Does Gender Affect the Outcomes of Multiple Valve Heart Surgery?

doi:10.4236/ojts.2012.21001

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Open Journal of Thoracic Surgery, 2012, 2, 1-4

http://dx.doi.org/10.4236/ojts.2012.21001 Published Online March 2012 (http://www.SciRP.org/journal/ojts)

Does Gender Affect the Outcomes of Multiple Valve Heart

Surgery?

Iskander Al-Githmi

Department of Surgery, Division of Cardiothoracic Surgery, King Abdulaziz University Hospital, Jeddah, Saudi Arabia.

Email: [email protected]

Received December 17th, 2011; revised January 26th, 2012; accepted February 4th, 2012

ABSTRACT

Background: Multiple valve surgery exposes patients to major morbidity and mortality. Little is known about the effect

of gender on the outcomes of multiple valve surgery. Methods: In 69 patients who had multiple valve surgery for

rheumatic valvular heart disease, 51 patients had mitral and aortic valve replacement, 9 patients had mitral and aortic

valve replacement and tricuspid valve repair, 4 patients had mitral valve replacement and tricuspid valve repair, 4 pa-

tients had mitral and tricuspid valve repair, and 1 patient had mitral and tricuspid valve replacement. Outcomes were

evaluated with univariate analysis. Results: Women had significantly smaller body surface area and smaller left ven-

tricular end-systolic area than men. Women and men had similar left ventricular ejection fraction and New York Heart

Association functional class. Univariate analysis showed that in women (but not men), older age, atrial fibrillation,

lower left ventricular ejection fraction, and New York Heart Association functional class II and III were associated with

longer hospital and intensive care unit stay. In men (but not women), longer cardiopulmonary bypass time was associ-

ated with increased left ventricular end-systolic area at 12 months after surgery. Longer aortic cross-clamp time was

associated with increased left ventricular end-systolic area in men but only weakly in women. Conclusion: We con-

cluded that gender is an independent predictor of outcomes after multiple valve heart surgery.

Keywords: Gender; Multiple Valves; Surgery; Outcomes

1. Introduction

During the past 2 decades, improvements have occurred

in the clinical outcomes of patients with multiple valvu-

lar heart disease. Many studies have examined the effect

of gender-related differences and outcomes after isolated

valvular heart surgery, isolated coronary artery bypass

grafting, and valvular heart surgery with coronary artery

bypass grafting [1-10]. However, knowledge about the

effects of gender-related differences on the outcomes of

multiple valvular heart surgery is limited. The current

prospective study aimed to examine the association of

gender with the outcomes of multiple valvular heart sur-

gery.

2. Materials and Methods

Multiple valvular heart surgery was performed on 73 con-

secutive patients from January 1999 to December 2005.

Of these 73 patients, 4 women were excluded because of

missing data, leaving 69 patients (43 women and 26 men)

who were enrolled in the study and were prospectively

followed. All 69 patients had rheumatic valvular heart

disease and underwent primary multiple valve surgery,

defined as a single operation that involved > 1 valve that

included a combination of aortic valve replacement, mi-

tral valve repair or replacement, and/or tricuspid valve

repair or replacement (Table 1).

The outcomes reviewed included duration of intensive

care unit (ICU) stay, hospital stay, and mechanical venti-

lation; and postoperative atrial fibrillation, left ventricu-

lar ejection fraction, left ventricular end-systolic area at

12 months after surgery and mortality at 30 days after

surgery.

3. Data Analysis

Two independent samples t-test, Mann-Whitney test,

Kruskal-Wallis test, exact chi-square test, and Spear-

man’s correlation coefficient were used to assess the

demographic characteristics of the patients and the ef-

fects of various risk factors on the different outcomes of

men and women separately, wherever appropriate. All

the statistical tests were performed using SPSS for Win-

dows (Release 14.0; SPSS Inc., Chicago, Illinois, USA).

The level of significance was set at P ≤ 0.05.

4. Results

Women and men were similar in age, left ventricular

Does Gender Affect the Outcomes of Multiple Valve Heart Surgery?

ejection fraction, New York Heart Association functional

class, medical comorbidities, valve disease type, and

cardiopulmonary bypass and cross-clamp times (Table

1). Women had significantly smaller body surface area

and smaller left ventricular end-systolic area than men

(Table 1). Surgery performed in most patients was com-

bined mitral and aortic valve replacement (Table 1).

