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.

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.

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.

A novel small diameter nanotextile arterial graft is associated with surgical feasibility and safety and increased transmural endothelial ingrowth in pig.

Globally, millions of patients are affected by myocardial infarction or lower limb gangrene/amputation due to atherosclerosis. Available surgical treatment based on vein and synthetic grafts provides sub-optimal benefits. We engineered a highly flexible and mechanically robust nanotextile-based vascular graft (NanoGraft) by interweaving nanofibrous threads of poly-L-lactic acid to address the unmet need. The NanoGrafts were rendered impervious with selective fibrin deposition in the micropores by pre-clotting. The pre-clotted NanoGrafts (4 mm diameter) and ePTFE were implanted in a porcine carotid artery replacement model. The fibrin-laden porous milieu facilitated rapid endothelization by the transmural angiogenesis in the NanoGraft. In-vivo patency of NanoGrafts was 100% at 2- and 4-weeks, with no changes over time in lumen size, flow velocities, and minimal foreign-body inflammatory reaction. However, the patency of ePTFE at 2-week was 66% and showed marked infiltration, neointimal thickening, and poor host tissue integration. The study demonstrates the in-vivo feasibility and safety of a thin-layered vascular prosthesis, viz., NanoGraft, and its potential superiority over the commercial ePTFE.

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.

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.

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.

Bleeding complications after dual antiplatelet therapy with ticagrelor versus dual antiplatelet therapy with clopidogrel-a propensity-matched comparative study of two antiplatelet regimes in off-pump coronary artery bypass grafting.

PURPOSE: Ticagrelor combined with aspirin had shown better saphenous vein graft patency than aspirin with clopidogrel after off-pump coronary artery bypass grafting. However, the safety of this drug in regard to bleeding complications remains unknown. The aim of our study was to assess the bleeding complications of dual antiplatelet therapy with aspirin and ticagrelor compared with aspirin and clopidogrel within the first 3 months after off-pump surgery. METHODS: Three hundred eighty-two consecutive patients who were prescribed aspirin with ticagrelor (ticagrelor group) were compared with 660 patients who received aspirin and clopidogrel (clopidogrel group). After propensity matching, 144 patients in each group were compared for bleeding events and major adverse cardiac and cerebral events. Major bleeding was defined as composite outcome of re-exploration for bleeding, any fatal bleeding, intracranial bleeding, and any bleeding requiring hospitalization. RESULTS: Patients in the ticagrelor group had more incidence of re-exploration for bleeding (p = 0.042), pericardial effusion requiring drainage (p = 0.007), readmissions (p < 0.01), gastrointestinal bleeding (p = 0.01), and major bleeding (5.8% vs. 2.1%, p < 0.01, OR 2.8 (1.43-5.58)). After propensity analysis, gastrointestinal bleed (p = 0.024), major bleeding (7.6% vs.1.4%, p < 0.001, OR 5.8 (1.28-26.97)), length of ICU stay (p = 0.039), and readmissions (p = 0.003, OR 11.83 (1.51-92.86)) were more in the ticagrelor group. Major adverse cardiac and cerebral events were similar between the groups. CONCLUSION: Dual antiplatelet therapy with aspirin and ticagrelor increased gastrointestinal bleeding events, major bleeding events, and readmission rates compared with aspirin and clopidogrel after off-pump coronary artery bypass grafting.

Early and Mid-Term Outcomes of Patients Undergoing Coronary Artery Bypass Grafting in Ischemic Cardiomyopathy.

Background Many observational studies and trials have shown that coronary artery bypass grafting improves the survival in patients with ischemic cardiomyopathy. However, these results are based on data generated from developed countries. Poor socioeconomic statuses, lack of uniformity in healthcare delivery, differences in risk profile, and affordability to access optimal health care are some factors that make the conclusions from these studies irrelevant to patients from India. Methods and Results One-hundred and sixty-two patients with severe left ventricular dysfunction (ejection fraction ≤35%) who underwent coronary artery bypass grafting from 2009 to 2017 were enrolled for this study. Mean age of the study population was 58.67±9.70 years. Operative mortality was 11.62%. Thirty day/in-house composite outcome of stroke and perioperative myocardial infarction were 5.8%. The percentage of survival for 1 year was 86.6%, and 5-year survival was 79.9%. Five-year event-free survival was 49.3%. The mean ejection fraction improved from 30.7±4.08% (range 18-35) to 39.9±8.3% (range 24-60). Lack of improvement of left ventricular function was a strong predictor of late mortality (hazard ratio, 21.41; CI 4.33-105.95). Even though there was a trend towards better early outcome in off-pump CABG , the 5-year survival rates were similar in off-pump and on-pump group (73.4% and 78.9%, respectively; P value 0.356). Conclusions We showed that coronary artery bypass grafting in ischemic cardiomyopathy was associated with high early composite outcomes. However, the 5-year survival rates were good. Lack of improvement of left ventricular function was a strong predictor of late mortality.

Early outcomes in patients undergoing off-pump coronary artery bypass grafting.

