valve
replacement
performed, followed by cannulation of the ascending aorta for
cardioplegia, using hypothermia (32oC) as a protective strategy,
followed by cardiopulmonary bypass (CPB). In the presence of
AR, the Aorta was opened and then injected the cardioplegic
solution into the coronary ostium. For those patients without
AR, the cardioplegic solution was injected directly into the
aortic root. Afterwards, the left atrium was opened to perform
the mitral and aortic valve replacement, in this respective order,
with mechanical or biological prostheses as indicated.
Statistical analysis was performed with SPSS (Version
17.0). Variables were tested for normality using the One Sam-
ple Test Kolmogorov-Smirnov and the appropriate statistical
test was applied according to its distribution. Continuous
variables were described as mean ± standard deviation. Con-
tinuous variables with normal distribution were compared
using Student’s t-test. Asymmetrical distribution variables
were analyzed by the Mann-Whitnney test, and their depiction
was done by their median, maximum and minimum values.
Categorical variables were described by their frequencies
and analyzed with the Chi-square test. The level of statistical
signicance in this study was 5% (P<0.05).
This study was approved by the institutional review board
of the Ana Nery Hospital (protocol 59/10).
RESULTS
This study sample was composed by 104 patients who
underwent double valve replacement surgery between January
2007 and December 2011. The mean age±standard deviation
was 38.04±14.45 years. Clinical and epidemiological charac-
teristics of the study population are shown in Table 1.
In the study population, 100% of the patients underwent
mitral and aortic valve replacement. This surgery was associ-
ated with another surgical procedure in only 30.8% of cases.
The postoperative hospitalization period ranged from one day
to a maximum of 56 days (median 13 days).
The aortic and mitral valves were the most affected in this
study population, but the tricuspid and pulmonary valves were
also impaired, as follows. Three patients presented mild tricus-
Abbreviations, acronyms & symbols
AR Aortic regurgitation
CPB Cardiopulmonary bypass
MR Mitral regurgitation
NYHA New York Heart Association
RF Rheumatic fever
INTRODUCTION
Rheumatic fever (RF) is a major public health problem,
especially in developing countries[1]. Valvular heart disease
accounts for a signicant portion of cardiovascular hospital
admissions in Brazil. Unlike most developed countries, its
main cause is RF, responsible for 70% of the cases[2]. During
the acute phase of the disease, mitral regurgitation (MR) is the
most frequent impairment, followed by aortic regurgitation
(AR). Obstructive valve lesions usually do not occur in the ear-
ly stages of the RF. Recurrence of the acute phase of rheumatic
heart disease increases the long term risk of permanent heart
injuries and may cause multiple valves lesions[3]. Therefore,
patients with rheumatic valve disease tend to have multiple
valve lesions: either due to rheumatic valve involvement (ste-
nosis and/or regurgitation) or secondary to ventricle dilation,
leading to mitral or tricuspid insufciency.
Surgical treatment is usually focused at the most severe
valve lesion. However, double valve replacement surgery is
being performed more frequently nowadays as an attempt to
achieve better quality of life and to improve cardiovascular
hemodynamics, reducing mortality among these patients[2,4].
Present literature lacks data on clinical or echocardiograph-
ic variables associated to in-hospital mortality in rheumatic
patients undergoing double valve replacement surgery. Thus,
this study aims to assess which of these determinants has
impact in this population.
METHODS
This is a cross-sectional retrospective study including all
rheumatic patients admitted to the Ana Neri Hospital, Salvador,
BA, Brazil, older than 18 years old, that underwent double valve
replacement surgery from January 2007 to December 2011.
Medical records were reviewed and evaluated for data collection.
The surgical procedure was performed with the patient in the
dorsal decubitus position, with a central arterial line to monitor
the mean arterial pressure and a central venous line. Median
sternotomy and systemic heparinization (0.4 mg/Kg) were
variáveis: média de idade dos pacientes que receberam alta
para casa e foram a óbito, respectivamente (36,30±13,03 vs.
45,35±17,8, P=0,011); média de hemoglobina, (11,10±2,19 vs.
