Survival in Patients with Post-myocardial Infarction Ventricular Septal Rupture: A Retrospective Observational Study
Correspondence Address :
Dr. Shilpa Suresh,
2092, Prestige South Ridge, Hosakerehalli, Banashankari 3rd Stage, Bangalore-560085, Karnataka, India.
E-mail: shilpa.suresh@gmail.com
Introduction: Post-myocardial infarction ventricular septal rupture (post-MI-VSR) is a dreaded complication with high mortality. There is a varied survival pattern among patients who have undergone surgical repair.
Aim: To assess the survival rates in patients who underwent surgical repair for post-MI-VSR in a single centre.
Materials and Methods: A retrospective observational study was conducted in the Department of Cardiothoracic Surgery at Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, India. The patient records from January 2005 to December 2020, who underwent surgical repair of post-MI-VSR, were reviewed. The perioperative variables, mortality, and survival data were analysed. Kaplan-Meier analysis was performed to assess the survival time.
Results: The mean age of the studied patients was 58.4±7.5 years. A total of 73 patients underwent surgery for post-MI-VSR. A total of 40 (55.80%) were males and 33 (45.20%) were females. Overall, 36 (49.32%) patients had diabetes, and 27 (36.99%) had hypertension. Anterior Myocardial Infarction (MI) (n=56, 76.71%) was the most common location of MI. The mean Cardiopulmonary Bypass (CPB) and clamp times were 144.05±59.09 and 105.38±38.34 minutes, respectively. The mean survival time was 2619.564 days {95% Confidence Interval (CI) 2105.936 to 3133.192}.
Conclusion: As revascularisation confers a significant survival advantage, VSR repair with concomitant Coronary Artery Bypass Graft (CABG) appears beneficial.
Cardiac, Complications, Surgery, Ventricle
Ventricular Septal Rupture (VSR) is an uncommon but dreaded complication of Acute Myocardial Infarction (AMI) (1). Post-MI-VSR is a fatal complication that shows poor outcomes with medical treatment and is associated with high morbidity and mortality (42.9%) when surgical interventions are performed (2). The incidence of VSR following ST-segment elevation MI has decreased from 1%-3% in the pre-reperfusion era to 0.17%-0.31% following primary percutaneous coronary intervention (3),(4),(5),(6),(7),(8). Optimal reperfusion of the infarct-affected artery prevents VSR by salvaging myocardial tissue and limiting infarct expansion. In contrast, late reperfusion is associated with an increased risk of complications (5). The most common cause of VSR is full-thickness (transmural) MI in one of the following coronary arteries: Left anterior descending coronary artery (apical VSR), Dominant right coronary artery (basal VSR), and dominant left circumflex artery. Partial-thickness infarcts can also increase the risk of VSR (9). VSR frequently occurs within the first week post-MI (3-5 days). The clinical symptoms of VSR range from a symptomless cardiac murmur to cardiogenic shock (10).
The outcome is poor and is seen in old age, female sex, unstable haemodynamics at presentation, and delay in surgery. Perioperative haemodynamic shock and incomplete revascularisation are strong predictors of poor survival (11). The first open repair of a VSR was performed by Cooley DA et al., in 1957 (12). Since then, techniques have improved, leading to better outcomes (13),(14). It is challenging to determine the exact border between infarcted and healthy myocardium, making suture placement difficult in such conditions. Therefore, considering this literature background, the present study was planned to assess the survival pattern of post-MI-VSR patients who underwent surgery in a single centre.
A retrospective observational study was conducted in the Department of Cardiothoracic Surgery at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, India. The records of patients with Post-MI-VSR were retrospectively retrieved from the hospital database. The records were retrieved over a period of 15 years (from January 2005 to December 2020). Institutional Ethical Clearance (IEC) was obtained (ref: SJICR/EC/2020/026).
Inclusion criteria: All patients who underwent surgery for VSR were included in the study.
Exclusion criteria: Incomplete records and patients who were managed medically were excluded from the study.
Study Procedure
The post-MI-VSR patients were admitted and evaluated by cardiologists, following the hospital protocol, and then referred for surgery. As the study site was a tertiary care set-up, the patients presented at different stages of the disease. Elective surgery was planned for haemodynamically stable patients, while emergency surgery was planned for haemodynamically unstable patients or those showing a trend of clinical deterioration (falling blood pressure, raising creatinine, decreasing oxygen saturation). In most cases, an Intra-aortic Balloon Pump (IABP) was inserted.
Patient demographics, including age, sex, diagnosis, and co-morbidities such as diabetes, hypertension, and renal dysfunction, were reviewed. Timing of IABP insertion and preoperative evaluation details of coronary angiogram and echocardiogram findings were noted. All patients underwent surgery with conventional CPB established, and VSR repair was performed using an exclusion technique with a Gore-Tex patch and interrupted sutures. The left ventricular cavity was closed using interrupted sutures with the buttressing technique. Patients who had non-graftable target vessels, complete occlusion, and large infarct areas did not undergo concomitant CABG, while this was performed in the remaining cases based on indications. Some patients also underwent additional procedures such as mitral valve replacement and the Dors procedure (15). Postoperative mortality was considered as the outcome variable, and CPB time, revascularisation of the culprit vessel, preoperative status, and surgical characteristics were studied as relevant variables.
Statistical Analysis
Data analysis was performed using Statistical Package for Social Sciences (SPSS) version 22.0. Descriptive analysis of categorical variables was done using frequency and percentage, while mean and Standard Deviation (SD) were used for continuous variables. Kaplan-Meier survival analysis was conducted to evaluate cumulative survival and time to event for outcome variables. Mean survival was calculated for the study participants.