Univariate analysis showed that in women (but not

men), older age, atrial fibrillation, lower left ventricular

ejection fraction, and New York Heart Association func-

tional class II and III were associated with longer hospi-

tal and ICU stay (Table 2). In men (but not women),

longer cardiopulmonary bypass time was associated with

increased left ventricular end-systolic area at 12 months

after surgery (Table 2). In addition, longer aortic cross-

clamp time was associated with increased left ventricular

end-systolic area in men but only weakly in women (Ta-

ble 2).

Table 1. Clinical characteristics of patients who had multiple valve heart surgery*.

Clinical characteristics Women Men P ≤ †

Number of patients 43 26 -

Age (y) 50 ± 11 49 ± 15 NS

Body surface area (m2) 1.5 ± 0.1 1.7 ± 0.2 0.003

Left ventricular end-systolic area (mm2) 36 (29, 31) 39 (35, 49) 0.02

Left ventricular ejection fraction (%)

<40 3 (7%) 2 (8%)

40 - 60 20 (47%) 14 (56%) NS

>60 20 (47%) 9 (36%)

NYHA class

I 6 (4%) 3 (12%)

II 23 (53%) 13 (50%) NS

III 14 (32%) 9 (35%)

IV 0 1 (4%)

Comorbidities

Atrial fibrillation 28 (68%) 15 (63%) NS

Congestive heart failure 7 (18%) 9 (35%) NS

Hypertension 4 (10%) 2 (8%) NS

Diabetes mellitus 7 (16%) 0 (0%) NS

Stroke 2 (5%) 1 (4%) NS

COPD 2 (8%) 0 (0%) NS

Aortic valve disease

Stenosis 26 (61%) 12 (46%) NS

Regurgitation 35 (81%) 25 (96%) NS

Mixed 23 (54%) 12 (46%) NS

Mitral valve disease

Stenosis 32 (74%) 18 (69%) NS

Regurgitation 36 (84%) 21 (81%) NS

Mixed 25 (58%) 13 (50%) NS

Tricuspid valve disease

Stenosis 0 (0%) 1 (4%) NS

Regurgitation 31 (72%) 18 (69%) NS

Operations

MVR + AVR 29 (67%) 22 (85%)

MVR + AVR + TV repair 6 (14%) 3 (12%)

MVR + TV repair 3 (7%) 1 (4%) NS

MV repair + TV repair 4 (9%) 0 (0%)

MVR + TVR 1 (2%) 0 (0%)

Cardiopulmonary bypass time (min) 142 (120, 160) 153 (125, 188) NS

Aortic cross-clamp time (min) 119 (95, 129) 121 (106, 147) NS

Postoperative mechanical ventilation (>1 d) 58 (43,63) 48 (22,55) NS

*N = 69 patients. Data reported as mean ± SD; number (percent) patients, or median (interquartile range). Abbreviations:

AVR, aortic valve replacement; COPD, chronic obstructive pulmonary disease; MV, mitral valve; MVR, mitral valve re-

placement; NYHA, New York Heart Association; TV, tricuspid valve; TVR, tricuspid valve replacement; †NS, not signifi-

cant (P > 0.05).

Does Gender Affect the Outcomes of Multiple Valve Heart Surgery? 3

Table 2. Univariate analysis of postoperative outcomes after multiple va l ve he art surger y *.

Risk Factor Length of

hospital stay

Intensive care

unit stay

>1 day

Mechanical

ventilation

>1 day

Left ventricular

end-systolic area at 12

months after surgery

Age

Women 0.418#* 58 (34, 63) 58 (38, 63) 0.169

Men –0.046 48 (22, 55) 48 (22, 55) –0.496

All 0.25* 52 (22, 63) 52 (22, 63) –0.137

Left ventricular ejection fraction (%)

Women <40 12 (8, 35) 2 (67%) 0 (0%) 32 (32, 32)

40 - 60 10 (6, 36) 3 (15%) 3 (15%) 31 (25, 45)

>60 12 (7, 25) 0 (0%) 0 (0%) 32 (15, 45)

