Predictors for the Outcome of Aortic Regurgitation After Cardiac Surgery in Patients with Ventricular Septal Defect and Aortic Cusp Prolapse in Saudi Patients.

BACKGROUND AND AIM: Aortic valve (AV) prolapse and subsequent aortic regurgitation (AR) are two complications of ventricular septal defects (VSD) that are located close to or in direct contact with the AV. This finding is one of the indications for surgical VSD closure even in the absence of symptoms to protect the AV integrity. The goal of our study was to assess the outcome and to identify the predictors for improvement or progression of AR after surgical repair.
MATERIALS AND METHODS: A retrospective study of all children with VSD and AV prolapse who underwent cardiac surgery at King Abdulaziz Cardiac Centre in Riyadh between July 1999 and August 2013.
RESULTS: A total of 41 consecutive patients, operated for VSD with prolapsed AV, with or without AR, were reviewed. The incidence of AV prolapse in the study population was 6.8% out of 655 patients with VSD. Thirty-six (88%) patients had a perimembranous VSD, and four had doubly committed VSD. Only one patient had an outlet muscular VSD. Right coronary cusp prolapse was found in 38 (92.7%) patients. Preoperative AR was absent in five patients, mild or less in 25 patients, moderate in seven, and severe in four patients. Twenty-six patients showed improvement in the degree of AR after surgery (Group A), 14 patients showed no change in the degree of AR (Group B) while only one patient showed the progression of his AR after surgery. Those with absent AR before surgery remained with no AR after surgery. Improvement was found more in those with mild degree of AR preoperatively compared to those with moderate and severe AR. Female gender also showed a tendency to improve more as compared to male.
CONCLUSION: Early surgical closure is advisable for patients with VSD and associated AV prolapse to achieve a better outcome after repair and to prevent progression of AR in future.

INTRODUCTION

Aortic valve (AV) prolapse and subsequent regurgitation are two important complications of ventricular septal defects (VSD) that are located close to or in direct contact with the AV, with an incidence ranging from 5% to 10%.[1234] This includes all the perimembranous and doubly committed juxta-arterial defects and outlet muscular VSD. While the right coronary cusp (RCC) is usually involved in case of AV prolapse with VSD, the noncoronary cusp is less frequently affected. Involvement of the left coronary cusp is very rare. Pathophysiology of AV prolapse and aortic regurgitation (AR) in patients with a VSD is attributed to many mechanisms that include deficient structural support for leaflets adjacent to the VSD, abnormal commissural suspension, lack of appositional forces, lack of continuity between the aortic media, annulus of AV, and the ventricular septum,[567] in addition, to the venturi effect which leads to suction and subsequent deformity of leaflets adjacent to the defect.

With time, the prolapsing AV becomes incompetent because of significant damage to the valve cusp and annulus.[8] The prolapsing AV may completely close the VSD so that the shunt physiology may disappear with progressive development of AR.

Surgical closure of the defect is indicated for patients with heart failure and those with associated AV complications, and it is recommended by some authors to close the defect early, even in the absence of AV deformities, to prevent AV complications.[9] Surgical intervention with aortic valvuloplasty has been offered in some patients with AV prolapse and regurgitation. It is usually performed if the degree of AR or cusp prolapse is moderate to severe particularly when there is obvious prolapse of cusp and sinus through the VSD into the right ventricular outflow stract during systole and diastole.[1011]

This study aims to evaluate the short- and intermediate-term outcome of patients who underwent surgery for VSD with AV prolapse and AR and to assess the predictors for improvement or progression of AR after surgery.

MATERIALS AND METHODS

This is a retrospective study in which all children with VSD and AV prolapse who underwent cardiac surgery at King Abdulaziz Cardiac Centre in Riyadh between July 1999 and August 2013 were reviewed by transthoracic and transoesophageal echocardiography (TTE) using Hewlett Packard Sonos 550 and Philips IE-33.

Patients with AV prolapse in addition to the concomitant subaortic membrane or bicuspid AV, and patients with VSD and AR but with no evidence of coronary cusp prolapse (CCP) were excluded from the study. The size and type of the VSD were determined, the degree of AR preoperatively was assessed using jet width, jet area ratio, vena contracta, and reversal flow in descending, or abdominal aorta (according to the American Society of Echocardiography Guidelines).[12] The RCC deformity (RCCD) index and RCC imbalance index (R/L) were measured on the echocardiograms as described by Tomita et al.[1314] RCCD was calculated by dividing the length of the prolapsed part of the RCC at the end of systole by the ring diameter of the AV while R/L was obtained as the width of the RCC divided by the width of the left coronary cusp at end diastole [Figure 1].

Figure 1

The right coronary cusp deformity index and right coronary cusp imbalance index (R/L)

Patients underwent VSD closure alone or with AV repair if AR was moderate or more in its severity. Patients were categorized according to the degree of AR preoperatively into: None, mild, moderate, and severe. Serial postoperative TTE were reviewed to assess the progression of AR. We defined AR to have improved if the degree of AR changed one step back and AR to have deteriorated if it progressed to one step more, in addition to the entity of no change. Based on this definition, patients were divided into two groups: The first group consists of patients who showed improvement of their AR after surgery (Group A), the second group consists of those patients in whom surgical closure of VSD did not result subsequently in any change in the degree of their AR (Group B).

Statistical analysis

Baseline characteristics and demographic data of the study population are presented in Table 1.