9,22±2,26 g/dL, P=0,002); média do hematócrito, (34,22±5,86 vs.
28,44±6,62%, P<0,001). As classes funcionais III e IV (New York
Heart Association) estiveram associadas estatisticamente com a
mortalidade (P=0.022).
Conclusão: Os dados encontrados no estudo apresentam uma
população pouco estudada na qual os principais achados foram
a média do nível de hemoglobina/hematócrito e classe funcional
NYHA. Deve se levar em conta esses dados para a escolha do
melhor momento de cirurgia para essa população.
Descritores: Febre Reumática. Doenças das Valvas Cardíacas.
Mortalidade Hospitalar. Período Pré-Operatório.

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Rev Bras Cir Cardiovasc 2014;29(4):537-42
Fernandes AMS, et al. - Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease undergoing double valve
replacement
pid stenosis and one patient had moderate tricuspid stenosis.
Two patients presented with mild pulmonary regurgitation and
one patient presented with severe insufciency. No patients
presented pulmonary stenosis (Figure 1).
The left atrium was analyzed through echocardiography in
96 patients, ranging from a minimum of 33 mm until 129 mm
(median 53 mm). The left atrium size was not associated with
hospital mortality (P=0.785). The left ventricle diameters and
left ventricular systolic function were also not associated with
mortality (Table 2), as well as the degree of valve lesion.
When considering two distinct groups, those who were dis-
charged after surgery and those who died during hospital stay,
some statistically signicant differences can be noticed: their
mean age, respectively (36.30±13.03 vs. 45.35±17.8 years old,
P=0.011), mean hemoglobin (11.10±2.19 vs. 9.22±2.26 g/dL,
P=0.002); and mean hematocrit (34.22±5.86 vs. 28.44±6.62
%, P<0.001).
Comparisons of gender, city of origin, body mass index,
diabetes mellitus, hypertension, atrial brillation, class of heart
failure, urea, creatinine, previous cardiac surgery and kind of
prosthesis between the groups and outcomes are presented
in Table 3.
The anoxia time was 129±30 minutes, CPB time
was 163±40 minutes, and the total time of surgery was
305±66 minutes. The comparison between the mean
anoxia time, CPB time, and total surgical time in both
hospital outcomes (death x discharge) were, respec-
tively, 149.17±40.99 and 123.99±24.125 (P=0.001),
185.53±54.597 and 157.34±34.623 (P=0.006), 350.29 and
295.23±56.692±63.983 (P=0.002).
DISCUSSION
Five clinical variables were associated with mortality
during the hospitalization of rheumatic patients who under-
went double valve replacement surgery: age, hemoglobin,
hematocrit, diabetes mellitus and NYHA functional class (New
York Heart Association (NYHA) functional classication of
heart failure).
Fig. 1 - Distribution of studied patients by valvular’s injury degree of. Salvador 2007-2011.
*MI=Mitral Regurgitation; **MS=Mitral Stenosis; ***AoR=Aortic Regurgitation;
****AoS=Aortic Stenosis; *****TI=Tricuspid Regurgitation
Table 1. Clinical and epidemiological characteristics of the study
population. Salvador, 2007-2011.
Characteristics
Sex (n=104)
Man
Woman
Origin (n=104)
Capital
Interior
Body Mass Index (n=97)
Underweight
Normal
Overweight
Obesity Grade 1
Diabetes Mellitus (n=104)
Present
Absent
Systemic Arterial Hypertension (n=104)
Present
Absent
Chagas Disease (n=104)
Present
Absent
Atrial Fibrillation before DVRS (n=100)
Yes
No
Class of Heart Failure NYHA (n=94)
Class I
Class II
Class III
Class IV
Previous cardiac surgery (n=100)
Yes
No
Type of prosthesis (n=103)
Biological
Metallic
Hospital outcome (n=104)
Death
Discharged home
Nº
60
44
34
70
8
67
18
4
3
101
50
54
0
104
28
72
2
36
33
23
38
62
65
38
20
84
%
57.7
42.3
32.7
67.3
8.2
69.1
18.6
4.1
2.9
97.1
48.1
51.9
0
100
28
72
2.1
38.3
35.1
24.5
38
62
63.1
36.9
19.2
80.8
DVRS- Double valve replacement surgery; NYHA- New York Heart
Association.

