Recent developments in controlling sternal wound infection after cardiac surgery and measures to enhance sternal healing.

One of the major risks of cardiac surgery is the occurrence of infection at the sternal wound site. Sternal wound infections are primarily classified into superficial infection and deep sternal wound infection or mediastinitis. A patient is diagnosed with mediastinitis if microorganisms are present in their mediastinal tissue/fluid or with the observation of sternal wound infection during operation and with characteristic symptoms including chest pain, fever, and purulent drainage from the mediastinum. It is usually caused by Staphylococcal organisms in 75.8% of cases and the rest is caused by gram-negative bacteria. Currently, in cardiac surgery, hemostasis is achieved using electrocautery and bone wax, and the sternum is closed using wire cerclage. Several studies show that bone wax can act as a nidus for initiation of infection and the oozing blood and hematoma at the site can promote the growth of infectious organisms. Many research groups have developed different types of biomaterials and reported on the prevention of infection and healing of the sternum. These materials are reported to have both positive and negative effects. In this review, we highlight the current clinical practices undertaken to prevent infection and bleeding as well as research progress in this field and their outcomes in controlling bleeding, infection, and enhancing sternal healing.

Outcomes after surgery for infective endocarditis.

The role of surgery in infective endocarditis is becoming established the world over. In spite of all recent advances, endocarditis remains a lethal disease following surgery. With the emergence of more difficult-to-treat microorganisms, sicker and older patients with multiple co-morbidities, and an increase in healthcare-associated infections, the need for surgery in the management of infective endocarditis is only bound to increase. Data on the use of surgery in endocarditis till date is largely from observational data due to the relative rarity of the disease and variable practice patterns around the world. Hopefully, with increasing awareness and more inter-institutional and international collaborations, more robust data will emerge to further establish the role of surgery. For the time being, individual patient management will require the active multi-disciplinary approach of an endocarditis team to provide the best possible outcomes. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-023-01647-9.

Selecting the appropriate patients for coronary artery bypass grafting in ischemic cardiomyopathy-importance of myocardial viability.

Patients who undergo coronary artery bypass graft (CABG) surgery in ischemic cardiomyopathy have a survival advantage over medical therapy at 10 years. The survival advantage of CABG over medical therapy is due to its ability to reduce future myocardial infarction, and by conferring electrical stability. The presence of myocardial viability does not provide a differential survival advantage for CABG over medical therapy. Presence of angina and inducible ischemia are also less predictive of outcome. Moreover, CABG is associated with significant early mortality. Hence, careful patient selection is more important for reducing the early mortality and improving the long-term outcome than relying on results of myocardial viability. Younger patients with good exercise tolerance benefit the most, while patients who are frail and patients with renal dysfunction and dysfunctional right ventricle seem to have very high operative mortality. Elderly patients, because of poor life expectancy, do not benefit from CABG, but the age cutoff is not clear. Patients also need to have revascularizable targets, but this decision is often based on experience of the surgical team and heart team discussion. These recommendations are irrespective of the myocardial viability tests. Optimal medical treatment remains the cornerstone for management of ischemic cardiomyopathy.

Early and long-term outcomes of mitral valve replacement with mechanical valve in rheumatic heart disease.

Background: Rheumatic fever and rheumatic heart disease is endemic in India. Mitral valve replacement with mechanical valve is the commonest surgical procedure performed in rheumatic heart disease (RHD). However, there are no studies reporting the long-term outcomes of mechanical mitral valve replacement in rheumatic heart disease from India. Objective: The primary objective of the study was to look at the long-term survival following mechanical mitral valve replacement in RHD. The secondary objectives included follow up complications and event-free survival. Methods: For this study, 238 patients who underwent mitral valve replacement with TTK Chitra™ valve from 1st January 2006 to 31st December 2018 for RHD were included for analysis and reporting. The median follow-up period was 3371.50 days (9.3 years). Total follow-up was 2044 patient-years. Results: The mean age of the study population was 39.72 ± 10.48 years (range: 18-68 years). Out of 238 patients operated, 155 patients (65.12%) were alive and 69 patients (28.99%) were dead, and 14 patients (5.88%) were lost to follow-up. The operative mortality was 6 (2.52%) and the follow-up mortality was 63 (26.47%). The reasons for follow-up mortality were cardiac complications in 22 (34.9%) patients, valve-related complications in 18 (28.5%) patients, sudden unexplained death in 13 (20.6%) patients, and non-valve/ non-cardiac death in 10patients (15.8%). The one-year survival was 94.0%, five-year survival was 83.6%, ten-year survival was 70.6% and 15-year survival was 62.9%. During follow-up, valve-related events occurred in 123(52%) patients. The 15-year event-free survival was 33.0%. Conclusions: The long term outcome of mechanical valve replacement of the mitral valve in RHD patients was less than favorable. Both cardiac complications and mechanical valve related complications reduced their survival.