Men <40 9 (8, 9) 0 (0%) 0 (0%) 0 (0)

40 - 60 12 (7,27) 1 (7%) 1 (7%) 42 (39, 49)

>60 13 (8, 30) 1 (11%) 1 (11%) 35 (28,39)

All <40 9 (8, 35) 2 (40%) 0 (0%) 32 (32, 32)

40 - 60 10 (6, 36) 4 (12%) 4 (12%) 36 (25, 49)

>60 12 (7, 30) 1 (3%) 1 (3%) 33 (15, 45)

Atrial fibrillation

Women Yes 12 (8, 36) 5 (18%) 3 (11%) 33 (15, 45)

No 8 (6, 20) 0 (0%) 0 (0%) 28 (25, 33)

Men Yes 12 (8, 30) 1 (6%) 1 (7%) 37 (30, 43)

No 12 (9, 27) 1 (11%) 1 (11%) 37 (28, 41)

All Yes 12 (8, 36) 6 (14%) 4 (9%) 35 (15, 45)

No 10 (6, 27) 1 (5%) 1 (5%) 29 (25, 41)

Chronic obstructive pulmonary disease

Women Yes 13 (8, 18) 2 (100%) 2 (100%) 0 (0)

No 10 (6, 36) 2 (9%) 1 (5%) 32 (25, 45)

Men Yes 0 (0%) 0 (0%) 0 (0)

No 12 (7, 30) 3 (20%) 3 (20%) 41 (39, 49)

All Yes 13 (8, 18) 2 (100%) 2 (100%) 0 (0)

No 11 (6, 36) 5 (14%) 4 (11%) 33 (25, 49)

Cardiopulmonary bypass time

Women 0.247 147 (81, 304) 147 (81, 304) –0.068

Men –0.07 219 (122, 324) 219 (122, 324) 0.703

All 0.169 183 (81, 324) 183 (81, 32) 0.263

Left ventricular end-systolic area

Women –0.086 34 (24, 52) 34 (30, 38) 0

Men –0.336 38 (22, 47) 38 (22, 47) –5.5

All –0.117 38 (22, 52) 38 (22, 47) –4

Aortic cross-clamp time

Women 0.163 122 (51, 219) 122 (51, 187) –0.125

Men –0.087 142 (106, 260) 142 (106, 260) 0.527

All 0.096 132 (51, 260) 132 (51, 260) 0.158

Data reported as number (percent) patients, median (interquartile range), or #Spearman correlation coefficient, *P < 0.05;

**P < 0.01; ***P < 0.001.

Does Gender Affect the Outcomes of Multiple Valve Heart Surgery?

There were 2 deaths within 30 days of surgery, in-

cluding 1 woman (2%) who died of multiple organ fail-

ure after primary aortic and mitral valve replacement and

tricuspid valve repair, and 1 man (5%) who died of aortic

dissection after primary aortic and mitral valve replace-

ment.

5. Discussion

This study showed that older age, atrial fibrillation, lower

ejection fraction, and NYHA functional class II and III

were associated with longer hospital and ICU stay in

women. In men, longer cardiopulmonary bypass time

was associated with greater left ventricular end-systolic

area at 12 months after surgery. Other risk factors also

may have influenced the outcomes of multiple valve

procedures but could not be identified because of the

small number of patients included in this study.

Several reports have assessed the effect of gender on

isolated coronary artery bypass grafting procedures, with

contradictory outcomes [1-6]. Women undergoing com-

bined valvular surgery and coronary artery bypass graft-

ing may be at greater risk of morbidity during the pe-

rioperative period, but long-term survival may be similar

in woman and men [7]. The association between longer

cardiopulmonary bypass duration and left ventricular

end-diastolic area at 12 months in men may explain why

men have higher levels of gene expression changes in

response to cardiopulmonary bypass [8]. Direct com-

parison of outcomes between men and women may be

confounded by differences in disease patterns and tech-

nical surgical considerations between men and women

[9,10]. Nevertheless, women and men have similar bene-

fits from combined procedures [7].

In summary, the present data suggest that 1) women

and men have similar benefits from multiple valve pro-

cedures and 2) men experience more negative effects of

prolonged cardiopulmonary bypass on left ventricular

end-systolic area at 12 months after surgery than women.

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