Transcatheter Aortic Valve Implantation (TAVI) Versus Surgical Aortic Valve Replacement (SAVR): A Retrospective Analysis from a Tertiary Care Hospital

Introduction

The most prevalent heart valve disease, aortic valve stenosis, is a leading cause of morbidity and mortality globally. The aortic valve (AV) is located between the left ventricle and the aorta, which is a main systemic blood channel that supplies blood to all bodily organs and tissues. Left ventricular enlargement, as well as the accompanying symptoms of exertion dyspnea, chest discomfort, and possibly syncope, might occur. The severity of the problem determined by a number of echocardiographic pa- rameters, including Aortic Stenosis jet velocity, mean transval- vular pressure gradient, and AV area by continuity equation, in addition to the extent of these clinical symptoms.

Aortic valve replacement is the ultimate treatment for severe Aortic Stenosis. The defective heart valve replaced with a new, functional valve, which can be constructed of mechanical or bio prosthetic material. Surgical AVR has long been the gold standard of therapy for severe, symptomatic AS, and it is rec- ommended by US and European standards. It has been demon- strated to improve symptoms and increase survival rates. Tran- scatheter aortic valve implantation (TAVI), commonly known as Trans catheter aortic valve replacement is a less invasive method to AVR that has lately gained popularity. Both techniques used to provide sufficient hemodynamic parameters, symptom allevi- ation, and increased survival.

A thorough sternotomy or minimally invasive surgical incisions are two surgical techniques to AVR that have shown equivalent results. The femoral artery is the standard route for TAVI. Alter- native access locations are used in some groups, such as patients with severe peripheral artery disease. The Trans subclavian ar- tery and, less typically, the Trans carotid or transcaval methods are among them. The advantage of such techniques is that they allow access in a less invasive manner, without having to open the chest cavity, which makes them a desirable option for old, frail patients who are at high surgical risk. The Trans apical and direct Trans aortic methods are two more common alternate ac- cess locations. SAVR is now being tested in comparison to TAVI in different populations, indicating a rising trend toward less in- vasive techniques.

There has been a lot of interest and growth in TAVR because of the shifting patient profile and the degree of comorbidities. In patients with AS, TAVR is a less intrusive and morbid technique to AVR that has recently been investigated in comparison to me- dicinal treatment and SAVR. The first TAVR investigations in-cluded inoperable and high-risk patients, as determined by their STS-PROM scores. When compared to medical therapy, TAVR resulted in higher survival, a lower risk of repeat hospitalization, and a lower rate of cardiac symptoms (25.2 percent vs 58 percent after one year; all P.05). In high-risk patients TAVR compared to SAVR lead to a somewhat improved survival at 1 year (75.8% vs 73.2%; P =.44).

In recent years, minimally invasive aortic surgery has estab- lished itself as a viable alternative to traditional sternotomy in the operational management of aortic disease; however it is only available at a few cardiac surgery centers and in locations where TAVR is not available. MAVR is associated with better clinical results especially in high-risk elderly patients. Previously pub- lished findings from a 10-year study of 552 matched pairs, find- ing that MAVR patients had shorter ventilation times, shorter ICU stays, and shorter LOS, but no differences in short- or long- term survival or the need for operative intervention.

While TAVR appears to offer a demonstrable benefit in terms of reducing acute kidney injury and the need for blood transfu- sions, and it is linked to a higher risk of permanent pacemaker installation, moderate-to-severe paravalvular regurgitation, and vascular problems. Furthermore, there is a lack of long-term data on the TAVR valve's longevity, which is cause for concern. Daubert et al. recently looked at the long-term performance of TAVR valves in terms of hemodynamic and valvular profile in patients who had previously participated in the PARTNER I trial and found no change in AV area, total transvalvular or paraval- vular aortic regurgitation, or total transvalvular or paravalvular aortic regurgitation over 5 years [8]. Despite these results sug- gesting that valve performance and cardiac hemodynamics are stable after implantation of TAVR valves, valve durability is still unknown and has to be cautiously indicated in the young low- risk population.

In Pakistan, Ali Ammar and colleagues led the first study to judge the safety and effacy outcomes following TAVI. His study included 100 consecutive patients with severe Aortic Stenosis undergoing TAVI. Sixty-three (63.0%) patients were males, and the mean age was 67.38 ± 10.73 years. Atrioventricular block- ages were reported in 22% of instances, with major vascular access site problems occurring in 14% of cases. Patients' symp- toms were significantly different before and after the operation. During their stay in the hospital, eight individuals (8%) died. At the one-month follow-up, 76 percent of patients had no restric- tions on their physical activity.

Objective

To compare the post-operative complication rate in Transcath- eter Aortic Valve Implantation [TAVI] vs Surgical Aortic Valve Replacement [SAVR] within one week of the operation.

Methods

Study Type: Two separate cohorts of patients would be included in this retrospective cohort study. The first group is of patients who undergo traditional open-heart surgery at our hospital for valve replacement, whereas the other cohort would be of pa- tients who undergo valve replacement procedure using TAVI.