Evaluation of TTK Chitra heart valve prosthesis in pediatric patients.

This report highlights the outcome of valve replacement using TTK Chitra heart mechanical valve in a subgroup of pediatric patients This cohort of 27 pediatric patients with implantations during January 2006 to December 2018 was followed up prospectively. The cohort consisted of 12 aortic valve replacement (AVR), 14 mitral valve replacement (MVR), and 1 double valve replacement (DVR) patients. Total follow-up was 254 patient-years (AVR = 107, MVR = 136, DVR = 11) being 90% complete. The results show that the survival rates and event-free rates were satisfactory. Despite many reservations due to the high risk involved, the long-term benefits of having a durable valve replacement seem to outweigh the risks and offer acceptable long-term survival.

Long-term evaluation of TTK Chitra™ heart valve prosthesis - a retrospective-prospective cohort study.

Purpose: The TTK Chitra™ heart valve has more than 1,40,000 implantations so far, but no long-term data has been published. This study aims to provide long-term results of the valve. Methodology: A cohort of 476 patients with implantations from January 2006 to December 2018 were followed up prospectively consisting of 104 aortic valve replacement (AVR), 87 double valve replacement (DVR), and 285 mitral valve replacement (MVR) patients. Total follow-up was 4079 patient-years (py) (AVR = 983, MVR = 2392, DVR = 704), being 96% complete. Results: The results showed that actuarial survival at 15 years was 82.3% for AVR, 60.7% for MVR, and 52.2% for DVR. Freedom from all valve-related mortality and morbidity at 15 years was 73.8%, 64.8%, and 61.9% for AVR, MVR, and DVR, respectively. There was one instance of structural failure of valve disc leading to severe valvar regurgitation. Valve thrombosis incidence was 1 in AVR (0.1%/py), 6 in MVR (0.25%/py), and 1 in DVR (0.14%/py). Thrombo-embolic episodes occurred in 50 patients (AVR = 7 patients at 0.7%/py; MVR = 36 patients at 1.5%/py; DVR = 7 patients at 0.99%/py) and major hemorrhage (bleeding) in 24 patients (AVR = 0.61%/py; MVR = 0.5%/py; and DVR = 0.85%/py). The linearized rates of adverse events in this study were found to be lower than earlier published results. Conclusion: The results highlight the continued safety and performance of the TTK Chitra™ heart valve (TTKCHV) in the long term at 15 years. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-022-01437-9.

Early and midterm outcomes after off pump coronary artery bypass surgery.

Purpose: There has been debate whether off pump coronary artery bypass surgery (OPCAB) has results comparable to conventional on pump bypass surgery. This has led to the low uptake of OPCAB in the West. In India, OPCAB is the default mode of coronary revascularization. However, there is scarce data on mid-term outcomes of OPCAB in our patients. This study aims to evaluate both short and mid-term mortality and analyze factors associated with mortality. Methods: This is a single center study of all consecutive patients undergoing isolated OPCAB from October 2014 to December 2019. Patient data was collected from hospital records and follow-up was from the hospital electronic medical records and telephone interviews. Mortality and factors contributing to survival were analyzed. Results: Operative mortality was 2.3%. Mid-term mortality was 5.5%. Preoperative renal dysfunction, post-operative renal failure, use of the intra-aortic balloon pump (IABP), re-exploration for bleeding, postoperative stroke, ventilation > 24 h, and postoperative atrial fibrillation were associated with operative mortality. Factors associated with mid-term mortality were age > 62 years, postoperative renal failure, IABP usage, ventilation time > 24 h, and postoperative atrial fibrillation. The mean survival time was 2343.55 + / - 15.27 days and 6-year survival was 88.7%. Conclusion: OPCAB can safely be performed with satisfactory short and mid-term outcomes. Further corroborative studies from different regions of the country or a multi-center study will help to establish the suitability of the technique in Indian patients.

Cardiac tamponade as a presentation of COVID-19 after cardiac surgery.

We present two patients who turned positive for coronavirus disease 2019 (COVID-19) after elective cardiac surgery, developing postoperative pericardial effusion with tamponade. One of the patients who presented with tamponade had no other symptoms of COVID-19 infection. COVID-19 can rarely present with cardiac manifestations including pericardial effusion and tamponade. In the post cardiac surgery setting, this effect of the virus may be accentuated. Hence, a high index of suspicion and prompt management are the keys for a successful outcome.