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Rev Bras Cir Cardiovasc 2014;29(4):537-42
Fernandes AMS, et al. - Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease undergoing double valve
replacement
Table 3. Clinical and epidemiological characteristics and comparison between groups of hospital outcome.
Variable
Sex (n=104)
Man
Woman
Origin (n=104)
Capital
Interior
Body Mass Index (n=97)
Normal
Not normal
Diabetes Mellitus (n=104)
Present
Absent
Arterial Hypertension (n=104)
Present
Absent
Atrial Fibrillation (n=100)
Present
Absent
Class of HF NYHA (n=94)
I or II
III or IV
Urea (n=97)
Normal
Not normal
Creatinine (n=99)
Normal
Not normal
Previous cardiac surgery (n=100)
Yes
No
Type of prosthesis (n=103)
Biological
Metallic
Nº
48
36
25
59
56
26
1
83
37
47
20
60
35
41
55
23
65
15
29
51
50
33
%
46.2
34.6
24
56.7
57.7
26.8
1
79.8
35.6
45.2
20
60
37.2
43.6
56.7
23.7
65.7
15.2
29
51
48.5
32
HF NYHA=Class of Heart Failure New York Heart Association
Nº
12
8
9
11
11
4
2
18
13
7
8
12
3
15
9
10
12
7
9
11
15
5
P value
0.816
0.192
0.698
0.034
0.092
0.181
0.022
0.056
0.088
0.471
0.219
%
11.5
7.7
8.7
10.6
11.3
4.1
1.9
17.3
12.5
6.7
8
12
3.2
16
9.3
10.3
12.1
7.1
9
11
14.6
4.9
Discharged Home Death
Table 2. Average of echocardiography’s measurements of normal distribution in the study population and
average’s comparison on hospital outcome. Salvador, 2007-2011.
ECO
LVDD (n=92)
LVSD (n=91)
EF (n=94)
PASP (n=63)
Global average
63.73±15.77
42.81±12.56
60.74±12.27
58.63±22.19
Outcome
Discharged home
Death
Discharged home
Death
Discharged home
Death
Discharged home
Death
LVDD=Left Ventricular Diastolic Diameter; LVSD=Left Ventricular Systolic Diameter; EF=Ejection
Fraction; ECO=Echocardiographic Measurements; PASP=Pulmonary Artery Systolic Pressure
Average
63.52±13.5
64.65±23.89
43.53±12.50
39.71±12.76
60.78±11.51
60.56±15.92
57.38±22.14
64.55±22.49
P Value
0.792
0.261
0.948
0.335
The double valve replacement surgery is a risk factor for
death independent of preoperative data[5], mainly due to longer
duration of surgery, CPB and aortic clamping[2,6,7].
The mortality rate in the study population was 19.2%.
Despite elevated when compared to other referral centers in
developed countries, different socioeconomic proles and
different access to health between developed and developing
countries lead to a comparison limitation[8,9].

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Rev Bras Cir Cardiovasc | Braz J Cardiovasc Surg
Rev Bras Cir Cardiovasc 2014;29(4):537-42
Fernandes AMS, et al. - Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease undergoing double valve
replacement
In this study population, 59.6% of patients had functional
New York Heart Association (NYHA) class III or IV, and
24.5% were in NYHA functional class IV. No other study has a
number of patients in a so severe functional class. Studies with
low mortality rates show a maximum of 8% of the population
with NYHA functional class IV[8,10]. The lowest mortality rate
was 0.7% presented by a study which had only 0.5% of patients
in NYHA functional class IV[11] and NYHA functional class IV
has been presented as an independent risk factor for operative
mortality in double valve replacement surgery. Possibly, this
is due to an increased release of proinammatory vasodepres-
sive cytokines in NYHA functional class IV[12]. Patient with
advanced heart failure presents a state of chronic inammation,
especially in episodes of decompensation, generating greater
degree of difculty and complications during the surgical
technique performing[12].
Preoperative anemia is associated with increased morbidity
and mortality among patients undergoing cardiac surgery[13].