Table 1

Baseline characteristics and demographic data

Categorical data are shown as total number and in percent. Continuous data are presented as a mean and standard deviation for normally distributed data and median and interquartile range for nonnormally distributed data. Student t-test and nonparametric tests were applied to compare continuous variables. Chi-square test and Fisher's exact test were used to compare categorical values in the two groups as appropriate. All the analysis was run using IBM SPSS statistic program version 21 (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, Ny: IBM Corp).

RESULTS

The total number of patients who underwent VSD surgical closure during the study period was 655 children, of those 45 patients (6.8%) had VSD with CCP [Figure 2]. Four patients were excluded: Three of them had a subaortic membrane, and one had bicuspid AV.

Figure 2

Flow chart of our study population

Median follow-up period was 14 months. Thirty-six cases out of 41 (88%) had perimembranous VSD (PMVSD), four patients out of 41 (10%) with doubly committed VSD (DCVSD), and one patient had muscular outlet VSD (2%). Mean age at the time of surgery was 3.5 years (±2.8) [Table 1]. There were no operative mortalities nor postoperative morbidities in the study group. Twenty-six patients (Group A) showed improvement of their AR after surgery while 14 patients (Group B) did not show any change. One patient showed worsening of AR after surgery; thus, he was not fitting with any of the groups. There were no differences between Group A and Group B with regard to their demographic data including weight, height, or age at the time of surgery, but there was a difference related to gender: 86.7% of females showed improvement compared to 56% of males (P = 0.044) [Table 2].

Table 2

Baseline characteristics in both groups (improvement vs. no change) postsurgical intervention

There was no statistical difference between the two groups with regard to type or size of the VSD and the type of prolapsed coronary cusp; the same was true for RCCD and R/L. No statistical difference was found between those who had AV repair and those who did not [Table 3]. When comparing the two groups in regard to the degree of AR preoperatively, we found five patients with no AR; none of these patients developed AR after surgery during a median follow-up time of 14 months. Seventy-three percent of the patients in Group A (improved group) had mild, 19.2% moderate, and 7.7% severe AR before surgery (P = 0.031) [Figure 3]. Two patients needed redo surgery: One continued to have severe AR and required later AV replacement, in the second patient, the AR progressed from moderate to severe and a second surgery for AV repair had to be carried out, but the patient is still under observation and follow-up.

Table 3

Echocardiographic assessment of postoperative improvement

Figure 3

The impact of the degree of aortic regurgitation preoperatively on postoperative outcome

DISCUSSION

In our study, the incidence of aortic cusp prolapse is 6.8% of all patients with VSD. The PMVSD is the most common type (88%) of VSD associated with aortic cusp prolapse in our series. In contrast, it was reported in the oriental population that the DCVSD has a higher association with aortic cusp prolapse.[15]

We found that patients with mild AR at the time of VSD repair will improve or at least will not progress to more severe AR postsurgery. Similar to our result, Chiu et al.[16] reported that patients with a less than moderate degree of preoperative AR rarely progressed with their AR after VSD repair. They concluded that severity of preoperative AR and older age (≥15 years) at the time of VSD repair were the major risk factors for significant postoperative AR and subsequent AV replacement while the VSD type was not a predictor for AR progression after surgical repair.[16] In our study population, we could not find a significant difference between the two groups in regards to age at the time of surgery. However, compared to the patients in the study by Chiu et al.,[16] our patients were operated at a younger age with a mean of 3.5 years. Trusler et al.[11] reported that age at repair and position of the VSD were not significant risk factors for valvuloplasty failure or reoperation.

Similarly to our findings, Sim et al.[17] reviewed 45 patients with DCVSD and concluded that if the surgical closure of VSD was performed before the onset of AV deformity, the progression of AR can be prevented. Hence, they recommended to close DCVSD once the AV deformity is present before the onset of AR.[18]

On the other hand Saleeb et al.[19] recommended that in patients with subaortic VSD and prolapse of the AV with no evidence of AR, prophylactic surgery has not proved to change the clinical course in this group as many of these patients may not develop AR; however, they should be followed closely for the development of AR. In line with this opinion, Bütter et al.[20] recommended that for children with small PMVSD and cusp prolapse surgery is indicated only if there is clinical evidence of AR and progressive left ventricular enlargement. Furthermore, Karpawich et al.[21] commented that surgery can be delayed in children >5 years of age with minimal valvular involvement.

Okita et al.[22] reported that a PMVSD and multiple valvuloplasties were significant contributing factors for residual regurgitation after aortic valvuloplasty. In another study, Elgamal et al.[23] found that plication of more than one end of the prolapsed cusp was one of the possible risk factors of AV repair failure while in our study, aortic valvuloplasty failed in only two patients. One of them continued to have severe AR requiring AV replacement, and the other one progressed to severe AR resulting in a redo AV repair.

As reported in previous papers, progress in surgical technique has substantially decreased the morbidity and mortality of surgical closure, with the risk of mortality for all patients being <1%.[24]

CONCLUSION

Based on the results of this study, we think that early surgical closure is advisable for patients with VSD and associated AV prolapse to achieve a better outcome after repair and to prevent progression of AR in future.

Study limitations

Our study is not without limitations. The first limitation is the fact that we used a cross-sectional retrospective design; thus, our study is subject to all of the inherent biases that are inevitably related to this type of investigation. We need a prospective study in future to detect the influence of the different predictors. The next limitation of our study is associated with the fact that our population number is small as the study has been conducted at a single center. Further, our postoperative follow-up interval is probably too short in some patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.