Aortic root widening: "pro et contra".

In patients with a small aortic annulus, the clinical benefits of aortic valve replacement depend on avoidance of patient-prosthesis mismatch as it is associated with reduced overall survival. Aortic root widening or enlargement is a useful technique to implant larger valve prosthesis to prevent patient-prosthesis mismatch. Posterior annular enlargement is the commonest technique used for aortic root enlargement. Consistent enlargement of the aortic root requires more extensive procedures like Manouguian or Konno-Rastan techniques. The patients commonly selected are younger patients with good life expectancy. However, caution is advised in applying this procedure in elderly patients, patients with heavily calcified annulus and when performing concomitant procedures. There is no definitive conclusion on the best material to use for the reconstruction of aortic annulus and aorta in aortic root enlargement procedures.

Do alternative approaches work in surgical septal myectomy?

Trans-aortic septal myectomy is the gold standard for septal reduction therapy. This technique has low peri-procedural mortality and excellent long-term survival. Moreover, it relieves the heart failure symptoms and improves the quality of life. Secondary chordal cutting along with septal myectomy has shown to improve the outcome but can potentially cause deterioration of left ventricular function. In patients with relatively thin inter-ventricular septum, abnormalities of mitral valve apparatus may be the main reason for systolic anterior motion and left ventricular outflow tract obstruction. These patients may require additional procedures on the mitral valve to shift the coaptation plane away from outflow tract. Mitral valve replacement should be performed only in patients with intrinsic mitral valve abnormalities that are not suitable for repair and its routine use along with limited septal myectomy should be discouraged. Minimal access surgery although attractive in concept requires more robust data before universal application.

Posterior mitral leaflet plication with extended septal myectomy for hypertrophic obstructive cardiomyopathy.

Abnormalities of the mitral valve apparatus are a phenotypical expression of hypertrophic cardiomyopathy and can contribute to systolic anterior motion and left ventricular outflow tract obstruction. In patients with significant abnormalities of the mitral apparatus, adjunct procedures like plication of the anterior mitral leaflet and/or release of papillary muscles may be required to obtain sufficient relief of obstruction. Very rarely, an elongated posterior mitral leaflet is the main culprit for systolic anterior motion. In such cases, plication of the posterior mitral leaflet is a useful technique, in addition to septal myectomy, to abolish left ventricular outflow tract obstruction. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12055-021-01213-1.

Role of fibroblast growth factor-23 (FGF-23) in the prediction of postoperative atrial fibrillation after coronary artery bypass surgery.

Introduction: Fibroblast growth factor-23 (FGF-23) is a bone-derived hormone which had shown a significant association with the occurrence of atrial fibrillation (AF) in patients with chronic kidney disease. We hypothesized that FGF-23 could be a very useful predictive biomarker for atrial remodeling and in turn for postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG). We also looked at the correlation of cardiac remodeling in right atrial biopsy and its correlation with POAF and with the FGF-23 level. Methods: This study was a single-center cross-sectional observational study. All the patients who were planned for CABG with no prior history of AF were included in the study. All the patients were tested for preoperative serum FGF-23 level. During CABG, biopsy specimen of the right atrial appendage was sent for histopathology evaluation. All patients were monitored for POAF until discharge from the hospital. Results: This study involved 60 patients who underwent elective CABG. Multivariate analysis revealed a significant association between preoperative FGF-23 levels with the occurrence of POAF (p < 0.001). The area under the curve of FGF-23 was 0.894 with a sensitivity of 92.3% and specificity of 87.23%. The cut-off value for serum FGF-23 levels was found to be 6.50 ng/ml. Analysis of biopsy specimens revealed that the presence of hypertrophic myocytes had a significant association with the occurrence of POAF/POAE and with FGF-23. Conclusion: Preoperative FGF-23 levels can predict the incidence of POAF in post-CABG patients. Histopathologically, the presence of hypertrophic myocytes correlated well with the occurrence of POAF.

Effects of the COVID-19 Pandemic on Cardiac Surgery Practice and Outcomes.