Patients with lower hemoglobin levels and preoperative he-
matocrit are more likely to be transfused, and the use of blood
derivates bags is an independent risk factor for mortality and
clinical complications such kidney failure, infections, and
cardiac complications, pulmonary and neurological in the rst
thirty postoperative days[14,15]. Studies evaluating mortality in
patients undergoing double valve replacement not present data
on hemoglobin and hematocrit preoperatively patients[9-11].
This prevents a proper comparison of the results of this study
which showed hemoglobin and hematocrit signicantly lower
in patients who had hospital death. The magnitude of the effect
of anemia in the preoperative surgical double valve replace-
ment as well as the optimal management of these patients lack
of data in literature.
The mean age of patients who died was 45.35±17.8 years.
Age as a mortality predictor in cardiac surgery is described
in the literature as one of the main risk factors in most
scores[15-22]. However, it should be noted that each score has its
own cut-off point from which the surgical risk is established.
The EuroSCORE indicates that there is an increased risk of
death above 60 years old and one point is given for every 5
additional years[16,17].
A previous study states that patients who were at least 50
years old had higher in-hospital mortality, regardless of the
valve surgery performed: aortic or mitral valve replacement,
double valve replacement, with or without coronary bypass
revascularization[23]. This study shows a higher surgical risk
among those with a lower mean age when compared to pre-
viously published data, since it is a more complex surgery in
critically ill patients. Therefore, existing scores in the literature
may not be suitable for predicting the actual risk for this spec-
ied population. It is possible that the relative risk with age
is established at a lower age range for this group of patients.
Some clinical variables assessed in this study showed no
inuence on in-hospital mortality. Some are part of major
risk scores for mortality risk in heart surgery, such as: female
gender, previous cardiac surgery and serum creatinine[16,19].
However, most studies evaluated these variables in all types
of cardiac surgeries, not specically double valve replacement.
Otherwise, one study that presented independent risk factors
for double valve replacement surgery, also found no inuence
of the variables mentioned above. It is noteworthy that most
of these studies were conducted in major medical centers of
the United States and Europe. This demonstrates the need to
develop scores of preoperative risk in populations with dif-
ferent socioeconomic characteristics.
Echocardiography’s measurements of the left ventricle
compared between the two groups of patients (who were dis-
charged home and who died) were not statistically signicant,
in agreement with previously published data[7]. Because they
are variables characteristic of chronic disease, it seems possible
that a certain degree of adaptation to the hemodynamic status
may occur, with no impact on in-hospital mortality. However,
it is necessary to investigate the inuence of these variables
on morbidity and mortality in a long term way.
The study has quite few limitations. It was a single center
study, which may cause bias due to the restricted population
size, limiting extrapolation of data to other populations.
CONCLUSION
This study is remarkable for highlighting the value of
age, hemoglobin, hematocrit, diabetes mellitus and NYHA
functional class as possible variables associated to in-hospi-
tal mortality of rheumatic patients undergoing double valve
replacement surgery.
A precise cut off point in the hemoglobin value to determine
and predict mortality risk should be studied in order to improve
the therapeutic management of patients who will undergo
double valve replacement. Furthermore, early indication of
heart valve surgeries may avoid a delayed procedure at an
advanced stage of the disease.
Therefore, new prospective studies in national territory are
needed to compare mortality rates between different Brazilian
centers, enabling an advance in the management of this disease
that still represents a serious public health problem.
Authors’ roles & responsibilities
AMSF Planning and writing of the manuscript
GMA Collection and analysis of data and writing of the manuscript;
statistical analysis; conception and design of the study;
completion of the operations and/or experiments
RMO Collection and analysis of data
GTB Collection and analysis of data
FFBR Interpretation and review of the manuscript
CRM Interpretation and review of the manuscript
ARD Review of the manuscript and approval of nal version
RAJ Review of the manuscript and approval of nal version

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Rev Bras Cir Cardiovasc 2014;29(4):537-42
Fernandes AMS, et al. - Evaluation of variables responsible for hospital
mortality in patients with rheumatic heart disease undergoing double valve
replacement
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