Study Location: The study was conducted at a medical hospital based in Peshawar. The departments of cardiology were request- ed to allow requisition of data from both surgical procedures.

Sampling Technique: Records of all the patients who under- went TAVI and SAVI in the last 5 years preceding the survey and fulfilling our inclusion were included in our study using purpo- sive sampling method until the desired sample size is achieved.

Study Population: All the patients who underwent Transcathe- ter Aortic Valve Implantation [TAVI] and Surgical Aortic Valve Replacement [SAVR] in the last 5 years preceding the survey at the hospital in Peshawar.

Inclusion Criteria

The inclusion criteria include:

1. Patients who underwent primary valve replacement surgery at our institute through either of these procedures.

2. Patients who remained admitted in the hospital for at least one week.

3. Patients whose medical records are readily available at the hospital.

Exclusion Criteria

1. Any patient with secondary valvular surgeries, by either means will not be included in the study.

2. Also patients with incomplete medical records will be ex- cluded.

3. Any patient who was discharged before completing one week.

Study Duration: The total duration of this study, following ERC review will be approximately 6 months.

Sample Size: Using open epi, with a two-sided confidence inter- val of 95%, power of 80%, ratio of controls to cases 1.0, percent of controls exposed 40, and an odds ratio of 2.0, the calculated sample size is 268 (134 each cohort). Adjusting for a 10% attri- tion rate due to incomplete files, the sample size then turns out to be 295.

Data Collection: After getting, a clearance from the Ethics and Review Committee of the Hospital at Peshawar, ICD-10 coding for open-heart surgery, and TAVI and valve replacement would be used to identify patients. Following identification, a request form would be made to the HIMS department to pull out charts for the patients. A structured proforma would be used to extract the data of relevance from the files.

Data Analysis: The data analysis would be carried out on IBM SPSS Version 26. Mean and S.D will be calculated for continu- ous variables while frequencies and proportions will be reported for categorical variables. Chi-square test at 5% level of signifi- cance will be applied to compare the patient demographics, (in- cluding gender, co-morbidities, BMI, work, and NYHA classifi- cation of heart dysfunction) between the two groups. Moreover, in case of continuous variables (e.g. age) independent sample t-test is applied. Cross tabs would be done to find association between variables such as NYHA classification and type of surgery, between ejection fraction (and other cardiac markers) to the surgery time, and between surgery type and associated post-operative complications (such as bleeding, ICU admission, infections), morbidities, and mortalities to identify any statisti- cal significance. Incidence of post-operative complication rate (within 1 week of surgery) will be calculated for both the proce- dures separately using the below formula.

Number of patients who developed complications within one postoperative week multiply by 100 divided by total number of patients who underwent there procedure.

Ethical Considerations: An exemption review would be ap- plied for in the Ethics and Review Committee of the Frontier Medical & Dental College Abbottabad. Data recorded digitally would be kept in password protected files, the password of which would be kept in secrecy, and available only to the principal in- vestigator and those who he/she authorizes for use. Any patient identifier, including name, and MR number would be removed from all patient accounts entered in the proforma.

Result

Based on a cohort of 200 patients (100 in each group), a higher Postoperative Complication Rate was observed with SAVR com- pared with TAVI (39.0% vs 13.0%, respectively). Among SAVR patients, the most common complications were postoperative bleeding (51.2%), infection (30.7%) and cardiac tamponade (17.9%). Patients who underwent TAVI had higher incidence of other postoperative complications, which were vascular compli- cations (53.8%) and need for pacemaker implantation (46.1%). On comparison the two groups did show significant differences in the mortality rate (SAVR = 15.0% & TAVI = 4.0%).

Discussion

Previously, SAVR was the sole effective treatment, however af- ter TAVI invention; TAVI became associate choice for patients with severe symptomatic aortic stenosis who were considered inoperable or in patients at high risk for surgical complications. To the most effective of our information, TAVI reported with a lower postoperative complication rate than SAVR. Compared with SAVR, TAVI reduced the incidences of surgical hemor- rhage, cardiac arrhythmia, Infection and tamponade however in- creased the incidences of major vascular complication, paraval- vular leak, and need for pacemaker implantation. The incidences of myocardial infarction, acute kidney disease and Stroke were reported higher after SAVR compared to TAVI. Furthermore, Patients who underwent TAVI reported shorter hospital stay and a healthy recovery profile compared to SAVR.

Limitations

Retrospective nature is the main limitation to this study. Sec- ondly, long-term outcomes were not studied because long-term data is limited. Thirdly, the comparatively small size of the study cohorts might have an effect on the liableness of these results. Fourthly, the high value of TAVI was a substantial reason that created many patients opt to bear typical surgery, even though they were appropriate candidates for TAVI.

                                      Table 1

Conclusion

TAVI has Low Postoperative Complication Rate and Mortality Rate compared to SAVR .Our Data confirm that TAVI is a safer and more reliable procedure for Patients suffering from Aortic Stenosis [1-10].

Authors Contribution

Muhammad Ammad Khan wrote the paper, collected the data and data analysis. Ghanwa Alam wrote the paper and collected the data.

References

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10. https://www.openepi.com/SampleSize/SSPropor.htm