BACKGROUND: While the coronavirus disease 2019 (COVID-19) pandemic has affected all aspects of health care, its impact on cardiac surgical practice and outcomes is yet to be determined. We compared the outcomes of our cardiac surgical practice from the past year during the pandemic to those in a similar pre-pandemic period. METHODS: Retrospective data were collected from 307 patients who were involved in all adult cardiac surgical procedures performed between March 2020 and February 2021, which was considered the pandemic period, at Amrita Institute of Medical Sciences, India. These were compared with data from the 1-year period between March 2019 and February 2020. During that earlier period, 491 patients underwent surgery, and the surgical outcomes were assessed. Outpatient visit data were also collected to evaluate the effect of COVID-19 on outpatient follow-up visits. RESULTS: A 37% decrease in surgical case volume was observed during the study period. No difference was found in operative mortality between the 2 time periods (3.3% vs. 2.6%, p=0.383). Overall postoperative complications were less frequent during this period, at 23% compared to 38% the previous year (p<0.001). CONCLUSION: The COVID-19 pandemic caused a dramatic decrease in surgical volume and outpatient medical follow-up. However, the pandemic and its attendant social restrictions did not yield a significant change in the surgical outcomes of our patients. Hence, it is reasonable to continue cardiac surgical care during global health crises, and this can be done with good results.

Perioperative right ventricular function and dysfunction in adult cardiac surgery-focused review (part 2-management of right ventricular failure).

The single most important factor in improving outcomes in right ventricular (RV) failure is anticipating and recognizing it. Once established, a vicious circle of systemic hypotension, and RV ischemia and dilation, occurs, leading to cardiogenic shock, multi-organ failure, and death. RV dysfunction and failure theoretically can occur in three settings-increase in the pre-load; increase in after load; and decrease in contractility. For patients deemed low risk for the development of RV failure, when it occurs, the correction of underlying cause is the most important and effective treatment strategy. Therapy of RV failure must focus on improving the RV coronary perfusion, lowering pulmonary vascular resistance, and optimizing the pre-load. Pre-load and after-load optimization, ventilator adjustments, and improving the contractility of RV by inotropes are the first line of therapy and should be initiated early to prevent multi-organ damage. Mechanical assist device implantation or circulatory support with extracorporeal membrane oxygenation (ECMO) may be needed in refractory cases.

Perioperative right ventricular function and dysfunction in adult cardiac surgery-focused review (part 1-anatomy, pathophysiology, and diagnosis).

Right ventricle (RV) dysfunction and failure are now increasingly recognized as an important cause of perioperative morbidity and mortality after cardiac surgery. Although RV dysfunction is common, RV failure is very rare (0.1%) after routine cardiac surgery. However, it occurs in 3% of patients after heart transplantation and in up to 30% of patients after left ventricular assist device implantation. Significant RV failure after cardiac surgery has high mortality. Knowledge of RV anatomy and physiology are important for understanding RV dysfunction and failure. Echocardiography and haemodynamic monitoring are the mainstays in the diagnosis of RV dysfunction and failure. While detailed echocardiography assessment of right heart function has been extensively studied and validated in the elective setting, gross estimation of RV chamber size, function, and some easily obtained quantitative parameters on transesophageal echocardiography are useful in the perioperative setting. However, detailed knowledge of echocardiography parameters is still useful in understanding the differences in contractile pattern, ventriculo-arterial coupling, and interventricular dependence that ensue after open cardiac surgery. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12055-021-01240-y.

IACTS position statement on "2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization": section 7.1-a consensus document.

American College of Cardiology (ACC), American Heart Association (AHA) and Society for Cardiovascular Angiography and Interventions (SCAI) recently released the Clinical Practice Guidelines for myocardial revascularization [1]. The guidelines were the felt need of the fraternity and this single all-encompassing document, relegating the previous six guidelines on the subject to archives, is indeed welcome. However, the downgrading of coronary artery bypass surgery for stable multivessel coronary artery disease and its bracketing with percutaneous coronary interventions has caused a lot of anguish in the surgical fraternity. This document presents the official viewpoint of the Indian Association of Cardiovascular and Thoracic Surgeons on the matter.

Transesophageal Echocardiographic Assessment of the Repaired Mitral Valve: A Proposed Decision Pathway.

The indications for mitral valve repair extend across the entire spectrum of degenerative mitral valve disease, ranging from fibroelastic degeneration to Barlow's disease. Collaboration between the surgeon and anesthesiologist is essential for ensuring optimal results. Echocardiographic assessment of the repair can be challenging but is essential to the success of the procedure, as even mild residual mitral regurgitation can portend poor patient outcomes. In addition to determining the severity of residual regurgitation, the anesthesiologist must elucidate the mechanism of disease in order to inform appropriate re-intervention measures. Finally, there are unique complications of mitral valve surgery for the anesthesiologist to understand and assess by echocardiography. This review describes a systematic pathway for a comprehensive intraoperative assessment of the mitral valve following surgical repair.