BACKGROUND: In spite of general decline worldwide, off-pump coronary artery bypass grafting (CABG) surgery is performed in more than 60% of patients undergoing CABG in India; mainly because of shorter operative time and reduced procedure cost. However, paucity of data exists in literature about early outcomes following off-pump CABG from India. METHODOLOGY: We conducted a prospective observational study of 800 consecutive cases that underwent off-pump CABG (OPCAB) from August 2015 to October 2017. Primary end point of the study was the 30-day/in-hospital mortality from any cause. RESULTS: On multivariate analysis, emergency surgery (OR 9.72; CI 1.96-48.21, p value 0.005), severe left ventricular dysfunction (OR 2.28; CI 1.25-4.76, p value 0.026), postoperative atrial fibrillation (OR 9.95; CI 3.12-32.01, p value 0.05), and dialysis-dependent renal failure (OR 29.7, CI 10.02-87.99, p value 0.006) were the factors associated with mortality. The observed mortality was 1.6%, and the expected mortality by EuroSCORE II was 2.6%. The median EuroSCORE II of expired patients was 3.03 and of entire cohort was 1.54 (p value 0.001). Stroke rate was 0.9%. Deep sternal wound infection occurred in 0.9%, and 3.8% patients were readmitted to the hospital after discharge. CONCLUSION: Early outcome of off-pump CABG was excellent in this study. Increased incidence of deep sternal wound infection remains a concern. Multicenter study with a larger sample size is required for a dependable evaluation of the efficacy of off-pump CABG in Indian population.

Predictors of acute kidney injury in patients undergoing adult cardiac surgery.

BACKGROUND: Acute kidney injury (AKI) after cardiac surgery (CS) is not uncommon and has serious effects on mortality and morbidity. A majority of patients suffer mild forms of AKI. There is a paucity of Indian data regarding this important complication after CS. AIMS AND OBJECTIVES: The primary objective was to study the incidence of AKI associated with CS in an Indian study population. Secondary objectives were to describe the risk factors associated with AKI-CS in our population and to generate outcome data in patients who suffer this complication. METHODS: Serial patients (n = 400) presenting for adult CS (emergency/elective) at a tertiary referral care hospital in South India from August 2016 to November 2017 were included as the study individuals. The incidence of AKI-CS AKI network (AKIN criteria), risk factors associated with this condition and the outcomes following AKI-CS are described. RESULTS: Out of 400, 37 (9.25%) patients developed AKI after CS. AKI associated with CS was associated with a mortality of 13.5% (no AKI group mortality 2.8%, P = 0.001 [P < 0.05]). When AKI was severe enough to need renal replacement therapy, the mortality increased to 75%. Patients with AKI had a mean hospital stay 16.92 ± 12.75 days which was comparatively longer than patients without AKI (14 ± 7.98 days). Recent acute coronary syndrome, postoperative atrial fibrillation, and systemic hypertension significantly predicted the onset of AKI-CS in our population. CONCLUSIONS: The overall incidence of AKI-CS was 9.25%. The incidence of AKI-CS requiring dialysis (Stage 3 AKIN) AKI-CS was lower (2%). However, mortality risks were disproportionately high in patients with AKIN Stage 3 AKI-CS (75%). There is a need for quality improvement in the care of patients with AKI-CS in its most severe forms since mortality risks posed by the development of Stage 3 AKIN AKI is higher than reported in other index populations from high resource settings.

Transforming Nanofibers into Woven Nanotextiles for Vascular Application.

This study investigates the unique properties, fabrication technique, and vascular applications of woven nanotextiles made from low-strength nanoyarns, which are bundles of thousands of nanofibers. An innovative robotic system was developed to meticulously interweave nanoyarns in longitudinal and transverse directions, resulting in a flexible, but strong woven product. This is the only technique for producing seamless nanotextiles in tubular form from nanofibers. The porosity and the mechanical properties of nanotextiles could be substantially tuned by altering the number of nanoyarns per unit area. Investigations of the physical and biological properties of the woven nanotextile revealed remarkable and fundamental differences from its nonwoven nanofibrous form and conventional textiles. This enhancement in the material property was attributed to the multitude of hierarchically arranged nanofibers in the woven nanotextiles. This patterned woven nanotextile architecture leads to a superhydrophilic behavior in an otherwise hydrophobic material, which in turn contributed to enhanced protein adsorption and consequent cell attachment and spreading. Short-term in vivo testing was performed, which proved that the nanotextile conduit was robust, suturable, kink proof, and nonthrombogenic and could act as an efficient embolizer when deployed into an artery.

Superior Vena Cava Syndrome Caused by Pacemaker Leads.

Superior vena cava syndrome is one of the rare adverse events associated with pacemaker leads. We describe a 47-year-old woman with a pacemaker implanted 10 years earlier who presented to us with superior vena cava syndrome managed surgically. We report the presentation, diagnosis, and treatment of this patient and the causes and management options of superior vena cava obstruction associated with pacemaker leads.