A total of 73 patients were included in the study. The mean age of the studied patients was 58.4±7.5 years (range: 35 to 72 years), and 40 (55.80%) of them were males. The mean serum creatinine in the preoperative evaluation was 1.97±0.94 mg/dL, and 44 (60%) of them had renal dysfunction with serum creatinine levels >1.5 mg/dL. Overall, 65 (89.04%) of the patients underwent IABP insertion. Among the patients, 36 (49.32%) had one-vessel disease, 12 (16.44%) had two-vessel disease, and 17 (23.29%) had three-vessel disease. A total of 19 (26.03%) patients experienced postoperative complications, including renal failure (n=9), residual VSR (n=5), respiratory failure (n=3), and bleeding (n=2) (Table/Fig 1).
The mean survival time was 2619.564 days (95% CI 2105.936 to 3133.192) (Table/Fig 2),(Table/Fig 3).
The median survival time was 2190.000 days for patients who underwent CABG and VSR repair (Table/Fig 4),(Table/Fig 5).
The mean CPB time was 194.024 minutes (95% CI 162.936 to 225.112) (Table/Fig 6),(Table/Fig 7). The univariate logistic regression analysis had shown statistically significant association with survival time (odds ratio;1.002 and p<0.001) (Table/Fig 8).
The VSR is a rare and life-threatening complication that can occur after AMI (2),(8). The incidence of AMI-VSR has decreased with the introduction of reperfusion procedures (15). However, the mortality rate associated with VSR remains high (4). VSR typically occurs within 2-8 days of MI, and if not diagnosed and surgically treated, patients may die from congestive cardiac failure (16). Even with timely surgery, the in-hospital mortality rate remains high, and there has been no significant reduction in this rate over the years, making VSR the most lethal cardiac surgical condition (2),(3),(17). However, due to the relatively low incidence of post-MI-VSR, there is limited available literature on the topic (2),(18),(19),(20). Clear guidelines on management and timing of surgical intervention are also lacking (3),(17),(21),(22).
Haemodynamic instability in these patients can lead to cardiogenic shock, with involvement of the right ventricle and friable tissue around the infarct area, resulting in complex defects that can expand over time. Therefore, preoperative stabilisation of the patient is critical. Management of haemodynamically compromised patients involves decreasing left-to-right shunt with afterload reducing agents and insertion of an IABP. IABP increases coronary blood flow, reduces stress on the ventricular walls, and decreases oxygen demand (8). In the present study, the majority of patients (91.78%) underwent IABP insertion. However, more evidence from prospective studies is needed to confirm the association between IABP insertion and patient survival.
The role of concomitant CABG in post-MI-VSR is debated. While CABG can address the underlying coronary artery disease and protect against long-term ischaemic risk, it also carries the risk of longer CPB and cross-clamp times (23). Revascularisation of the culprit vessel can be technically challenging, especially if it is located within the infarcted segment and cannot be preserved within the repair zone. In such cases, CABG may be necessary, but it is associated with higher mortality in patients with multivessel CAD (23). In the present study, revascularisation of the culprit vessel was possible in only 50.68% of the patients. The findings of the present study were compared with published literature in (Table/Fig 9) (2),(3),(16),(24),(25),(26),(27).
Limitation(s)
The present retrospective study conducted in a single centre provides insights into the post-MI-VSR condition and its survival. However, it is important to note that the current study has certain limitations due to its retrospective nature. One limitation is the potential presence of confounding variables, such as other systemic diseases or infections, which may have not been addressed or accounted for in the analysis. Additionally, other factors that could influence mortality, such as liver and kidney functions, may have been missed due to the extraction of only study-relevant variables from the hospital records.
To overcome these limitations and gain a more comprehensive understanding of post-MI-VSR, it is recommended to conduct prospective studies with a larger sample sizes and in multicentre settings. Such studies would allow for better control of confounding variables and provide more robust and Generalisable results.
In conclusion, the present analysis of post-MI-VSR repair using a single-centre database demonstrates that post-MI-VSR remains a devastating complication. Repairing post-MI-VSR is still associated with a high-risk, particularly in cases requiring emergency surgery, which has a higher mortality rate. The present study findings indicate that prolonged CPB time and postoperative complications are factors significantly associated with mortality. Patients in whom CABG was feasible showed a survival advantage. Given that revascularisation offers a survival benefit, the authors recommend VSR repair with concomitant CABG.
The authors would like to thank Dr. Sumitra Selvem, Senior Resident, Department of Biostatistics, St. John’s Medical College for her contribution in the statistical analysis of the project; and Dr. Giridhar Kamalapurkar, Professor, Department of Cardiothoracis Surgery, Sri Jayadeva Institute of Cardiovascular Sciences and Research for performing surgeries in all the cases included in the study, guidance in the protocol and editing of the manuscript.
DOI: 10.7860/JCDR/2023/63247.18471
Date of Submission: Feb 27, 2023
Date of Peer Review: May 18, 2023
Date of Acceptance: Jun 15, 2023
Date of Publishing: Sep 01, 2023
AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? Yes
• Was informed consent obtained from the subjects involved in the study? Yes
• For any images presented appropriate consent has been obtained from the subjects. Yes
PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Mar 07, 2023
• Manual Googling: May 26, 2023
• iThenticate Software: Jun 13, 2023 (14%)
ETYMOLOGY: Author Origin
EMENDATIONS: 6
- Emerging Sources Citation Index (Web of Science, thomsonreuters)
- Index Copernicus ICV 2017: 134.54
- Academic Search Complete Database
- Directory of Open Access Journals (DOAJ)
- Embase
- EBSCOhost
- Google Scholar
- HINARI Access to Research in Health Programme
- Indian Science Abstracts (ISA)
- Journal seek Database
- Popline (reproductive health literature)
- www.omnimedicalsearch.com